Pediatrics

Question 1

How do you caculate PGA?

Answer 1

Post-gestational age

weeks gestation @ birth +current age in weeks

Question 2

What is a neonate? Preterm?

Low birth weight?

Answer 2

neonate= birht - 30 days

preterm <37 weeks

low birth weigth <2500 grams

Question 3

What is extremely low gestational age (ELGAN)

Answer 3

23-27 weeks gestations; all organs immature

most vulnerable peds patient

Question 4

What are pre-terms at risk for?

Answer 4

• Respiratory distress
• apnea
• hypoglycemia
• electolyte disturbance (particularly hypomagnesemia and hypocalcemia)
• infection
• hyperbilirubinemia
• polycythemia
• thrombocytopenia

Question 5

Definitions for neonatal period?

Normal gestation? Postmature?

Risks for both age groups?

Answer 5

• Normal gestation 37-42 weeks
  
  • all gestational ages have risk for
    
    • congenital abnormalities,
    • viral infection,
    • perinatal depression,
    • fetal alcohol syndrome
    • thrombocytopenia
• Postmature >42 weeks
  
  • risk of meconium aspiration
  • birht trauma if large for gestational age (LGA)
  • hypoglycemia
  • hyperbilirubinemia
  • plus above risks for normal gestations.

Question 6

What is the significance of 60 weeks PGA?

What should you always evaluate?

Answer 6

• Former premature infancts up to 60 weeks PGA are at increased risk for postoperative apnea and braydcardia
• requires postop monitoring, admission, and 12 hour period free of apnea
• Always evaluate perinatal history
  
  • gestation age and size at birth
  • maternal infections
  • eclampsia
  • diabetes
  • drug abuse
  • prolonged or traumatic labor
  • NICU/Intubation following delivery

Question 7

Why is size at birth important?

Answer 7

• small or large for gestational age babies are more likely to have problems with metabolic, developmental, infectious or structural abnormalities, drug addiction and withdrawl

Question 8

Characteristics of fetal circulation?

Answer 8

• High pulmonary vascular resistance and low systemic circulatory resistance
• minimal intrauterine pulmonary blood flow: only 10% CO
• At birth, placenta is no longer primary source for oxygenated blood
• Basics
  
  • placenta–> umbilical vein–> liver sinusoids and ductus venosus–> IVC–> RA–> foramen ovale (because of pressure, blood shoots across here)–> LA (small amt of mixing with blood from pulmonary veins)–> LV–> ascending aora–> heart, brain UE (most oxygenated blood)–> mixing with deoxygenated blood from ductus arteriosus–> mixed blood feeds thoracic/abd brances–> end of aorta gives 2 umbilical arteries that return blood to placenta
  • Blood from SVC mixes with blood in RA–> RV–> 10% goes pulmonary artery to lungs, most blood goes–> ductus arteriosus–> aorta arch that mixes with pre-ductal blood

Question 9

What are some primary changes that occur in the transition from fetal circulation to birth?

Answer 9

• Ductus venosus closes
• blood is oxygenated via lungs
• ductus arteriosus closes (due to increased arterial O2 concentration)
• pulmonary vascular resistance DECREASES
• peripheral vascular resistance increases
• foramen ovale closes
  
  • true closure weeks later; 25-30% of adults have patent foramen ovale
  • only a functional closure at birth
• all these changes can reverse in stressed newborn.

Question 10

What is transitional ciruclation?

Prevention? Treatmenbt?

Answer 10

• occurs at birth for the first several weeks
  
  • hypoxia, hypercapnia, or hypothermia can lead to increased pulmonary artery pressure, which causes reversal of flow through foramen ovale (meaning returning to fetal circulation), reopening of ductus arteriosus and shunting
• deoxygenated blood perfuses systemic circulation and this hypoxia is difficult to correct
• prevention: optimal oxygenation, correct acidosis, keep warm
• treatment: hyperventilate to reduce PaCO2

Question 11

Characteristics of newborn heart?

Answer 11

• Newborn heart:
  
  • structurally immature
  • fewer myofibirls (not parallel)
  • sarcoplasmic reticulum immature and cardiac calcium stores reduced
  • ventricles less compliant: CO is HR dependent
• baroreceptor reflex immature, won’t have increase in HR in response to decrease BP
• Heart not as responsive to volume c/t adult
• PSNS dominance- immature SNS, and much more likely to have bradycardia with any kind of stress/suctioning/ etc
  
  • premedicate prior to DL/suction etc

Question 12

Resting cardiac ouput for neonate, infant, and adolescent?

Answer 12

• Neonate at birht 400mL/kg/min
• Infant 200 mg/kg/min
• Adolescent 100 mL/kg/min

Question 13

CV characteristics in neonate?

Answer 13

• Dependence on ionized calcium- particularly vulnerable to effects of citrated blood products
  
  • also vulnerable to myocardial depression caused by potent anesthetics
• Neonate myocardium relatively noncompliant c/t older kids
  
  • increased preload does not increase SV to same degree
  • poor tolerance to increase afterload (development of BiV failure)
  • hypovolemia and bradycardia produce dramatic decrease in CO that threaten organ perfusion
• Epinephrine rather than atropine increases contractility and HR
  
  • preferred txmt of bradycardia and decreased CO in ped patients
• In 1st 3 months, heart does not respond as well to inotropic support
  
  • immature beta respons
    *

Question 14

Pulmonary system in infants?

Answer 14

• Alveoli increase in number & size up until 8yo
• Infants: small airway diameter; increased resistance
  
  • Highly compliant airway & chest wall
    
    • ​however, lung tissue not as compliant. less elastin tissue. this can lead to airway collapse and chest wall collapse
  • Closing capacity is greater than FRC in the very young and very old: airway closure can occur before end exhalation
  • Early fatigue of diaphragmatic & intercostal muscles until age 2 (type 1 muscle fibers not mature)
    
    • ​only 10% type 1 muscle fibers in the diaphragm in infant. adult has 55%
• O2 consumption is 2-3 x’s the adult with increased alveolar ventilation; leads to rapid desaturations especially during cold stress and in the case of airway obstruction
  
  • MV: FRC ratio 2-3 x higher than adult causes faster anesthetic onset, fast desat and less O2 reserve
• Angulation of right mainstem bronchus

Question 15

Airway differences in infant?

Answer 15

• Infant:
  
  • larger tongue in smaller submental space
  • higher larynx(C2 to C4)
  • short stubby (omega shaped) epiglottis
  • angled vocal cords (slant caudally)<bolded></bolded>
  • funnel shaped larynx with narrowest region @ cricoid ring
  • obligate nasal breathers
  • large occiputs & the “sniffing” position is favored for axis alignment
    
    • shoulder roll useful. large head c/t body, no hyperextension!
  • endentulous
  • short trachea (4-5 cm)
• Tooth eruption normally occurs between 4 and 12 months of age for the first tooth; eruption of the 20 primary teeth should be complete between 24 and 30 months of age.

Question 16

Gas flow in young children?

Answer 16

• Young children have elevated airway resistance at baseline
• Turbulent airflow is present to 5th bronchial division
• A 50% reduction in radius increases the pressure 32-fold
• Very prone to respiratory distress with any upper airway irritation or swelling
  
  • laminar flow R to 4th power (poiseuille’s law!)
  • turbulent radius to 5th power–> even more reduction in flow

Question 17

Neurological characteristics of infant?

O2 consumption? Growth of brain? Location of conus medullaris?

Fontanel closure (ant and post)?

Answer 17

• Oxygen consumption & CBF in the brain of children is ~50% greater than adults
  
  • O2 consumption
    
    • infant 5.5 mL/100g/min
    • adult 3.5 mL/100g/min
  • CBF
    
    • ​infant 100 mL/min/100g
    • adult 50 mL/min/100g
• Myelinization & synaptic connections not complete until age 3-4 years
• Rapid growth of brain in first 2 years of life
• Conus medullaris is at level of L3 at birth & migrates to level L1-L2 by age 3
• Fontanels: anterior fontanel closed by 18 mo’s; posterior fontanel closed by ~2 mo’s

Question 18

What is anesthesia induced developmental neurotoxicity?

Answer 18

Anesthesia-Induced Developmental Neurotoxicity: our knowledge is still growing in this area

• Increased and accelerated neuroapoptosis with virtually all anesthetics
• Single exposures of short duration are usually of no consequence
• Repeated &/or prolonged exposures at a young age (<3-4 years) may be associated with later behavioral & learning difficulties- we do not have conclusive evidence
  
  • _​_current thought to delay elective/non-urgent sx until children >3-4 yrs from neurocognitive standpoint. have not proven delays
• most GA cause morphology changes in developing brain
  
  • ​some human sutdies have gound association b/w exposure to aneshesia and surgery in early childhood
    
    • ​may be explained by confounding factors
  • increasing evidence shows one hour of aneshteisa in infancy does not have lasting impact on cognition

Question 19

Neuraxial considerations in pediatrics

Answer 19

• The conus medullaris ends at approximately L1 in adults and at the L2–L3 level in neonates and infants.
• In infants, the line across the top of both iliac crests (the intercristal line) crosses the vertebral column at the L4–L5 or L5–S1 interspace, well below the termination of the spinal cord
• The dural sac in neonates and infants also terminates in a more caudad location compared to adults, usually at about the level of S3 compared to the adult level of S1
• Infants: lack of a lumbar lordosis compared to older children predisposes the infant to high spinal blockade with changes in positioning

Question 20

Renal characteristics of infants?

Answer 20

• GFR is significantly impaired at birth but improves throughout the 1st year
  
  • greatest impairment is in 1st 4 weeks of life
  • renal maturation will be delayed further with prematurity
    
    • UOP low at birth x 24 hours then increases to 1-2mL/kg/hr
    • be concerned after 24 hours with low UOP
    • in utero kidney only receives 3% blood flow. adult 25%.
• Renal tubular concentrating abilities do not achieve full capacity until ~2years
  
  • difficulty with concentrating and diluting urine
  • does not respond as well to aldosterone
    
    • hypo/hypernatremia can easily become an issue
• Half-life of medications excreted by glomerular filtration are prolonged in the very young (antibiotics; etc.)
• In contrast, during childhood, renal clearance rate may increase to levels higher than even adult clearance rates
  
  • higher CO, more blood flow in childhood

Question 21

Liver function in infants?

Answer 21

• Enzyme systems are still developing up until 1 year of age
• Phase I Cytochrome P450 system is 50% of adult values at birth
  
  • 3A4 50% drugs
  • 2D6= 10-20% drugs
• Phase II (conjugation reactions) are impaired in neonates
  
  • Long half life of BZD and morphine
  • Decreased bilirubin breakdown due to reduction in glucuronyl tranferase (leading to jaundice)- also metabolize tylenol
• Hepatic synthesis of clotting factors reach adult levels within a week of birth
  
  • ​Vit K dependent factors (II, VII, IX, X)
    
    • ​at birth 20-60% adult values
    • preterm values even less
• Lower levels of albumin/ other proteins for drug binding in newborns- larger proportion of unbound drug circulating
  
  • increases effect of highly protein bound drugs.
• Minimal glycogen stores- prone to hypoglycemia

Question 22

GI system in pediatrics?

Answer 22

• Obligate nose breathers
  
  • Coordination of swallowing with respiration not mature until 4-5 months of age (grow out of it eventually)
  • high incidence of reflux especially in pre-terms
    
    • coanal atresia- blockage of nasal to trachea
      
      • resp depression bc want to breathe through nose! Will breath better when crying
• Gastric juices are less acidic (more neutral) up to ~3 years of age
  
  • Less absorption of drugs
• Absorption of oral medications is generally slower compared to adults (less effective)
  
  • The gastrointestinal tract is generally slower in children than in adults
  • Children have differences in gastric pH, emptying time, intestinal transit, immaturity of secretions, and activity of both bile and pancreatic fluids

Question 23

What are factors that lead to difficulty in thermoregulation in infants?

Answer 23

• Large surface area to body weight
• Lack of subcutaneous tissue as an insulator
• < 3 mo →Inability to shiver:metabolize brown fat to increase heat production
  
  • can lead to metabolic acidosis & increased O2 consumption
    
    • Brown fat: tissues in neck, vertebral column, around adrenal glands → Metabolically stressful!
• Factors: cold OR, anesthetic-induced vasodilation, room-temp IV fluids, evaporative heat loss from surgical site, cool irrigating solutions on field, cool/dry anesthetic gases
  
  • In picture
  1. Conduction- cold fluid, cold OR table (cold surface/fluid absorbing heat)**​
     
     1. decrease heat loss by placing baby on warming mattress and warm surgical unit
  2. Evaporation- cold gas vent to pt, cold irrigating fluid r/t heat loss
     
     1. ​humidifaciton of inspired gases, use plastic wrap and warm skin disinfectant solutions
  3. Convection- air flowing over
     
     1. ​keep infant in incubator and cover with blankets
     2. head should be covered
  4. radiation from image- giving off heat
     
     1. ​use double shelled isolette during transport
  • % of heat loss in children: 39% radiation; 34% convection; 24% evaporation; 3% conduction

Question 24

How can we maintain temperature in infants?

Answer 24

• Active warming is critical:
  
  • warm the OR (dec convection) 72-76^{o (or 80’s)}
    
    • as warm as everyone can tolerate in infants
  • use a warming mattress
  • use incubators
  • cover with blankets- dec radiation
  • head coverings (up to 60% of heat loss)
  • transport in isolette
  • humidify gases- dec evaporation
    
    • single limb circuit**- gases getting warmed up by exhaled air
  • use plastic wrap on the skin
  • warm prep & irrigation solutions
  • change wet diapers & remove wet clothing
  • Forced air warmers: the most effective strategy to minimize heat loss in surgery in children > 1 hr
    
    • Careful w/ injury!
• Anesthetics alter non-shivering thermogenesis in neonates

Question 25

What are some best practices for temperature monitoring in pediatrics?

Answer 25

• Essential for all pediatric cases
• Mid-esophageal placed probe- best core temp!
  
  • can also be used as stethoscope
• Axillary temp: Advantage - if properly positioned:
  
  • proximity to deltopectoral group improves recognition of elevated temp in MH
• NO FOREHEAD TEMP- not advised
  
  • 10 MH episodes occurred that were unrecognized with forehead temp (Barash)
• Hypothermia: consequences →
  
  • delayed emergence- metabolism of drugs slower
  • reduced degradation of drugs
  • increased infection
• Hyperthermia: MH? → primary presentation not always fever (1^st see ETCO2)
  
  • Stop VA, high flow on, switch to TIVA, evaluate (stop anesthetic d/t Ca dysregulation getting worse)

Question 26

Body composition of infant? Electrolytes?

Answer 26

• Total body water is highest in premature infants & decreases with age
  
  • Larger SA per Kg
  • Metabolism correlates to O2 consumption, CO2 production CO, alveolar vent
    
    • Better to look at Body SA (BSA) rather than wt (better measure of metabolism)
  • Infants: ECF > ICF
  • Adults: ECF < ICF
    
    • Infants: don’t have ICF reserve → cant pull from when dehydrated (??)
    • Childhood: ICF proportion increases → reserve for dehydration
• Electrolytes:
  
  • Same as adult → but know:
    
    • Issues w/ Na levels
    • K slightly higher 1^st 1-2 days

Question 27

How can body composition of infants alter pharmacokinetics?

Answer 27

• Water soluble drugs have a larger volume of distribution (have higher TBW)
  
  • Need a larger initial dose (Sch; abx- higher dosing of water soluble drugs)
  • Delay excretion – from larger volume of distribution
• Acidic drugs tend to bind mainly to albumin (e.g., diazepam, barbiturates)
  
  • plasma protein binding of many drugs is decreased in the neonate relative to the adult in part because of reduced total protein and albumin concentrations.
• Basic drugs bind to globulins, lipoproteins, and glycoproteins. (e.g., amide local anesthetic agents)
• Half-life of medications in >2 years of age is shorter than adults or equivalent due to significant CO to liver & kidneys
  
  • More fentanyl/propofol mg/kg
• Pharmacokinetics in children varies with body composition, renal and hepatic function, and with altered protein binding
• Neonates have less fat & muscle
  
  • Drugs that depend on redistribution to fat for termination of action will have prolonged effects (fentanyl; propofol)
• Protein binding: < 6 months old have reduced albumin & alpha-1 acid glycoprotein (AAG)
  
  • higher free-fraction of protein bound drugs → higher risk of toxicity!!
    
    • Free fraction of lidocaine will be higher in the very young!

“In general, most medications will have a prolonged elimination half-life in preterm and term infants, a shortened half-life in children older than 2 years of age up to the early teenage years, and a lengthening of half-life in those approaching adulthood.” – patient to patient variability ***

Question 28

Difference in drug pharmacokinetics in infant, childhood to adulthood?

Answer 28

• Preterm/infants: prolonged elimination half-life
• >2 yo to early teenage yrs: shorted half-life
• Adulthood: lengthened half-life

Question 29

Difference in hematocrit and blood volume in infant?

How do we dose blood transfusions in infants?

Answer 29

Fetal Hgb:

• Lower P50 (19 mmHg vs. adult normal of 26 mmHg) → left shift = Holds onto O2!
• Low levels of 2,3 diphosphoglycerate
  
  • This lower P 50 allows the fetus to load more oxygen at low placental oxygen tension, but it makes unloading oxygen in tissues more difficult.
  • 3- 6 months after birth → fetal hemoglobin has been replaced with adult hemoglobin.
    
    • Tolerate Anemia more poorly bc left shift
    • Blood products helpful d/t having adult Hgb that allows released O2 to tissues
• Target hct in neonates is higher
  
  • Hct minimum 40% (instead of 30%)
  • Why?: bc
    
    • L shift
• Tx: 4-5 ml/kg of transfused PRBC’s increase hgb ~1g/dL
  
  • Order blood based on body weight
  • Ex: 15 kg pt = 75 ml blood

Question 30

What is physiologic natar?

Answer 30

• Physiologic Natar: lowest point of anemia as fetal Hgb being replaced (PERIOD OF TRANSITION)
• Physiologic anemia at 2-3 months of age→ lower threshold to give blood products (low P50 & physiologic anemia)

Question 31

How do you calculate MABL?

Considerations for blood transfusions threshold?

Answer 31

• Maximum allowable blood loss calculation:
  
  • ​MABL= EBV x (starting HCT- target HCT)/ starting HCT
    
    • variables: EBV, patient starting hct (est by chart w/o labs), minimum allowable hct
      
      • *gives threshold when need to start giving blood
    • Threshold varies (ex: ~30%)
      
      • Ex: < 3 mo → higher threshold d/t physiologic anemia & low P50
• Initial blood loss replaced at 3:1 with crystalloid
• Transfusion threshold: somewhere around hct ~24- 30%; minimal target hct should be discussed based on individual child
  
  • consider blood sooner in the following: (higher tx threshold)
    
    • preterm infants
    • term newborns
    • children with cyanotic congenital heart disease
    • children with respiratory failure in need of high oxygen-carrying capacity
  • young infants (< 3 months) may need a higher transfusion threshold due to left shift & physiologic anemia
  • incidence of apnea is high in neonates and preterm infants who have hematocrit values < 30%

Question 32

How do you determine how much blood to transfuse in infant?

Answer 32

• Once MABL is approaching, if blood loss is expected to continue then blood will be given
  
  • always use a blood warmer
• Calculation of blood to be transfused: (desired hct - current hct) x EBV

hct of PRBC’s (which is 60%)

• > 1 blood volume replaced → FFP will be needed
• Watch for ionized hypocalcemia & resultant CV depression (esp w/ rapid infusion of FFP)
  
  • Reasons for it being risk:
    
    • Ca stores already low in neonates
    • FFP has highest concentration of citrate
  • neonates & children with liver failure are at pronounced risk
• Platelets: need for replacement depends on starting platelet count- clinical oozing on the field is the typical indicator
  
  • Starting normal platelet count usually does not need platelets UNTIL EBL > 2 blood volumes

Question 33

Average Hgb/HCT for newborn, 3 month, 6-12 months and adult female/male?

EBV for preterm neonate? term neonate? infant? >1 yr?

Answer 33

Question 34

Coagulation in newborns/infants?

Answer 34

• At birth, vitamin K-dependent coag factors are low ( 2,7, 9,10)
  
  • reach adult levles by 6 months age
• fibrinogen polymerization does not reach its full capacity during first few postnatal months
  
  • leads to prolonged thrombin time
• PLT number at birth comparable to adults
  
  • however, PLT function impaired in early life
• Postnatal period represents hypercoaguable state
  
  • d/t inhibitor of coagulation decreased by 30% to 50% in newborn
• Antithrombin III and protein S levels reach maturity by 3 months of age
  
  • protein C and plasminogen levels reach adult levels after 6 months of life
• higher risk for thrombotic complications in neonates and infants.

Question 35

Standard components of fluid replacement in pediatrics?

Answer 35

• Components of fluid replacement:
  
  • 1. Fasting (NPO) deficit (maintenance rate x hours NPO for deficit)
       * don’t always replace NPO def in healthy child for elective procedure
  • 2. Baseline maintenance fluid requirement- using LR (balanced salt solution- not dextrose unless risk pop) in most cases (4:2:1)
  • 3. Replacement of blood loss- hourly
       * (3:1 crystalloid replacement until MABL reached then 1:1 colloid (blood)
  • 4. Evaporative losses (based on invasiveness of surgery)
• Now believe holliday segar not necessary
  
  • Miller refers to using holiday segar for infnats <6 months. >6months 10-40mL/kg over 1-4 hours appropraite for NPO and replacement.

Question 36

Fluid replacement considerations in pediatrics?

Dehydration guidelines?

Answer 36

• LR is typically used for maintenance in healthy children
  
  • < 6 mo’s & in others at risk for hypoglycemia: glucose containing IVF may be needed in infants
    
    • Ex: D51/2
• Minimize potential for error: smaller IV bags (250/500 ml bag); buretrols
• Eliminate all air from IV line
  
  • Volume of air and rate of entrainment leads to VAE
  • If PFO opens because of surgical stress, air will go straight up to brain
• Recognize dehydration in infants: the best measure of deficit is weight
  
  • Mild: ~50ml/kg deficit dry mouth, poor skin turgor
  • Moderate: ~100ml/kg mild sx plus deficit sunken fontanel, oliguria, tachycardia
  • Severe: ~150 ml/kg moderate sx plus sunken eyes, hypotension, & anuria
    
    • Pulse pressure really useful, respiration,

Question 37

Considerations of glucose and hypoglycemia prevention in infants?

Answer 37

• Routine use of glucose-containing IVF in the perioperative setting in children is NOT recommended
  
  • Exception: Children at high risk of hypoglycemia- can use D5 1/2NS @ maintenance rates
    
    • Don’t use for BL or evaporative loss replacement (must use balanced Na solution)
  • Continuous TPN:
    
    • must NOT suddenly stop
    • consider leaving on at a reduced rate
    • some providers may use D10 to bridge- monitor glucose!!
  • Children with mitochondrial disease will definitely need glucose containing replacement fluid

Miller says cut the TPN rate by one third and leave running

Question 38

Why is uptake more rapid in children?

Answer 38

Uptake (Wash-in) more rapid in children for several reasons:

• increased respiratory rate
• increased cardiac index<< this is somewhat contradicted in Miller? Miller says uptake is dependent on CO. We learned before increase CO= slower onset?
• larger proportion of blood to VRG (heart, brain, GI, kidneys, endocrine)
• Reduced tissue/blood and blood/gas solubility in infants
• Increased Alveolar ventilation to FRC ratio
  
  • Infants: 5:1
  • Adults: 1.5:1
• *Increased risk of anesthetic overdose in infants/ toddlers
  
  • Faster equilibration to what set on dial (from co-exist lecture last semester)
    
    • Determinants of “wash in” of VA → FRC, inspired concentration, alveolar ventilation
      
      • Wash in is inversely related to solubility= lower solubility→ higher wash in
        
        • Less is binding to tissue, less dissolved in blood
    • Removal → CO, solubility, alveolar-venous partial pressure
• 18% BF to VRG in infants as opposed to only 8% in adults

Question 39

MAC for sevo and des in neonate, infant and children?

Answer 39

• Sevoflurane:
  
  • Neonates: 3.3%
  • Infants (1-6 mo): 3.2%
  • Children (> 6 mo): 2.5%
• Desflurane:
  
  • Neonates: 9.2%
  • Infants (1-6 mo): 9.4
  • Infants (6-12 mo): 9.9%
  • 1-3 yo: 8.7%
  • 5-12 yo: 8%
• All VA: MAC increases until 2 to 3 months of age (max: 1 to 2 years old) and steadily declines with age thereafter
• Sevo (Exception): MAC remains constant in neonates and infants up to 6 months
  
  • MAC up to 6 months is ~3.2%
  • MAC 6 months to 12 years is constant at 2.4% (decrease)

Question 40

Can you use a BIS monitor in kids?

Answer 40

No, children have higher BIS for a specific fraction of MAC c/t adults

Question 41

Use of various VA in neonates and infants?

Answer 41

• Increase hypotension incidence in neonates & infants upon inhalational induction
  
  • More rapid uptake can unmask negative inotropic effects of the volatiles in infants

Agents and use:

• Sevoflurane – primary agent for inhalational induction
  
  • Well tolerated by mask
  • No irritation of airway (least pungency)
  • Potent bronchodilator
• Halothane
  
  • low pungency
  • no longer used in US
  • bradycardia at induction (higher solubility- slower onset, phase 2, laryngospasms)
    
    • most dangerous → MAC multiples if turned all the way up, go up to 5.7x MAC (risk of overdose)
• Desflurane – limited use
  
  • Pungent!
    
    • Leads to: Breath holding, coughing, salivation, laryngospasm
  • Low solubility → can use for maintenance for long sx/obese children
    
    • Faster wake up

Question 42

Respiratory and CV effects of various inhaled anesthetics in pediatrics?

Answer 42

• Respiratory: same as adults:
  
  • Dose related respiratory depression
  • decrease response to CO2 & hypoxia
    
    • As concentration increases, apnea ensues
• CV:
  
  • dose dependent depression
    
    • Myocardial depression may be exaggerated in neonates d/t:
      
      • immaturity of sarcoplasmic reticulum → more susceptible to calcium-channel blocking effects of volatile anesthetics
    • Delicate balance of achieving adequate depth at induction & avoiding cardiovascular depression
• all can cause prolonged QT
• Sevo usually maintains or increases HR during induction
• halothane has greatest depression of contractility → induction arrests! Over pressuring during induction and had negative inotropic affect
  
  • Halothane: high lipid solubility; slow onset & offset; low pungency; no longer used in US
  • Halothane hepatitis- antibody reaction; repeated exposure
• Isoflurane:
  
  • limited utility for induction due to noxious smell
  • increased risk of laryngospasm/ coughing
  • confers more cardiac stability (as in adults)
• Emergence delirium is commonly associated with all inhaled agents (sevo>des>halothane)
  
  • Halothane less likely bc comes off slower

Question 43

Induction agent use in pediatrics?

Propoofl, ketamine, etomidate, thiopental, methohexital doses?

Answer 43

• Neonates: Immature BBB & decreased metabolism can increase sensitivity
  
  • increased permeability of BBB makes more sensitive

Older children & adolescents generally require increased doses of induction agents compared to adults

• Dosing:
  
  • Propofol (Diprivan): have extra available
    
    • < 2 yo: 2.9 mg/kg
    • 6-12 yo: 2.2 mg/kg
  • Ketamine:
    
    • 2 mg/kg IV
    • 4-8 mg/kg IM (plus atropine 0.02 mg/kg IM/IV → for hypersalivation)
  • Etomidate:
    
    • 0.25-0.3 mg/kg
  • Thiopental sodium (Pentothal):
    
    • neonates (< 1 month): 3 to 4 mg/kg
    • infants (1 m–1 yr): 7 to 8 mg/kg
    • Children: 5-6 mg/kg
  • Methohexital: ECT therapy
    
    • 2 mg/kg IV or 15-25 mg/kg of a 1% or 20-30 mg/kg of a 10% solution PR

Question 44

Propofol use in pediatrics?

Answer 44

• Most commonly used IV induction agent in children
• Greater Vd than adults
• More rapid redistribution
• Pain of injection can be reduced with a mini Bier block with 0.5-1 mg/kg of Lidocaine for 60 seconds (BP cuff)
• Antiemetic properties
• TIVA- lower rate of PONV/emergence delirium
  
  • Propofol infusion syndrome: long term infusions in ICU avoided in infants & children (acidosis); still appropriate for TIVA case
  • Egg/soy: only avoid if documented anaphylaxis with eggs

Question 45

Ketamine use in pediatrics?

Answer 45

• can be used IM, IN, PO, IV → hemodynamic compromised pts
  
  • Induction with ketamine preferred in
    
    • severe hypovolemia,
    • cyanotic heart disease,
    • septic shock, & induction for mediastinal mass (need spontaneous ventilation)
  • Increased secretions (premedicate w/ anticholinergic)
    
    • Ex: atropine
  • Emergence irritation
    
    • reduced with co-administration w/ Midazolam
    • waking up in a dark/quiet room

Question 46

Etomidate use in children?

Answer 46

• only approved for use in age >10 yo in U.S (0.2-0.3 mg/kg IV)
  
  • Pain on injection
  • Adrenal suppression concern

Question 47

Midazolam use as sedatives in pediatrics?

Metabolism?

Reversal agent?

Answer 47

most widely used anxiolytic pre-op

• Oral dosing:
  
  • dose increases in younger patients
  • poor oral bioavailability
  • bitter taste
  • allow 10-15 minutes
    
    • ORAL dosing: dose decreases w/ age
      
      • 18 mo-3yo: 0.75-1 mg/kg
      • 3-6 yo: 0.6-0.75 mg/kg
      • 6-10 yo: 0.5 mg/kg 6-10 yo
• IV: 0.1-0.2 mg/kg (immediate onset)
• Intranasal: 0.3 mg/kg
  
  • MAX DOSING: 15 mg
• Reversal:
  
  • flumazenil 0.01mg/kg IV
• Hepatic metabolism (CYP 3A4) & renal excretion

Question 48

Ketamine use in peds as sedatives?

Answer 48

• Severe cognitive/ behaviorally challenged older children → IM administered preop ** preferred
  
  • IM dose: 4-5 mg/kg
  • Onset: 3-5 minutes
  • Duration: 30-40 minute duration
• Oral onset: 15-20 min

Question 49

Dexmedetomidine as sedative in pediatric patients?

Answer 49

• hypotension with loading doses
• bradycardia with high dose infusion
  
  • (note biphasic response with transient hypertension initially) → then hypotension
• will not be adequate as a sole anesthetic but can be helpful as adjunct
• opioid sparing effects
  
  • Uses:
    
    • useful in awake FOB
    • radiological procedures
    • reduction of emergence delirium
• Dosing:
  
  • IV:
    
    • initial dose: 0.7-1.0 μg/kg administered over 10 minutes
    • → followed by infusion: 0.5-1 μg/kg/hr
  • Intranasal: 80% bioavailability!! great premed!! But takes long to peak
    
    • Dose: 1-2 mcg/kg
    • Peak: 30-40 min (long time)

Question 50

Considerations of opioids in pediatrics?

morphine? fentanyl? dilaudid? remi? demerol? codeine?

Answer 50

• Variety of choices: onset, potency, duration, & metabolism are factors just like in adults
  
  • Also consider previous exposure to opioids (tolerance), severity of pain, & other multi-modal strategies
• Morphine:
  
  • active metabolite (morphine-3- glucuronide)
    
    • → cause prolonged respiratory depressant effects in neonates and preterm and critically ill infants
  • Dosing: 50-100 mcg/kg (IV) per single dose
• Dilaudid dosing: 10-20 mcg/kg (IV) per single dose
• Fentanyl: most widely used opioid intra-op in children
  
  • stable CV profile
  • Caution: chest wall rigidity
  • Dosing variability
    
    • ~ 0.5-1 mcg/kg range
      
      • Work up to 1-3 mcg/kg range (IV) per single dose & titrated for effect
      • Safely go up to 10 mcg/kg depending on sx
• Remifentanil:
  
  • excellent for neonates
    
    • great choice in renal/hepatic failure/immaturity (due to metabolism via esterases → mature system in neonate)
    • predictable eliminiation
  • Caution:
    
    • bolus injections can cause significant bradycardia/hypotension
    • must have plan for analgesia once infusion discontinued
  • Dose: 0.05-0.1 mcg/kg/min
• Demerol:
  
  • Admin for shivering in small doses (0.25-0.5 mg/kg)
  • Metabolite: normeperidine
• Codeine:
  
  • historically very commonly prescribed postop
  • withdrawn from many markets due to respiratory events
    
    • SNP’s in ultra-rapid metabolizers confer risk of OD (CYP affected)→ BLACK BOX warning
    • Slow metabolizers- placebo

Question 51

Acetaminophen and ketorolac use in peds?

Answer 51

• Acetaminophen:
  
  • PO 10-15 mg/kg
  • IV: 15 mg/kg q 6 hours (10-15 min onset)
  • rectal absorption: SLOW (1-2 hours)
• Ketorolac:
  
  • Dose: 0.5 mg/kg IV
  • Ask surgeon before administration
  • CAUTION:
    
    • Severe asthma → caution all NSAIDs
      
      • Nasal polyps, eczema, and asthma → tend to have NSAID allergies

Question 52

Consideration of muscle relaxanat use in pediatrics?

Answer 52

• NMJ not fully mature until ~2 months of age
  
  • Infants: may be more sensitive to NDNMB but also have larger VD → so dose/kg is usually the same as adults
    
    • EXCEPTION: Rocuronium- dose is lower in infants
      
      • ex: infants 0.3 mg/kg
      • ex: children: 0.6 mg/kg
      • RSI: same
    • Always use nerve stimulator → response is highly variable (neonates not have normal resp to NS)
    • Use small doses
    • Reassess frequently
    • May see prolonged duration of action due to immature renal/ hepatic elimination

Question 53

Succinylcholine use in pediatrics?

Answer 53

• Higher Sch doses needed in neonates & infants due to larger VD
  
  • < 1yo: (2-3mg/kg)
  • Older → dose gets smaller

Sch is limited to RSI and emergency tx of laryngospasm in Peds

• Cardiac sinus arrest may follow 1^st dose of succs → more common after repeated bolus admins in any age
• Co-administer w/ vagolytic drug (atropine) should probably be intravenously administered just before the first dose of succinylcholine in all children, including teenagers
  
  • unless a contraindication to tachycardia (e.g., a cardiomyopathy) exists
• RISKs:
  
  • Bradycardia
  • Hyperkalemia
  • masseter spasm
  • MH in children w/ undiagnosed myopathies

Question 54

NMB reversal in pediatrics?

Answer 54

• Routine reversal for TOFR < 0.9
  
  • Neostigmine: dose for infants & children 30-40% lower than adults
    
    • Dose: 0.02-0.04 mcg/kg
    • co-administered with anticholinergic
• Sugammadex: not FDA approved in peds
  
  • Dose: 2 mg/kg
  • Always reverse peds pts!

Question 55

Local anesthetic use in pediatrics?

Answer 55

• Cardiac output and local blood flow: 2-3x greater in infants than in adults
  
  • → so systemic LA absorption is increased (higher chance of LA toxicity)
• Epinephrine is effective in slowing systemic uptake
• Very Low Plasma concentration of AAG at birth (0.2 to 0.3 g/L) and does not reach adult levels (0.7 to 1.0 g/L) before 1 year of age
• Free fraction of all local anesthetics is increased in infants

Maximum doses of all amino-amides must be reduced (KNOW DOSES!) → think about cumulative amount going to give

Question 56

VS for pediatrics?

Shortcut for SBP 2-10 yo?

Answer 56

• Age related increase in HR that declines with age
• systolic lower in ped young patient and BP gradually increases
• RR much higher in preterm neonate/infant c/t adult pt
• shortcut for BP?
  
  • 2-10 yo - SBP: minimum SBP → 70 + (age x 2)

Ex: 5 yo → 70 +5 x 2 = SBP 80

>10 yo: SBP 90

< 1 yo: SBP 70

Question 57

Developmental considerations with children?

Answer 57

• Preschool age: distraction & premedication
• Offer flavoring for the oxygen mask if available
• Pre-operative preparation with OR equipment (see the mask, pick a flavor, etc.); child life specialists can assist
• Distractions: music/ singing, story telling, jokes, guided imagery; “changing the flavor” of the mask
• Avoid bright lights, loud voices, & lots of extra personnel in the room
• Consider parental presence (especially in ages 1-6); parents must be educated on what to expect at induction (irritation)→parent leave room once child lostconciousness
  
  • 9-10 mo range- consider midaz 10-15 prior
  • Toddler
  • Child- play games

Question 58

Generic Preop eval for pediatric patient?

Answer 58

• Standard adult history and physical exam must be adapted; some topics that require further emphasis in children
• Birth history; prematurity
• Neurologic development- appropriate for chronological age? psychological issues?
• Airway anomalies, surgical history, previous intubations, and general medical health (heart, lung, endocrine, renal disorders)
• AW exam:
  
  • Indicators for Difficult AW:
    
    • check for facial dysmorphias
    • signs of stridor, dysphonia, swallowing disorders, difficulty in breathing, difficulty in speaking, and hoarseness
• Genetic or dysmorphic syndrome?
  
  • Potential for anomalies in the cervical spine (eg, Down syndrome) or craniofacial dysmorphia
    
    • Down syndrome- atlantoaxial subluxation at C1-C2 level
• Family history: fevers or troubles waking up? MH, PD
  
  • (1) malignant hyperthermia (MH)
  • (2) pseudocholinesterase deficiency
  • (3) postoperative nausea and vomiting
  • (4) congenital myopathies
  • (5) bleeding (brushing teeth)
• No laboratory work is indicated for healthy children undergoing a procedure with minimal blood loss anticipated
• Routine pregnancy testing: controversial; parents may decline; history alone can be unreliable
  
  • Have waver ready
  • Midaz- iatrogenic effect
• Higher risk for latex allergy in certain pediatric populations:
  
  • Ex: spina bifida, myelodysplasia, urinary tract malformations; multiple previous surgeries

Question 59

s/s of difficult airway in peds?

Answer 59

• Mandibular protrusion
• mallampati
• movement of atlantooccipital join
• reduced mandibular space
• increase tongue thickness
• age <1 yo
• ASA II-IV
• Obesity
• maxillofacial and cardiac sx

Question 60

What questions can you ask during preop eval focusing on respiratory system

Answer 60

• Frequent upper respiratory infections (URIs)?
  
  • Risk for post op resp complications/laryngospasm
  • Up to 6 weeks after URI
• History of wheezing? History of noisy breathing? Hospitalizations? History of intubations?
• History of eczema/skin allergy/atopy? → likely to have bronchospasms/AW issures
• In daycare? Immunization status? Smokers in the house? → prone to reactive AW dx
• Infant: Frequent vomiting after feeds/“choking” episodes? → reflux
• Child: Frequent tonsillitis? Ear infections? Snoring?

Question 61

CV focused questions to assess during preop pediatric patient?

Infant vs older child?

Answer 61

Any family history of CHD/chromosomal abnormalities, sudden/premature death; maternal illness/infections (both chronic and during pregnancy); maternal medications/drug use

• Infant: look for clues on undiagnosed congenital heart defect →
  
  • Any problems with poor feeding, sweating (especially on the forehead) during feeding, poor weight gain, FTT, decreased activity level
  • Symptoms of CHD often occur with feeding because of increased oxygen consumption and the need for greater cardiac output.
    
    • Need further testing
  • Babies with cyanotic heart disease turn dark blue or ruddy in color when crying because of prolonged expiratory phase and resulting increase in right-to-left shunting.
  • Hypercyanotic spells are often associated with extreme irritability and rapid, deep, and sometimes labored respirations.
• Older child/ adolescent:
  
  • Any inability to keep up with the activity level of peers, need for frequent periods of rest, anorexia, cough, wheezing, rales, chest pain, leg cramps, syncope, light-headedness, palpitations; any history of drug use; any family history of sudden death, syncope, or arrhythmias
• Any changes in color or cyanosis when crying? → undiag congenital heart defect

Question 62

How to practice cultural humility?

Answer 62

• 25% of all children younger than 5 years in the United States come from racial or ethnic minority backgrounds
• Do not assume (based on language or ethnicity) to know the ideas or beliefs of a family
• Understand the family hierarchy- who are the decision makers? Who answers questions?
• Make every effort to use, pronounce, and record names correctly- important expression of respect
• Try to learn a few words or phrases in the foreign languages you commonly encounter- this goes a long way with a child
• Do not ask a parent to sign a consent that is not in their native language without full access to interpretation
  
  • allow extra time and do not rush the consent process
• Talking with interpreters (best practices): Always look at the parent and child (not at the interpreter); speak slowly; in short sentences; in a normal tone of voice; allow enough time for the interpreter to translate; encourage questions;
  
  • Be very cautious of false fluency – may pretend to understand fully if only understand partially
• Interpreter vs. translator:
  
  • Translator: deals only in words.
  • *Interpreter: understands and communicates the meaning of looks, gestures, customs, traditions, and health practices in both directions between families and caregivers.
• Alternative medicine: do not approach this with skepticism or bias but certainly ask about herbal & natural remedies & ask if they are working

Question 63

Physical exam in peds?

Answer 63

• Always talk through your assessment; children like to know what to expect; get on the child’s eye level; stay calm
• Airway: inspect face (include profile view), mouth opening, tongue mobility (“stick out tongue”), neck extension, loose teeth*
• Assess respirations in position of comfort (moms arms), look for flaring, retractions
• Auscultate heart and lungs
  
  • Rales or wheeze? request a cough and listen again (just stuff in upper airway)
  • Murmur detected?
    
    • Further investigate- cyanosis, syncope, arrhythmias, tachycardia, poor feeding, activity tolerance
      
      • Innocent murmurs: up to 50% of normal children (especially age 2 to 6) → typically systolic murmurs
        
        • Soft, short, systolic ejection murmurs → accentuated by stress, anemia, fever
      • Investigate: Diastolic murmurs &/or symptomatic murmurs, new ones (esp. associated with poor feeding/FTT)
        
        • Harsh, radiating loudly, systolic or diastolic murmur → investigate (most diastolic not ok)
          
          • Get echo!
• Palpate liver if any reason to suspect fluid overload:
  
  • Normal liver: 1-2 cm below intercostal margin
    
    • Sticking lower- fluid overload**
      
      • Hepatomegaly → sign of RV failure
• Cyanosis in the infant: Arterial desaturation or central cyanosis is best detected in the perioral area, the mucous membranes of the mouth, lips, and gums.
  
  • Central cyanosis should be distinguished from peripheral cyanosis
    
    • Central cyanosis: concerning
    • Peripheral: occur in a cold environment, and acrocyanosis, which in newborns is due to sluggish circulation in the fingers and toes

Question 64

Pain in pediatrics?

Answer 64

• Somatic pain: conveyed in part by unmyelinated C fibers (“slow”)
  
  • leads to protective reflexes → autonomic reactions, muscle contraction, and rigidity (spastic)
    
    • C fibers are fully functional from early fetal life onward
    • Connections between C fibers and dorsal horn neurons are not mature before the second week of postnatal life but nociceptive stimulations transmitted to the dorsal horn by C fibers elicit long-lasting responses
      
      • → Neonates have an exaggerated response to nociceptive stimuli
        
        • profound and prolonged response
      • With large amounts of pain- can make abnormal pathways that make more sensitive and lifelong
    • Inhibitory control pathways are immature at birth and develop over the first 2 weeks
• Painful procedures during the neonatal period modify subsequent pain responses in infancy and childhood
  
  • With large amounts of pain- can make abnormal pathways that make more sensitive and lifelong
• Pre-emptive analgesia → leads to a reduction in the magnitude of long-term changes in pain behaviors
• Must use a pain scale appropriate to the developmental level of the child (< 3 yo usually unable to self-report)
  
  • Procedural pain in infants and young children: common use of FLACC scale
    
    • FLACC- face, legs, activity, cry, consolability
    • (preverbal use) - < 3 yo usually unable to self-report

Question 65

Fasting guidelines for peds?

Answer 65

• 2006 ASA guidelines
• Clear liquids: Include only fluids without pulp, clear tea, or coffee without milk products
• Gum chewing:
  
  • 70% increase in gastric fluid volume in the first 15 minutes after initiating gum chewing, mostly saliva
  • most providers will proceed as long as gum is spit out (not swallowed)

Question 66

Considerations for room setup in peds?

Answer 66

• Always have a range of sizes of airway equipment (face masks, OPA’s, ETT’s, LMA’s, blades)
  
  • Need size up and size down from anticipated size
  • Straight blades are most commonly preferred in infants due to anatomical differences (get both out)
  • Appropriate size LMA should always be available even if intubation is planned in case of unanticipated difficult airway
• Ensure appropriate sized BP cuff and pulse oximeter is present & functional
• Calculate drug doses, allowable blood loss, & fluid requirements
• Have primed bag of IV fluid ready and all supplies to start & secure IV set up & accessible
• Prepare a pediatric circuit/bag
  
  • 0.5, 1, 2 L bag → use peds circuit if < 5-8 yo
  • If can pull TV > than volume of bag → negative pressure in system (switch over to bigger bag)
• Preset vent settings appropriate for size (& program in weight to anesthesia machine if applicable)
  
  • Pressure control better
  • Volume control- TV/kg can be calculated
  • Appropriate sized mask- injury, eyes, bad seal, VAGAL response!
• Emergency drugs for every pediatric case:
  
  • Sch & Atropine + IM needle: Weight appropriate doses with a small gauge needle appropriate for IM injection
    
    • Laryngospasm, take on every transport
  • Propofol syringe – have backup
    
    • facilitate intubation, break laryngospasm, increase depth of anesthesia quickly
  • Epi diluted to 10mcg/ml: not always drawn up but definitely consider drawing up in a sick patient/ complex case (cardiac arrythmias→ bradycardia not responsive to O2—ex: O2 typically primary tx )
    
    • Comes 100 mcg/ml → need to dilute down to 10 mcg/ml
• Plan for age appropriate distractions: have flavors for masks; consider parental presence if facility allows (cover supplies to hide anxiety)
• Warm the room

Question 67

Premed use in peds?

Answer 67

• Often needed at the age ~10 months when separation anxiety becomes an issue
  
  • Be aware of secretions from crying → laryngospasm risk
• Oral versed most common- SEE DOSING
• Severe distress/ need for profound sedation
  
  • may combine medications (ketamine, atropine, versed combo PO)
  • may use IM route if uncooperative with PO sedation
• Intranasal route is sometimes used but can really burn & make child more agitated
  
  • Intranasal dex (good bioavail) → alternative to intranasal midaz (burns)

Question 68

Mask ventilation considerations in peds?

Answer 68

• Sniffing position is critical – no hyperextend neck
  
  • Tongue bigger/oral AW smaller → prone to obstruct
    
    • Align oral, pharyngeal, laryngeal axis – slightly displace mandible forward/neutral
    • Put little pillow behind to put nose to ceiling
    • Shoulder roll
• Avoid pressure on the soft tissue in the submental triangle – might cause obstruction
• Jaw thrust
• Low threshold for 2-person ventilation

Question 69

Circuit configuration of maplesons?

Answer 69

• Common to use Jackson-Rees for transport ventilation (Mapelson F)**
  
  • Low resistance and dead space
• Pop-off valve
  
  • added to endo of reservoir to provide assisted ventilation
  • Should be open for spontaneous ventilation
• Requires relatively high FGF (2-3 x’s minute ventilation)
• Keep pop-off open for spontaneous ventilation → adds extra resistance (don’t want)
• Mapleson A best for spontaneuous, D best for controlled breathing

Question 70

Induction considerations in peds?

Answer 70

• Stay flexible! All monitors may not go on before induction (try for pulse ox); child may be afraid of mask
• Stay calm! Be warm and reassuring
• Inhalational induction is most common
  
  • Particular attention should be paid to frequent monitoring of blood pressure and heart rate during induction
    
    • Inhalational arrest high risk, get BP on ASAP when started gas
• Premedication:
  
  • < 9-10 months: usually no premedication required
  • 1-3 yo: separation anxiety usually worst → plan to do premed (oral midaz/nasal dex)
• Allow them to have pacifier
• Alternative is pre-op IV with standard induction: topical anesthetics can be used for IV starts; EMLA cream onset is 45-60 minutes
  
  • Ex: < 8 yo → no IV preop
• IM Ketamine is rarely used for inductions in larger cognitively impaired/ extremely uncooperative children

Question 71

Inhalational induction in peds?

Answer 71

Inhalational induction is common: seated or supine position

One approach:

• Higher flows with 70% N2O and 30% O2 (7L N2O and 3L O2)
• Fully open APL
• Allow a few breaths of N2O mixture and then incrementally turn on Sevo to 8% (some providers turn up sevo to 8% without using incremental technique after a few breaths of N2O- especially if crying)
• Turn off N2O to provide 100% O2
• Assist spontaneous ventilation PRN- caution about high inspired volatile agent with assisted or controlled ventilation (keep spontaneously breathing!)
  
  • Decrease inspired anesthetic if need to ventilate
    
    • ​do not want to get to this point!
• Obtain IV
• Once IV is in, induction proceeds- give some propofol, narcotic, +/- NMB, etc at this point and then proceed with airway management appropriate for case (LMA, ETT)
  
  • NOTE: intubation is often completed without NMB’s
• Be sure to turn down Sevo to normal MAC range for the child; watch VS closely during induction

Question 72

RSI in children?

Answer 72

• Same principle as adults to prevent aspiration
  
  • Cricoid pressure in infants/ children is +/- (Barash says no) → increased likelihood of obstructing an infants airway with little proven benefit
  • Note that children will have rapid desaturation with hypoxia (limited reserve) and often hard to preoxygenate an uncooperative child
• Equipment: ETT (pre-stylet) age calculated plus 0.5 smaller & 0.5 larger; laryngoscope (working), suction immediately available at HOB, functioning IV, pre-drawn drugs
  
  • Propofol 2-4 mg/kg (stable) vs. ketamine 1-2 mg/kg or etomidate 0.2-0.3 mg/kg (unstable)
    
    • plus Sch 2 mg/kg (premed with Atropine 0.02 mg/kg)
    • consider Rocuronium 1.2 mg/kg if Sch contraindicated (45 to 75 minute duration)
  • Calcium (IV) should be immediately available in the event Sch leads to unanticipated hyperkalemia w/ ventricular arrhythmias
    
    • Succs used in DAW patient → have Ca available

the younger the pediatric patient, the less reserve they have

Question 73

Airway management in children?

Answer 73

• Mask management is more critical skill in peds airway
• Always have ranges of ETT sizes
  
  • (0.5 smaller than calculated & 0.5 larger)
• Short trachea favors right mainstem intubation
• Breath sounds are often referred → bilateral chest rise and fall/w/ sounds
• Common formula over 2 yo
  
  • (Age + 16)/4
  • Cuffed tubes: reduce size by 0.5 mm
• Cuffed tubes are fine as long as cuff pressures are monitored
• Rough estimate of depth is 3x ID
  
  • Ex: using 4 tube → depth should be 12 cm
• A leak should be maintained around cuff regardless @ 20-30 cmH20 (not want pressure on trachea)
  
  • If turn APL to 20, should hear leak
  • If leak at 10- will be polluting OR and wont get TV

Question 74

LMA sizes for peds?

Use, contraindication?

Answer 74

• Used during routine surgeries & as a rescue device for failed intubation
  
  • Low failure rate for insertion (< 1%)
• Contraindicated in children with risk of pulmonary aspiration
• Other specific pediatric contraindications:
  
  • mediastinal masses
  • children requiring high peak airway pressures to ventilate
  • tracheomalacia
  • very limited mouth opening

Question 75

Considerations for known difficult airway in peds?

Answer 75

• Have LMA out & ready for back up
  
  • may use LMA as conduit for FOB

Sample plan: known difficult airway plan for nasal intubation with FOB → MAINTAIN SV!!! No apnea!!

• Apply standard ASA monitors; inhalational induction with sevoflurane, and maintain spontaneous ventilation (may require an oral airway)
• Obtain intravascular access if not previously obtained.
• Administer:
  
  • glycopyrrolate (5 mcg/kg)
  • propofol as needed to deepen anesthetic (larger doses may cause apnea) → don’t induce apnea
• Prepare nasal cavity with oxymetazoline → reduce bleeding
• Size both nostrils with a nasal pharyngeal airway (NPA). Keep the NPA in the smallest nostril and attach endotracheal tube connector to the end of the NPA. The patient can now entrain air : oxygen and sevoflurane during spontaneous ventilation.
• Place a fiberoptic scope with a previously loaded nasal RAE endotracheal tube through the opposite nostril. Suction should be attached to the suction port.
• Visualize the glottic opening. Spray the vocal cords with lidocaine (use 2% if over age 2 years, 4% if over age 8 years). Enter the trachea, and spray the trachea.
• Lubricate the endotracheal tube and slowly pass through the nose into the trachea. Downsize the endotracheal tube by 0.5. Apply slow, steady pressure.
• Place endotracheal tube connector from the NPA onto the ETT and confirm end-tidal CO2

Question 76

Ventilation considerations for peds?

Answer 76

• 6 to 8 mL/kg is typical
• Sustained plateau airway pressures > 35 cm H2O can lead to barotrauma:
  
  • Pneumothorax
  • Pneumomediastinum
  • subcutaneous emphysema
• Lung protective strategies apply
• Pressure control ventilation is proffered
• Peak inspiratory pressure: 15-18 cmH2O
  
  • Titrate as needed
• Resistance in circle system: unidirectional valves, kinking of ETT, CO2 absorbent, humidity and moisture exchanger
  
  • Issue with infant: sometimes need less valves, less resistance → use Mapleson circuit to limit resistance

Question 77

ETT size cuff pressure monitoring in peds?

Risk factors associated with acquired SGS?

Answer 77

• 95% of subglottic stenosis is acquired from excessive cuff pressures
• Postintubation injury is the most common cause of acquired subglottic stenosis
• Risk factors associated with acquired SGS:
  
  • trauma during intubation
  • ETT movement during intubation
  • Prematurity
  • presence of infection at the time of intubation
• Avoid oversized ETT’s*
  
  • Feels tight → exchange to smaller
• Cuff pressures must be monitored throughout long cases/ extended intubations
  
  • maintained at a level below 20-30 cm H2O (should hear leak)
    
    • N2O use → can cause cuff to expand
    • < 10 cm → pollutes OR
• Microcuff tubes- cause less trauma to airway

Question 78

Laryngospasm, symptoms, risk, treatments?

Answer 78

• More frequent in infants; risk decreases with increasing age
• Reflex closure of false & true vocal cords
• Sx: stridor, retractions, flailing of lower ribs; “rocking horse” chest wall movement; stridor will be absent with complete closure “silent inspiratory effort” (NO FOGGING OF MASK)
  
  • Can lead to profound bradycardia & desaturation if unrelieved
• Risks:
  
  1. recent URI (w/in 3 wks),
  2. secondhand smoke,
  3. stimulation while “light,”
  4. secretions in airway (CRYING, BLOOD IN AW)
• Treatment: Continuous positive airway pressure,100% oxygen, jaw thrust at condyles of mandible (Larson’s Maneuver)- anterior displacement, suction secretions/ blood etc., deepen anesthesia (propofol)
  
  • Unresolved?
    
    • Atropine & Sch- if no IV access then give IM
• Severe Laryngospasm/Bit through ETT: → lead to negative pressure pulmonary edema especially in healthy, muscular adolescents- may have to remain intubated for 12-24 hours & may need furosemide (flash pulmonary edema)

Question 79

Bradycardia in pediatric patient?

causes?

treatment?

Answer 79

THINK VENTILATION & OXYGENATION

• Infants: <100 bpm
• 1-5 yo: <80 bpm
• >5 yo: < 60 bpm
  
  • If O2 and vent don’t help → chest compressions!
• Causes:
  
  • Hypoxia → leading cause of bradycardia in children (and asystole)
  • Single dose Sch
    
    • other causes: vagal stimulation, increased ICP, meds (Sch), CHD, hypothermia, air emboli, tension pneumothorax
• Treat cause: think oxygenation and ventilation first!! Then…
• → Atropine if vagal origin 0.02 mg/kg IV
• Epinephrine if decompensated 10 mcg/kg
• if HR <60 with s/s of poor perfusion, call for help and start chest compressions

Meds bradycardia: clonidine, beta blockers, Sevo esp in downs syndrome, propofol infusion syndrome, some eye drops, Sch without atropine

The most frequently encountered arrhythmia in pediatric populations is hypoxia-induced bradycardia that can lead to asystole, if not appropriately handled. Ventricular fibrillation is extremely rare in infants and children.

Question 80

Emergence in peds for awake extubation

Answer 80

• Neuromuscular function- check & reverse if appropriate
• Different techniques for extubation; always prioritize patient safety
  
  • light anesthesia is the most common cause of laryngospasm
• Awake extubation: must be awake & purposeful; laryngospasms happen when patients are extubated in the early & second phase, “if in doubt…don’t take it out!”
  
  • 3 phases waking up:
    
    • early phase- coughing intermittently, gagging, struggling, moving nonpurposefully
    • second phase- apnea, agitation, straining, breathholding, RR not regular
    • third (final) phase- regular respiratory rate, purposeful movement, coughing, opening eyes spontaneously → extubation now appropriate

Question 81

Deep extubation in peds?

Answer 81

• Deep Extubation:
  
  • Sevo increased to 1.5-2 MAC for at least 10 minutes
  • ensure no response (cough, breath holding) to suctioning or tube movement; & ensure regular respirations
    
    • place oral AW and allow them to breathe off gas or assist them
    • No deep extubate: DAW or aspiration risk
• Transport in lateral decubitus position “recovery position”
• Tx w/ O2
• PACU complications in ~5% of children:
  
  • vomiting 77% (more common in >8 yo), airway compromise 22% (more common in <1 yo); CV compromise is <1%

Question 82

Regional anestheisa in peds?

Answer 82

• Caudal anesthesia
  
  • lower abdominal & LE surgery in < 5-6 years of age (> 6 yo- doesn’t work as well)
  • single shot block with LA will last 4-6 hours
  • done following GA induction in lateral position
    
    • type of epidural block sacral-coccygeal ligament- easier accessed in this age group bc fusion not finished (easy)
• Epidural & spinal anesthesia are also used in children but are most frequently completed under general anesthesia
  
  • technique is similar to the adult patient
  • spinal anesthesia is technically difficult in neonates and infants; the overall failure rate ranges from 10% to 25%.
• Regional nerve blocks usually done following induction of general anesthesia- ultrasound is very helpful since no patient feedback is available

Question 83

Contraindication for neuraxial anesthesia in peds?

Answer 83

• (1) severe coagulation disorders (hemophilia, DIC)
• (2) severe infection such as septicemia or meningitis
• (3) hydrocephaly and intracranial tumoral process
• (4) true allergy to local anesthetics
• (5) certain chemotherapies (such as with cisplatin) prone to induce subclinical neurologic lesions that can be acutely aggravated by a block procedure
• (6) uncorrected hypovolemia
• (7) cutaneous or subcutaneous lesions, whatever their nature (infection, angioma, dystrophic or tumoral, tattoo) at the contemplated site of puncture
• Parental refusal is a non-medical absolute contraindication

Question 84

Caudal anesthetic technique?

Answer 84

• The most commonly used technique of epidural blockade in children
• Simple technique; low complication rate
• Anatomy of the sacral hiatus:
  
  • a U -shaped or V -shaped aperture resulting from the lack of dorsal fusion of the fifth and often fourth sacral vertebral arches
    
    • limited laterally by two palpable bony structures, the sacral cornua
    • covered by the sacrococcygeal membrane (sacral continuation of the ligamenta flava)
• 25-mm needles are long enough to reach the sacral epidural space and short enough to prevent inadvertent dural puncture in most patients
• Contraindications:
  
  • major malformations of the sacrum (myelomeningocele, open spina bifida)
  • meningitis
  • intracranial hypertension.
• Rare: unrecognized dural puncture can lead to cardiovascular collapse or respiratory arrest
• Position: lateral or prone position with the legs flexed in the “frog” position
• Single shot or placement of epidural catheter can be threaded to 2-3 cm (same as regular epidural block)
• Upper limit of dosing:
  
  • 1 ml/kg (1.25 ml/kg can lead to block above T4)→ resp consequences!

Question 85

PONV in kids?

high risk sx, prevention, treatment?

Answer 85

• Increased risk in certain surgeries: hernia; orchidopexy; T&A; strabismus; middle ear; laparoscopic
  
  • Strabismus sx pt- higher risk of MH (high risk of concurrent myopathies) (MD)
• Prevention:
  
  • Hydration
  • multi-modal analgesia (opioid sparing- use less)
• Peak incidence in females age 10-16
• Typical 2-3 agent strategy for prevention in at-risk (decreases risk by 80%):
  
  • Ondansetron 0.05-0.15 mg/kg IV (note risk in undiagnosed long QT syndrome)
  • Dexamethasone 0.0625-1 mg/kg IV

Question 86

Emergence delirium in kids?

Answer 86

• Agitation & inconsolability unrelated to pain
• Peaks in age 2-6 yo
• Most common after Sevo (then Desflurane); less common with TIVA
• Usually self-limiting (lasts ~ 10-20 minutes)
• Tx:
  
  • Small dose of fentanyl clonidine, or propofol
• Patient self-harm can be an issue (thrashing, etc.)
• need to go through and rule out hypoxemia/metabolic derangements
  
  • ​agitation may be due to pain, cold, full bladder, presence of casts, fear, anxiety, or having tantrum

Question 87

Providing anesthesia for pt with cleft lip?

Answer 87

• varying degrees
  
  • Risks: aspiration, feeding difficulty; frequent otitis
    
    • **Aspirations precautions
• not alway difficult airway, just take aspiration precautions

Question 88

What are some disorders with mandibular hypoplasia?

Anesthetic plan considerations for these patients?

Answer 88

• mandibular hypoplasia- tongue displaced posteriorly causing obstruction
• Universally difficult airway:
  
  • Pierre-Robin: intubating conditions improve with age
  • Treacher Collins: becomes more difficult to intubate with age
  • Hemifacial microsomia (Goldenhar)
  • → Very difficult mask ventilation & intubation:
    
    • preserve spontaneous ventilation during induction
    • fiberoptic should be at the bedside (backup equip and support)

Question 89

What are some disorders with midface hypoplasia?

Anesthetic consideration?

Answer 89

• Apert Syndrome
• Crouzon Syndrome
  
  • Difficult Mask ventilation but may not be as difficult to intubate → must avoid eye injuries (protruding eyes are a feature)

Question 90

What is epiglottitis?

Anesthetic considerations?

Answer 90

• Life threatening bacterial infection of the epiglottis, aryepiglottic folds, arytenoids, & sometimes the uvula
  
  • s/s: high fever, severe sore throat, drooling, ill appearing, tripod positioning
    
    • Rapid deterioration may occur
    • Common Age: 2-6 yo**
    • Tx: antibiotics, securing AW!!
• Technique:
  
  • Calm, sitting inhalational induction, maintain SV**
  • Do not manipulate the airway without a backup for surgical airway in place
  • Do not agitate the child (hold down for IV start; separate from parents)

Question 91

What is croup?

Anesthetic considerations?

Answer 91

Croup= (Laryngotracheobronchitis)- LTB

• Viral infection of the subglottic structures; more gradual onset
  
  • S/S: barky or seal-like cough along with hoarse voice and inspiratory stridor
• Technique:
  
  • Most cases resolve with simple management
    
    • Tx: humidified air or oxygen, steroids
    • <10% require hospitalization

Question 92

Croup vs epiglottitis?

Answer 92

• Both epiglottitis and croup have supraglottic swelling
• really nothing else in common
• epiglottitis 2-6 yo
  
  • stirdoe uncommon
  • thumb sign
  • abx
  • need sx availability of airway, get airway secured
• LTB <2 yo
  
  • stridor common
  • steeple sign (subglottic narrowing)
  • use things to decrease swelling but typically don’t need to intubate.

Question 93

Laryngomalacia in peds? s/s?

Answer 93

• most common airway problem in infants & children
  
  • Immature cartilage of the supraglottic larynx leads to symptoms
    
    • slowly resolves by 12–18 mo
    • self-limiting & resolves w/ age
• Symptoms: Inspiratory stridor w/ activity/feeding that IMPROVES when the child is calm
  
  • can lead to airway collapse

Question 94

What is tracheomalacia? Symptoms?

Answer 94

• Weakened/ “floppy” trachea that leads to symptoms
• Symptoms:
  
  • Harsh noise/stridor on expiration caused by airway collapse
  • Onset: early neonatal period
• Dx: bronchoscopy

Question 95

Asthma considerations in pediatric patients?

Answer 95

• Optimize patients preoperatively
• Pre-op review: ever been hospitalized for asthma? intubated? ER visits (last 6 mo)? age of onset? treatments used (today)? need for steroids?
• Assessment:
  
  • Auscultate for wheezing
• Cancel elective cases for ACTIVE wheezing!
• Technique:
  
  • Admin pre-op bronchodilators in mild/moderate asthma even if not wheezing
• Avoid intubation where facemask or LMA can be used (think sx type and aspiration risk)
• Have bronchodilators present in OR
  
  • Refractory asthma (not moving air) → admin IV epi w/ refractory bronchospasms bc inhaled bronchodilators cant pass

Question 96

OSA considerations in pediatrics? Main cause for OSA in kids?

Preop assessment and anesthetic considerations?

Answer 96

• Prolonged upper airway obstruction and/or intermittent complete obstruction (obstructive apnea) that disrupts normal ventilation during sleep
  
  • altered response to CO2
• Anesthesia concerns:
  
  • opioid sensitivity
  • post-op respiratory complications
    
    • post-op admission for monitoring depending on results of sleep study
• Primary cause of OSA in children: large tonsils & adenoids → T&A sx most likely for OSA
  
  • Other: craniofacial abnormalities, neuromuscular disorders, obesity

Assessment of risk factors:

• loud snoring, witnessed apnea, nocturnal enuresis, ADHD, behavioral problems, inattention at school; increased risk in African American
  
  • Daytime somnolence is not a common feature of OSA in children (opposite than adult pts)
  • AHI score- apnea-hypopnea index (AHI)
    
    • graded by # of apnea and hypopneic episodes during 1 hour obs
    • Mild >5 but <15/hour
    • moderate 15-30/hr
    • severe >30/hour

Question 97

What is the major concern with a history of OSA?

Answer 97

• Intermittent hypoxia → may lead to remodeling
  
  • Consequences: pulmonary hypertension & right heart failure (cor pulmonale)
    
    • Preop: Echocardiography recommended when severe OSA suspected to have CV involvement
  • Red flags:
    
    • systemic hypertension
    • right ventricular dysfunction (s/s: peripheral edema, hepatic enlargement (below 1-2 cm costal margins), elevated liver enzymes)
    • frequent severe desaturations (<70%)

Question 98

Anesthetic consideraitons with OSA?

Answer 98

• CONSIDER NON-OPIOID ALTERNATIVES:
  
  • local anesthetics
  • tylenol
  • ketorolac
  • ketamine
  • dexmedetomidine
• When opioid is given: REDUCE DOSE! (usually by 1/2)
  
  • Admin in small doses and assess for response
• High risk patient?
  
  • Safest route: Admit for postoperative monitoring even if no sleep study has confirmed diagnosis
  • Council family members about transporting child home → watch for obstruction

Question 99

URI considerations in pediatrics? When to proceed or cancel a case?

Answer 99

• Most common co-morbidity in children presenting for surgery
• Increased risk complications/ bronchospasm at induction/emergence
  
  • Laryngospasm, bronchospasm, excess secretions
    
    • The most common perioperative respiratory adverse events (PRAEs) associated with URI are:
      
      • **laryngospasm, bronchospasm, breath holding, atelectasis, arterial oxygen desaturation, bacterial pneumonia, and unplanned hospital admission
• Caution but proceed: clinically look OK
  
  • clear runny nose
  • no fever
  • playful
  • clear lungs
• Cancel:
  
  • purulent nasal discharge
  • fever
  • lethargy- ill looking
  • persistent cough, wheezing/ rales
  • previous preemie
  • <1 yo
• Consider waiting at least 2 weeks for elective surgery
  
  • Complications can persist up to 6-8 weeks

Question 100

Anesthetic considerations with recent URI?

Answer 100

• Airway manipulation (ETT) increases the risk of bronchospasm
  
  • Techniques:
    
    • ensure deep plane of anesthesia before manipulate AW
      
      • (risk of airway reflex response: face mask < LMA < ETT)
    • Avoid intubation if case can be done with less invasive airway (mask case; LMA)
    • Add propofol/local anesthetic
• Considerations:
  
  • Tx for bronchospasm available @ bs
  • anticipate increased potential for laryngospasm
• Most common perioperative respiratory adverse events associated w/ URI are:
  
  • laryngospasm
  • bronchopasm
  • breathholding
  • atelectasis
  • arterial oxygen desat
  • bacterial pna
  • unplanned hospital adm

Question 101

Laryngospasm in infancts? symptoms and risk?

Answer 101

• More frequent in infants
  
  • risk decreases with increasing age
• Reflex closure of false & true vocal cords
  
  • ​Afferent (sensory) limb of reflex= internal branch of SLN (superior laryngeal nerve)
  • Efferent (MOTOR) limb of reflex is recurrent laryngeal nerve (affects all laryngeal muscles except cricothyroid) and external branch of SLN (affects cricothyroid)
• Sx: stridor, retractions, flailing of lower ribs; “rocking horse” chest wall movement; stridor will be absent with complete closure “silent inspiratory effort”
  
  • Can lead to profound bradycardia & desaturation if unrelieved
• Risks:
  
  • recent URI
  • secondhand smoke
  • stimulation while “light”
  • secretions in airway

Question 102

Treatment and possible complications of laryngospasm

Answer 102

• Treatment:
  
  • Continuous positive airway pressure
  • 100% oxygen
  • jaw thrust at condyles of mandible
  • suction secretions/ blood etc.
  • deepen anesthesia (propofol)
  • ask for help
    
    • Unresolved?
      
      • Atropine & Sch- if no IV access then give IM
• Can lead to negative pressure pulmonary edema especially in healthy, muscular adolescents
  
  • May have to remain intubated for 12-24 hours & may need furosemide (0.5-1 mg/kg)
  • Self-limiting but can be severe

Question 103

Anesthesia for tonsillectomy

Indications, considerations, technique, complications?

Answer 103

• One of the most commonly performed pediatric surgeries

Indications:

• recurrent infections
• OSA
• Most tonsillectomy patients have enlarged tonsils without other airway deformities
• Must consider presence of sleep apnea
  
  • potential need for admission
  • use of multi-modal analgesia (reduce opioid doses)

Technique:

• LMA used by some but majority still intubate
• RAE tube

Complications:

• Post-op hemmorhage
  
  • occurs in 0.1-3% of T&A
  • can be primary (day of surgery) or 7-10 days later
  • Consider: active bleeding in airway →
    
    • visualization difficult
    • full stomach- swallowing blood
      
      • RSI**
    • hypovolemic shock potential

Question 104

Indications and anesthesia technique for myringotomy and tympanostomy tubes?

Answer 104

• Indications: one of the most common peds diseases in 1^st decade of life
  
  • Acute otitis media
• Short outpatient procedure
  
  • 5-10 minutes of operating time for the experienced surgeon in uncomplicated patient

Anesthesia technique:

• Usually no premedication unless extremely apprehensive (may delay discharge)
• Standard monitors
• Inhalation induction is performed with a combination of sevoflurane and oxygen (with or without N2O); maintenance with mask is usually appropriate
• Usually IV access is not necessary (other comorbidities may want IV)
• May have co-existing tonsillar hypertrophy- airway obstruction is usually relieved by continuous positive pressure &/or oral airway
• Rectal or PO acetaminophen or intranasal fentanyl can be used for pain control in the absence of an IV

Question 105

Pectus excavatum and carinatum?

Answer 105

• Pectus carinatum: abnormal PROTRUSION of xiphoid process and sternum
  
  • predominantly in males 4:1
  • associated w/ other abnormalities: (affects w/ anesthetics)
    
    • scoliosis → restrictive lung dx
    • Marfan syndrome → vacular problems (at aortic root) & joint laxity
    • congenital heart disease
• Pectus excavatum: abnormal DEPRESSION of sternum
  
  • many times medically insignificant- mostly cosmetic sx
  • if severe → may have restrictive lung dx

Question 106

Considerations for congenital heart disease?

L to R and R to L shunting?

Answer 106

• most common birth defect
  
  • incidence: 1:25 live births
• L-to-R shunting:
  
  • increases pulmonary BF → potentially decreases systemic blood flow
• R-to-L shunting:
  
  • Blood bypasses pulm circulation → Deoxygenated BF into systemic circulation → causes reduced pulmonary blood flow and increased cyanosis
    
    • *deoxygenation BF into periphery
• PDA present
  
  • have pulse ox on RUE (preductal oxygenation) and any other extremity (postductal oxygenation)
    
    • Preductal: BF feeds head, neck, and RUE
    • Postductal: any other extremity

Question 107

General L to R shunt managmenet in pediatrics?

Answer 107

• Management is dependent on specific anatomy and physiology
• Attempt to maintain pt baseline (same SpO2 and other vital signs)
• L-to-R shunts:
  
  • Avoid increases in SVR and decreases in PVR (which will increase shunt)
  • Avoid negative inotropes
  • Avoid hypervolemia
  • Desaturation → Could be reversal of shunt
  • Anesthetic considerations:
    
    • minimal impact on uptake of volatile anesthetics

Question 108

General R to L shunt management

Answer 108

R-to-L shunts:

• Maintain high SVR to decrease shunt:
  
  • Ex: Ketamine, phenylephrine
• Avoid increased PVR
• Minimize intrathoracic pressure
• Avoid air bubbles in IV
• Anesthetic Considerations:
  
  • decreased wash-in of VA
    
    • → IV supplementation may be required

Question 109

What is tetralogy of fallot?

What are tet spells?

What do we want to avoid?

Answer 109

• Most common cyanotic CHD
  
  • primary repair done at 3-12 months
• Anatomy:
  
  • Right ventricular outflow (RVOT) obstruction
  • Infundibular narrowing, pulm stenosis, PA hypoplasia, pulm atresia
  • Ventricular septal defect (VSD): Large, unrestrictive
  • Overriding aorta
  • RV hypertrophy
• Tet spells: (Left unrepaired) → cyanotic episodes!!!
  
  • Crying and agitation leading to tet spell leading to more hypoxemia, hypercarbia, acidosis (avoid)
  • Consequences: lead to RVH, RV failure, and death (50% in first year of life)
• Increased R-to-L shunting caused by:
  
  • decreased SVR or
  • increased PVR
• Avoid hypoxia, acidosis, high airway pressures, excitement, and agitation

Question 110

Anesthetic considerations for repaired CHD?

Single ventricle? Williams syndrome?

Answer 110

• Can be associated with the later development of dysrhythmias (esp if approach was ventriculotomy → conduction system violated)
  
  • repaired single-ventricle physiology → high risk sudden death as a result of pathologic arrhythmias
  • any intraoperative arrhythmias must be reported to cardiologist → may require RF ablation
• Children with a single-ventricle physiology (Fontan) require very specific anesthetic management:
  
  • well hydrated
  • avoid PEEP
  • avoid laparoscopic surgery (avoid intrathoracic/intraabdominal pressure)
• Williams syndrome → high risk sudden death with anesthesia
  
  • Anatomy: aortic stenosis, abnormal coronary arteries, pulmonic stenosis
• Former cardiac transplantation:
  
  • must rule out small vessel coronary artery disease

Question 111

What is sickle cell?

Possible complications?

Answer 111

• Hgb SS homozygous: Hgb S permits deoxygenated Hgb molecules to polymerize into rigid insoluble fibers → resulting in sickled erythrocytes
  
  • Sickled erythrocytes = shortened life span → leading to chronic hemolysis and anemia

Complications:

• anemia, stroke,
• acute chest syndrome- lead to sig pulm failure
  
  • A vascular occlusive crisis in the lungs leads to acute chest syndrome (ACS). ACS is leading cause of death and second most common complication in sickle cell disease.
• , myonecrosis, CHF, MI, splenic sequestration, retinal hemorrhage, hematuria, ESRD, seizure, wound infection, UTI, and unexplained death

Question 112

What should we avoid in sickle cell patients?

Answer 112

AVOID:

• Dehydration
• Stasis
• Hypoxia
• Hypothermia
• Acidemia
• pain

ANY OF THESE LEADS TO → Vaso-occlusive crises

• Vaso-occlusive crisis → lead to subsequent end-organ ischemia
  
  • Ex: Bone, chest, brain- may have significant sequelae from previous crises

Question 113

Preop, intraop and postop considerations in sickle cell disease?

Answer 113

Pre-op:

• warm, well-oxygenated, and hydrated!
• Thorough multi-system assessment
  
  • may have chronic pain, hx of stroke, pulmonary complications from infection or acute chest syndrome, anemia, infections, renal disease, AVN of hips
• Consult hematologist preop:
  
  • Possible preop transfusion to target hgb (10 g/dL)
  • ensure pre-op hydration- admit night before to hydrate
  • IV access can be challenging

Intra-op:

• Maintain euvolemia & normothermia
• avoid tourniquets

Post-op:

• Adequate IV hydration; early mobilization and incentive spirometry; supplemental O2; consider multimodal analgesia (many are opioid tolerant)

Question 114

Considerations for appendicitis, managmeent?

Answer 114

• One of the most common abdominal emergencies
  
  • most likely in teen years
  • > 24 hrs delaying dx → increased risk perforation
  • s/s: classically RLQ pain
• Risks of intraabdominal perforation:
  
  • Abscess
  • Ileus
  • sepsis

Considerations:

• Aspiration risks
• active nausea and vomiting
• tachycardia due to pain, dehydration, or sepsis

Management:

• Preop IV antibiotics w/ gram negative coverage
• correct fluid deficits
• use full stomach precautions – RSI
• evacuate stomach with NG/ OG

Question 115

What are some common myopathies in pediatrics?

Answer 115

Myopathies: need preop echo & ECG

• Duchenne muscular dystrophy- x-linked
  
  • lack of dystrophin in skeletal & cardiac muscle
  • progressive cardiomyopathy adolescence
• Becker muscular dystrophy- milder form of Duchenne
  
  • seen in 2nd decade of life
• Emery Dreiffuss- may have concurrent heart block

**Careful w/ NMB and Succs!!! → why we avoid succs < 8yo

Question 116

What is the most common pediatric oncologic diagnosis?

What is tumor lysis syndrome? Triad?

Answer 116

• Childhood cancer → leading cause of disease related mortality

Pediatric acute lymphoblastic leukemia (ALL): most common pediatric oncologic diagnosis

• Tumor lysis syndrome:
  
  • metabolic crisis that often occurs when chemo started
    
    • Cause: acute lysis of a large number of tumor cells
  • Classic triad:
    
    • Hyperuricemia
    • Hyperkalemia
    • hyperphosphatemia
      
      • elevated phosphate causes hypocalcemia (Concerning: High K, Low Ca**)

Question 117

Anesthetic considerations for malignancies in pediatrics?

Answer 117

• Anesthesia is frequently needed for central line placement, lumbar punctures, bone marrow aspirates, etc.
• Consider effects of cancer and its treatment:
  • Anthracyclines (doxorubicin, daunorubicin): cardiotoxicity
  • Bleomycin, mitomycin: pulmonary toxicity
  • Many other long term side effects and toxicities
    
    • **be sure to complete a thorough multi-system evaluation, how long its been since tx

Question 118

Common etiologies of mediastinal masses?

Symtpoms?

Answer 118

• Causes: lymphoma, teratoma, thymoma, thyroid tissue
• Sx: vary based on size and location
  • **Stridor or SVC syndrome
    
    • symptoms can progress rapidly especially in non-Hodgkins lymphomas → life-threatening AW obstruction

Question 119

Anesthetic considerations for mediastinal masses in peds?

Answer 119

CAUTION:

• Induction of GA → life threatening AW obstructions and CV collapse!!
  
  • Do NOT want to lose AW reflexes!!!
    
    • large masses may need radiation and steroids before anesthesia can be safely provided
• IR for needle biopsy
  
  • local preferred if cooperative
• Technique:
  
  • Sit up
  • PRESERVE SPONTANEOUS BREATHING
  • Ketamine- light w/ anesthesia
• SVC syndrome:
  
  • will need IV in lower extremity
• Preferred to keep patient in semi-sitting position
  
  • Severe obstruction may require repositioning prone or lateral
  • CV collapse may require cardiopulmonary bypass (may have bypass on standby in large mediastinal mass)

Question 120

What is down syndrome? physical exam findings?

What may they require surgery for?

Considerations for induction?

Answer 120

• 3rd copy of chromosome 21
  
  • 1:1000 live births
  • increased incidence in moms over 35
• Physical exam findings: Midface hypoplasia, brachycephaly, epicanthal folds, simian crease, downward medial slant of eyes, high-arched palate, glossoproptosis, and murmur (DAW)
• May require surgery for tympanostomy, strabismus, CHD repair, duodenal/esophageal atresia, marrow aspiration/biopsy, cervical spine fusion
• Considerations:
  
  • **5-fold risk of bradycardia during Sevo induction (first 6 minutes) in children with Downs (Barash)
  • Difficult intubating d/t macroglossia & glossoproptosis
  • Difficult masking d/t midface hypoplasia
  • Chart →
    
    • Keep neck neutral (d/t subluxation of C1/2)

Question 121

Down syndrome anesthetic considerations?

Answer 121

• Airway
  
  • Have variety of devices available (e.g., oral and nasal airways, laryngeal mask, glidescope, fiberoptic) to manage airway obstruction.
  • Avoid neck extension during laryngoscopy if possible.
  • Smaller endotracheal tube may be necessary for narrowed subglottic space.
• Vascular Access
  
  • Meticulously avoid injected air due to likelihood of CHD
• Anticipated Problems/Concerns
  
  • Bradycardia with inhalational induction (sevo)
  • Resistance to separation from caregiver

Question 122

Random misc syndromes referenced in lecture?

Answer 122

• VACTERL: vertebral anomalies, anal atresia, congenital heart disease, tracheoesophageal fistula, esophageal atresia, and renal and radial dysplasia, limb defects
• CHARGE: coloboma, heart defects, choanal atresia, retardation of growth and development, genitourinary problems, and ear abnormalities
• CATCH 22: cardiac defects, abnormal facies, thymic hypoplasia, cleft palate, and hypocalcemia
  
  • chromosome 22q11.2 deletion syndrome

Question 123

Disorders to remember:

Large tongue?

Small/underdeveloped mandible?

Cervical spine anomaly?

Answer 123

Question 124

Malignant hyperthermia considerations?

Answer 124

• Blood relative or muscle biopsy
• Technique:
• First case of the day
• Remove vaporizers from machine
  
  • flush per manufacturer guidelines (w/ charcoal filter)
• Use trigger-free anesthetic: propofol, opioids, BZD’s, NDNMB’s, N2O, regional
• Mandatory Monitoring:
  
  • EtCO2*
    
    • increased etCO2 earliest indicator
  • temp monitoring*
• MH-susceptible children can have outpatient procedures as long as trigger-free anesthetic is used * (no Succs or VA)

Question 125

Definition for childhood obesity?

LBW calc? IBW?

Answer 125

• Definitions for obesity in children are based on BMI
  
  • obesity = BMI >95th percentile
  • morbid obesity= BMI >99th percentile
  • IBW calculation for children:
    
    • < 8 years: 2 x Age (years) + 9
    • >8 years: 3 x Age in years
• LBW calculation= IBW + 1/3(TBW-IBW)

Question 126

Consequences of childhood obesity?

Answer 126

• Consequences:
  
  • Restrictive pulmonary pattern
  • Increased O2 consumption
  • decreased chest wall compliance
  • FRC
  • vital capacity
• CV effects:
  
  • Htn
  • LVH
  • premature atherosclerosis
• Insulin resistance is common

Question 127

Drug dosing consideraitons in obese children?

anesthetic considerations?

Answer 127

• Drug dosing is complex (see chart)**
  
  • Ex: Induction
    
    • TBW: succs, sugammadex
• Technique:
  
  • Airway:
    
    • position HOB 25 degrees
    • plan for possible difficult mask ventilation
    • note rapid desaturation
  • Consider Desflurane for maintenance (least fat soluble) if airway reactivity is not a concern

Question 128

Post premie anesthetic considerations?

Answer 128

• Look at post-conceptual age
  
  • Gestational age + postnatal age
    
    • Ex: born at 28 weeks and now 12 weeks old= 40 weeks postconceptual age
• Former preemies will require post-op admission if < 60 weeks postconceptual age- regardless of type of surgery
• Admission d/t Risk of post-op apnea & desaturations
• Discharge: >12 hours apnea free
• Techniques:
  
  • Opioids avoided/used sparingly in this pop
  • LA- great alternative