Pediatrics Flashcards
1
Q
What is overarchign difference between peds and most adults?
A
- Complete lack of reserve
- decompensation different from adults
- 82% of arrests in OR occur on inducation
- when you put child to sleep, before IV started
2
Q
How do you caculate PGA?
A
Post-gestational age
weeks gestation @ birth +current age in weeks
3
Q
What is a neonate? Preterm?
A
neonate= birht - 30 days
preterm <37 weeks
low birth weigth <2500 grams
4
Q
What is extremely low gestational age (ELGAN)
A
23-27 weeks gestations; all organs immature
most vulnerable peds patient
5
Q
What are pre-terms at risk for?
A
- Respiratory distress
- apnea
- hypoglycemia
- electolyte disturbance (particularly hypomagnesemia and hypocalcemia)
- infection
- hyperbilirubinemia
- polycythemia
- thrombocytopenia
6
Q
What is PGA that is most at risk for postoperative apnea and bradycardia?
A
anything <60 weeks PGA are at an increased risk for postop apnea and bradycardia
- Requires postop monitoring and admission
- Duration of anesthesia and anesthesia depth does not make difference in risk post op apnea
7
Q
What are cardiovascular changes that occur at birth?
A
- At birth, the placenta is no longer the primary source for oxygenated blood
- primary changes that occur
- ductus venosus closes
- ductus arteriosus closes (due to increased PaO2)
- pulmonary vascular resistance DECREASES
- Peripheral vascular resistance increases
- foramen ovale closes
8
Q
What is transitional circulation?
A
transitional circulation
- occurs at birht for the first several weeks
- factors that can lead to increased pulmonary artery pressure, reversal of flow through foramen ovale, reopening of ductus arteriosus and shunting are:
- hypercapnia
- hypothermia
- hypoxia
- This hypoxia is difficult to correct
- the ductus arteriosis, foramen ovale are only functionally closed
9
Q
How can you test preductal ABG? Post ductal?
A
- Preductal- RUE
- Post ductal- LLE, umbilical artery or femoral
10
Q
What is pulmonary vascular resistance and systemic circulatory resistance like in fetus?
A
High pulmonary vascular resistance
low systemic ciruclatory resistance
minimal intrauterine pulmonary blood flow: only 10% of CO
11
Q
What are some characteristics of the newborn heart?
A
- Structurally immature
- fewer myofibrils
- sarcoplasmic reticulum immature and cardiac calcium stores are reduced (greater dependency on serum ionized ca)
-
ventricles are less compliant
- do not see increase in Co with increase in preload like in adult
- CO is HR dependent
-
baroreceptor reflex immature in neonates
- inability to substantilaly compensate of rhypotension with reflex tachycardia
-
Neonatal heart has PSNS dominance
- sympathetic nervous system is immature
- tendency to have bradycardia with suctioning and laryngoscopy
12
Q
What is resting CO for neonate? infant? adolescent?
A
- Neonate at birth 400mL/kg/min
- Infant is 200 mL/min
- Adolescent is 100mL/kg/min
13
Q
What is preferred drug to treat bradycardia in children?
A
Epinephrine rather than atropine because epi increases HR as well as contractility in peds
14
Q
Differences in pulmonary system in children?
A
- Alveoli increase in number and size up until 8yo
- infants: small airway diameter; increased resistance
- highly compliant airway and chest wall
- early fatigue of diaphragmatic and intercostal muscles until age 2
- type 1 muscle fibers not mature (these are the ones that help us run marathons)
- type II fatigue easily
- why kids wear out fast
- O2 consumption is 2-3 x the adult with increased alveolar ventilation
- angulation of right mainstem bronchus
- comes off at higher angle
- also shorter distance
15
Q
What is O2 consumption in neonate c/t adults
alveolar ventilation?
RR?
TV?
A
Neonate
- O2 consumption 6mL/kg/min
- Alveolar ventilation 130 mL/kg/min
- RR 35 bpm
- Tidal voluem 6mL/kg
Adult
- O2 consumption 3.5 mL/kg/min
- Alveolar ventilation 60 mL/kg/min
- RR 15 bpm
- TV: 6 mL/kg
Bascially, neonate has 2x the O2 consumption, double the alveolar ventilation and respiratory rate, but same TV mL/kg as adult
16
Q
Difference in airway in infants?
A
- Larger tongue in smaller submental space
- higher larnyx (C2-C4)
- Omega shaped epiglottis- narrower, more dififcult to lift
- Angled vocal cords (slant caudally)
-
funnel shaped larynx with narrowest region @ cricoid ring
- Current recommendation is to use cuff tube, monitoring cuff pressure to maintain <20
- if using cuff tube, size down 1/2 size
- obligate nasal breathers
- large occiputs and the sniffing positon is favored for axis alignment
- endentulous
- short trachea (4-5 cm)
17
Q
What is gas flow like in young children?
A
- Young children have elvated airawy resistance at baseline
- tubulent airflow is present to the 5th bronchial division
- a 50% reducitonin radius increases the pressure 32 fold
- Very prone to respiratory distress with any upper airway irritation or swelliing
- Resistance in Laminar flow is 1/radius^4. Resistance in Turbulent flow 1/radius ^5
- Diameter of small airways (divisions) does not increase significantly until age 5
18
Q
What is neurological system like in peds? Concern with anesthesia and brain development?
O2 consumption? Cerebral blood flow? myelinization?
When do fontanels close?
A
-
Oxygen consumption and CBF in the brain of children is 50% greater than adults
- Child o2 brain consumption is 5.5 mL/100g/min
- Adult is 3.5 mL/100g/min
- Child CBF is 70-110mL/min/100g vs 50 mL/min/100g in adults
- Child o2 brain consumption is 5.5 mL/100g/min
-
myelinizationa nd synaptic connection not complete until age 3-4
- may experience more pain than adults
- nervous sytem is anatomically complete at birth
- functionally it remains immature with the continuation of myelination and synaptogenesis. myelination usually complete by 7 yo
- rapid growth of brain in first 2 years of life
-
fontanels: anterior fontanel closed by 18 mo. Posterior frontanel closed by 2 months
- check for hydration and open state
-
Anesthesia-induced developmental neurotoxicity: our knowledge still growing in the area
- increased and accelerated neuroapoptosis with virtually all anesthetics
- single exposure of short duration is usually of no consequence
- repeated and or prolonged exposures at young age (3-4 yo) may be associated with later behavioral and learning difficulties- we do not have conclusive evidence
- hold off on elective procedures until after >3-4 yo
19
Q
Pain in pediatrics?
A
- Somatic pain: conveyed in part by unmeylinated C fibers “slow”
- leads to protective reflexes such as autonomic reactions, muscle contraction and rigidity
- C-fibers are fully functional from early fetal life onward
- connection b/w c fibers and dorsal horn neuron are not mature before the second week of postnatal life but nociceptive stimulations transmitted to the dorsal horn by C fibers elicit long-lasting resposnes
- more profound and longer response to pain
- neonates can have exaggerated responses to nociceptive
- inhibitory contorl pathways are immature at birht and develop over the first 2 weeks
-
Painful procedure during the neonatal period modify subsequent pain responses in infancy and childhood
- preemptive analgesia leads to a reduciton in the magnitude of long-term changes in pain behaviors
-
Must use a painscale appropriate to the developmental level of the child (<3 yo usually unable to self report)
- procedural pain in infants and young children: common to use FLACC scale (face, legs, activity, cry, consolability)
20
Q
What are some neuraxial considerations in peds?
A
- Conus medularis ends at approximately L1 in adults and L2-L3 in neonates and infants
- migrates to level L1-L2 by age 3
- In infants, the line across the top of both iliac creast (intercristal line) crosses the vertebral column at the L4-L5 or L5-S1 intersapce, well below termination of the spinal cord
- The dural sac in neonates and infants also terminates in a more caudad location compared ot adults, usually about level of S3, compared to adult level of S1
- Infants: lack of lumbar lordosis compared to older children predisposes the infant to high spinal blockade with change in postioniong
- goes more cephalad
21
Q
What is the renal system like in peds?
A
- GFR significantly impaired at birth but improves throughout 1st year
- greatest impairement is 1st 4 weeks of life
- renal maturation will be delayed further with prematurity
- Renal tubular concnetration abilities do not achieve full capacity until 2 yo
- Half-life of meds excreted by GF are prolonged in very young
- in contrast, during childhood, renal clearance rate may increase to levels higher than even adult clearance rates
- 1st year-2 yrs immaturity until toddler–> increase BF and filtration normal, so they filter faster and may see increase in clearance rate
- in contrast, during childhood, renal clearance rate may increase to levels higher than even adult clearance rates
-
premature infants at high risk for hyponatremia because proximal absorption are impaired
- as many as one-third of elbw neonates develop hyponatremia
22
Q
What are some characteristics of the pediatric liver?
A
- Liver enzymes are developing up until 1 yo
-
phase I cyp450 system is 50% of adult values at birth
- phase 1 reactions responsible for majority of drug metabolism in liver via cyp450. 3A4= ~50%, 2D6~ 10-20%
-
Phase II (conjugation reactions) are impaired in neonates
- long half life of BZD and morphine
- decreased bili breakdown due to reduction in glucuronyl tranferase (leading to jaundice)
- glucuronyl tranferase is needed for metabolism of tylenol
- these reactions make drugs more water soluble to facilitate excretion
-
hepatic synthesis of clotting factors reach adult levels within a week of birth
- at birth, vit K-dependent factors (II, VII, IX, and X ) are 20-50^ adult values. In preterm, even less
- Lower levels of albumin/other proteins for durg binding in newobrns- larger proportion of unbounnd drug circulating
- minimal glycogen stores- prone to hypoglycemia
23
Q
What are some characteristics of GI system in kids?
A
-
Coordination of sweallowing with respiration is not mature until 4-5 months of age- high incidence of reflux especially in pre-terms
- infant <5 mo are obligate nose breathers
- gastric juices are less acidic (more neutral) up to ~3 yo
-
absorption of oral meds is generally slower compared to adults (kids don’t absorb meds as well)
- the GI tract is generally slower in children than in adults
- children have diff in gastric pH, emptying time, intestinal transit, immaturity of secretions and activity of both bile and pancreatic fluid
24
Q
What is thermoregulation like in the infant?
A
- Large surface area to body weight
- lack of subcutaneous tissue as an insulator
- inability to shiver
- metabolize brown fat to increase heat production
- can lead to metabolic acidosis and
- increased O2 consumption
- metabolize brown fat to increase heat production
- factors: cold OR, anesthetic induced vasodilation, room temp IV fluids, evaporativ eheat loss from sx site, cool irrigating solutions on field, cool/dry anesthetic gases
-
Active warming is critical
- warm OR, use warming mattress, incubators, cover with blankets, head coverings (up to 60% head loss here), transprot in isolette, humidify gases, use plastic wrap on skin, warm prep and irrigation solution, change wet diapers and remove wet clothing
- forced air warmers, most effective strategy to minimize heat loss in surgery for children <1 yo
- Anesthetics alter non-shivering thermogenesis in neonates
25
Temp monitoring in pediatrics?
* Essential for all ped cases
* **core temp best measure: mid esophageal placed probe**
* advantage to axillary temp if properly positioned: proximity to deltopectoral group improves recognition of elevated temp in MH
* Forehead temp: **not advised** 10 MH episodes occurred that were unrecognized with forehead temp
* hypothermia: delayed emergence, reduced degradation of drugs, increased infection
* hyperthermia: MH?
26
What is the body composition of pediatrics?
* Total body water is highest in premature infants and decreases with age (*don't need exact % of chart below, just relative)*
* *BSA is better measure of metabolism rather than kg (no drug we use really in anesthesia)*
* **wate-r** **soluble** durgs have a **larger** volume of distribution
* **need a larger initial dose (Sch, abx)**
* larger volume of distribution can delay excretion
* half life of meds in \>2 yo is shorter than adults or equivalent d/t significant CO to liver and kidneys
* neonates have **less fat and muscle**
* drugs that depend on redistribution to fat for termination
* protein binding: \<6mo old have reduced albumin and alpha-1 acid glycoprotein (AAG)
* higher free-fraction of protein bound drugs
* **_free fraction lidocaine will be higher in the very young_**
* *acidic drugs (diazepam, barbs) tend to bind mainly to albumin, whereas basic drugs (amide LA) bind to globulins, lipoproteins and glycoproteins. in general, plasma protein binding of many drugs is decreased in neonate relative to adult in part because of reduced total protein and albumin*
27
What is hematocrit and blood volume like in infant?
* **normal P50 of fetal hgb- left shift** (**19 mmHg** in peds vs adult 25mmHg)
* *left= loves O2, holds onto the oxygen*
* *3-6 months after birth, fetal HGB has been replcaed with adult hgb*
* *lower p50 allows fetal blood to extract o2 from maternal hgb*
* target HCT in neonates is higher due to L shift and decreased CV reserve (**min HCT 40% instead of 30%)**
* neonatal polycythemia (central HCT \>65%) occurs in 3-5% of full term neonates
* **neonates have an increased susceptibility to bacterial infections**
* related to immaturity of leukocyte function
* **physiologic anemia at 2-3 mo of age******
* *****as fetal Hgb is replaced by adult hgb, have drop*
* *may have lower threshold for giving blood products in peds vs adults*
* **4-5ml/kg of transfused PRBC increase hgb 1g/d**L
* maximum allowable blood loss calculation
* variables: EBV, PT starting HCT, min allowable hct)
* MABL= EBV \* (starting hct- target hct)/ starting hct
28
What are components of fluid replacement?
1. fasting (NPO) deficit (maintenance rate x hours NPO for deficit)
2. baseline maintenance fluid requirement- using LR in most cases
3. replacement of blood loss
* 3:1 cystalloid replacement
4. evaporative loss )based on invasivenes of surgery)
29
What is the Holliday-Segar formula?
4:2:1
* \<10 kg= 4mL/kg
* 11-20 kg: 40 mL + next 10 mkg @ 2mL/kg
* \>20kg 60 mL + anything over 20 kg @1 mL/kg
30
What are the new trends in the hollidary segar formula?
* Thoughts on fluid management are shifting
* rather than 4-2-1, new guidlines are recognizing impace of ADH secretion on fluid status
* simple strategy for healthy children undergoing elective sx
* admin of 20-40 mL/kg of cystalloid (balanced salt solution) over the duraiton of the case
* this takes into account maintenance fluid, as well as NPO deficit
* need to be familiar with both (old holliday segar and this)
* For postop period new 2-1-0.5 rule applies (2mL 1st 10 kg, 1 mL/kg for 10-20. 0.5mL/kg \>20kg
* if no oral intake after 12 hours, then D5 0.45% saline should be given using 4-2-1
31
What is used for fluid repalcement in peds?
What do we do with TPN during sx?
What is best measure of fluid deficit in infants?
* LR is typically used for maintenance in healthy children
* glucose containing IVF may be needed in infants \<6 mo and in other at risk for hypoglycemia
* minimize potential for error: smaller bags, buretrols
* eliminate all air from IV line
* **TPN should not be stopped suddenl**y; either continued in OR or ramped down and bridged with glucose containing IVF (ok to stop lipids)- deduct this from hourly maintenance calculated rate
* *circulating insulin levels have acclimated to basal infusion of glucose and hypoglycemia can be a problem if TPN stopped aburptly*
* *can cut back TPN 1/3-1/2 d/t increase in glucose release d/t surgical stress- if done, make sure to monitor glucose*
* Recognize dehydration in infants; the best measure of deficit is **weight**
* **mild** - 50 mL/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, and anuria
32
What are some questions to anazlye fluid status of infant?
What should you do when hypovolemia expected?
* Is the hR persistently increased or does it vary with surgical stimulation
* *need to know normals!*
* Is the pulse pressure narrow, or, more ominously, is the BP reduced for age
* Does it vary with positive pressure breaths?
* Are the exremities warm?
* Is cap refill brisk?
* What is urine output?
* Are these variables changing?
* What is the rate of the change?
When hypovolemia is suspected, observing response to a 10-20mL/kg bolus of isotonic cystralloid or colloid may test hypothesis
33
What is postoperative fluid management?
* Isotonic crystalloid (LR) at half the rate described in the original 4-2-1 fluid regmen (2mL/kg for 1st 10 kg, 1 mL/kg for next 10, 0.5mL/kg for each additional kg after)
* If NO oral intake after 6-12 hours, standard maintenance therapy (4-2-1) using hypotnoic saline (0.45% saline) with +/- glucose supplementation should be intiated to avoid hypernatremia and fluid overload from prolonged admin of isotonic solution
* this regimen will limit ADH response and reduce risk for postop hyponatremia and hypernatremia
34
What is role of glucose containing IVF in peds?
* Routine use of glucose containing IVF in perioperative setting in children is not recommneded
* exception: children at high risk of hypoglycemia- can use D5 1/2 NS @ maintenance rates
* continuous PTN : must not stop suddenly
* children with mitochondiral disease will definitely need glucose containing replacement fluid
* *Miller says to cut TPN rate by 1/3 and leave running*
* Hypoglycemia in:
* neonate \<30
* infant \<40
* child \<60
35
Overarching principle of pharmacokinetic alteration in peds?
* In general, most meds will have prolonged eliminiation half life in preterm and term infants
* shortened half-life in children \>2 yo up to early teenage years
* lengthening of half-life in those approaching adulthood
36
How are inhaled anesthetics altered in peds?
* Uptake is more rapid in children for several reasons
* increased respiratory rate and cardiac index
* larger proportion of blood to VRG (18%) compared to adults (8%)
* reduced tissue and blood solubility in infants
* Alveolar ventilation to FRC ratio is 5:1 in infants vs 1.5:1 in adults
* **increased risk of anesthetic overdose in infants/toddlers**
* MAC of volatiles other than sevo increases until 2-3 months of age and steadily declines iwth 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 up to 12 yrs constant at 2.4%
* Increased incidence of hypotension in neonates and infants upon inhalational induction
* more rapid uptake can unmask negative inotropic effects of the volatiles in infants
* sevoflurane is primary agent used for inhalational induction
* halothane has low pungency but is no longer used in US- halothane frequently caused bradycardia at induction
* use of desflurane limited d/t pungency
37
What are VA determinants of washin ? wash out?
* Washin- inspired concentration, alveolar ventilation, FRC
* washin inversely proportional to solubility
* Washout- CO, solubility, alveolar to venous partial pressure gradient
38
How does MAC vary with age?
MAC varies with age
* Infant 1-6 months: MAC higher than the adult
* infant 2-3: MAC peaks at highest level
* Neonate 0-30 days: MAC lower than infant
* premature: MAC is lower than neonate
MAC requirement pattern for sevo is diff
* 0-6 month MAC is higher (3.2%)
* 6mo-12 yo: MAC is lower, but still higher than adult (2.5%)
39
What are some inhaled anesthetic effects on peds?
Resp? CV?
* Respiratory: same as adults, overall decrease in minute ventilation (decreased tidal volume with increased RR; depressed response to CO2 and hypoxia)
* *don't mistake for pain!!*
* as concnetraiton increases, apnea ensues
* CV: dose dependent depression
* sevo usually maintains or increases HR during induction
* all can cause prolonged QT
* Halothane has greatest depression of contractility
* halothane hepatitis: antibody reaction; repeated exposures
40
Induction agents in peds?
* Neonates: immature BBB and decreased metabolism can increase sensitivity
* older children and adolescents generally require increased doses of induction agnets c/t adults
* see dosing chart provided in class (on PDF on canvas)
41
Propofol in peds?
* Most commonly used IV induciton agent in children
* pain in injection can be reduced with a mini bier block with 0.5-1 mg/kg of lidocaine for 60 seconds
* antiemetic properties
* propofol infusion syndrom: long term ICU avoided in infants and children; still appropriate for TIVA
* Egg /soy: only avoid if documents anaphylaxis with eggs
42
Ketamine in peds?
* Can be used IM, IN, PO, IV
* Induction with ketamine preferred in cyanotic heart disease, septic shock, and induction for mediastinal mass ( need spontaneous vent)
* emergence irritation can be reduced with co-admin w/ midazolam and waking up in a dark, quiet room
43
Etomidate in peds? Thiopental?
* Etomidate: only approved for use in age \>10 yo. in USA
* 0.2-0.3 mg/kg IV
* Thiopental: no longer available in US
* 3-5 mg/kg IV
44
Midazolam in kids?
* Midazolam- most widely used anxiolytic preop
* oral dosing: dose increases in younger pt; poor oral bioavailability; bitter tast; allow 10-15 min
* Reversal : flumazenil 0.01 mg/kg IV
* Hpeatic metabolism CYP 3A &4 & renal excretion
45
Ketamine in kids?
* Severe cognitive/behaviorally challeneged older children may have to be given IM ketamine for sedation in preop 2-5mg/kg
* onset will be 3-5 min with 30-40 min duration
* *want to admin anticholinergic w/ ketamine to prevent secretions*
46
Dexmedetomidine in kids?
* Hypotension with loading doses; bradycardia with high dose infusion
* will not be adequate as a sole anesthetic but can be helpful as adjunct
* useful in awak FOB (fiberoptic bronch), radiological procedures, and reduction of emergence delirium (evidence isn't overwhelming)
47
Opioids in peds?
Fentanly, remi, demerol, codeine?
* Variety of choices: onset, potency, duartion and metabolism are factors just like in adults
* also consider previous exposure to opioids (tolerance) severeity of pain, and other multi-modal strategies
* **Fentanyl**: most widely used opioid in introp children
* dosing typically 1-3 mc/gkg range (IV)
* **Remifentanil**: excellent for neonates d/t immaturity of renal/hepatic metablism/excretion (esterase)
* **Demerol**: primarily given for shivering in small doses
* **codeine**: historiclaly commonly prescribed post op, withdrawn from many markets d/t repsiratoyr events
* SNPs in ulta-rapid metabolizes confer risk of OD
48
Non opioids in peds? Tylenol and ketoralac?
* Acetaminophen
* PO 10-15 mg/kg
* 15mg/kg IV q 6 hours (10-15 min onset)
* rectal absorption is slow (1-2 hours)
* Ketoralac: typical dose IV 0.5 MG/KG
* ask surgeon before admin
* **caution with all NSAIDS in severe asthma**
* *****triad of symptoms: nasal polyps, asthma and excema= increase risk for NSAID allergy*
49
Muscle relaxants in peds?
* 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 usualyl same as adults
* except Roc- dose is lower in infants
* always use nerve stimulator, response is highly variable
* may see prolonged DOA d/t immature renal/hepatic elimination
* routine reversal for TOFR \<0.9; dose of neostigmine infants and children is 30-40% lower than adults (0.02-0.04 mcg/kg) co admin with anticholinergic
50
Succinylcholine in peds?
* Higher dose sch doses are needed in neonates and infants d/t larger VD (3mg/kg) IV
* 4mg/kg IM works in 1-2 min
* sch is limited to RSI and emergency tx of laryngospasm in peds
* when given, concurrent atropine admin is a routine practice (0.02 mg/kg)
* risk of bradycardia; hyperkalemia; masseter spasm; MH in children with undiagnosed myopathies
51
Local anesthetics in peds?
* Cardiac output and local blood flow are 2-3 times greater in infants than in adults so systemic LA absorption is increased
* epi is effective in slowing systemic uptake
* plasma concentration of AAG is very low at birth (0.2-0.3 g/L) and does not reach adult levels (0.7-1.0 g/L) before 1 yo
* free fraction of all LA is increased in infants
* max dose must be reduced
52
Max dose lido? with epi?
Max dose ropi?
Max dose bupi?
Max dose chloroprocaine?
* Lidocaine 4 mg/kg w/ epi 7 mg/kg
* Ropi 3 mg/kg
* Bupi 2.5 mg/kg
* Chloroprocaine 12 mg/kg
53
VS normal in children? Shortcut?
* Minimum tolerated SBP is (age in years x2) + 70
* works for 2-10 yo
*
54
RR normal for children?
neonate, 0-12 months, 1-5 years, 5-9 years, 9-12 years \>12yo
55
Developmental considerations in peds?
* Preschool age: distraction and premed
* offer flavoring for the oxygen mask if available
* preop preparation with OR equipment (see the mask, pick a flacor, ) child life specialist can assist
* distractions: music/singing, story telling, guided imagery "changing the flavor"
* Avoid bright lights, loud voices, lots of extra personnel in room
* consider parental presence (esp in age 1-6) parents must be educated on what to expect at induction
56
Psychological asessment in various age groups?
neonate?
infant (1-12 mo)
toddler 1-3 yo
child 4-12 yo
teenager 13-19
57
Preop eval for peds?
* Standard adult hx and physical exam must be adatped; some topics that require further emphasis in children
* birth hx; prematurity
* neuro development- appropriate for chronoclogical age
* airway anomalies; surgical hx, previous intubation and general med health
* genetic or dysmorphic syndrome
* potential for anomalies in cervice spine (down syndrome) or craniofacial dysmorphia
* family hx: MH, psuedocholinesterase deficiency, postop N/V, congenital myopathies, bleeding
* no lab work indicated for health children undergoing a procedure with minimal blood loss anticipated
* routine pregnanycy testing controversial
* higher risk for latex allergy in certain ped population
* spina bifida, myelodysplasia, UT malformations, multiple previous sx
58
Things to note on airway hx for peds?
* **Presence of URI (increase r/f laryngospasm for up to 6 weeks)**
* ****predisposition to coughing, laryngospasm, bronchospasm and desat during anesthesia or to postintubation subglottic edema or postop desat)
* **Snoring or noisy breathing**
* ****adenoidal hyperrophy, upper airway obstruction, OSA, pulm HTN
* **presence and nature of cough**
* ****may indicate subglottic stenosis or previous tracheoesophageal fistula repair.
* productive cough may indicate bronchitis/pna
* **past epidodes of coup**
* ****postintubaiton croup, subglottic stenosis
* **inspiratoyr stridor, usualyl high pitch**
* ****subglottic narrowing, larngyomalacia, macroglossia, laryngeal web
* **hoarse voice**
* ****laryngitis, vocal cord palsy, papillomatosis
* **asthma and bronchodilator therapy**
* ****bronchspasm
* **repeated PNA**
* ****incompetent larynx w/ aspiration, GERD, cystic fibrosis, bronchiectasis, pulm sequestration
* **previous anesthetic problem partciularly related to airway**
* ****difficult intubation, difficult mask, failed or problematic extubation
* **atopy allergy**
* ****increased airway resistance
* **history of congenital sydnrome**
* **parents smoke in house?**
* ****increased airway reactivity
* **suspcision of c-spine anomaly?**
59
What are some conditions with cervical spine anomalies?
* Down syndrome
* klippel fiel malformation
* goldnehar syndrome
* fracture, subluxation, neck burn contracture
* rheumatoid arthritis
* mucopolysaccharidosis (morquio syndrome)
60
What to focus on in resp and cv (in peds)?
* Resp focus: frequent URI? Hx wheezing? hx noisy breathing? Hospitalizations, hx intubation? hx eczema/skinallergy? in daycare? immunization? smoker in house?
* infant: frequent vomiting after feeds "choking" episodes
* children: frequent tonsillitis, ear inx? snoring?
* CV focus: any family hx CHD? Sudden /premature death? maternal illness/infection (both chronic and during pregnancy)
* infant: any problem with poor feeding (think CHD), sweating (especially on forehead) during feeding, poor weight gian, FTT, decreased activity level?
* *feeding for infant= exercise for adults*
* older child: inability to keep up with activity level of peers, need frequent periods of rest, anorexia, cough, wheezing, rales, CP
* any changes in color or cyanosis when crying?
61
Cultural humility while taking care of peds?
* 25% of children younger than 5 yo in US come from racial or ethnic minority backgrounds
* do not assume (based on language or ethnicity) to know the ideas or bleifs of family
* udnerstand family hierarcy
* make every effort to use, pronounce and record names correctly
* try to learn a few words/phrases
* do not ask parent to sign a consent that is not in their native lanauge without full access to interpretation
* talk with interpretor: always look at parents/child
* interpreter vs translator: translator only does words. interpreter also takes in meaning of looks/gestures/cutoms etc
* cautious of false fluency
* alternative med: do not approach with skepticism or bias but ask about herbal/natural remidies and ask if working
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What to note in physical exam in peds?
* always talk through assessment; children like to know what to expect, get on child's eye level, stay calm
* **airway**: insepct face (include profile view), outh opening, tongue mobility, neck extension, loose teeth
* assess resp in position of comfort, look for flaring, retractions
* **auscultate heart and lungs**
* rales or wheeze? request cough
* murmur detected? furth investiage- cyanosis, syncope, arrhythmias, tachycardia, poor feeding, activity tolerance
* innocent murmurs found in up to 50% children- systolic ejection murmur and are accentuated by stress, anemia and fever
* diastolic murmur and or symptomatic murmurs need investigation
* **palpate liver** if any reason to suspect fluid overload
* normal liver 1-2 cm below costal margin
* hempatomegaly sign of RV failure
* **cyanosis in infant:** arterial desat or central cyanosis is best detected in perioral area, mcuous membrane of mouth, lips and gumg
* central cyanosis should be distinguished form peripheral cyanosis, which can occur in cold environment and
* acrocyanosis, which in newbowns is due to sluggish circulation in fingers and toes
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Fasting guidlines in children?
* Clear liquids: includ only fluids without pulp, clear tea or coffee without milk products
* gum chewing: 70% increase in gastric fluid volume in first 15 minutes after initiating gum chewing. mostly saliva; most providers will proceed as long sa gum is spit out (not swallows)
* Clearliquids- 2 hours
* breask milk 4 hours
* infant formula 6 hours
* solids (fatty or fried foods)- 8hours
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Room setup in peds?
* always have arnage of sizes of airway equipment (face mask, OPA, ETT, LMA, blades)
* straight blades are most commonly preferred in infants d/t anatomical diff
* appropriate size LMA should always be avialable even if intubation is planned in case of unanticipated difficult airway
* ensure appropriate sized bp cuff and pulse ox is present and functional
* calculate drug doses, allowable blood loss and fluid requirements
* have primed bag of IV fluid ready and all supplies to start and secure IV setup and accessible
* prepare a ped cirucit/bag. preset vent settings appropriate for size (\<5yo use peds setup, but careful if you think pt can pull whole TV)
* too big mask can press on eyes and cause vagal response
* emergency drugs for every ped case
* weight appropriate dose of sch and atropine with small guage needle appropriate for IM injection (laryngospasm)
* syringe of prop
* facilitate intubation, break laryngospasm, increase depth anesthesia quickly
* plan for age appropriate distraction; flavors for masks, parental presence
* warm room
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Premeds for peds?
* often needed at the age 10 months when separation anxiety becomes an issue
* oral versed most common- see dosing
* severe distress/need for profound sedation
* may combine med (ketamine, atropine, versed combo)
* may use IM routh if uncooperative with PO sedation
* intranasal route is sometimes used but can really burn and make child more agitated
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Mask ventilation in peds?
* sniffing position is critical
* head neutral with nose to ceiling
* avoid pressure on the soft tissue in the submental triangle
* jaw thrust
* low threshold for 2 person ventilation
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Inductions in peds?
* 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 BP and HR during induction
* \<10 months: usually nopremed required
* alternative is preop IV with standard induction: topical anesthetics can be used for IV starts; EMLA cream onset is 45-60 min
* IM ketamine is rarely used for inductions in larger cognitively impaired/extremely uncooperative children
* safest to maintain spontaneous ventilation of the child for induction; taking over ventilation willl increase risk of anesthetic voerdose- negative feedback loop exists where when anesthetic depth increases, ventilation decreases
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Example of inhlational induction?
* higher flows with 70% N2O and 30% O2
* Fully open APL
* Allow few breats of N2O mixture and 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 spon ventilation PRN- caution about high inspired VA with assisted or controlled vent
* obtain IV
* once IV in, induction proceeds- give some prop, narc, NMB, proceed with airway mgmt appropriate for case
* be sure to turn down sevo to nomral MAC range for the child; watch VS closesly in induction
* *can have pacifier for comfot druing induciton and remove whne loses consciousness*
* *be courteous of OR pollution*
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RSI in kids?
* same principle as adults to prevent aspiration
* cricoid pressure in infants /children is +/-
* increases likelihood of obstructing an infants airway with little proven benefit
* not that child will have rapid desat with hypoxia (limited reserve)
* equipment: ETT (prestyle) age calculated plus 0.5 smaller and 0.5 larger; larygnoscope, suction immediately avaialbe at HOB
* prop 2-4mg/kg (stable) vs ketamine 1-2 mg/kg or etomidate 0.2-0.3
* PLUS Sch 2mg/kg (premed with atropine 0.02mg/kg)
* consider roc 1.2 mg/kg if succ contraindicated
* calcium should b eimmediately available in event sch leads to unanticipated hyperkalmiea with vent arrhthmias
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Airway mgmt in peds?
* always have a range of ETT sizes (0.5 smaller and larger)
* short trachea favors right mainstem intubation
* breath sounds often referred
* common formular over 2 yo
* age+16/4
* cuffed tubes are fine as long as cuff pressures are monitored
* rought estimate of depth is 3xID
* A leak should maintained around cuff regardless @ 20-30 cmH2O
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LMA in children?
* Used during routine surgeries and as rescue device for failed intubation
* low failure rate for insertion (\<1%)
* contraindicated in children with risk of pulmonary aspiration
* other specific pediatric contraindications
* med masses, children requiring high peak pressures to ventilate, tracheomalacia, veyr limited mouth opening
* **need to know LMA sizes by weight (See chart)**
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ETT size cuff pressure monitoring in peds?
* 95% of subglottic stenosis is acquired
* postintubation injury is most common cause of acquired subglottic stenosis
* risk factors associated with acquired SGS: trauma during intubation, ETT movement during intubation, prematurity, and presence of infection at time of intubation
* avoid oversized ETT
* Cuff pressures must be omnitored thoughout long cases/extended intubation
* maintained at a level below 20-30
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Ventilation in peds?
* 6-8 mL/kg is typical
* sustained plateau airway pressure \>35 can lead to barotrauma: pneumothorax, pneumomediastinum and subcutaneous emphysems
* lung protective strategies apply
* P/C ventilation preferred 15-18 cmh2o
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Layngospasm in kids?
* more frequent in infants, risk decreases with increasing age
* reflex closure of false and true VC
* **SX;** stridor, retractions, flailing of ribs, rocking horse, chest wall mvmt,
* stridor will be absent with complete closure" silent inspiratory effort"
* can lead to profound bradycardia and desat if unrelieved
* **risks:** recent URI, secondhand smoke, stimulation while light, secreiton in airway
* **treatment**: **continous positive airway pressure**, 100% o2, jaw thrust at condyles of mandible, suction secretion/blood, deepend anesthesia
* unresolve
* atropine and sch- if no IV then give IM
* Can lead to negative pressure pulmonary edema esp in health, muscular adolescnets- may have to remain intubated for 12-24 hours and may need lasix
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Bradycardia in peds?
* Infants \<100 bpm; 1-5 yo \<80 bpm; \>5yo \<60 bpm
* hypoxia is the leading cause of bradycardia in children
* other causes: vagal stimulation, increased ICP, meds (SCH), CHD, hypothermia, air emboli, tension pneumo
* single dose sch can cause bradycardia in children
* **treat cause: think oxygenation and ventilation first**
* atropine if vagal origin 0.02mg/kg IV
* epinephrine if decompensated 10mcg/kg
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Emergence in ped pt?
* NM function- check and reverse if appropraite
* diff techqniques for extubation; always prioritize pt safety
* awake extubation: must be awake and purposeful; laryngospasms happen when pt are extubated in early and second phase: if in doubt, don't take it out
* 3 phases
* early phase- coughing intermittently, gagging, struggling, moving non purposeful
* second phase- apnea, agitation, straining, breathholding
* third (final) phase- regular RR, purposeful movement, coughing, opening eyes spontaneously- extubaion now appropraite
* deep extubation: sevo increased to 1.5-2 MAC for at least 10 min
* ensure no resposne (cough, breath holding) to suctioning or tube movmvt. ensure regular respriation
* transport in lateral decubitus position "recovery position"
* PACU complications in 5% of children
* vomiting 77% (more common \>8yo), airway compromise 22%; CV compromise is \<1%
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Regional anesthesia inpeds?
* Caudal anesthesia
* lower ab and LE surgery in \<5-6 yo
* single shot block with LA will last 4-6 hours
* done following GA induction in lat position
* epidural and spinal anesthesia are also used in children but are most frequenyl completed under general anesthesa
* technique similar to adult patient
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PONV in children
* increased risk in certain surgeries: hernia, orchidopexy. T&A, strabismus (increase risk MH), middle ear, laparoscopic
* prevention: hydration, multimodal analgesia
* peak incidence in female age 10-16
* typical 2 agnet strategy for prevention in at risk (decrease risk by 80%)
* ondansetron 0.05-0.15 mg/kg IV
* Dexamethasone 0.0625-1 mg/kg IV
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EMergence delirium in peds?
* Phenomenon characterized by non purposeful restlessness and agitation. thrashing, crying or moaning and disorientation
* '18% of children undergoing sx and anesthesia develop emergence delirium
* factors: young age, previous sx, type of procedure, type of anesthtic all affect incidecne of emergence delirium
* level of preop anxiety is predictive
* peaks age 2-6 yo
* most common after sevo (then des)
* usually last 10-15 min
* protect from self harm
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What is postductal/preductal circulation in the fetus?
* **Post-ductal:** More deoxygenated blood going to system circulation
* **Liver, kidney, lower extremities**
* **RA--\> RV--\> PA--\> DA--\> SYSTEMIC**
* **Pre-ductal:** More oxygenated blood going to head, neck, RUE
* **From IVC--\> RA--\> LA (via foramen ovale)--\> LV--\> AORTA**
