Prematurity Flashcards

1
Q

Anesthetics have both________and _________ properties.

_________protect against __________Ischemic injury

A

Anesthetics have both neuroprotective and neurotoxic properties
• Volatiles protect against hypoxic-ischemic injury
• Better than IV agents
c/surgeries c/ risk of brain ischemia
• VP shunt, cardiac, vein embolization

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2
Q

Anesthesia DOES

A

PRE CONDITIONING in heart and brain

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3
Q

• Studies showed prolonged exposure of commonly used anesthetics in primates and rats →

A

neuroapoptosis

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4
Q

• Human premies might have more risk of

A

anesthetic neurotoxicity

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5
Q

• However, neurodegeneration and apoptosis is part of

A

normal developmental phenomenon

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6
Q

When anesthesia is combined with surgery, more

A

neuroapoptosis occurs than with either alone

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7
Q

• Anesthetic neuro-degeneration depends on

A

age, brain region, and duration

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8
Q
  • Inhalational anesthetics

* MAC of isoflurane in micropremie (

A

32 weeks PCA; 20% less than term neonates

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9
Q

• All ages experienced a @ 1 MAC of iso

A

20-30% decrease in SBP (SVR goes down, myocardial suppression)

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10
Q

Premies might have more risk of cardiac depression

A

Neonatal heart depends on iCa2+ for contractractility

Inhalational anesthetics block calcium channels

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11
Q

Only FDA approved for induction

A

SEVOFLURANE

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12
Q

NO inhalation with bad lung condition s

A

DESFLURANE

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13
Q
  • Intravenous agents
  • Preterm infant might be inherently amnestic by virtue of age
  • Fentanyl =
A

hemodynamic stability, no amnesia or areflexia

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14
Q

Conditions to PRODUCE ANESTHESIA

A

Sedation, amnesia, analgesia, AREFLEXIA

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15
Q

Clearance in premies remained constant up to_______

A

120 minutes = ↓clearance

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16
Q
  • Elimination ½ life in premies =

* ↑

A

6-32 hours (2-3 hr in children/adults)

Vd of fentanyl

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17
Q

Hepatic in PREMIES

A

• Might be due to immature CYP 450 3A4 and ↓hepatic function

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18
Q

PREMIES have

A
ABNORMAL PHARMACOKINETICS
May go apneic, BRADYCARDIA
Slow to recover
RESPIRATORY DEPRESSIOn 
MORE RISK OF POST OP APNEA
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19
Q
  • Intravenous agents
  • Morphine
  • Elimination half-life in micropremie =
  • Reduced elimination of__________
  • More _________effects when compared c/ fentanyl
A

6-16hrs (2-4 in adults)
morphine-6-glucuronide
hemodynamic

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20
Q

Remifentanil
• Elimination half-life =_________
•____________
• Premies have normal-high levels of_____________

A

3-4 min in all pts
Independent of duration
nonspecific esterase activity

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21
Q

REMIFENTANYL

A

NO PAIN RELIEF AFTERWARDS

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22
Q

CAUTION with Fentanyl products

A

CHEST WALL RIGIDITY

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23
Q
Ketamine
•\_\_\_\_\_\_\_,\_\_\_\_\_\_\_,\_\_\_\_\_\_
• Minimal\_\_\_\_\_\_\_\_\_\_\_\_
• Can\_\_\_\_\_\_\_\_\_ →
• Always\_\_\_\_\_\_\_ unless brief painful procedure
A

Analgesia, amnesia, unconsciousness
↓CV function (stimulates)
↓ventilation/airway reflexes; airway obstruction, apnea, aspiration
use ETT

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24
Q

• Caution c/ blousing (1-3mg/kg IV) =

A

protracted hypotension +↓CO in otherwise stable infants → hypoxia

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25
• Possibilities of Propofol
systemic vasodilation, acute pulmonary HTN with reversion to persistent fetal circulation
26
• Recovery delayed in micropremies
(↓ fat/muscle for redistribution, ↓ clearance)
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* Intravenous agents * Midazolam * ______clearance in micropremie * Further prolonged________ * _______________ * Hypotension even greater if administered
↓ with ↓ liver function Systemic hypotension, ↓ ventilation, impaired airway reflexes in premies c/ fentanyl
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* Regional anesthesia | * None of the complications listed above!
↑risk of infection, injury, bleeding ↑local doses per kg required in infants (↑Vd in CSF, ↑surface area of spinal cord/nerve roots, ↑CO/BF to spinal cord = faster distribution, uptake, and elimination = ↓ DOA
29
Preparation for a Neonatal Emergency
* Is it an “urgent” emergency? * Normally have time to medically optimize * Warm the patient * ↑OR temp 80°F to 85°F (normally 60-65°F) * Radiant warming units * Forced air heating pads * Humidify FGF (or rebreathe)
30
Preparation for a Neonatal Emergency: Monitors
• EKG, chest/esophageal stethoscope, BP, temperature probe, pulse oximeter, ETCO2 and agent analyzer
31
Preparation for a Neonatal Emergency: Oxygen saturation
Normally limit use of O2 to keep SpO2 between 83-95% to ↓ oxidative stress • Anesthesia and surgery adversely affect oxygenation → we use it! • In event of PDA still present, take sats at right hand and left hand/foot to assess extra-pulmonary shunting of DeO2 blood via PDA
32
* Circuit adds __________ → ETCO2 underestimates _______ * Large VD when neonates use ___________ * Usually have _________ * Might need to _____ ________ during parts of surgery * Esp with old ventilators * Consider asking NICU to send one * Umbilical venous catheter =________ * Umbilical arterial catheter = _________ * Umbilical catheters can only be used up to______Days
* Circuit adds dead space volume (VD) → ETCO2 underestimates PaCO2 * Large VD when neonates use very small TV * Usually have bad lungs * Might need to ventilate manually during parts of surgery * Esp c/old ventilators * Consider asking NICU to send one * Umbilical venous catheter = central line * Umbilical arterial catheter = A-line * Umbilical catheters can only be used up to 7-10 days
33
Equipment to always have on hand
Suction catheters, various face masks, oral airways, pediatric breathing circuits, laryngoscopes, numerous small ETT, IVF warmer, body warmers, LR, D10W, NS, 5% albumin
34
• Emergency drugs:
atropine, epi (1:10,000), dopamine, calcium, bicarbonate, isoproterenol
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``` • Medication administration • Only draw up ____________ • Tuberculin needle needed _________ (e.g. 5 mcg fentanyl) • If diluting, __________________ • Always administer_________always _____________________ • Keep empty labeled syringes until the end of case ```
• Only draw up what you intend to give • Tuberculin needle needed for small doses (e.g. 5 mcg fentanyl) • If diluting, verify concentration c/ someone • Always administer in port closest to pt, always flush line after administering • Keep empty labeled syringes until the end of case
36
* Fluid maintenance * Fluid overload can open _______________ * NO _____________ * Continue whatever they were getting in ______because it Contains ______and _________ * Do NOT stop _____or _________ why? * If no fluids are going, use ________or _____
* Fluid overload can open a DA and cause CHF * NO AIR BUBBLES * Continue whatever they were getting in NICU * Contains glucose and calcium * Do NOT stop TPN or dextrose * Maybe slightly ↓rate to ward off hyperglycemia * If no fluids are going, use LR or plasmalyte
37
****CHOANAL ATRESIA is Developmental failure of ______ _____________ • Associated with ____________ • CHARGE syndrome * Treacher-Collins * Pfeiffer * VATER * _____________________
Developmental failure of nasal cavity to communicate c/ nasopharynx • Associated c/ other congenital anomalies • CHARGE syndrome • (Coloboma,Heart disease, Atresia choanae, Retarded growth, Genital anomalies, Ear anomalies) • Treacher-Collins • Pfeiffer • VATER • (Vertebral defects, Anal atresia, Tracheoesophageal fistula c/ Esophageal atresia, and Radial and renal anomalies
38
``` *****CHOANAL ATRESIA Only a surgical emergency if___________ • Presents c/in_________ • Resp distress, _________cyanosis • High risk for airway obstruction • Oral airway early ```
bilateral stenosis present 5 days of life (associated c/feeding; relieved by crying)
39
****TEF is Error in _______________ around______week gestation • VACTERL association __________________ • Diagnosis: ____________________ MOST SEEN IS ______________ Early postnatal s/s: excessive salivation, choking/coughing/regurgitation at first feed → cyanosis and/or respiratory distress, distended abdomen (stomach filling c/ air every time the baby cries) → may compress the lung and ↓ resp
Error in separation of trachea from floor of the foregut around 4th-5 th wk gestation • VACTERL association • (Vertebral anomalies, imperforate Anus, Congenital heart disease,Tracheoesophageal fistula, Renal abnormalities, ***LIMB ABNORMALITIES****) • Diagnosis: polyhydramnios (cant swallow) Early postnatal s/s: excessive salivation, choking/coughing/regurgitation at first feed → cyanosis and/or respiratory distress, distended abdomen (stomach filling c/ air every time the baby cries) → may compress the lung and ↓ resp
40
MOst common TEF
TYPE C
41
Most common type TEF
(Gross classification C, type IIIB in Vogt) consists | of blind proximal esophageal pouch (atresia) c/ a distal TEF just above the carina • (80%–90% of cases)
42
``` TEF • NOT a _______________ • IV access, correct anemia, F/E imbalances, type and crossmatch, *****look for o________________*****, place ________________ • Surgical repair • Traditional =_______________________ • Thorascopic repair gaining popularity • OLV no longer required ```
• NOT a surgical emergency • IV access, correct anemia, F/E imbalances, type and crossmatch, look for other congenital anomalies, place gastrostomy tube • Surgical repair • Traditional = open thoracotomy c/manual lung retraction • Thorascopic repair gaining popularity • OLV no longer required
43
With TEF
Can't feed through ESOPHAGUS
44
TEF Anesthesia Considerations
* Anesthesia considerations * Option 1: keep baby spont. vent. * Inhalation induction * Avoiding positive pressure ventilation ↓ amount of gas entering stomach Option 2: gentle mask ventilation c/low peak pressure ventilation • ↓ amount of gas entering stomach • Tip of ETT must be placed above carina but distal to fistula • Right mainstem tube on purpose, then slowly c/draw until you have first bilateral breath sound • Fiberoptic scope • Pain: epidural catheter threaded from caudal to thoracic space
45
``` Congenital Diaphragmatic Hernia (CDH) ✤ Failure of ______ • Inhibits normal________________ _______ of bronchi/alveoli •__________PVR/ Pulmonary HTN ✤ Etiology _________ ✤ Diaphragm formation at __________ Separates the chest and abdomen • Hernia forms around ________ ✤ Hernia: Intestine penetrates the hole in the diaphragm and enters the chest ✤ Not a surgical emergency • Optimize medically first ```
``` ✤ Failure of closure of pleural + peritoneal canal → herniation of abd contents into thorax • Inhibits normal lung growth • ↓# of bronchi/alveoli • ↑PVR + primary pulmonary HTN ✤ Etiology unknown ✤ Diaphragm formation at 5 - 10 wks gestation • Separates the chest and abdomen • Hernia forms around 8 wks ✤ Hernia: Intestine penetrates the hole in the diaphragm and enters the chest ✤ Not a surgical emergency • Optimize medically first ```
46
Congenital Diaphragmatic Hernia | CDH
Left side closes last • 90% CDH occur at foramen of Bockdalek • Largest degree of pulm hypoplasia • Associated c/ congenital heart defects, chromosomal abnormalities, GU/GI malformations • ↑PVR → R-to-L shunt via PFO and DA • Hypoxemia • Respiratory distress, tachycardia, tachypnea, and cyanosis observed shortly after delivery • At birth: ↓ breath sounds, bowel sounds in thorax, resp insuff, barrel chest, scaphoid abd
47
``` Anesthesia considerations of CONGENTIAL DIAPHRAGMATIC HERNIA Anesthesia considerations: • Gentle mechanical ventilation to avoid _______________________ • Frequent, small ____________ • Permissive hypercapnia ___________ • Avoid ________ • ______________________ • Avoid introducing ____________ • Insert ________ • Avoid_______________ • Avoid ___________ ```
* Gentle mechanical ventilation to avoid pneumothorax/barotrauma/volutrauma * Frequent, small TV breaths c/limited peak inspiratory pressures (< 20 cm H2O) * Permissive hypercapnia 60-65 mm Hg * Avoid ↑PVR * Hypoxemia, acidosis, hypothermia, hypercarbia * Avoid introducing air to GI tract * Insert NGT before induction * Avoid CPAP and prolonged mask vent * Avoid N2O
48
CDH surgical
• Open surgical transabdominal approach vs thoracoscopy • If abd too small to accommodate additional bowels → intense ↓pulm compliance, desaturation, hypercapnia • OLV not always necessary anymore • CO2 insufflation to collapse lung
49
``` CHD Temporary fetoscopic tracheal plugging Performed ______weeks of gestation • Prevents outflow of_______________ • Retained fluid helps enlarge lungs, accelerates growth, reduces mass effect of herniated bowels ```
• Temporary fetoscopic tracheal plugging • Performed 25 -28 weeks gestation • Prevents outflow of surfactant -rich fetal fluid
50
GI PATHOLOGY NOT a surgical emergency UNLESS
• All considered full stomachs • Suction gastric contents first, then RSI • Avoid N2O d/t intestinal distention *****NOT a surgical emergency unless compromised organ blood flow****** • Correct underlying medical issues and achieve euvolemia • Prone to: • ↓BP • Metabolic abnormalities (↑K+) • Anemia • Thrombocytopenia
51
Hypertrophic Pyloric Stenosis What kind of Vomiting? How long does it take for metabolic derangements to be fixed? Signs of proper optimization
• 1/500 live births • Usually presents 2-8 weeks of age c/: • Nonbilious projectile vomiting → ↓K+ ↓Cl- metabolic alkalosis-->Severe cases progress to metabolic acidosis ***NOT a life threatening emergency*** Fixing metabolic derangements and fluid status takes 24-48hrs ``` Signs of proper medical optimization: UOP of 1-2 mL/kg/hr or more Na+ > 130 mEq/L K+ > 3.0 mEq/L Cl- > 85 mEq/ ```
52
Hypertrophic is______Vomiting
NON-BILIOIUS
53
Treatment of HPS
pyloromyotomy • Anesthesia considerations: • Modified RSI • Maybe inhalation induction • Muscle relaxation not always necessary in every case • Opioids typically not needed • Local combined c/ acetaminophen or an NSAID normally enough
54
``` Duodenal Atresia • Duodenal Atresia it is a _________ __________ associated c/ other congenital anomalies (OBSTRUCTION after bile duct) • Presentation: ________vomiting beginning __________→____________ NOT a surgical emergency, medically optimize first • Abdominal XR show ________________ ```
Congenital absence or complete closure of a portion of the lumen of duodenum 50 -70% associated c/ other congenital anomalies Presentation: • Bilious vomiting beginning 24 -48hrs after birth →dehydration + F/E imbalance • NOT a surgical emergency, medically optimize first • Abdominal XR show “double bubble” sign • Air trapped in stomach and proximal duodenum
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INGUINAL HERNIA IT is a Protrusion of _____________ • Typically occurs within _____________ _____________ →***true surgical emergency • Elective should receive _______ • Caudal, spinal, ilioinguinal block, TAP block
Protrusion of abdominal cavity and gonadal structures through the inguinal canal • Failure of process vaginalis to close • Typically occurs c/in 6 mo of life and more prevalent in males • Incarcerated or strangulated hernia →true surgical emergency • Elective should receive regional • Caudal, spinal, ilioinguinal block, TAP block
56
Necrotizing Enterocolitis (NEC) It is a multifactorial ____________ _____mortality rate Potential etiologies: Associated with
Multifactorial disease that can lead to bowel necrosis • Leading cause of neonatal mortality • 10-50% mortality rate • Potential etiologies: • Unbalanced inflammatory responses of bowel mucosa, alterations in normal intestinal flora by antibiotics and feeds, and lack of a fully developed intestinal mucosal barrier → breakdown of intestinal wall and bowel necrosis Associated c/: • Prematurity, low systemic cardiac output, hypoxia, PDA, infection, red blood cell transfusion, and enteral feedings (especially formula-fed neonates)
57
Leading cause of NEONATAL MORTALITY
NECROTIZING ENTEROCOLITIS
58
Early signs of NEC
• Early Signs • Temp instability, poor feeding c/ residual volumes or vomiting, lethargy, apnea, bradycardia, mild abdominal distention, and bloody stools
59
Late signs of NEC
• Late signs • Tachycardia, poor perfusion/hypotension, | metabolic acidosis, thrombocytopenia, abdominal tenderness, and peritonitis
60
• Abd XR of NEC shows
ileus c/ thickened bowel walls and dilated loops, later gas in the intestinal wall and in hepatobiliary tract or portal venous system
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***PROMPT SURGICAL INTERVENTIO of NEC, if you find
****• Finding free air in abd cavity = prompt surgical | intervention
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* Fast preop prep of NEC * Predisposed to ________________ * Septic and volume depleted c/ ______________as the result of massive third-space losses * Enormous need for ____________ just to maintain intravascular volume (up to 1 blood volume of more) because of third spacing * Hypokalemia c/ renal failure common * Commonly need plt and FFP transfusion * CVP for inotropic support (dopamine, epi)
Predisposed to hypovolemia, CV and resp failure, capillary leak syndrome, DIC, and hypoglycemia • Septic and volume depleted c/ very large fluid requirements as the result of massive third-space losses • Enormous need for 5% albumin just to maintain intravascular volume (up to 1 blood volume of more) because of third spacing • Hypokalemia c/ renal failure common • Commonly need plt and FFP transfusion • CVP for inotropic support (dopamine, epi)
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OMPHACELE
Failure of gut to migrate from yolk sac into abd during gestation • 1/5000 births • Commonly have other issues: • associated genetic, cardiac, urologic, metabolic abnormalities, visceromegaly, macroglossia, hypoglycemia, polycythemia • Bowel looks and functions normally
64
Gastroschisis
• Results from occlusion of the omphalomesenteric artery during gestation • 1/2000 births • Usually not associated c/congenital anomalies • Due to exposure, present c/inflammation, edema, and dilated, foreshortened, functionally abnormal bowel • Keep covered c/ saline-soaked dressings • Extreme evaporative volume loss and hypothermia --> More than omphalocele
65
Anesthesia Considerations for GASTRO and OMP
Volume replacement • Prevention hypothermia • Monitor intra-abdominal pressure (IAP) • > 20 mm Hg after surgery → abd ischemia, urgent reoperation → ↓ organ perfusion and ventilatory reserve, including perfusion of the intestines, kidney, and liver • Altered metabolism/eliminatio n/prolongation of meds
66
Malrotation and Midgut Volvulus
Etiology: • Abnormal migration or incomplete rotation of intestines from yolk sac back into abdomen • 1/500 births • 30-60% have other congenial anomalies ``` Presentation: • Bilious emesis, tender and distended abdomen, increasing abdominal girth, hypotension, hypovolemia, and electrolyte abnormalities • True neonatal surgical emergency • Do NOT delay surgery to correct F/E imbalances ```
67
Hirschsprung Disease
• Absence of parasympathetic ganglion cells in large intestine • Nonperistaltic segment, tonically contracted anorectal sphincter, and delayed passage of meconium • Functional obstruction • Symptoms: bilious vomiting, abd distention • Compromised blood supply →perforation • Enteric bacteria invasion of bowel wall to bloodstream → toxic megacolon • 60% have other associated anomalies • Require massive volume replacement and vasopressor support
68
Ligation of Patent Ductus Arteriosus
• Controversial procedure due to conflicting evidence • 1/3 develop severe cardiovascular instability • Increased risk of chronic lung disease, ROP, and neurosensory impairment after ligation • Medical management: cyclooxygenase inhibitor, such as indomethacin or ibuprofen • Indomethacin in premies may cause: thrombocytopenia, renal failure, hyponatremia, and intestinal perforation • Ibuprofen works just as well s/complications • Paracetamol being used c/ equal effectiveness
69
Ligation of Patent Ductus Arteriosus surgica
• Surgical correction: Left thoracotomy c/ manual retraction of lung • Hard to distinguish PDA from aorta • Monitoring BP and pulsox on right arm (preductal) and oximetry on the foot (postductal) will assist surgeon to ID correct vessel to be ligated • Temporary clamp placed on perceived PDA • If aorta is clamped → loss of post ductal oximetry • If PA is clamped → ↓in both oximeters and ↓ETCO2 • Successful PDA ligation → ↑MAP (↑DBP) + NO changes in pulse oximeters
70
Ligation of Patent Ductus: Transcatheter occlusion of PDA MOST COMMON complications are
* Coils or occlude device * Similar efficacy to traditional surgery * Can be done in NICU c/ echo guidance * More rapid recovery of resp function • Most common complications - ->Femoral artery thrombosis - -> Left pulmonary artery stenosis - -> Aortic coarctation
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COMPARE OMPHACELE and GASTROCHISIS
Know