Pediatrics II

Question 1

Premature Infant

Anesthetic Considerations

Answer 1

Already intubated ICU transport
Uncuffed/cuffed ETTs
Difficult intubation - subglottic stenosis
Difficult ventilation - poor compliance; avoid barotrauma & excessive oxygen
Position change → check ETT
NSAIDs contraindicated
Consider IV caffeine to prevent apneas

Question 2

Why are NSAIDs contraindicated in premature infants?

Answer 2

Immature renal system
Premature PDA closure

Avoid IV Ketorolac until 6mos-1yo

Question 3

What effect do inhalational anesthetics have on premature infants?

Answer 3

More susceptible to the cardio-depressant effects

Neonatal heart dependent on plasma Ca2+

Question 4

Neonate MAC

Answer 4

Sevo 3.2% (2)
Iso 1.6% (1.2)
Des 9.2% (6)

Question 5

Infant MAC

Answer 5

Sevo 3.2% (2)
Iso 1.8% (1.2)
Des 10% (6)

Question 6

Child MAC

Answer 6

Sevo 2.5% (2)
Iso 1.4% (1.2)
Des 8.2% (6)

Question 7

Fentanyl

Answer 7

↑Vd
↓elimination 1/2 life
Premature infants 6-32hrs
Children & adults 2-3hrs

Question 8

Propofol

Answer 8

Protracted hypotension & ↓CO
↓dosages
Infusions rarely used long-term

Question 9

Midazolam

Answer 9

↓clearance especially w/ impaired liver function

Question 10

Dexmedetomidine

Answer 10

Propofol pre-treatment to alleviate neuronal cytotoxicity

Question 11

HbF

Answer 11

Fetal hemoglobin
Main O2 transport protein in fetus during development in-utero & persists until 6mos
↑oxygen binding affinity
LEFT SHIFT
Carries 20-50% more oxygen than maternal Hgb

Question 12

Physiologic Anemia

Answer 12

Transition HbF → HbA
Full-term infants 10-11g/dL
↓erythropoiesis & shorter RBC lifespan

Premature infants 7-9g/dL
Consider transfusion when Hct <30%

3mos Hgb level stabilizes to 11-12g/dL until 2yo

Question 13

PDA

Answer 13

L → R shunt
Excessive pulmonary blood flow
CHF & respiratory failure

R → L shunt
Pulmonary HTN → cyanosis

Question 14

PDA Ligation

Answer 14

Medical:
- Admin COX inhibitor
- Indomethacin (Indocin) or Ibuprofen
Surgical:
- L thoracotomy w/ lung retraction
- Clip or transcatheter closure "plug"

Question 15

PDA Ligation

Preop

Answer 15

Assess arterial pressure ↓diastolic (widened pulse pressure), HR, arterial blood gas, ventilator setting, FiO2
PRBCs on hold
Antibiotics - endocarditis risk

Question 16

PDA Ligation

Intraop

Answer 16

Blood pressure monitoring on R arm (reflects cerebral perfusion & pre-ductal)
Pox pre & post-ductal
ETCO2 monitoring
Minimal ETT leak (lung retraction ↑ventilator inspiratory pressures & FiO2)
Opioids, amnesia, & muscle relaxation
Intercostal nerve block placed by surgeon at surgery completion

Question 17

PDA Ligation

Complications

Answer 17

Inadvertent aorta or pulmonary artery ligation or laceration
Aorta clamp → Pox loss signal LE
Pulmonary artery clamp ↓oxygen saturation & ETCO2

Question 18

NEC

Answer 18

Necrotizing enterocolitis
Low birth weight infants mortality up to 50%
85% cases infants < 1,500g birth weight
Morbidity associated w/ short bowel syndrome, sepsis, & adhesions

Intestinal mucosal injury 2° to bowel ischemia & ulceration

Question 19

NEC S/S

Answer 19

Early signs - abdominal distension, bloody diarrhea, temperature instability, & lethargy
Metabolic & hematologic abnormalities - hyperkalemia, hyponatremia, metabolic acidosis, hypo/hyperglycemia, coagulopathy, DIC, anemia
Often already intubated d/t abdominal distension w/ OG/NG tube suctioning & hemodynamic instability

Question 20

NEC Treatment

Answer 20

1° NICU medical management
Peritoneal drainage often performed at bedside
Bowel perforation & free air present in abdominal cavity → urgent/emergent surgery
Exploratory laparotomy w/ necrotic bowel resection
Risk life-threatening sepsis after perforation d/t bacteria entering bloodstream

Question 21

NEC

Anesthetic Considerations

Answer 21

Aspiration risk → RSI or awake intubation
Inhalational agents poorly tolerated
- Consider narcotic technique w/ muscle relaxation to maintain hemodynamic stability
Avoid nitrous oxide
PIV x2
A-line or UAC
Fluid & blood loss
- Admin PRBCs (10-15mL/kg), FFP (10-15mL/kg), platelets
Correct electrolytes
Monitor glucose

Question 22

Allowable Blood Loss

Answer 22

[EBV x (starting Hct - allowable Hct)] / starting Hct
25%

Relatively small amount blood loss → severe hypovolemia

Question 23

NEC

Preop

Answer 23

Optimize hemodynamic & coagulation status
Check blood product availability
ETT & catheter placement
Adequate IV access
Know acceptable hemodynamic parameters (HR, BP, SpO2, FiO2)

Question 24

NEC

Intraop

Answer 24

Standard monitoring
Arterial catheter
Maintain hemodynamic stability
Vasoactive support (Dopamine or Epi gtt)
Opioids or low-dose inhalation anesthetic agent w/ neuromuscular paralysis
Check glucose levels & electrolytes
Fluid resuscitation
PRBC, FFP, cryo
Temperature homeostasis - forced air warmer

Question 25

NEC | Postop

Answer 25

Mechanical ventilation Sedation Analgesia

Question 26

Inguinal Hernia

Answer 26

1/3 pre-term infants | 1% full-term neonates

Question 27

Inguinal Hernia | Complications

Answer 27

``` Incarcerated bowel Intestinal obstruction Gonadal infarction Infection Hematoma Recurrent hernias ```

Question 28

Inguinal Hernia Repair

Answer 28

General or regional anesthesia Small defect consider LMA Large defects requiring muscle relaxation → ETT Ilioinguinal, iliohypogastric, or caudal/epidural blocks

Question 29

ROP Treatment

Answer 29

Cryotherapy - freezing probe to avascular retina, requires general anesthesia, 32-42wks corrected Laser photocoagulation - moderate ROP 10-30min every few weeks Scleral bucking surgery or vitrectomy - severe ROP w/ retinal detachment > 6mos-1yo - Requires general

Question 30

CDH

Answer 30

Congenital diaphragmatic hernia Anatomic defects permit abdominal contents to intrude into thoracic cavity Asymptomatic → life-threatening Early - abdominal mass inhibits normal cardiopulmonary growth; severe lung hypoplasia associated w/ morbidity & mortality; negatively correlates w/ gestational age at time hernia occurred Late - occurs near or even after delivery, mature well-developed lungs, minimal problems w/ ventilation

Question 31

When does the diaphragm formation complete in utero?

Answer 31

Week 7-10

Question 32

Most common CDH type

Answer 32

Bochdalek hernia 95% More likely to have concurrent birth defects & chromosomal abnormalities L sided lesions 7x more frequent

Question 33

CDH S/S

Answer 33

Hypoxia Scaphoid abdomen Bowel sounds in thorax

Question 34

CDH Complications

Answer 34

Abdominal viscera present in thoracic cavity itself not life-threatening rather the compression effects on developing pulmonary structures obstruct smooth transition from fetal to neonatal circulatory pattern - Hypoplastic lungs - Intrapulmonary shunting & inadequate gas exchange - ↓total cross-sectional area results in pulmonary arteriole HTN

Question 35

CDH | Anesthetic Considerations

Answer 35

Initial management - airway control & optimize oxygenation/ventilation Avoid mask ventilation to limit gastric insufflation Place NG tube to decompress stomach Supine or lateral dependent on defect location Pre & post-ductal monitoring R → L shunt or pulmonary HTN - PIV x2 and/or CVC - A-line or UAC - Serial ABGs - EBL 5-10mL/kg - PRBCs available Limit inhalational agent, paralysis, & narcotics Avoid nitrous oxide Prevent excessive oxygenation Sedation important to limit catecholamine response

Question 36

CDH | Surgical Approaches

Answer 36

Recurrent defects - minimally invasive approach through abdomen Primary closure vs. synthetic path Delay closure until cardiorespiratory & medically stabilization Before, during, or after ECMO Transiently worsens pulmonary HTN → persistent fetal circulation (PDA open & shunts blood R → L bypassing lungs) Outcomes 1° dependent on underlying pulmonary hyperplasia & HTN Stabilize cardiorespiratory status during transition from intrauterine to extrauterine before surgical repair - 48hrs to 4-6 days old - Stabilize in NICU before OR

Question 37

Inhaled Nitric Oxide

Answer 37

Pulmonary vasodilator (avoids systemic hypotension) Refractory pulmonary HTN treatment ↓ R → L shunt & improve oxygenation Short acting

Question 38

VV ECMO

Answer 38

Temporary measure allows lungs to rest & mature while providing appropriate gas exchange through membrane oxygenators Venovenous Double lumen resides in IJ vein

Question 39

VA ECMO

Answer 39

Temporary measure allows lungs to rest & mature while providing appropriate gas exchange through membrane oxygenators Venoarterial Two catheters - IJ vein & carotid artery

Question 40

ECMO Contraindications

Answer 40

IVH | Obtain HUS 1st

Question 41

How should CRNAs approach & treat severe cardiovascular compromise in CDH?

Answer 41

Volume & inotropic support | Dopamine

Question 42

Malrotation

Answer 42

Intestines twist around superior mesenteric artery → kink & compress vascular supply Atretic segments, compromised perfusion, & intestinal ischemia

Question 43

Volvulus

Answer 43

Bowl strangulation & shock

Question 44

Malrotation & Midgut Volvulus | Presentation

Answer 44

``` Bilious emesis Abdominal distension Hemodynamic instability Hypotension Hypovolemia Electrolyte abnormalities Bloody stools ``` Surgical emergency - necrosis risk

Question 45

Omphalocele

Answer 45

Hernia or rupture at the umbilicus Failure gut to migrate from yolk sac into the abdomen Associated genetic, cardiac, urologic, & metabolic abnormalities Viscera emerge from umbilicus & covered w/ membranous sac

Question 46

Gastroschisis

Answer 46

Herniated viscera exposed to air after delivery Risk inflammation, edema, & dilation /w abnormal bowel function Not usually associated w/ other congenital abnormalities

Question 47

Omphalocele & Gastroschisis | Medical Management

Answer 47

Maintain perfusion & prevent fluid loss Goal = abdominal closure (often delayed to avoid exposing the viscera to excessive pressure) ↑intra-abdominal pressure → cardiorespiratory failure, renal failure, ↓hepatic function, ischemic bowel, & death Pressures >20mmHg poorly tolerated

Question 48

Omphalocele & Gastroschisis | Postop

Answer 48

Assess ability to extubate Continue gastric suction IV nutrition TPN weeks → months Often remain intubated w/ IV sedation, paralytics, & opioids

Question 49

Criteria to Abort 1° Closure

Answer 49

Intra-gastric pressure >20mmHg Intra-vesical pressure >20mmHg ETCO2 >50mmHg PIP (ventilatory pressures) >35cmH2O

Question 50

VACTERL

Answer 50

``` Vertebral abnormalities Imperforated anus Congenital heart disease Tracheo- Esophageal fistula Renal abnormalities Limb abnormalities ```

Question 51

Esophageal Atresia

Answer 51

Esophagus does not connect to stomach

Question 52

Tracheoesophageal Fistula | S/S

Answer 52

TEF Normally diagnosed immediately after birth Excessive secretions, coughing, & choking after 1st feeding Additional indicators - recurrent pneumonias & unable to pass OG

Question 53

TEF Associated Risks

Answer 53

Pneumonia, poor nutrition, gastric distension → impaired ventilation

Question 54

TEF Types

Answer 54

``` Esophageal atresia w/ distal TEF Isolated esophageal atresia 8% Isolated TEF 4% Esophageal atresia w/ proximal TEF 1% Esophageal atresia w/ double TEF 1% ```

Question 55

Most common TEF type _____

Answer 55

Esophageal atresia w/ distal TEF 87% | Type C/IIIB

Question 56

TEF | Anesthetic Considerations

Answer 56

``` Consider "awake" fiberoptic intubation Avoid +pressure ventilation RSI induction Place ETT b/w fistula & carina Avoid nitrous oxide Surgical traction effect on lung, vasculature, trachea, heart, & Vagus nerve ```

Question 57

What does precipitous O2 desaturation in TEF repair indicate?

Answer 57

Atelectasis & secretions → pulmonary blood flow shunt Lung tissue retraction Tracheal & bronchial compression Bleeding ETT malposition (utilize L sided precordial to assess tube migration) Arterial hypoxia → surgeon release traction & perform alveolar recruitment maneuvers

Question 58

TEF Complications

Answer 58

``` Anastomosis leaks & strictures GERD Feeding aversions Esophageal dysmotility Strictures Pulmonary disease Tracheomalacia ```

Question 59

Average neonate oxygen consumption

Answer 59

5-8mL/kg/min | Adult 2-3mL/kg/min

Question 60

What causes an increased CO2 production in neonates? | How do they compensate for this change?

Answer 60

↑metabolic rate ↑CO2 production | ↑respiratory rate to facilitate CO2 elimination

Question 61

Fetal Hgb has an _____ oxygen affinity

Answer 61

INCREASED | ↓oxygen Hgb release → tissues

Question 62

What postop complication needs to be closely monitored for in neonates?

Answer 62

APNEA