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Congenital Anomalies — TOF, Pyloric, TEF

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Pediatric II · 10 min read

Three peds-specific surgical anomalies with three signature anesthetic challenges. Recognize and manage the physiology.

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Recognize common congenital heart lesions by physiology.
Plan anesthetic for shunt-dependent vs balanced lesions.
Anticipate the failed Fontan circulation.
Identify lesions where air bubbles in IV lines kill.

Tetralogy of Fallot — tet spell

KeyTet spell: increased RVOT obstruction + R-to-L shunt cyanosis + acidosis.

Treatment

knee-to-chest position (increases SVR → decreases shunt)
100% O₂
phenylephrine 5-10 mcg/kg IV (increases SVR, paradoxically helps)
morphine (decreases RV outflow obstruction by relaxing infundibulum + reducing catechol-induced spasm)
volume expansion
beta-blocker (propranolol) if persistent

Avoid

decrease SVR
tachycardia
ketamine high-dose

Tetralogy of Fallot anatomy: pulmonary stenosis, RVH, overriding aorta, and VSD produce right-to-left shunt with cyanosis. Magnitude depends on RVOT obstruction and SVR; tet spells improve with knee-to-chest position and phenylephrine.

Pyloric stenosis — medical urgency

KeyNOT surgical emergency.

Classic teaching: medical urgency.

Hypochloremic + hypokalemic metabolic alkalosis from vomiting.

Correct fluid + electrolytes + alkalosis BEFORE OR.

IV NS + KCl resuscitation to normal pH + electrolytes + chloride.

Surgery (pyloromyotomy) after lab normalization.

RSI given full stomach status.

Apneic oxygenation marginal in infants — be ready for fast desaturation.

TEF — tracheoesophageal fistula

KeyType C most common (esophageal atresia + distal TEF).

Concern: PPV inflates stomach via fistula impair ventilation + risk perforation.

Avoid mask ventilation before ETT placement.

Awake intubation or spontaneous-ventilation induction preferred.

ETT distal to TEF (often >3 cm below cords) — fiberoptic guidance.

Pre-op Replogle tube + head elevation reduces aspiration risk.

Coordinate with pediatric surgeon.

CDH — congenital diaphragmatic hernia

KeyLung hypoplasia + pulmonary hypertension.

Gentle ventilation (low pressures <25-30 cmH₂O), oxygenation, permissive hypercapnia (preferred over high pressures).

HIGH PVR is the dominant problem — inhaled NO often needed to lower PVR.

Pre-op stabilization often days (delayed surgery has better outcomes).

Avoid mask ventilation (stomach insufflation worsens lung compression).

PDA management — keep open via PGE-1 if needed for shunting around the hypertensive right heart.

ECMO for severe respiratory failure refractory to optimization.

Cardiac disease in pregnancy: management of congenital lesions, regurgitant valves, cardiomyopathy and pulmonary hypertension; key issues include arrhythmias, heart failure decompensation peri-delivery, and need for invasive monitoring.

Syndromic airway risks

KeyDown syndrome: large tongue + atlantoaxial instability (verify pre-op imaging) + subglottic stenosis + bradycardia tendency.

Pierre Robin: micrognathia + glossoptosis difficult intubation.

Treacher Collins: similar mandibular hypoplasia + difficult airway.

Awake fiberoptic or video laryngoscopy preferred for known syndromic airways.

Difficult airway cart with appropriate pediatric sizes essential.

Post-PDA-closure considerations

KeyAfter PDA ligation: increased systemic blood pressure (afterload now full systemic — no shunt to absorb).

Reduce afterload pharmacologically if needed (clevidipine, milrinone).

Reduced shunt fraction improved oxygenation but ventilation/perfusion balance may shift acutely.

Surgical: left thoracotomy (or VATS/transcatheter) in neonate — pain management with thoracic epidural or intercostal blocks + opioid.

Postop ventilation 24-48 hr typical in preterm.

Risk of recurrent laryngeal nerve injury (hoarse cry post-procedure).

Inguinal hernia repair in infants: high recurrence and apnea risk in former preterm; spinal anesthesia an option to reduce postoperative apnea, with postop monitoring per gestational age.

Single-ventricle physiology (HLHS, etc.)

KeyHypoplastic left heart syndrome + similar single-ventricle anatomies: ductal-dependent for systemic circulation.

PGE1 infusion essential.

Balanced systemic + pulmonary blood flow (Qp/Qs ≈ 1) goal — TOO MUCH pulmonary flow steals from systemic (hypotension + acidosis); TOO LITTLE causes hypoxia.

INCREASE PVR with: hypoxia (room air), permissive hypercapnia, low FiO2 (controversial; some centers avoid).

DECREASE PVR with

hyperoxia (avoid in single-ventricle pre-Norwood)
iNO
mild hyperventilation

Staged repairs: NorwoodGlenn (~6 mo)Fontan (~3 yr).

Each stage has unique anesthetic considerations.

Cardiac anesthesia subspecialty.

Eisenmenger syndrome anesthesia: long-standing L->R shunt becomes R->L due to pulmonary vascular disease; avoid drops in SVR and increases in PVR; maintain preload, slow induction, avoid air bubbles in IV lines.

Necrotizing enterocolitis (NEC) emergency

KeyPremature infants with NEC requiring laparotomy: HIGH MORTALITY (~20-30%).

Hemodynamically unstable, septic, often DIC.

Acidotic, often on vasopressor + ventilator pre-op.

Anesthetic plan

gentle induction (low-dose fentanyl + ketamine, often NO induction agent — patient already obtunded)
continue vasopressor
ventilate per pre-op settings
aggressive product resuscitation

Hypothermia + hypoglycemia + acidosis all worsen outcomes — actively prevent.

Adequate IV access + arterial line + foley for monitoring.

ECMO standby in some centers.

Multidisciplinary team essential.

Necrotizing enterocolitis (NEC) in preterm neonates: high-risk anesthesia with sepsis, hemodynamic instability and DIC; aggressive resuscitation, lung-protective ventilation, and broad-spectrum antibiotics required.

Sepsis-3 definition: life-threatening organ dysfunction from dysregulated host response to infection; SOFA score increase >=2; septic shock = persistent hypotension requiring vasopressors and lactate >2 despite fluids. — Necrotizing enterocolitis (NEC) in preterm neonates: high-risk anesthesia with sepsis, hemodynamic instability and DIC; aggressive resuscitation, lung-protective ventilation, and broad-spectrum antibiotics required.

⚠ Common pitfalls

Routine IV flush without bubble removal — paradoxical embolism in shunt patients.
Excessive O₂ in single-ventricle physiology — drops PVR + steals blood from systemic to pulmonary.
Forgetting endocarditis prophylaxis for cyanotic + repaired lesions.
Aggressive hyperventilation in cyanotic — drops PVR but also CO in single-ventricle.

💎 Clinical pearls

Tet spell treatment: knees-to-chest + 100% O₂ + IV fluid + phenylephrine + opioid + ± propranolol.
Fontan circulation: preload-dependent, low PVR essential, sinus rhythm matters.
VSD/ASD: avoid air in IV lines — micro-bubble filter on every drip in shunt patients.
Single-ventricle palliated: keep PVR-systemic balance; avoid hypoxia, hypercarbia, acidosis.

Recap

Tet spell treatment: knees-to-chest + 100% O₂ + IV fluid + phenylephrine + opioid + ± propranolol.
Fontan circulation: preload-dependent, low PVR essential, sinus rhythm matters.
VSD/ASD: avoid air in IV lines — micro-bubble filter on every drip in shunt patients.
Single-ventricle palliated: keep PVR-systemic balance; avoid hypoxia, hypercarbia, acidosis.

Mark each section done to complete the module.