Anesthesiology APPLIED Exam › Pediatric and neonatal

Tracheoesophageal fistula

T1Pediatric and neonatal·1032 words · ~6 min read·v0.1DRAFT

Why examiners ask this

A neonate with a tracheoesophageal fistula is a ventilation problem with an anatomic cause, and the examiner wants to see whether I understand where the gas goes. The topic tests application of knowledge (the VACTERL associations, neonatal physiology), judgment (awake or asleep, relaxant or spontaneous breathing, where the tube tip sits) and adaptability when the stomach distends or the saturation falls after the chest is opened.

The 60-second answer

This is a neonate who cannot protect the airway from secretions or the lungs from gastric contents, and who will be a preterm infant with a cardiac lesion until proven otherwise. Before the operating room I keep the baby head-up with a sump catheter in the upper pouch on continuous suction, avoid mask ventilation, and get an echocardiogram and a renal ultrasound because the cardiac lesion changes mortality and the right-sided aortic arch changes the surgical side. In the operating room I induce with the infant breathing spontaneously on sevoflurane, or with a gentle intravenous induction, and I avoid positive pressure until the tube is below the fistula. I confirm the tip position with the surgeon's bronchoscopy, listen for bilateral breath sounds, and keep a precordial stethoscope on the dependent left chest. I watch for abdominal distension and a rising airway pressure as the sign that I am ventilating the stomach.

Decision points and the "why"

Gastrostomy first or not — a baby with pneumonia or a distended stomach benefits from a decompressing gastrostomy under local, because positive pressure escaping through the fistula inflates the stomach and splints the diaphragm. In a stable term baby the surgeon goes straight to thoracotomy or thoracoscopy. I ask which plan the surgeon has before I pick the induction.
Spontaneous ventilation at induction — gas under positive pressure follows the path of least resistance, and in a fistula that path is the esophagus. I keep the baby breathing until the tube tip is positioned, then relax. I change my mind with a large fistula and a gastrostomy already in place, where I can occlude the gastrostomy tube or vent it under water.
Tube position — the classic maneuver is to intubate the right mainstem deliberately, then withdraw until breath sounds appear on the left; the bevel faces anteriorly so the posterior tracheal wall fistula is covered. I confirm with rigid bronchoscopy by the surgeon, which also shows whether the fistula is at the carina, where no tube position excludes it. A fistula at the carina means I plan for a Fogarty balloon occlusion.
Lines — an arterial line, because the retracted right lung and mediastinum cause hypoxemia and hypotension; I accept a right-sided preductal pulse oximeter and a second postductal probe. A central line only if the baby is going to need parenteral nutrition.
Thoracoscopic repair — insufflation of CO2 into a neonatal chest causes hypercarbia and acidosis; I ask for pressures no higher than 5 mmHg and lower flows, and I follow gases every 30 minutes.
Extubation — I extubate in the operating room a term baby with no pneumonia and a short gap; I leave a preterm infant or a long-gap repair intubated, and I tell the surgeon I will avoid reintubation because the blade and tube can disrupt the anastomosis. If reintubation is unavoidable I do it with a measured tube depth that stays above the anastomosis.

The complication they will inject

After the chest is open and the right lung retracted, the saturation falls to 78 percent and the airway pressure climbs. I tell the surgeon to release the retractor and I hand-ventilate with 100 percent oxygen. I auscultate and look at the abdomen: a tense abdomen with poor breath sounds means the tube has migrated into the fistula or the fistula is large, so I pull the tube back a centimeter and vent the gastrostomy; a collapsed lung means secretions or blood have plugged a mainstem, so I suction. I ask whether the surgeon can ligate the fistula first, which solves both problems at once. If the saturation does not recover with the retractor out, I ask for the lung to be reinflated under direct vision and I check the tube for kinking from the retractor, because the right-sided approach pushes the trachea into the mediastinum.

Pitfalls that cost points

Launching into the airway plan without the echocardiogram and the search for the other VACTERL anomalies.
Giving a relaxant and bag-mask ventilating with no plan for where the gas goes.
Stating that the tube "goes below the fistula" without saying how I confirm it or what I do when the fistula is at the carina.
Forgetting that the dependent left lung is what I am ventilating; a precordial stethoscope on the left axilla is the monitor that detects tube migration.
Describing extubation without the warning about the anastomosis and the limit on neck extension.

Rapid-why

Q: Why does a right aortic arch matter? A: The surgeon approaches through the side opposite the arch, so a right arch means a left thoracotomy and I set up to retract the left lung.

Q: Why avoid nitrous oxide? A: It expands the gas in the stomach and bowel and reduces the inspired oxygen in a baby with a retracted lung.

Q: Which type is most common? A: Type C, esophageal atresia with a distal fistula, in about 85 percent; an H-type fistula presents later with coughing on feeds and recurrent pneumonia.

Q: Why does a precordial stethoscope beat capnography here? A: The stethoscope detects loss of left-sided breath sounds within one breath; end-tidal CO2 changes later and is distorted by the leak through the fistula.

Numbers to know

Item	Value
Type C frequency	~85 percent of cases
Congenital heart disease in TEF	~30–35 percent; the main mortality driver
Thoracoscopic insufflation	≤5 mmHg, low flow
Upper pouch sump	Continuous suction, head up 30 degrees
Reintubation after repair	Fixed depth above the anastomosis, by the most experienced hands

Sources

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