Anesthesiology Case Report #1
A one-week old girl is scheduled for the correction of a tracheoesophageal fistula*
Prepared by Melissa Pujazon (MS4, UT Southwestern Medical School, July 2001)

I. Preoperative Evaluation (pertinent medical/surgical history)

A. How do you know the patient has a TE fistula?

1. The newborn infant with excessive salivation, frequent coughing, choking and cyanosis with feeding and respiratory distress should be investigated. Suspect the diagnosis when maternal polyhydramnios and premature labor occur. The inability to pass a gastric tube in the delivery room may be the first sign. Early diagnosis is important to prevent pulmonary damage that results from aspiration of oral and gastric secretions.

B. Pertinent medical history

1. Thorough evaluation of pulmonary status.

2. Cardiac evaluation - auscultate for murmur, ECG, chest film, ECHO

C. Associated congenital anomalies

1. Present in 50% of infants.

2. VACTERL: (V: Vertebral anomalies, A: Anal atresia, C: Cardiovascular, TE: Tracheoesophageal fistula, R: Radial and renal anomalies. L: Limb anomalies)

II. Preoperative Labs/Tests

A. The characteristic diagnostic test is the inability to pass a suction catheter into the stomach.

B. Confirming the diagnosis - Radiograph. A plain radiograph of the chest and abdomen reveals air or gas bubbles in the stomach and intestines that has entered through the fistula.

C. Esophageal atresia with a fistula to the trachea occurs in 1 in 4000 births. Fistulas/atresias are classified as follows:

1. Type A: Esophageal Atresia without TE fistula (8%)

2. Type B: Proximal esophageal atresia with proximal TE fistula (1%)

3. Type C: Proximal esophageal atresia with distal TE fistula (85%). This is the most common type. The fistula usually originates near the carina.

4. Type D: Proximal esophageal atresia with both proximal and distal TE fistulas (2%)

5. Type E: "H-type" TE fistula without esophageal atresia (4%)

D. Labs: Focus on hematologic evaluations, renal function, electrolyte profiles, blood gas analysis….

III. Preop Management and Medication

A. Avoid feedings.

B. Continuous suction of blind-ended pouch by multiple-lumen tube (Repogle).

C. Child placed in prone, semi-upright position.

D. If the child has pneumonia, treatment should be initiated; surgery may be postponed until pneumonitis improves or clears.

i. The child may be a candidate for gastrostomy to provide a means of nutrition during recovery from pneumonitis.. Therefore, because a change in oxygen saturation may be the first indication that all is not well, the pulse oximeter is one of the most useful monitors in managing these patients

E. Surgical issues

1. Correction of TEF is usually a one step procedure

2. In moderate or high-risk infants unable to withstand a thoracotomy, a gastrostomy is performed under local or general anesthesia.

i. an endotracheal tube is usually placed to protect the lungs from aspiration during surgical manipulation.

ii. Definitive repair usually follows when the infant can withstand surgery and anesthesia - 24-72 hrs later.

iii. Gastrostomy tube maintained to decompress stomach and prevent regurgitation into the lungs.

iv. Once the neonate's clinical status has improved, primary repair of TEF is attempted.

v. Postop, baby is fed through gastrostomy until weight of 20 lbs or 1 year of age has been reached.

F. Premedication: Atropine, IV or IM, is the only premedicant used in neonates. Vagolytic effect counteracts bradycardia and hypotensive effects of inhalationals. Good for antisialogue properties

IV. Intubation

A. Awake intubation is regarded as the safest approach in neonates with TEF.

1. Minimizes risk of gastric distension from inspired gases through the fistula.

2. Disadvantages: increased intracranial pressure, bradycardia, apnea and mechanical trauma to the airway.

B. After intubation, low concentrations of isoflurane should be administered with oxygen while the ET tube is positioned.

C. The ET tube is advanced gently into the right mainstem bronchus and then withdrawn to just above the carina. This position is desired because the fistula is usually just proximal to the carina on the posterior aspect of the trachea.

D. the endotracheal tube is then slowly withdrawn until breath sounds are heard on the left. This technique ensures that the tip of the endotracheal tube is placed beyond the origin of the fistula, thus avoiding massive distention of the stomach.

E. A change in the distance of insertion of the endotracheal tube of as little as 1 to 2 mm may determine whether the anesthesiologist is ventilating both lungs, one lung, or the fistula.

F. Care must be taken to avoid rupturing the stomach; therefore, spontaneous and gently assisted ventilation may be appropriate until gastrostomy is performed.

V. Induction Anesthesia Agents/Muscle Relaxants

1. After ET tube is placed, anesthesia is induced with an inhalational anesthetic.

a. Halothane, with its less pungent smell, is popular in peds cases

b. Isoflurane - reduces myocardial contractility about as much as Halothane, but has potent peripheral vasodilation.

c. Nitrous oxide has minimal adverse cardiovascular and respiratory effects. Provides inadequate anesthesia alone and is contraindicated in some conditions, like diaphragmatic hernia, omphalocele, gastroschisis.

2. Neonates:

a. have a faster rate of induction than adults.

b. have rapid myocardial uptake

c. attain a higher concentration of Halothane in the heart and brain than adults.

d. have increased blood supply to brain, heart, liver and kidneys

3. Muscle Relaxants

a. Neonates are more sensitive to non-depolarizing muscle relaxants than adults.

b. After induction with an inhalation agent, a non-depolarizing muscle relaxant, like 0.1 mg/kg pancuronium, may be administered.

VI. Maintenance Anesthesia Agents

A. Most general anesthetics administered to pediatric patients are inhalants.

B. Halothane

1. Preferred for induction

2. Used as maintenance anesthetic in short, simple cases.

C. Isoflurane

1. Used for more complicated procedures

2. Provides better cardiovascular stability

3. Minimal biodegradation in liver

VII. Intraoperative Medical Care

A. Intraoperative monitoring

1. Precordial stethoscope - monitor air entry and heart sounds continuously.

2. In high risk infants, an arterial catheter is inserted (umbilical or right radial); otherwise a pulse oximeter is used to monitor oxygenation.

i. Inspired oxygen concentration should keep arterial saturation between 92-99%.

ii. Increased inspired oxygen concentrations will be necessary when the right lung is compressed and retracted.

3. End-tidal gas monitoring is used to monitor gas exchange.

4. ECG, pulse oximeter, and blood pressure are routinely monitored.

5. Arterial cannula allows continuous blood pressure monitoring and sampling of blood for blood gases, glucose, hematocrit, electrolytes and acid-base status.

6. Patient's temperature is monitored carefully and measures are taken to prevent hypothermia.

B. Temperature regulation

1. Infants and children maintain their body temperature by metabolizing brown fat, crying, and moving about vigorously. They rarely shiver to maintain temperature. It is difficult for infants to maintain their body temperature because they have larger surface to volume ratios, increased metabolic rate, and lack body fat for insulation.

2. Operating room should have: a temperature of 26 - 28 degrees C, an overhead radiant warmer during induction and preparation, warming blanket, heated, humidified inspired gases, and wrapping of exposed skin

C. Intraoperative fluid therapy: Maintenance fluid 4 ml/kg/h of 10% dextrose in LR solution and replace fluid deficits.

VIII. Special Intraoperative Measures

Anesthesiologist should observe the surgical field. Surgeon must be alerted to maneuvers that result in impairment of ventilation. Intermittent suction of endotracheal tube to prevent accumulation of tracheal secretions.

IX. Extubation Plan

1. Most infants can be extubated after repair of the TEF.

2. The action of the nondepolarizing muscle relaxant is reversed with atropine and neostigmine.

3. Criteria for extubation include: normal neuromuscular function as evidenced by sustained clonus of extremities, regular respiratory pattern, eye opening

4. Infant not satisfying criteria for extubation should be returned to the NICU for continued controlled ventilation and intensive monitoring.

5. Tracheomalacia or a defective tracheal wall at the fistula site can cause collapse of the airway, requiring endotracheal tube reinsertion.

a. In infants with these conditions, ET tube should be left in place and controlled ventilation continued for 24-48 hours. Postoperative ventilation is also planned for babies whose lungs were contaminated and those who have problems associated with prematurity.

X. Early Postoperative Care - Pain Management

1. Study (Lippman et al, 1976) stated that newborn infants did not appreciate pain the way older children and adults do and therefore do not require anesthetic or analgesic agents. Studies have since shown that pain, such as circumcision without analgesia, is felt by the newborn and causes prolonged disruption of behavioral development (Dixon and others, 1984).

2. Anand et al (1987) reported that premature infants had marked endocrine responses to surgically induced stress.

3. Preventing post-op pain (taken from American Academy of Pediatrics Guidelines)

A. Regional (Conduction) Analgesia

i. Indwelling epidural catheters threaded from the caudal or lumbar region may provide analgesia for procedures above the diaphragm.

ii. In neonates, intermittent administration of dilute local anesthetics with low-dose extradural opioids, such as fentanyl, offers less potential for the toxic effects of drugs than continuous infusion techniques with either drug alone. Careful calculation of doses is mandatory to avoid toxic effects for all uses of local anesthetic agents and for all other medications used to provide analgesia, sedation, and relief of anxiety. iii. Continuous caudal or epidural blockade may be administered for several days postoperatively by using a continuous infusion pump.

B. Opioids

i. There are insufficient data to recommend one opioid over another. In general, meperidine is not recommended for prolonged administration owing to the possibility of the accumulation of toxic metabolites capable of causing seizures.

C. Nonsteroidal Anti-inflammatory Drugs

i. Generally, this category of medications is used to treat less intense pain and as an adjunct to reduce the total dose of more potent analgesics, such as opioids.

*This is a handout for a presentation I gave in my Anesthesiology rotation in July 2001. I welcome any corrections from anesthesiology residents or physicians and will update this page with any corrections.