Tracheoesophageal fistula and massive pneumoperitoneum after prolonged mechanical ventilation.

ABSTRACT. We describe a patient who had two unusual complications of prolonged mechanical ventilation--tracheoesophageal fistula and pneumoperitoneum--with a fatal outcome. Recurrent pulmonary aspirations and massive abdominal distention in the setting of longstanding artificial ventilation should alert the physician to these possibilities.

TRACHEOESOPHAGEAL FISTULA is one of the uncommon but serious sequelae of endotracheal intubation. We describe a patient who had this unusual complication along with a large pneumoperitoneum after prolonged mechanical ventilation through a tracheostomy tube.

CASE REPORT

A 66-year-old woman became unresponsive and had respiratory failure after intracerebral bleeding, necessitating mechanical ventilation through a tracheostomy tube for 4 months before admission to our hospital. She was being managed at a nursing home with assist-control ventilation at a tidal volume of 600 mL, rate of 12/min, and 40% of [FiO.sub.2]. She had been fed through a percutaneous endoscopic gastrostomy (PEG) tube for most of the previous 4 months. She also had a history of type 2 diabetes mellitus, hypertension, grade IV sacral decubitus, and urinary tract infection. She was sent to our hospital because of abdominal distention and fever.

She was unresponsive, but her vital signs were stable on admission. Bilateral rhonchi were heard on chest auscultation. The abdomen was distended and soft, without guarding or rigidity. Bowel sounds were normal. Arterial blood gas values were pH 7.53, [PO.sub.2] 82 mm Hg, and [PCO.sub.2] 23 mm Hg. Laboratory values were total leukocyte count 5,300/[micro]L (neutrophils 79%, lymphocytes 16%, monocytes 5%), hemoglobin 8.2 g/dL, platelet count 114,000/[micro]L, total protein 6.1 g/dL, albumin 2.7 g/dL, bilirubin 2.9 mg/dL, aspartate aminotransferase 212 U/L, alkaline phosphatase 58 U/L, amylase 209 U/L, and lipase 1,018 U/L. Urinalysis showed moderate leukocyte esterase, white blood cells 20 to 30/HPF and bacteria 4+. Chest radiograph showed bilateral infiltrates suggestive of aspiration pneumonia (Fig 1), and abdominal radiograph (kidneys, ureter, bladder) showed colonic distention. Ultrasonography of the abdomen was unremarkable.

Cultures grew multiple organisms from several sites. Urine culture grew Escherichia coli, sputum culture grew Pseudomonas aeruginosa, Providencia stuartii and E coli, and the culture from the sacral decubitus ulcer grew several organisms including methicillin-resistant Staphylococcus aureus. The patient was initially treated with clindamycin, gentamicin, and ceftazidime.

Multiple episodes of aspiration pneumonia followed, and the tube feedings were withheld. On restarting the tube feedings, a fall in the oxygen saturation was noted, and positive end-expiratory pressure (PEEP) of 2.5 cm [H.sub.2]O was added to the ventilatory cycles. Progressive abdominal distention subsequently developed, and artificially colored tube feeding given through the PEG tube was seen leaking around the tracheostomy tube. Barium series done through the PEG tube did not show any evidence of intestinal perforation or reflux into the esophagus. Flexible bronchoscopy done via the tracheostomy stoma showed a tracheoesophageal fistula of about 0.5 cm in diameter draining saliva at the level of the cuff of the tracheostomy tube. There was bruising on the anterior tracheal wall.

Because the patient was a poor surgical risk, surgical intervention was deferred. Abdominal distention progressed, and repeated plain abdominal radiography showed a large amount of air under the diaphragm (Fig 2). The poor prognosis was discussed with the relatives, a do-not-resuscitate order was posted, and the ventilator was disconnected. The patient continued to breathe spontaneously but died a few days later.

DISCUSSION

Previous reports of tracheoesophageal fistula occurring after prolonged mechanical ventilation implicated such factors as high endotracheal tube cuff pressure and subsequent reduced perfusion ad ischemic damage of the trachea as the underlying pathologic mechanisms. (12) Complications such as sepsis and poor general condition are believed to facilitate this potentially lethal complication. The most common site of tracheoesophageal fistula is at the level of the cuff of the endotracheal tube. (3,4) The long-term presence of a nasogastric tube in the esophagus just behind the trachea might contribute to pressure necrosis and increased chance of fistula formation. Although a previous report recommends PEG placement to avoid this complication, (5) our patient had tracheoesophageal fistula despite being fed through a PEG tube.

Pneumoperitoneum was also described as a rare complication of mechanical ventilation. Air is believed to dissect first through the perivascular tissues around the alveoli, then traveling through the mediastinum, paraesophageal tissue, and retroperitoneal space and finally reaching the adominal cavity. (6) We believe that air reaching the stomach through the tracheoesophageal fistula might have escaped around the PEG tube into the peritoneum in our patient. The barium study did not show any perforation. The air leak was probably accentuated by the addition of PEEP to the ventilatory cycles.

Massive gastric distention occurring in an intubated patient should alert the physician to the possibility of a tracheoesophageal fistula. (7) Surgical repair of the fistula offers some hope in low-risk patients. Patients with several comorbid conditions and requiring prolonged mechanical ventilation usually are not surgical candidates and die. (8,9) Our case illustrates the occurrence of two rare complications with lethal potential in the setting of long-term tracheal intubation and mechanical ventilation.

References

(1.) Abbey NC, Green DE, Cicale MJ: Massive tracheal necrosis complicating endotracheal intubation. Chest 1989; 95:459-460

(2.) Payne DK, Anderson WM, Romero MD, et al: Tracheoesophageal fistula formation in intubated patients. risk factors and treatment with high-frequency jet ventilation. Chest 1990; 98:161-164

(3.) Tan KK, Lee JK, Tan I, et al: Acquired tracheo-oesophageal fistula following tracheal intubation in a burned patient. Burns 1993; 19:360-361

(4.) Marzelle J, Dartevelle P, Khalife J, et al: Surgical management of acquired post-intuhation tracheo-oesophageal fistulas: 27 patients. Eur J Cardiothorac Surg 1989; 3:499-502

(5.) Iro H, Kachlik HG, weidenbecher M, et al: Significance of percutaneous endoscopically controlled gastrostomy in the prevention and therapy of esophagotracheal fistula following long term intubation. Anasth Intensivt her Notfalirned 1987; 22:283-286

(6.) Stringfield JT, Graham JP, watts CM, et al: Pneumoperitoneum. a complication of mechanical ventilation. JAMA 1976; 235:744-746

(7.) Tessler S, Kupfer Y, Lerman A, et al: Massive gastric distention in the intubated patient. a marker for a defective airway. Arch Intern Med 1990; 150:318-320

(8.) Mathisen DJ, Grillo HC, Wain JC, et al: Management of acquired nonmalignant tracheoesophageal fistula. Ann Thorac Surg 1991; 52:759-765

(9.) Giudicelli R, Sainty JM, Barthelemy A, et al: Nonmalignant esophagotracheal fistulas in adults. experience with 35 cases fin French]. Ann Chir 1992; 46:738-741

KEY POINTS

* Long-term mechanical ventilation can be associated with life-threatening complications.

* Our patient had a trachecesophageal fistula and massive pneumoperitoneum after mechanical ventilation. Recurrent episodes of aspiration pneumonia with hypoxia were clue to the diagnosis.

* Flexible bronchoscopy through the tracheostomy stoma confirmed the diagnosis.