Pneumatosis Intestinalis in Pediatric Acquired Immunodeficiency Syndrome

Pneumatosis intestinalis is an increasingly reported phenomenon in patients with AIDS. There are several case reports in the adult literature including a case series of six patients.1-4 To date there have only been four cases of pneumatosis intestinalis reported in children with AIDS.5, 6 Here we review the cases of three children seen at Duke University Medical Center (DUMC) who developed pneumatosis intestinalis in the setting of AIDS. Because of the small number of reported cases there are no standard guidelines for management. Case 1. JW is a 10-year-old black male child with congenitally acquired HIV, admitted to DUMC in July, 1994, with a 3-day history of nausea, emesis, anorexia, abdominal pain and fatigue. He had no recent fevers but did have a loose stool during his evaluation in the emergency department. JW's chronic medical problems included disseminated Mycobacterium avium complex infection, recurrent herpes labialis, wasting and neutropenia. His medications at that time were zidovudine, didanosine, rifampin, ciprofloxacin, clarithromycin, trimethoprim-sulfamethoxazole and acyclovir. On admission JW had a temperature of 36.5°C with normal vital signs. The examination was unremarkable except for his abdomen, which was soft and diffusely tender, particularly in the left upper and left lower quadrants. Normal bowel sounds were present, but rebound tenderness and guarding were not detected. His liver edge was 2 cm below the right costal margin. The rectal examination was normal and there was no occult blood in the stool. Abdominal radiographs revealed profound pneumatosis of the colon but no free intraperitoneal gas. Laboratory studies revealed normal serum electrolytes and normal values for hemoglobin and platelet count. The white blood cell count was elevated at 15 300 cells/μl, with 61% neutrophils, 23% band forms and 5% lymphocytes. The absolute CD4 lymphocyte count was 16 cells/μl. Stool studies revealed no evidence of Salmonella, Shigella, Campylobacter, parasites or Clostridium difficile toxin. On admission JW was managed with bowel rest, hyperalimentation, ampicillin, gentamicin and metronidazole. His oral medications were discontinued. Four days after admission JW's abdominal radiographs showed complete resolution of pneumatosis and he started taking clear liquids by mouth. On the eighth day of hospitalization antibiotics were discontinued without complication, and on the ninth day he was sent home. Case 2. AR is an 11-year-old female child with congenitally acquired HIV. She was admitted to DUMC in March, 1997, with a 7-day history of crampy abdominal pain, intermittent emesis, anorexia, fatigue and her usual three to four loose stools each day. She had no recent fevers. The chronic medical problems included wasting, chronic diarrhea, chronic cryptosporidiosis and molluscum contagiosum. Her medications were ACTG Study Medication 1592, paromomycin, trimethoprim-sulfamethoxazole, acyclovir and loperamide. On admission her temperature was 37.1°C and she had mild tachycardia. AR's examination was unremarkable except for a moderately distended abdomen, which was soft and nontender, with normal bowel sounds. No rebound tenderness or guarding was present and the liver and spleen were of normal size. Abdominal radiographs showed profound pneumatosis, predominantly in the ascending colon, and free intraperitoneal gas (Fig. 1). Laboratory evaluation revealed normal serum electrolytes, a hemoglobin of 8.8 g/dl, platelet count of 467 000 cells/μl and a white blood cell count of 3500 cells/μl, with 49% neutrophils, 11% band forms, 16% lymphocytes and 8% eosinophils. The absolute CD4 lymphocyte count was 8 cells/μl. Stool studies revealed no evidence of Salmonella, Shigella, Campylobacter, Clostridium difficile toxin or enteric viruses by electron microscopy. The Cryptosporidium load in her stool was moderate.Fig. 1: Plain abdominal radiograph demonstrates pneumatosis intestinalis, predominating in the right colon and free intraperitoneal gas under the diaphragm.On admission AR began bowel rest, hyperalimentation, ampicillin, gentamicin and metronidazole. All oral medications were stopped. Intraoperative findings during exploratory laparotomy were free intraperitoneal gas, pneumatosis intestinalis and a well-perfused bowel without evidence of focal lesions, perforation or leakage of enteric contents. AR had an uncomplicated postoperative course. Two weeks after surgery pneumatosis had resolved and antibiotics were discontinued. She continued to have difficulty tolerating even small amounts of enteric tube feedings without emesis and was managed at home with hyperalimentation. Case 3. KH is a 7-year-old black female child with congenitally acquired HIV. She was admitted to DUMC in October, 1997, with a 2-day history of chest, back and abdominal pain, sore throat, cough and fever. She had no recent diarrhea or emesis. Her chronic medical problems include wasting and M. avium complex infection. Her medications were stavudine, nevirapine, nelfinavir, ethambutol, fluconazole, amikacin and ursodiol. On admission she had a temperature of 38.4°C, mild tachypnea and tachycardia. The examination was remarkable for rales in her lower lung fields and hepatomegaly. Her abdomen was mildly distended, but soft nontender with normal bowel sounds. Initial laboratory studies revealed a lactic acidosis with a blood pH of 7.11 and a lactic acid of 7.5 mmol/l. Other serum electrolytes were normal except for a bicarbonate of 7 meq/l. The white blood cell count was 2700 cells/μl with 57% neutrophils, 16% band forms, 18% lymphocytes and a CD4 count of 126 cells/μl. She was mildly anemic with a normal platelet count. Liver enzyme concentrations were moderately elevated with an aspartate aminotransferase of 166 units/l, alanine aminotransferase 142 units/l, alkaline phosphatase 468 units/l and bilirubin 3.4 mg/dl. Electron microscopic results showed no evidence of active Giardia, Cryptosporidium, Epstein-Barr virus, cytomegalovirus, hepatitis A, B, or C or enteric viruses. Abdominal radiographs showed moderate pneumatosis in the small bowel of the left abdomen, without free intraperitoneal gas. KH was managed with bowel rest, hyperalimentation and metronidazole. Radiographic evidence of pneumatosis resolved during the next 24 h. She remained clinically stable despite a persistent lactic acidosis and went home on the fifth hospital day. Discussion. Pneumatosis intestinalis is an uncommon, but recognized complication in children with AIDS, with seven cases reported since 1990, including the three reported here. The etiology of this problem remains unclear. The paucity of reported cases and limited knowledge of the disease process complicate the management of these children. Free intraperitoneal gas is especially concerning for intestinal rupture, and it is unclear whether exploratory laparotomy is warranted for this finding. The cause of pneumatosis intestinalis in children with AIDS is not known. In the four previously reported cases microorganisms recovered included Cryptosporidium, rotavirus, cytomegalovirus, Pseudomonas and C. difficile.5, 6 In the first and third cases reported here no common pathogens were recovered. In Case 2 no pathogens were recovered except for her chronic Cryptosporidium in moderate quantities. In the adults reported, several different microorganisms were recovered, but no predominant pathogen was identified.1-4 Causality is difficult to prove in AIDS patients with frequent infections and prolonged shedding periods. Pneumatosis intestinalis is a fairly uncommon finding in pediatrics except in neonates with necrotizing enterocolitis and bowel ischemia, which frequently requires small bowel resection. Adult patients with pneumatosis intestinalis and AIDS have not shown evidence of intestinal ischemia or perforation, even in patients with free intraperitoneal gas. Case 2 is the first report of free intraperitoneal gas being associated with pneumatosis intestinalis in a child with AIDS. Unlike the previously reported children she underwent exploratory laparotomy because of concern for intestinal perforation. Intraoperatively there was no evidence of bowel ischemia and the free intraperitoneal gas probably leaked from a pneumatic cyst without compromise of the lumen. The appropriate management of pneumatosis intestinalis in children with AIDS is unclear, especially in the setting of free intraperitoneal gas. Kenji M. Cunnion, M.D., M.P.H.