Nonsurgical pneumoperitoneum

Benign pneumoperitoneum in a neonate receiving positive pressure ventilation: A case report and clinical insights

The presence of air in the peritoneal cavity demonstrated radiographically as the crescent of air under the diaphragm is termed pneumoperitoneum. The causative agents may be divided into spontaneous, traumatic, iatrogenic, and miscellaneous. The majority (∼ 90%) of cases are attributed to hollow viscus perforation which requires immediate surgical attention. Neonatal pneumoperitoneum is a surgical emergency unless proven otherwise. A distinct entity termed benign pneumoperitoneum occurs in the absence of clinical and paraclinical features of peritonitis. Benign pneumoperitoneum may be caused by various thoracic, abdominal, and gynecological conditions. In neonates with respiratory distress pneumoperitoneum is a frequent association especially when treated with mechanical ventilation. The air leak phenomenon leads to air tracking from the ruptured alveoli along the interstitium to the mediastinum then to the retroperitoneum and ultimately into the peritoneal cavity. Such patients usually do not require surgical intervention and are managed conservatively. Knowledge of the existence of benign pneumoperitoneum helps to avoid unnecessary surgery thereby reducing operative morbidity and mortality.

Gastrointestinal tract perforation: CT diagnosis of presence, site, and cause

Gastrointestinal tract perforation is an emergent condition that requires prompt surgery. Diagnosis largely depends on imaging examinations, and correct diagnosis of the presence, level, and cause of perforation is essential for appropriate management and surgical planning. Plain radiography remains the first imaging study and may be followed by intraluminal contrast examination; however, the high clinical efficacy of computed tomographic examination in this field has been well recognized. The advent of spiral and multidetector-row computed tomographic scanners has enabled examination of the entire abdomen in a single breath-hold by using thin-slice sections that allow precise assessment of pathology in the alimentary tract. Extraluminal air that is too small to be detected by conventional radiography can be demonstrated by computed tomography. Indirect findings of bowel perforation such as phlegmon, abscess, peritoneal fluid, or an extraluminal foreign body can also be demonstrated. Gastrointestinal mural pathology and associated adjacent inflammation are precisely assessed with thin-section images and multiplanar reformations that aid in the assessment of the site and cause of perforation.

Pneumoperitoneum in peritoneal dialysis patients

There has been recent controversy regarding the clinical significance of pneumoperitoneum in patients undergoing peritoneal dialysis. The incidence of pneumoperitoneum has been estimated to be 21.2% to 33.7% in prior studies of peritoneal dialysis patients. Of the peritoneal dialysis patients with pneumoperitoneum, only a small percentage (5.9% to 14.3%) had documented visceral perforations. The controversy arises in that anywhere from 20% to 100% of peritoneal dialysis patients with pneumoperitoneum and peritonitis had visceral perforation, and 32.4% to 57.1% of chronic ambulatory peritoneal dialysis patients had asymptomatic pneumoperitoneum of unknown etiology. These disparate incidences made clinical interpretation of pneumoperitoneum difficult. In addition, prior study result disagreed as to the usefulness of the extent of pneumoperitoneum in predicting visceral perforation. We retrospectively reviewed 694 chest x-ray film and acute abdominal series reports from 1982 to 1993 in 75 peritoneal dialysis patients, with 9.3 +/- 1.3 (mean +/- SEM) x-ray films per patient. The reports were confirmed by reviewing 363 x-ray films (52%). Eight patients (10.7%) had 10 episodes of pneumoperitoneum. Six of these eight patients had asymptomatic pneumoperitoneum from a known etiology: four had undergone abdominal surgery for catheter placement the prior week and two had catheter manipulation immediately preceding the x-ray. One patient had three episodes of pneumoperitoneum: one after catheter placement and two not associated with a known etiology for pneumoperitoneum while on the cycler. One patient had a surgically confirmed colonic perforation with a large pneumoperitoneum and peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence and significance of pneumoperitoneum in continuous ambulatory peritoneal dialysis

In a retrospective study we reviewed upright chest x-ray films of 101 continuous ambulatory peritoneal dialysis (CAPD) patients to determine the incidence and significance of free subdiaphragmal air. A pneumoperitoneum (PP) was diagnosed if a minimal shadow of free air was detected under the diaphragm. The amount of free air was determined by measuring the height and width of the subdiaphragmal air shadow. Of all CAPD patients, 33.6% (34 of 101) had at least one occurrence of PP. Thirteen of these 34 patients (38.2%) were diagnosed within 30 days after catheter implantation, 10 patients (29.5%) acquired a PP during an episode of peritonitis, and in 11 patients (32.4%) no additional risk factor could be determined. Patients radiographed within 30 days after catheter implantation showed a statistically significant higher incidence of PP compared with the same patients radiographed later (22% v 10%; P < 0.05). The incidence of PP in CAPD patients suffering from peritonitis (33%) was significantly higher than in patients without peritonitis (10%; P < 0.001). The amount of free air did not differ statistically significantly between the investigated groups. Only two patients with PP and peritonitis had surgically confirmed visceral perforation. Therefore, the main reason for PP seemed to be handling faults during CAPD bag exchange. There was no correlation between the organisms causing peritonitis and PP or the CAPD connector system and PP. In conclusion, a PP occurs in approximately one third of all CAPD patients and a visceral perforation cannot be diagnosed by the occurrence and amount of free subdiaphragmal air.

Abnormal intraabdominal gas collections visualized on computed tomography: a clinical and experimental study

Abnormal intraabdominal gas collections visualized on CT scans during a 1-year period were reviewed. There were 34 collections in 29 patients. Sixty-two percent of these abnormalities were noninfectious and iatrogenic in origin, usually a direct result of procedures such as surgery, diagnostic tests, and needle or tube placement. Infections/abscesses (18%), hernias (15%), and gastrointestinal perforations (6%) produced the other abnormal gas collections. In the experimental animal study, gas collections as small as 5cc could be visualized on CT images. Collections of up to 20cc were visible for similar periods of time on both CT scans and conventional radiographs. It is concluded that most abnormally placed gas collections seen on CT are iatrogenic and that CT scans are very sensitive for the detection of such collections.