Selective Use of Ultrasonography for the Detection of Pneumoperitoneum

Abstract

Objective: Whether ultrasonography is superior to plain radiography for the detection of pneumoperitoneum is unknown. The goal of this study was to determine the value of ultrasonography for the detection of pneumoperitoneum. Methods: One hundred thirty-two patients with suspected hollow-organ perforation were prospectively selected for study. All 132 patients received ultrasonography, upright chest radiography, and left lateral decubitus abdominal radiography examinations. The diagnostic accuracies of chest and abdominal radiographs for the detection of pneumoperitoneum were compared with corresponding values from ultrasonography. Results: Of the 125 patients who underwent laparotomy, 121 patients had hollow-organ perforation, three patients had perforated appendicitis, and one patient had acute cholecystitis. For the diagnosis of pneumoperitoneum, ultrasonography demonstrated a sensitivity of 93%, a specificity of 64%, a positive predictive value of 97%, a negative predictive value of 44%, and an accuracy of 90%. Plain radiography revealed a sensitivity of 79%, a specificity of 64%, a positive predictive value of 96%, a negative predictive value of 21%, and an accuracy of 77%. Conclusions: Ultrasonography is a more sensitive diagnosing modality than plain radiography for the diagnosis of pneumoperitoneum. The authors suggest that ultrasonography was a useful diagnostic modality when plain radiographs failed to reveal pneumoperitoneum among patients with suspected hollow-organ perforation. Key words: hollow-organ perforation; free air; pneumoperitoneum; ultrasonography. ACADEMIC EMERGENCY MEDICINE 2002; 9:643-645. Pneumoperitoneum most commonly results from a perforated hollow viscus, or a gas-forming intraabdominal or retroperitoneal abscess. Upright chest radiography using a horizontal x-ray beam is a standard method in the detection of pneumoperitoneum.1 Plain radiography can demonstrate 55% to 85% of patients with pneumoperitoneum. 2,3However, diagnosis based on this method has practical limitations. Because many patients are too sick or debilitated to stand for chest radiographic examinations, a left lateral decubitus (LLD) abdominal radiograph may also be used to attempt to demonstrate pneumoperitoneum.Ultrasonography has been widely used in the evaluation of the patient with an acute abdomen. 4,5 Although ultrasonography can detect pneumoperitoneum, the relative sensitivity and specificity of ultrasonography for this task remain unclear. We hypothesized that ultrasonography is superior to plain radiography for the detection of pneumoperitoneum. This study was done to compare plain radiography with ultrasonography for the diagnosis of pneumoperitoneum. METHODSStudy Design. This was a prospective clinical investigation of the accuracy of ultrasound in the detection of pneumoperitoneum.Study Setting and Population. From March 1996 to March 1999, 132 patients with suspected holloworgan perforation were prospectively included in this study. Suspected hollow-organ perforation was defined as peptic ...

Effectiveness of plain radiography in diagnosing hollow viscus perforation: study of 1,723 patients of perforation peritonitis

“…With the advent of newer diagnostic modalities, the value of plain radiograph is overshadowed to detect the pneumoperitoneum in current literature. A number of researches have shown better sensitivity and specificity of ultrasonography (USG) [12][13][14][15] and computed tomography scan [16][17][18] in detecting pneumoperitoneum along with their site of perforation in some cases.…”

Diagnostic Laparoscopy in the Intensive Care Unit

“…It has been shown by some studies to be more accurate for detecting pneumoperitoneum than a plain radiograph. 26,27 The US is also a very sensitive test for the detection of free abdominal fluid. Although the trauma literature suggests a high correlation between the presence of free fluid and surgical pathology, 28,29 critically ill patients often have small amounts of ascites that are readily detectable with US but do not need surgical intervention.…”

Pneumoperitoneum

“…Specificity was similar for both tests (1,2). Free air on ultrasound is usually identified in the intraperitoneal space between the chest wall and the liver, and is recognized by the presence of ring-down artifact or comet-tail artifact.…”