PP patients may have a medical history of gastrointestinal disease or recent surgery, and corresponding anamnestic data should be considered when interpreting clinical signs, before deciding on a therapeutic approach. While the presence of free air in the peritoneal cavity cannot be diagnosed during a general examination, abdominal distension, intense pain, rigidity and rebound tenderness are indicative of peritonitis and possibly GIT perforation. In these cases, bowel sounds are usually absent and patients present constitutive symptoms like fever, volume depletion, hypotension and tachycardia; they may suffer from nausea and vomiting. Furthermore, patients may report not to have passed stools or gasses since symptom onset [1].

In contrast, postoperative PP doesn't generally cause major complaints, and mild to moderate abdominal distension and pain may merely result from the underlying disease or surgery. This condition should normalize within a week.

• Fever

  The patient presented with chronic pain abdomen and fever which later evolved to acute abdomen during the course of hospital stay. [ncbi.nlm.nih.gov]

• Developmental Delay

  Four children had global developmental delay and were percutaneous endoscopic gastrostomy or jejunostomy fed, one was immunocompromised (acute lymphoblastic leukemia). The others had encephalitis and eosinophilic gastroenteritis. [ncbi.nlm.nih.gov]

• Chest Wall Pain

  To our knowledge, we present the first case of a non-iatrogenic and traumatic simultaneous pneumoperitoneum and pneumomediastinum in a previously independent 91-year-old man who presented to hospital with back and chest wall pain following mechanical [ncbi.nlm.nih.gov]

• Abdominal Girth Increased

  Report of a Case A 63-year-old man with a long-standing history of alcohol abuse was admitted to the hospital in September 1980 with increasing abdominal girth, increasing [jamanetwork.com]

• Peritoneal Disease

  Medium hochladen Wikipedia Ist ein(e) Krankheit Unterklasse von peritoneal disease, Emphysem Normdatei Q163469 Reasonator Scholia Statistik Unterkategorien Es werden 2 von insgesamt 2 Unterkategorien in dieser Kategorie angezeigt: In Klammern die Anzahl [commons.wikimedia.org]

• Hyperactive Bowel Sounds

  Physical examination revealed all patients with relaxed abdominal wall except 1 patient with abdominal distension had slight muscle stiffness and hyperactive bowel sounds. Abdominal X-ray suggested free air under the diaphragm in all cases. [ncbi.nlm.nih.gov]

• Weak Pulse

  The patient's condition deteriorated, as he became confused and pale with rapid weak pulse and hypotension. His abdomen became barrel-shaped, tender, and tympanic to percussion. [ncbi.nlm.nih.gov]

• Petechiae

  An emergency laparotomy showed petechia along the anterior gastric wall, haematoma of lesser omentum but showed no evidence of gastrointestinal perforation or organ injury. [ncbi.nlm.nih.gov]

• Otorrhagia

  We present the first reported case of bilateral spontaneous otorrhagia associated with robotically assisted laparoscopic surgery involving a reduced Trendelenburg position and low-pressure pneumoperitoneum. [ncbi.nlm.nih.gov]

• Renal Injury

  A new marker for the early detection of renal injury, neutrophil gelatinase-associated lipocalin (NGAL), has been shown to increase in various conditions that affect renal function. [ncbi.nlm.nih.gov]

• Hyperactivity

  Physical examination revealed all patients with relaxed abdominal wall except 1 patient with abdominal distension had slight muscle stiffness and hyperactive bowel sounds. Abdominal X-ray suggested free air under the diaphragm in all cases. [ncbi.nlm.nih.gov]

• Lethargy

  Hirschsprung's disease is a congenital colonic aganglionosis, usually presented as inability or difficulty in passing of meconium, chronic and persistent obstipation, maleficent feeding, vomiting, distension and lethargy. [ncbi.nlm.nih.gov]

Abdominal imaging is the mainstay of PP diagnosis. To this effect, plain radiography has long since been the technique of first choice. Very small volumes of free gas - as little as 1 ml - can be observed in images obtained by means of this technique. Upright, anterior-posterior chest radiographs are most suited and typically depict a translucent, crescent area below the diaphragm [7]. The Rigler's sign may be observed; it corresponds to the display of both sides of the intestinal wall [8]. Similarly, the telltale triangle sign implies PP: A triangle of gas may be visualized between three adjoining bowel loops, or two loops and the peritoneal wall [9]. In emergency settings, radiographs may be obtained from a patient in the supine decubitus position.

Computed tomography scans may be reserved for doubtful cases. Its superior spatial resolution is helpful to localize minimum quantities of free gas and to distinguish PP from pseudo- pneumoperitoneum. The latter term refers to any condition that mimics PP, such as pneumatosis cystoides intestinalis and interposition of viscera [10].

• Pneumoperitoneum

  […] selected to be involved in the study, and labeled as surgical pneumoperitoneum or pneumoperitoneum-induced peritonitis. [dx.doi.org]

  […] detection of pneumoperitoneum. [ncbi.nlm.nih.gov]

• Gastric Lesion

  lesion 7, 8 or to the pneumatic perforation of a gastric or duodenal ulcer. [ncbi.nlm.nih.gov]

• Ischemic Changes

  Therefore neoplastic cells were found in 8/131 cases, on the other hand 13/131 cases (9.9%) had evident ischemic changes and vasculopathy. [Table 3] 4. [dx.doi.org]

The term pneumoperitoneum (PP) refers to the presence of gas within the peritoneal cavity. Most commonly, this gas originates from the gastrointestinal tract (GIT) and thus indicates a disruption of its physical integrity. Any part of the GIT may be affected and PP may complicate diseases like gastric ulcer, mesenteric infarction, toxic megacolon, and abdominal cancer. Interestingly, perforated appendicitis seldom entails PP [1]. Rarely, emphysematous inflammation of abdominal organs may give rise to PP [2]. PP may also occur after penetrating abdominal trauma or abdominal surgery. Postoperative PP may or may not indicate leaking anastomoses, since air may be introduced into the peritoneal cavity during surgery [3]. Indeed, PP may be induced intentionally by insufflation of carbon dioxide or helium to facilitate laparoscopic procedures and intraperitoneal chemotherapy [4]. Although such a measure may be contraindicated in patients suffering from cardiorespiratory disorders and increased intracranial pressure [5] [6], the presence of gas within the abdominal cavity per se is not detrimental. However, pathological PP as described above is virtually always associated with the presence of pathogens and toxins in the peritoneal cavity. Therefore, it is an indicator of a life-threatening situation that requires emergency surgery.

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3. Lee CH, Kim JH, Lee MR. Postoperative pneumoperitoneum: guilty or not guilty? J Korean Surg Soc. 2012;82(4):227-231.
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7. Pinto A, Miele V, Schilliro ML, et al. Spectrum of Signs of Pneumoperitoneum. Semin Ultrasound CT MR. 2016;37(1):3-9.
8. Rigler LG. Spontaneous pneumoperitoneum: A roentgenologic sign found in the supine position. Radiology. 1941;37:604–607.
9. Huang MY, Chang WH. Images in clinical medicine. Telltale triangle of pneumoperitoneum. N Engl J Med. 2009;361(1):73.
10. Lo BM. Radiographic look-alikes: distinguishing between pneumoperitoneum and pseudopneumoperitoneum. J Emerg Med. 2010;38(1):36-39.