Pneumoperitoneum Explained

Pneumoperitoneum

Pneumoperitoneum is pneumatosis (abnormal presence of air or other gas) in the peritoneal cavity, a potential space within the abdominal cavity. The most common cause is a perforated abdominal organ, generally from a perforated peptic ulcer, although any part of the bowel may perforate from a benign ulcer, tumor or abdominal trauma. A perforated appendix seldom causes a pneumoperitoneum.

Spontaneous pneumoperitoneum is a rare case that is not caused by an abdominal organ rupture. This is also called an idiopathic spontaneous pneumoperitoneum when the cause is not known.

In the mid-twentieth century, an "artificial" pneumoperitoneum was sometimes intentionally administered as a treatment for a hiatal hernia. This was achieved by insufflating the abdomen with carbon dioxide. The practice is currently used by surgical teams in order to aid in performing laparoscopic surgery.

Causes

Perforated duodenal ulcer – The most common cause of rupture in the abdomen. Especially of the anterior aspect of the first part of the duodenum.
Perforated peptic ulcer^[1]
Bowel obstruction^[2] ^[3]
Ruptured diverticulum^[4]
Penetrating trauma^[5]
Ruptured inflammatory bowel disease (e.g., megacolon)^[6]
Necrotising enterocolitis/pneumatosis coli^[7]
Bowel cancer^[8]
Ischemic bowel^[9] ^[10] ^[11]
Steroids
After laparotomy
After laparoscopy
Breakdown of a surgical anastomosis
Bowel injury after endoscopy
Peritoneal dialysis (PD), although the prevalence of pneumoperitoneum is estimated to be less than 4% among people with PD in a more recent study in the United Kingdom.^[12]
Vaginal insufflation (air enters via the fallopian tubes; e.g., water-skiing,^[13] oral sex^[14] ^[15])
Colonic or peritoneal infection
From chest (e.g., bronchopleural fistula)
Non-invasive PAP (positive airway pressure) can force air down duodenum as well as down trachea.

Spontaneous pneumoperitoneum

A spontaneous pneumoperitoneum is a rare case that is not caused by an abdominal organ rupture. This is also called an idiopathic spontaneous pneumoperitoneum when the cause is not known.^[16] Causes of a spontaneous pneumoperitoneum, with no peritonitis include a barotrauma due to mechanical ventilation, and a tracheal rupture following an emergency intubation. In the ventilation case, air had passed from the chest into the abdominal cavity through the diaphragm. In the tracheal rupture air had passed along the great vessels.^[17]

Diagnosis

When present, pneumoperitoneum can often be seen on projectional radiography, but small amounts are often missed, and CT scan is nowadays regarded as a criterion standard in the assessment of a pneumoperitoneum.^[18] CT can visualize quantities as small as 5 cm³ of air or gas.

Signs that can be seen on projectional radiography are shown below:

The double wall sign marks the presence of air on both sides of the intestine.^[19] However, a false double wall sign can result from two loops of bowel being in contact with one another.^[20] The sign is named after Leo George Rigler.^[21] It is not the same as Rigler's triad.

The football sign is when the abdomen appears as a large oval radiolucency reminiscent of an American football on a supine projectional radiograph.^[22] The football sign is most frequently seen in infants with spontaneous or iatrogenic gastric perforation causing pneumoperitoneum. It is also seen in bowel obstruction with secondary perforation, as in Hirschprung disease, midgut volvulus, meconium ileus and intestinal atresia. Iatrogenic causes like endoscopic perforation may also give football sign.

The Cupola sign is seen when air is accumulated under the central tendon of the diaphragm.^[23]

Differential diagnosis

As differential diagnoses, a subphrenic abscess, bowel interposed between diaphragm and liver (Chilaiditi syndrome), and linear atelectasis at the base of the lungs can simulate free air under the diaphragm on a chest X-ray.

Treatment

Treatment depends on the cause of the condition.

Terminology

Pneumoperitoneum can be described as peritoneal emphysema,^[24] just as pneumomediastinum can be called mediastinal emphysema, but pneumoperitoneum is the usual name.

Notes and References

Web site: Peptic Ulcer Disease. The Lecturio Medical Concept Library . 10 August 2021.
Web site: Large Bowel Obstruction. The Lecturio Medical Concept Library . 10 August 2021.
Web site: Small Bowel Obstruction. The Lecturio Medical Concept Library . 10 August 2021.
Web site: diverticulum Definition of diverticulum in English by Lexico Dictionaries. https://web.archive.org/web/20190717154824/https://www.lexico.com/en/definition/diverticulum. dead. July 17, 2019. Lexico Dictionaries English. 2019-07-17.
Book: Stewart MG . Head, Face, and Neck Trauma: Comprehensive Management . Principles of ballistics and penetrating trauma . Stewart MG . 188–94. 2005. Thieme. 3-13-140331-4 . https://books.google.com/books?id=mOJpd-Sy1kgC&q=%22Penetrating+trauma%22&pg=PA195. 2008-06-12.
Web site: Megacolon. The Lecturio Medical Concept Library . 10 August 2021.
http://www.columbia.edu/itc/hs/medical/humandev/2004/Neonate2.pdf Necrotizing Enterocolitis
Web site: Colon Cancer Treatment (PDQ®). NCI. 29 June 2014. 2014-05-12. live. https://web.archive.org/web/20140705111552/http://www.cancer.gov/cancertopics/pdq/treatment/colon/Patient/page1/AllPages. July 5, 2014. mdy-all.
Higgins PD, Davis KJ, Laine L . Systematic review: the epidemiology of ischaemic colitis . Alimentary Pharmacology & Therapeutics . 19 . 7 . 729–38 . April 2004 . 15043513 . 10.1111/j.1365-2036.2004.01903.x . free . 9575677 . 2027.42/74164 .
Brandt LJ, Boley SJ . AGA technical review on intestinal ischemia. American Gastrointestinal Association . Gastroenterology . 118 . 5 . 954–68 . May 2000 . 10784596 . 10.1016/S0016-5085(00)70183-1 .
American Gastroenterological Association . American Gastroenterological Association Medical Position Statement: guidelines on intestinal ischemia . Gastroenterology . 118 . 5 . 951–3 . May 2000 . 10784595 . 10.1016/S0016-5085(00)70182-X . https://web.archive.org/web/20070927212511/http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=3069&nbr=2295 . 2007-09-27 . free .
Imran M, Bhat R, Anijeet H . Pneumoperitoneum in peritoneal dialysis patients; one centre's experience . NDT Plus . 4 . 2 . 120–3 . April 2011 . 25984130 . 4421564 . 10.1093/ndtplus/sfq208 .
Kizer KW . Medical hazards of the water skiing douche . Annals of Emergency Medicine . 9 . 5 . 268–9 . May 1980 . 7369581 . 10.1016/s0196-0644(80)80387-8 . Many injuries can result from water skiing accidents, but the water skiing "douche" is unique to this sport. Although generally causing only discomfort, significant trauma can result from the forceful entry of water into the various body orifices. .
Jacobs VR, Mundhenke C, Maass N, Hilpert F, Jonat W . Sexual activity as cause for non-surgical pneumoperitoneum . JSLS . 4 . 4 . 297–300 . Oct 2000 . 11051188 . 3113190 .
Cawich SO, Johnson PB, Williams E, Naraynsingh V . Non-surgical pneumoperitoneum after oro-genital intercourse . International Journal of Surgery Case Reports . 4 . 11 . 1048–51 . 25 Sep 2013 . 24121052 . 3825970 . 10.1016/j.ijscr.2013.08.022 .
Pfister J, Riedtmann-Klee HJ . [Idiopathic spontaneous pneumoperitoneum. Case discussion based on two cases, assessment procedure and therapy and review of the literature] . Helvetica Chirurgica Acta . 60 . 1–2 . 49–56 . September 1993 . 8226082 .
Gutkin Z, Iellin A, Meged S, Sorkine P, Geller E . Spontaneous pneumoperitoneum without peritonitis . International Surgery . 77 . 3 . 219–23 . July 1992 . 1399374 .
Pneumoperitoneum Imaging . Khan AN, Chandramohan M . Coombs BD, Gay SD . Emedicine, Medscape . WebMD LLC . 2017-12-06 .
Harkin DW, Blake G . Small bowel obstruction in a young adult . Postgraduate Medical Journal . 75 . 881 . 173–5 . March 1999 . 10448501 . 1741173 . 10.1136/pgmj.75.881.173 .
de Lacey G, Bloomberg T, Wignall BK . Pneumoperitoneum: the misleading double wall sign . Clinical Radiology . 28 . 4 . 445–8 . July 1977 . 872511 . 10.1016/s0009-9260(77)80161-x .
Hirsch M, Cortés C . El signo de Leo Rigler: doble pared en neumoperitoneo.. The sign of Leo Rigler: double pared in neumoperitoneo. . Spanish . Revista chilena de radiología . 2009 . 15 . 3 . 152–4 . 10.4067/S0717-93082009000300008 . free .
Rampton JW . The football sign . Radiology . 231 . 1 . 81–2 . April 2004 . 14990817 . 10.1148/radiol.2311011290 .
Sureka B, Bansal K, Arora A . Pneumoperitoneum: What to look for in a radiograph? . Journal of Family Medicine and Primary Care . 4 . 3 . 477–8 . 2015 . 26288798 . 4535122 . 10.4103/2249-4863.161369 . free .
Marian K, Monika K, Bartosz K . Spontaneous pneumoperitoneum in a patient after ventilation therapy . Polski Przeglad Chirurgiczny . 86 . 12 . 601–3 . March 2015 . 25803061 . 10.1515/pjs-2015-0008 .