Case Report

Pneumoperitoneum without peritonitis: a case report

Abstract

Pneumoperitoneum (PP), or air within the abdominal cavity, is frequently the harbinger of serious abdominal pathology and frequently represents visceral perforation. Most cases of PP ultimately need surgical exploration and intervention. In addition, cases of nonsurgical PP have also been described in the literature, and it has been suggested that these cases can be managed conservatively. This report documents the occurrence of incidentally found PP. However, it is unclear how often PP is found incidentally, and more importantly how to manage the patient with clinically unsuspected PP without peritoneal signs. Future research could help to better determine the incidence of unsuspected PP and to validate the various diagnostic and treatment algorithms in the literature.

Pneumoperitoneum (PP) is frequently the harbinger of serious abdominal pathology. Experience has shown that PP represents visceral perforation in 85% to 95% of all cases [1,2]. Although most of the cases of PP need surgical exploration and intervention, several past cases of non- surgical PP (NP) have also been described [1,3-9], and it is estimated that up to 15% of cases are a result of a process other than visceral perforation and do not require emergent surgery [1,2].

When abdominal pain is mild and there are no peritoneal signs, fever, or leukocytosis, nonsurgical cases of PP may be considered [2,4,5,8]. Otherwise, because of the morbidity and mortality associated with a delay in operative repair, it becomes difficult to avoid emergency surgical exploration to rule out visceral perforation.

A 73-year-old woman presented to the emergency department (ED) with a near-syncopal event, which was described as sudden onset of diaphoresis with severe nonradiating subxyphoid pain. By presentation to the ED, she stated that her symptoms had significantly improved. She also described a chronic, intermittent, burning Epigastric pain with radiation to her shoulders, which was dissimilar to her presenting complaint.

Her medical history included gastroesophageal reflux, emphysema, Abdominal aortic aneurysm, and a surgical history of a gastric-wrap procedure. Her medications included aspirin,

diphenhydramine, fenofibrate, hydrocodone/acetaminophen, hydroxyzine, and metoprolol. She had a 50-pack-year tobacco history, but no alcohol or illicit drug use. She denied any family medical history.

She was alert and oriented, in no apparent distress, with an oral temperature of 35.8?C, blood pressure of 139/76 mm/ Hg, pulse rate of 64 beats per minute, respirations of 16/min, and room air oxygen saturation of 98%. Her physical examination was unremarkable including a soft nontender abdomen, with no overt peritoneal signs.

Initial ED treatment included intravenous fluids and oral Mylanta with viscous lidocaine. Shortly after administration of the gastrointestinal cocktail, the patient was asymptomatic and asking for discharge. All laboratory tests, including liver function tests, amylase, and lipase, were within reference ranges, except for a leukocytosis of 20 300/uL. Chest radiography demonstrated a large PP suggestive of perfo- rated viscus (Fig. 1). In light of the benign Abdominal examination and absence of peritoneal signs, a noncontrast computed tomography was performed, which redemon- strated the PP.

The patient was emergently taken for laparoscopy to rule out perforated viscus. Intraoperatively, the stomach was distended and without evidence of perforation; there was no evidence of duodenum perforation; the bowel was inspected, and no leakage of colonic material was noted; copious irrigation was performed, with no succus material noted. The patient underwent esophagogastroduodenoscopy the follow- ing day, which revealed a hiatal hernia with thickened gastric folds and central ulcer, and duodenal erosions with healing ulcers; biopsies taken were negative for Helicobacter pylori. The patient was observed for 24 hours and discharged home the following day.

Although PP has been shown to represent visceral perforation in 85% to 95% of all cases [1,2], many cases of NP have also been described [1,3-7], and it is estimated that up to 5% to 15% of cases of PP may not require emergent surgery [1,2]. There have been numerous reports of NP in the literature, including many overviews of the etiology and causes of NP [2,4,6-9].

When PP is accompanied by generalized peritonitis, the decision for emergent surgical exploration is clear. Con- versely, NP is well described in the literature and may warrant consideration of conservative measures and observation for a select group of patients. However, the exact composition of

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841.e2 Case report

Fig. 1 Upright anteroposterior chest roentgenogram demonstrat- ing PP, which is highly suggestive of a perforated viscus.

patients who can be followed with observation remains unclear. In fact, most of the cases reported in the literature of NP were, in fact, explored surgically. What implication this has on the possibility of following these patients without any surgical management is unknown.

This report documents PP that was clinically unsuspected and discovered incidentally. Our case was ultimately explored surgically without any evidence to suggest the origin of the PP. According to the treatment algorithm offered by Rowe et al [9], this patient might have been followed by clinical observation (+-Diagnostic peritoneal lavage, contrast examination, and endoscopy). Most sources recommend that if a patient is afebrile, without signs of peritonitis, and with a normal white blood cell count, then conservative management is indicated [2,4,5,8]. In addition, several diagnostic algorithms for evaluation and manage- ment of PP have been described [3,9,10]; however, to our knowledge, there has not been clinical validation or data to support their use as clinical rules.

At present, the prevalence of incidentally found and unsuspected PP is unknown. Further research is needed to determine the prevalence and composition of patients with unsuspected PP. In addition, further investigation into the outcomes of true conservative observation of NP might better identify those patients who can be safely observed and to validate the clinical algorithms [3,9,10] that exist in the literature for evaluation and treatment of PP. Conservative management of NP might help avoid negative surgical exploration and spare the patient the added expense and complications of a possibly avoidable procedure.

Marc E. Breen MD Marc Dorfman MD Shu B. Chan MD, MS

Emergency Medicine Residency Program Resurrection Medical Center Chicago, IL 60631, USA

E-mail address: [email protected] doi:10.1016/j.ajem.2008.01.040

References

1. Omori H, Asahi H, Inoue Y, Irinoda T, Saito K. Pneumoperitoneum without perforation of the gastrointestinal tract. Dig Surg 2003;20:334-8.
2. Mularski RA, Sippel JM, Osborne ML. Pneumoperitoneum: a review of nonsurgical causes. Crit Care Med 2000;28(7):2638-44.
3. Karaman A, Demirbilek S, Akin M, Gurunluoglu K, Irsi C. Does pneumoperitoneum always require laparotomy? Report of six cases and review of the literature. Pediatr Surg Int 2005;21(10):819-24.
4. Mularski RA, Ciccolo ML, Rappaport WD. Nonsurgical causes of pneumoperitoneum. West J Med 1999;170:41-6.
5. Mezghebe HM, Leffall LD, Siram SM, Syphax B. Asymptomatic pneumoperitoneum diagnostic and therapeutic dilemmas. Am Surg 1994;60(9):691-4.
6. Gutkin Z, Iellin A, Meged S, Sorkine P, Geller E. Spontaneous pneumoperitoneum without peritonitis. Int Surg 1992;77:219-22.
7. Van Gelder HM, Allen KB, Renz B, Sherman R. Spontaneous pneumoperitoneum: a surgical dilemma. Am Surg 1991;57(3):151-6.
8. Williams NM, Watkin DF. Spontaneous pneumoperitoneum and other nonsurgical causes of intraperitoneal free gas. Postgrad Med J 1997;73 (863):531-7.
9. Rowe NM, Kahn FB, Acinapura AJ, Cunningham JN. Nonsurgical pneumoperitoneum: a case report and a review. Am Surg 1998;64: 313-22.
10. Hoover EL, Cole GD, Mitchell LS, Adams CZ, Hassett J. Avoiding laparotomy in nonsurgical pneumoperitoneum. Am J Surg 1992;164: 99-103.