DISCUSSION
The diagnosis of emphysematous cystitis was confirmed based on these scans. This rare entity is caused by an infection that produces pockets of air in and around the bladder wall. The infection can be fungal or bacterial, the most common cause being Escherichia coli.1 The infection can enter the GU tract as a result of other surrounding infections, trauma, fistulas from radiation therapy, rectal carcinoma, diverticular disease, inflammatory bowel disease, or instrument insertion.1 Emphysematous cystitis commonly manifests in females who are immunocompromised; in persons with diabetes mellitus, previous recurrent urinary tract infections, urinary stasis, or neurogenic bladder; and in transplant recipients.2 Patients commonly complain of irritative symptoms, abdominal pain, and pneumaturia. This last condition is highly suggestive of emphysematous cystitis, but the history is hard to elicit. If left untreated or if treatment is significantly delayed, the disease can progress into emphysematous pyelonephritis, emphysematous pyelitis, and gas-forming renal abscess.
Radiographic findings may provide the first and only diagnostic clue. CT allows the practitioner to appreciate the extent of the disease and, along with an appropriate history and physical examination, constitutes the best diagnostic test. CT produces cross-sectional views of the internal structures of the patient, giving far better information than a conventional radiograph. CT can be used with or without contrast medium. Contrast medium is x-ray dense and emphasizes blood vessels and other fluid-filled structures. In the evaluation of the urinary bladder, the use of contrast medium helps distinguish the urine-filled ureters and bladder from the mucosal wall, as seen in Figure 1B. In this patient, the presence of air in the bladder wall confirmed the diagnosis of emphysematous cystitis.
CT scans also can be reformatted
to project different cross sections of the body. As seen in Figure 2 and Figure 3, coronal cross sections show different portions of the urinary bladder versus sagittal cross sections of the bladder, allowing the practitioner to better visualize the progression of the infection and determine that it has not involved surrounding structures. CT has high specificity and sensitivity to detect air in the bladder and bladder wall3 and can detect the extent of the disease or whether underlying causes are present.
Treatment of emphysematous cystitis requires aggressive, prompt administration of parenteral antibiotics and bladder drainage. Empiric treatment should be started after urine culture is obtained. The chosen antibiotic should cover gram-negative and gram-positive bacteria; ciprofloxacin (Cipro, generics), 400 mg IV twice a day is a good choice.4 Once culture results are obtained, the patient should be switched to a narrower-spectrum agent, using the oral route as tolerated. Admission to the hospital is suggested when the patient cannot take medications by mouth, has a significant disability, or is known for nonadherence to treatment. Suggested duration of therapy is 7 to 14 days.4 In addition to antibiotic therapy, bladder drainage is indicated via Foley catheter.
Conclusion Emphysematous cystitis is rarely diagnosed by history and physical examination alone; imaging is essential to the detection of this uncommon condition. PAs should have a high index of suspicion for emphysematous cystitis in patients with painless gross hematuria and known risk factors and should consider use of CT in the diagnostic workup of patients who present with painless hematuria. Prompt diagnosis using the history, physical examination, and CT is imperative to prevent overwhelming infection, extension of infection into the ureters and renal parenchyma, or bladder rupture and death. Improved outcomes can be achieved with early diagnosis and appropriate treatment. JAAPA
Jennifer Pitts Hanopole is a student in the Jefferson College of Health Sciences Physician Assistant Program, Roanoke, Virginia. Andres Marte-Grau is a physician at and Rathnakar Sherigar is Chief of Imaging at the Veterans Affairs Medical Center, Salem, Virginia. The authors have indicated no relationships to disclose relating to the content of this article.
Julie Vajnar, PA-C, RT, department editor
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