Clinical Images - A Quarterly Column: Emphysematous Cystitis

DISCUSSION

Emphysematous cystitis can be seen as a rare complication of lower UTIs. Typical symptoms are similar to those of uncomplicated UTIs, including dysuria, hematuria, urinary frequency, fever, and possible suprapubic pain. Pneumaturia, although more specific, is a much less common presenting symptom. Some patients may be completely asymptomatic at the time of incidental diagnosis.^1,2 Although the overall incidence of emphysematous cystitis is unknown, it is seen more commonly in females than males (>2:1).^1,3 Diabetes mellitus is the leading risk factor and is present in more than half of reported cases. Other predisposing risk factors include being elderly or debilitated, bladder outlet obstruction, chronic UTIs, neurogenic bladder, chronic indwelling bladder catheters, and immune deficiency.^1,2,5 The majority of emphysematous cystitis cases (>60%-70%) are caused by E coli, as in our case.^1,2 Other common bacterial pathogens include Enterobacter species, Klebsiella pneumoniae, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and Streptococcus species. Fungal agents such as Candida species are a less common cause.^1,6,7 Laboratory and urinalysis findings in the setting of emphysematous cystitis often mimic those seen in uncomplicated UTI cases, including leukocytosis, microscopic or gross hematuria, leukocyturia, and bacteriuria.

Radiologic imaging is essential for diagnosis because of common overlap of clinical and laboratory findings. Conventional radiography and ultrasound may at times be useful in aiding with diagnosis, although CT examination is the preferred imaging technique for establishing the presence of intramural and/or intraluminal gas, thus confirming the diagnosis of emphysematous cystitis.² Isolated air within the urinary bladder lumen is not diagnostic on its own, as this finding may be seen in the setting of recent catheterization/instrumentation, surgery, trauma, colovesical fistula, or vesicovaginal fistula.⁸ Other key radiographic findings include diffuse urinary bladder wall thickening and possible pericystic inflammatory change that are best appreciated on CT.^7,8

Clinical presentations of emphysematous cystitis can vary greatly, ranging from patients in severe sepsis to asymptomatic patients who are incidentally diagnosed at the time of unrelated abdominal imaging.¹ Treatment typically includes broad-spectrum antibiotic coverage until the organism and antibiotic sensitivity are established from the urine culture. Long-term antibiotic therapy may be needed for 10 days to 6 weeks.³ Infectious disease consultation may be sought for determining the duration of treatment. Other management recommendations include proper glycemic control for diabetic patients. Adequate bladder drainage via catheterization may be needed in the setting of bladder outlet obstruction. Patients should also be closely monitored to ensure clinical improvement with medical management and for potential development of peritoneal signs at which point surgical consultation may be warranted.^1,8 Emphysematous cystitis is generally associated with good prognosis if accurately diagnosed and treated in a timely manner. If not properly or timely managed, emphysematous cystitis may have mortality as high as 7%-10%.^1,3