Emphysematous Cystitis: A Rare Urologic Emergency

Background

Emphysematous cystitis (EC) is a severe form of urinary tract infection (UTI) presenting with free air within the bladder wall [1]. Through aerobic glycolysis, gram-negative microorganisms (eg, Escherichia coli and Klebsiella pneumoniae) produce gas within the vesical lumen and muscular layer of the bladder [2]. EC has an array of clinical presentations, but prototypically presents in elderly, diabetic, and female patients, with macroscopic hematuria, abdominal pain, and fever [1]. Even though the most common clinical presentations can appear relatively benign, EC has a mortality of 10.4% and requires prompt diagnosis to effectively carry out the appropriate therapeutic management [3–5].

In the Emergency Department setting, it is crucial to consider EC when evaluating a patient with symptoms of UTI. While most cases of genitourinary infection are uncomplicated and present with typical symptoms of dysuria, urinary frequency, and urgency, it is important to avoid overlooking the possibility of more severe conditions like EC in those patients with gross hematuria and severe abdominal or pelvic discomfort. Failure to recognize and promptly treat EC can lead to life-threatening complications, including bladder rupture, necrosis, abscess formation, and even septic shock [5,6].

Treatment of patients with EC presenting with this potentially systemic infection requires a multi-disciplinary approach, with considerations for medical and surgical therapies; operative intervention, for example, is cited as necessary in up to 10% of cases [7]. Our case is one of few reported in the literature that was not associated with the classic risk factors of diabetes mellitus, immunosuppression, neurogenic bladder, or recurrent UTIs [8,9], highlighting the importance of a high degree of suspicion to effectively diagnose a patient with EC.

Case Report

A 67-year-old woman presented to the Emergency Department with gross hematuria, dysuria, and severe lower abdominal pain over the previous 3 days. In addition to dysuria, she reported the sensation that she was not fulling emptying her bladder. She denied any fevers, chills, vomiting, diarrhea, or recent history of urinary tract infection. The patient did endorse a recent fall 2 weeks prior, when she was found to have non-operative superior and inferior pubic rami fractures on the right side of her pelvis. She was under treatment at a rehabilitation facility and had limited mobility, using both a walker and wheelchair when she developed the genitourinary symptoms. She did not report any history of diabetes mellitus, immunosuppression, neurogenic bladder, or recurrent UTIs. Her medical history was significant, however, for migraines, prior history of brain aneurysm with coiling, carotid artery stenosis with stent placement, and chronic obstructive pulmonary disease. Medications relevant to this emergent presentation included clopidogrel 75 mg daily for prior history of carotid artery stenting, but the patient reported that this medication had been discontinued in the setting of her pelvic fracture 2 weeks ago. She denied any other anticoagulant use. She did report an episode of urinary retention, however, while at the rehabilitation facility, which was treated with an isolated episode of urinary catheterization without indwelling foley catheter placement.

Upon arrival to the Emergency Department, the patient’s vital signs revealed mild tachycardia, with a heart rate of 111, blood pressure of 100/85 mmHg, and temperature of 36.7°C. Physical examination was concerning for marked suprapubic abdominal tenderness without rebound or guarding. The patient’s skin was warm, dry, and well-perfused. She did also note right hip pain with range of motion testing, but this discomfort was at baseline after her recent fall. Initial laboratory evaluation was significant for a notable absence of leukocytosis, with white blood cell (WBC) count of 10.2×109/L, and hypokalemia, with potassium level to 2.6 mmol/L. The following levels were within the reference range: glucose, 109 mg/dL; creatinine, 0.43 mg/dL; albumin, 3.5 g/dL; and lactate, 1.9 mmol/L. Urinalysis revealed the presence of bacteria and small leukocyte esterase with >182 WBCs per high-power field and >182 red blood cells per high-power field. Given the patient’s findings on physical examination, computed tomography (CT) of the abdomen and pelvis without contrast was performed.

CT imaging revealed urinary bladder distension with wall thickening, stranding, and gas throughout the bladder wall and within the bladder lumen (Figure 1). Findings were consistent with emphysematous cystitis. There was no evidence on imaging of bladder fistula formation, renal calculi, hydronephrosis, or hydroureter. Interestingly, diffuse gas was also noted within the urinary bladder wall on plain film imaging obtained to assess the healing status of the prior pelvic fractures (Figure 2). Given this constellation of findings, blood cultures were obtained, broad spectrum intravenous antibiotics were administered in the form of piperacillin-tazobactam 3.375 mg, and the Urology Department was consulted. Recommendations from the urologist included insertion of 16-French foley catheter for bladder decompression and hospitalization for serial examinations to ensure improvement on intravenous antibiotics. Acute hematuria was presumptively secondary to her UTI. Foley catheterization was performed successfully, and the patient continued to drain dark bloody urine without any visible clots while in the Emergency Department.

The patient was admitted and remained hemodynamically stable during her hospitalization. Urine cultures were positive for Escherichia coli, and antibiotic coverage was narrowed to ciprofloxacin after results of sensitivity analysis were obtained. Blood cultures remained negative. The patient was discharged in good condition on hospital day 3, with an indwelling foley catheter in place, to complete a 14-day course of ciprofloxacin 500 mg PO twice daily. One week after her hospital stay, the patient was doing well in outpatient follow-up with the Urology Clinic, and a CT urogram scan showed normal bladder wall thickness, with the resolution of EC. Given the resolution of her hematuria, the foley catheter was removed as well in the Urology Clinic after a successful voiding trial. The patient did not require additional urologic evaluation or treatment in the subsequent timeframe, and outpatient urine cultures remained negative.

Discussion

In the Emergency Department, EC can be overlooked due to the heterogeneity in clinical presentation. One review suggests that only 50% of patients present with classic UTI symptoms [10]. In another series, the most common presentation included features of sepsis in 33% of individuals, along with abdominal pain in 26%; UTI symptoms were seen in only 17%, and hematuria in 6.2% of patients in this review [11]. In our case presentation, abdominal pain was present with UTI symptoms, but no features or findings were suggestive of sepsis. Late-stage complications of EC include septic shock, bladder rupture, and necrosis [11]. The natural evolution of the disease is comprised of 2 stages. The first stage usually presents as uncomplicated cystitis with bacterial colonization with nonspecific symptoms [3]. Detection in this stage has a more favorable prognosis and lower risk of complications [3]. The second stage, predominantly characterized by pneumaturia, has a reported mortality of 10.4% and worse prognosis [3]. Although pneumaturia was not observed in our patient, it should traditionally raise a high degree of suspicion for EC and prompt immediate imaging studies for its confirmation.

The criterion standard for diagnosis of EC is currently CT imaging, although plain film imaging can be helpful if a large amount of gas is present in the bladder wall or lumen, as was the case in our patient [12]. However, ultrasound imaging has emerged as a promising tool, offering valuable insights at the patient’s bedside, including possible findings of bubbles in the inferior vena cava or pathognomonic hyperechoic bladder-ring as potential indicators of the disease [13]. In the presence of these confirmatory images, prompt management with bladder decompression and administration of broad-spectrum antibiotics are crucial to mitigate the risk of adverse outcomes, emphasizing the importance of early action to avoid progression [3].

The majority of patients affected by EC are elderly females with diabetes mellitus [8]. In fact, up to 70% of cases of EC are seen in patients with diabetes mellitus, as glucose fermentation by gram-negative microorganisms can cause gas to form within the vesical wall [1]. Not all patients, however, described in the literature are diabetic, as in our patient’s case; in non-diabetic patients with normal urinalysis results, the mechanism described has been attributed to albumin fermentation [2]. Our patient’s laboratory evaluation did not reveal significant derangements other than findings of infection and hematuria on urinalysis. Other risk factors cited in the literature for EC include neurogenic bladder, recurrent UTIs, chemotherapy, and prior surgical interventions [11]. Although our patient’s history lacked these risk factors, she did report 1 isolated episode of urinary retention at the rehabilitation facility requiring drainage, suggesting that instrumentation might have played a role in the development of her EC condition.

Conclusions

As an emergency medicine provider, it is crucial to consider EC as a potential life-threatening condition when evaluating causes for hematuria and abdominal pain. Timely imaging to confirm the diagnosis with subsequent catheterization for bladder decompression and administration of broad-spectrum antibiotics can prevent fatal outcomes. Its tendency toward atypical presentations makes it imperative to consider EC even in non-diabetic patients and patients without the traditional risk factors [14]. Therefore, clinicians should remain alert to the possibility of EC in the emergent setting and strive for early intervention and treatment if identified.