Emphysematous cystitis due to Klebsiella pneumoniae

Emphysematous cystitis is a rare disease characterized by the presence of gas in the urinary bladder walls and often in the bladder lumen due to infection by gas-forming organisms. Clinical symptoms of dysurea, increased urinary frequency and hematuria may be present. Underlying diabetes mellitus is present in over half of reported cases with women being affected twice as often as men. CT is a highly sensitive imaging modality used in the detection of intraluminal or intramural gas¹ which forms the radiologic basis of the diagnosis. The most common offending organisms are E. coli and Enterobacter aerogenes, and less frequently, other agents such as Streptococci, Nocardia, and Candida albicans. Although a case of emphysematous pyelonephritis in a pediatric transplant patient² and another case of emphysematous pyelonephritis with extra-renal gas forming abscesses³ in an adult male have been reported in Saudi Arabia, to the best of our knowledge no case of emphysematous cystitis has been reported in Saudi Arabia. We report a case of a 95-year-old diabetic male who was diagnosed as having emphysematous cystitis secondary to Klebsiella pneumoniae infection.

CASE

A 95-year-old male presented with a history of deteriorating level of consciousness, productive cough and fever of 6-day duration. According to an attendant there was no history of preceding headaches, weakness of any limb, vomiting, diarrhea or urinary complaint. His past medical history is significant as he was diagnosed to be suffering from diabetes mellitus 15 years previously and recently established to have retinopathy, nephropathy and peripheral neuropathy and dementia for the previous 2 years. He had been on regular insulin 12 units subcutaneously before meals three times daily administered by the attendant, but had infrequent follow-up visits to the hospital, as he was not fully ambulatory. His glycemic control had remained poor previously. On examination, the patient was drowsy and disorientated. He was normotensive (110/70 mm Hg) with a pulse of 96 beats per minute and regular and a temperature of 38°C. Examination of the chest and heart was unremarkable and there was no hepatosplenomegaly on abdominal examination. Neurological examination revealed a Glasgow Coma Score of 13/15, an absence of neck rigidity and no motor deficit. A digital rectal examination found a normal prostate. Urgent investigations found a hemoglobin of 10.8 g/dL, a total lymphocyte count of 10.8×10³, a random blood glucose of 18.8 mmo/L, with normal renal and liver functions and serum electrolytes. A portable chest X-ray showed left lower zone haziness. The ECG was normal. Routine urine examination showed a pH of 5.0, and was nitrite positive, protein 2+, sugar 3+, with pus cells and numerous red blood cells (50–60/HPF). He was empirically treated with ceftriaxone 2 g intravenously once daily and gentamicin 80 mg intravenously every 8 hours pending the result of sputum and a urine culture and sensitivity (C/S) along with sliding scale regular insulin and intravenous fluids. The next morning the patient developed frank hematuria for which an urgent abdominopelvic ultrasound was requested that showed a thick walled urinary bladder with diverticula and echogenic foci along the bladder wall. The estimated weight of the prostate by transabdominal ultrasonography was 16 grams. A CT scan of the abdomen/pelvis showed bilateral hydronephrosis, a thick-walled urinary bladder with diverticula and air in the bladder wall suggestive of emphysematous cystitis (Figure 1). The urine C/S revealed growth of a highly resistant Klebsiella pneumoniae sensitive to only gentamicin/amikacin whereas sputum C/S revealed growth of Streptococcus pyogenes sensitive to all commonly used antibiotics including ceftriaxone. He responded with defervescence and a decline in his white cell count. Repeat CT scan examination after 2 weeks showed complete disappearance of intramural gas (Figure 2). He was discharged home after 4 weeks of therapy.

Figure 1.

Axial CT scan image showing intra-mural gas in the walls of the urinary bladder and two large diverticula.

Figure 2.

Axial CT scan image after two weeks of therapy shows complete disappearance of intra-mural gas from the urinary bladder walls, but diverticula still persist.

DISCUSSION

Although gas-producing infections account for a very small percentage of all bacterial infections of the urinary tract, they are extremely important because of their life-threatening potential.⁴ The spectrum of gas-producing infections includes emphysematous pyelonephritis, emphysematous pyelitis, and emphysematous cystitis. These are three distinct clinical entities whose clinical course, management, and ultimate prognosis differ appreciably. Gas collections within the urinary bladder wall were first described in an autopsy by Eisenlohr in 1888.⁵ It was first reported in a living human in 1932 and described radiologically by Mulsow in 1934.⁶ In 1961 Bailey proposed that emphysematous cystitis be used to describe gas collection within the bladder wall and lumen secondary to infecting micro-organisms.⁷ Emphysematous cystitis is defined by the presence of gas in the urinary bladder walls and often in the bladder lumen due to infection by gas-fermenting organisms.⁸ The major risk factors for the disease include old age and female sex, diabetes mellitus, neurogenic bladder and bladder outlet obstruction, although it has also been reported with other pre-existing conditions such as alcoholism,⁹ undernutrition¹⁰ or a disabled general medical condition.¹¹ Our case had poorly controlled diabetes with a neurogenic bladder. The most common organism is E. coli, but other organisms reported to produce emphysematous cystitis include Enterobacter aerogenes, Klebsiella pneumonia,¹² Proteus mirabilis, Staphylococcus aureus, streptococci, Clostridium perfringens, ¹³ and Candida albicans.¹⁴ In our patient Klebsiella pneumoniae was the causative organism.

Patients may complain of dysurea, increased frequency of micturition, abdominal discomfort, lower abdominal pain or pneumaturia. A history of pneumaturia is highly suggestive, but is rarely offered by the patient. The clinical features are inconclusive or actually unhelpful.¹⁵ The radiologic findings provide the most reliable diagnostic clues. Demonstration of intramural gas in the walls of the urinary bladder is the basis for the radiologic diagnosis of emphysematous cystitis. In emphysematous cystitis both intramural and intraluminal gas can be seen, but the intramural gas is diagnostic because intraluminal gas could be due to other conditions like recent urinary bladder instrumentation, trauma, or vesicocolic fistula due to colon/bladder malignancy or inflammatory bowel disease.

Conventional radiography of emphysematous cystitis characteristically shows curvilinear areas of increased radiolucency within the pelvis in the expected location of the urinary bladder. Ultrasound commonly demonstrate diffuse bladder wall thickening. Focal regions of high-amplitude echoes with posterior dirty acoustic shadowing into the lumen may be seen in extensive cases of emphysematous cystitis and these echogenic shadows may be misinterpreted as bladder calculi with ultrasound. CT is a highly sensitive examination that allows early detection as well as differentiation of intraluminal or intramural gas.¹⁶ Free intraluminal air is usually seen in nondependent areas, forming an airfluid level with urine in the bladder lumen while intramural air is seen as multiple small pockets of air along all the walls regardless of gravity as was seen in our patient. It is also useful in evaluating other causes of intraluminal gas such as enteric fistula formation from adjacent bowel carcinoma or inflammatory disease. An abdomino-pelvic CT scan can further delineate the extent of disease, whether the infection has spread to involve pelvicalyceal systems and renal parenchyma. It is important to differentiate emphysematous cystitis from emphysematous pyelonephritis, in which gas involves the renal parenchyma, since the latter has an increased mortality and generally requires nephrectomy. In contrast, surgical intervention is rarely needed in emphysematous cystitis except when an anatomical abnormality like an obstruction or stone is present.¹⁷

The prognosis for this condition is generally favorable, but there have been reports of severe necrotizing cystitis requiring cystectomy, and a mortality rate of 20%.¹⁸ As with any gas-producing infection, patient survival depends on early diagnosis with the correction of underlying causes, strict glycemic control, a prolonged course of antibiotics (3–6 weeks), relief of obstruction to urinary outflow, and surgical excision where necessary.¹⁹ Delayed diagnosis may lead to unfavorable outcomes including overwhelming infection, extension to ureter and renal parenchyma,²⁰ bladder rupture and death. Improved outcomes may be achieved by early recognition of the infection, by clinical and radiological assessment, and by appropriate antibiotic therapy. Prognosis for emphysematous cystitis is favorable as in our case if it is diagnosed promptly and treated properly.