Diabetes mellitus and urological infections

Special considerations

• Diabetes mellitus is a risk factor for urinary tract infections, including complicated infections.
• Increased risk of pyelonephritis, emphysematous pyelonephritis, and papillary necrosis.
• Atypical presentation (infection without fever).
• Immunosuppression, neuropathy (neurogenic bladder).

Common emergencies

• Complicated pyelonephritis.
• Emphysematous pyelonephritis (rare but life-threatening).
• Papillary necrosis.
• Renal abscess.
• Perinephric abscess.
• Fournier gangrene.

Diagnosis

• Urinalysis, culture.
• CT is the modality of choice when complicated infection is suspected (tissue gas, abscess, necrosis).
• Blood glucose profile, ketones.
• Assess kidney function and electrolytes.

Emergency management

• In pyelonephritis: intravenous broad-spectrum antibiotics, admission, and glycemic control.
• In emphysematous pyelonephritis, start sepsis treatment and intravenous antibiotics, obtain urgent CT, restore urinary drainage, and drain accessible collections. Consider nephrectomy for a destroyed kidney, uncontrolled infection, or failure of organ-preserving management.
• In renal or perinephric abscess, perform CT, obtain microbiological samples, and prescribe antibiotics. Percutaneous or surgical drainage is required for a large or accessible collection, sepsis, obstruction, or lack of clinical response.
• In papillary necrosis: rule out obstruction, give antibiotics, and support kidney function.
• If Fournier gangrene is suspected, immediately start resuscitation and broad-spectrum antibiotics, involve a urologist, surgeon, and ICU, and perform surgical debridement without delay. Repeat exploration until necrosis is fully controlled.

Fournier gangrene

• Red flags: severe pain, rapidly progressive perineal edema or erythema, necrosis, crepitus, foul-smelling discharge, fever, hypotension, and organ dysfunction. Early skin changes may be minimal.
• Imaging may define the extent of disease, but must not delay surgical debridement when the clinical presentation is clear.
• Sepsis treatment, broad-spectrum antibiotics, glycemic control, and repeated surgical exploration proceed in parallel.

Emphysematous pyelonephritis and abscess

• CT defines the extent of gas, obstruction, and collections. Management depends on organ dysfunction, disease extent, renal viability, and the response to drainage.
• Initial organ-preserving management includes resuscitation, antibiotics, and percutaneous drainage of an accessible collection or obstruction. Nephrectomy is not automatically the first step.
• If there is no response, reassess drainage, resistance, new collections, and the need for surgery.

Algorithm