A 72-year-old man with long-standing prostatism presents with a 4-day history of reduced urine output and abdominal distension. Creatinine has risen from 1.0 to 6.4 mg/dL. Ultrasound shows bilateral hydronephrosis and a distended bladder. The MOST appropriate immediate next step is:

• A Start furosemide infusion to increase urine output
• B Arrange transurethral resection of the prostate within 24 hours
• C Begin urgent haemodialysis
• D Insert a urethral catheter and monitor urine output closely ✓

Explanation

Bladder outlet obstruction from benign prostatic enlargement is the commonest cause of postrenal AKI, and prompt relief by urethral catheterisation is both diagnostic and therapeutic. Dialysis is reserved for refractory hyperkalaemia, acidosis, or fluid overload. After decompression, up to half of patients develop postobstructive diuresis from loss of medullary concentrating gradient, so fluid balance must be monitored rather than treated reflexively with diuretics.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.