Post-obstructive diuresis; underlying causes and hospitalization

This article discusses post-obstructive diuresis, its underlying causes, and hospitalization associated with its finding in patients. Post-obstructive diuresis is defined as urine production >200 mL/hr for two consecutive hours or urine output >3,000 mL/day [or 3 L] in 24 hours. It is more common in older men with the most common causes being obstructive – benign enlarged prostate, prostate cancer, bladder cancer, infection, neurological cause, post-op cause, other causes of obstruction, such as stricture or hematuria, alcohol intake and unknown causes. Management involves foley catheterization to decompress the bladder and relieve the patient’s discomfort. However, post-obstructive diuresis can be pathological with continued excretion of sodium and water, leading to risk of dehydration and electrolyte abnormalities, such as hyponatremia, which be life-threatening.

This article conducted a retrospective chart review of 64 patients [median age 72.5]  with the aim of estimating the incidence of post-obstructive diuresis in patients with urinary retention. It was found that the incidence of post-obstructive diuresis was 29.7% with prostate diseases being the main causes [55%] and more than half of the patients having post-obstructive diuresis for less than 4 hours. In addition, it found that there is a significant correlation between post-obstructive diuresis and increased residual urine, increased serum Creatinine, increased serum urea, increased systolic blood pressure, increased diastolic blood pressure, and decreased eGFR. Moreover, residual urine >1150 mL, which is indicated of post-obstructive diuresis, and elevated Creatinine are independent predictors of post-obstructive diuresis in patients with urinary retention with 84% sensitivity and 78% specificity.