Systematic review and meta-analysis of ketamine-associated uropathy.

INTRODUCTION
This systematic review and meta-analysis focused on the literature regarding ketamine-associated uropathy to summarise its clinical manifestations, the results of urological assessments, and current management.


METHODS
A literature search was conducted using keywords and MeSH terms related to ketamine abuse, urinary tracts, and urological examinations. Databases including Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched up to 26 June 2020.


RESULTS
In total, 1365 articles were retrieved; 45 articles (4921 patients) were included in the analysis of patient demographics, clinical manifestations, examination results, and treatments. Frequency was the most common manifestation (pooled prevalence 77.1%, 95% confidence interval [CI]=56.9%-92.2%), followed by urgency (69.9%, 95% CI=48.8%-87.3%) and suprapubic pain (60.4%, 95% CI=35.3%-82.9%). Upper urinary tract involvement was less common; the pooled prevalence of hydronephrosis was 30.2% (95% CI=22.0%-39.2%). Further workup revealed a pooled functional bladder capacity of 95.23 mL (95% CI=63.57-126.88 mL), pooled voided volume of 113.31 mL (95% CI=59.44- 167.19 mL), and pooled maximum urine flow rate of 8.69 mL/s (95% CI=5.54-11.83 mL/s). Cystoscopic examinations and bladder biopsy revealed frequent urothelial denudation, inflammatory changes, and inflammatory cell infiltration. Treatments included oral medications for symptomatic relief, intravesical therapy, and surgery (eg, hydrodistension and bladder reconstruction), but ketamine abstinence was necessary for improvement.


CONCLUSION
Ketamine-associated uropathy frequently involves frequency, urgency, and suprapubic pain; upper urinary tract involvement is less common. Affected patients showed reductions in bladder capacity and urine flow rate. Endoscopic and histological analyses often revealed cystitis. Despite variations in treatment, ketamine abstinence is important for all patients with ketamine-associated uropathy.