Urine Sample Collection in Patients with Indwelling Urinary Catheters in Emergency Settings

Indications for Catheter Change

The American Geriatrics Society recommends changing the catheter if it has been in place for ≥2 weeks before obtaining a urine sample for culture, and the sample should be obtained from the aspiration port of the new catheter, as changing the catheter in patients with long-term catheters (2.5-5 weeks) resulted in a significant decrease in polymicrobial bacteriuria at 28 days (p=0.02), faster clinical improvement at 72 hours (p<0.001), and a lower rate of recurrent urinary tract infection within 28 days (p<0.015) 1, 2
The Infectious Diseases Society of America suggests that if the catheter has been in place for <2 weeks, it does not need to be changed routinely, although the evidence is limited in this scenario 3

The Journal of Urology recommends allowing new urine to accumulate in the bladder by temporarily clamping the catheter, and then obtaining the sample by aspirating from the aspiration port of the new catheter 4
The American Geriatrics Society advises against obtaining the sample from the drainage bag 3, 4, 5 or extension tubes 4

The American Geriatrics Society recommends obtaining a urine culture only if there is suspicion of urosepsis (fever >38.8°C, chills, hypotension, delirium), catheter obstruction or recent catheter change with symptoms, or specific symptoms of the urinary tract 3, 6
The Infectious Diseases Society of America suggests not obtaining a urine culture in asymptomatic bacteriuria or non-specific symptoms without signs of urinary tract infection 3, 6, 7

If urosepsis is suspected, obtain urine and blood cultures simultaneously, along with a Gram stain of uncentrifuged urine 3, 6
If transport to the laboratory will be delayed >1 hour, refrigerate the sample to prevent bacterial overgrowth 5
The presence of pyuria or bacteriuria in patients with an indwelling catheter does not necessarily indicate infection, as 10-50% of patients have asymptomatic bacteriuria 7