Water bath prewarming of urine samples to facilitate automated microscopy and urinalysis

We sought to evaluate the effect of water bath prewarming of macroscopically turbid urine samples to facilitate automated microscopy and biochemical analysis. In addition, we sought to confirm that relevant microscopy and biochemical parameters for urine culture interpretation were not compromised by prewarming.

We analyzed 50 turbid urine samples submitted for urine culture. An aliquot of samples underwent manual and automated analysis before prewarming in a water bath at 80 °C for 50 seconds. Manual and automated analyses were repeated following prewarming.

Prewarming facilitated an improvement in the number of acceptable urine samples for automated analysis (from 3/50 [6%] to 46/50 [92%]). All biochemical parameters were concordant. Microscopy results were more than 85% concordant between prewarming and postwarming analysis.

Our testing demonstrated that brief prewarming in a water bath facilitates automated analysis without compromising relevant microscopy and biochemical parameters that affect the workup and interpretation of urine cultures.