NEW YORK (Reuters Health) – In a randomized study, rates of bacteriuria were significantly higher in laboring women with epidurals who had intermittent bladder catheterization relative to those who had continuous catheterization with an indwelling Foley catheter.
This isn’t what the researchers expected going into the trial. They hypothesized that intermittent catheterization would result in a lower rate of postpartum bacteriuria. Indwelling Foley catheters have been shown to increase the rate of bacteriuria in non-pregnant populations and the Centers for Disease Control and Prevention (CDC) currently recommends intermittent catheterization at regular intervals rather than indwelling catheters to help prevent catheter-associated urinary tract infections in patients with bladder emptying problems.
About 60% of laboring women now ask for epidural analgesia. Because urinary retention is a known side effect of epidurals, bladder catheterization has become routine in these women. The type of catheterization (continuous indwelling Foley catheter or intermittent catheterization) is usually determined by physician preference or institutional practice patterns.
In their study, Dr. Lauren Millet of the Department of Obstetrics and Gynecology, John A. Burns University of Hawaii School of Medicine in Honolulu and colleagues randomly assigned 160 laboring women to receive intermittent catheterization (IC group, n=84) or continuous indwelling Foley catheterization (CIF group, n=76). An initial catheterized urine culture was taken at the time of epidural placement and a second catheterized or voided culture was taken at discharge. Fourteen women were excluded, five for bacteriuria in sample one and nine for missing postpartum urine samples.
Of the remaining 146 women, 79 (54.1%) were in the IC group and 67 (45.9%) were in the CIF group. The groups were well matched in terms of demographics, labor characteristics and risk factors for infection. There were no statistically significant differences between the number of spontaneous vaginal deliveries, operative deliveries, and cesarean sections between the two groups. [abs/pg10]
In a report online now in the American Journal of Obstetrics and Gynecology, Dr. Millet and colleagues report that they observed a significantly higher rate of bacteriuria by both CDC and IDSA criteria in the IC group (p<0.05). The effect was maintained in all deliveries.
Overall, 5.48% of the urine samples met CDC criteria and 17.8% met IDSA criteria for bacteriuria. In the IC group, seven samples (8.9%) met CDC criteria and 18 (22.8%) met IDSA criteria for bacteriuria. In contrast, the corresponding percentages in the CIF group were 1.5% (one sample) and 12.1% (eight samples).
The researchers say the lower rate of bacteriuria in the CIF group may be due to the fact that the women were young, healthy, delivered quickly and had a continuous catheter removed within 24 hours. “Perhaps the minor trauma of repetitive catheterization introduced more bacteria into the bladder than an indwelling catheter,” they surmise. Women in the IC group were catheterized every four hours.
The investigators note in their report that the clinical significance of asymptomatic bacteriuria in postpartum women is unclear. Most of the cases of bacteriuria in the study were asymptomatic.
They conclude: “Before one catheter method can be recommended over another, more study is needed with larger randomized populations to assess if continuous versus intermittent catheterization truly makes a difference with regard to symptomatic postpartum urine infections.”
“A Foley balloon in the bladder,” they add, “may be a source of potential injury to the urethra during active labor or during the second stage. Advances in labor analgesia management also affect the need for catheterization in labor. Catheter-associated bacteriuria during labor could be eradicated or reduced by the use of the walking epidural, allowing patients to ambulate to the bathroom and void independently.”
The study was supported by the Hawaii Pacific Health/Kapi’olani Medical Center for Women and Children in Honolulu. The authors have no relevant disclosures.
Am J Obstet Gynecol 2012.