Patient Care/Clinical Decisionmaking

Preventive treatment with antibiotics appears to be more effective for severely ill patients

The benefits of treating patients in intensive care units with prophylactic antibiotics appear to increase with the patients' severity of illness. This finding is from a meta-analysis reported in Critical Care Medicine by Xiaolu Sun, M.D., and colleagues Douglas P. Wagner, Ph.D. and William A. Knaus, M.D. of the University of Virginia. The study was supported in part by a grant from the Agency for Health Care Policy and Research (HS07137), for which Dr. Knaus was Principal Investigator.

Dr. Knaus explains that these severely ill patients, especially when they have long ICU stays or are on mechanical ventilation, are extremely vulnerable to hospital-acquired (or nosocomial) infections. These infections are a major cause of sepsis ("blood poisoning") and subsequent failure of major organ systems.

The meta-analysis examined 23 studies involving a total of 4,142 adult ICU patients. Taken together, the studies showed that ICU patients at high risk of death who were treated with prophylactic antibiotics had a significantly lower mortality rate than patients who did not receive prophylactic antibiotics. The degree of antibiotic protection was related to the degree of mortality risk of the ICU patients at the time of study entry.

Details are in "Does selective decontamination of the digestive tract reduce mortality for severely ill patients?" by Drs. Sun, Wagner, and Knaus, which appears in Critical Care Medicine 24(5), pp. 753-755, 1996.

Pregnant women exposed to chicken pox should be tested for immune status before being given varicella-zoster immune globulin

Currently, it is recommended that all pregnant women who are exposed to chicken pox (varicella zoster virus, VZV) be given varicella-zoster immune globulin to prevent infection. However, a recent study found that this approach is neither cost effective nor necessary. Rather, these women should first be tested for immunity to VZV, since about 80 percent of women with no history of chicken pox infection are in fact immune and would not benefit from the treatment. Also, the immune globulin costs $400 per treatment compared with the $25 immune status test.

Varicella-zoster immune globulin is thought to modify the severity of or even prevent varicella infection if administered within 96 hours of exposure. According to members of the Patient Outcomes Research Team (PORT) on Low Birthweight in Minority and High Risk Women supported by the Agency for Health Care Policy and Research (contract 282-92-0055), it remains controversial whether chicken pox infection has severe consequences in pregnant women. The PORT researchers, led by Robert L. Goldenberg, M.D., of the University of Alabama, constructed a simple decision-analytic model to compare three strategies for managing pregnant women exposed to VZV using a hypothetical 25-year-old pregnant woman with a 55-year life expectancy. The strategies were: one, merely observe; two, test immune status and administer varicella-zoster immune globulin to women who test nonimmune; and three, administer varicella-zoster immune globulin to all exposed and presumed susceptible women.

Under most assumptions, the universal administration strategy was not cost effective when compared with the immune-testing strategy. The PORT researchers recommend selectively administering the varicella-zoster immune globulin based on the results of immune testing. This would allow most pregnant women who are actually at risk of contracting chicken pox to receive prophylaxis, while avoiding needless and expensive prophylaxis in the large number of women who are not at risk.

For more details, see "Management of the presumed susceptible varicella (chickenpox)-exposed gravida: A cost-effectiveness/cost-benefit analysis," by Dwight J. Rouse, M.D., Michael Gardner, M.D., M.P.H., Stephen J. Allen, M.D., and Dr. Goldenberg, in the June 1996 issue of Obstetrics & Gynecology 87(6), pp. 932-936.

Nonclinical factors may influence use of episiotomies

Routine performance of episiotomies during vaginal deliveries is falling into increasing disfavor. Recent studies show that they are necessary in only a few clinical situations and often prolong hospital stays. Yet a new study shows that 69 percent of women who give birth vaginally have episiotomies. Furthermore, nonclinical factors—such as physician attitudes and the patient's socioeconomic status—often figure into the decision to perform an episiotomy. At this rate, extra hospital days for women who undergo episiotomies would account for annual health care expenditures of $351 million, according to the study supported in part by the Agency for Health Care Policy and Research (HS07012).

It is difficult to change long-standing physician attitudes that episiotomies are needed to minimize perineal tearing and protect against excessive vaginal stretching, explains William J. Hueston, M.D., of the University of Wisconsin-Madison, author of the study. He analyzed the reasons for use of episiotomies during nearly 6,500 vaginal deliveries at five medical centers during 1991 and 1992 by retrospectively reviewing the medical records. He found that women without children were four times more likely to have an episiotomy than women with children, and that women whose babies were delivered with instruments (forceps or vacuum extraction) were four to five times more likely to undergo the procedure than other women. Delivery of a larger infant and use of epidural anesthesia also were associated with an episiotomy.

But clinical factors alone did not drive the decision to perform episiotomies. For example, white women and women with private health insurance were at higher risk for episiotomy than nonwhite women and those without private insurance. Providers may perceive privately insured patients as having higher expectations of perfect outcomes and as more apt to file malpractice suits, suggests Dr. Hueston. Midwives and some care sites were low users of episiotomies (39 percent of vaginal births). Obstetricians and other care sites were high users (68-79 percent), and family physicians and still other sites fell somewhere between the two.

More details are in "Factors associated with the use of episiotomy during vaginal delivery," by Dr. Hueston, which appears in the June 1996 issue of Obstetrics & Gynecology 87(6), pp. 1001-1005.

Return to Contents
Proceed to Next Section