Alcohol-based hand rub and surgical site infection after elective neurosurgery: an intervention

Controlled studies on the effect of alcohol-based hand rub before and after each patient contact on surgical site infection (SSI) among neurosurgical patients are scarce. Aim : To evaluate the effect of alcohol-based hand rub before and after each patient contact on SSI after elective neurosurgical procedures.

Department of Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala. An intervention study using a 'before-after' design.

Two 9-month study periods were compared; between these periods, an infection-control protocol incorporating an alcohol-based hand rub was implemented for a period of 3 months and continued thereafter. Consecutive patients who underwent neurosurgery between January and September 2006 (control group, before protocol) and between January and September 2007 (intervention group, after protocol) were included. Outcome measures included SSI rates, profile of microorganisms and patient survival. Statistical Analysis : SPSS statistics version 17.0.

A total of 1,899 operated cases were reviewed. The patients in the control and intervention groups were similar with regard to sex, age and type of neurosurgery. The surgical site infection rates were 22 (2.3%) out of 974 in the control group and 14 (1.5%) out of 925 in the intervention group (P = 0.2). Patient survival rates were 97.6% (control) and 98.3% (intervention). Post hoc power calculation for an alpha value equal to 0.05, the power obtained was 24.9%, showing inadequacy of sample size to get significant results. To achieve 80% power, the sample size required is about 4,800 each for the control and intervention groups.

Use of alcohol-based hand rub before and after each patient contact in the neurosurgical intensive care unit did not show a significant reduction in SSI in the present study. This lack of difference between the two groups may be related to the inadequate sample size. The other possibility is that both the strategies are of equal efficacy for prevention of SSIs.