Trends in Ventriculostomy-Associated Infections and Mortality in Aneurysmal Subarachnoid Hemorrhage: Data From the Nationwide Inpatient Sample.

BACKGROUND

Patients with aneurysmal subarachnoid hemorrhage (aSAH) are susceptible to various medical complications, including ventriculostomy-associated infections (VAIs) in those who undergo external ventricular drain (EVD) placement. Many preventative strategies for VAIs have been used during the last 20 years, but their overall effect is unknown. Using the Nationwide (National) Inpatient Sample, we examined trends in VAI rates and mortality during a recent 12-year period in the aSAH population.

METHODS

In this retrospective analysis, data from the Nationwide Inpatient Sample was obtained from January 1, 2000, through December 31, 2011, using International Classification of Diseases, 9th Revision, Clinical Modification codes. After adjustment for age, sex, race, and subarachnoid severity, annual estimated event rates of VAI, in-hospital mortality, and hospital length of stay were calculated. Changes in these parameters during the study period were analyzed.

RESULTS

From years 2000 through 2011, there were 116,013 aSAH admissions, with EVD placement in 38,163 (32.9%) cases. In patients who underwent EVD placement, the mean annual rate of VAI was 7.3 per 100 patients, with no change during the 12-year period (absolute risk reduction per year of -0.05%, 95% confidence interval -0.22, 0.13). The mean mortality rate in this population was 19.8 per 100 patients, significantly declining over the study period (absolute risk reduction per year of -0.55%, 95% confidence interval -0.82, -0.29).

CONCLUSIONS

Despite numerous VAI-preventative strategies, the national VAI rate in aSAH patients has not changed; however, a reduction in mortality is suggested. Further studies are needed to determine how best to reduce VAIs, and to identify factors influencing observed trends in VAI and mortality.