Valproic acid attenuates the risk of acute respiratory failure in patients with subarachnoid hemorrhage.

ABSTRACT

BACKGROUND: Valproic acid (VPA) has shown potent anti-inflammatory effect and attenuates acute lung injury. AIM: To determine whether the use of VPA is associated with a decreased risk of acute respiratory failure (ARF) in patients with subarachnoid hemorrhage (SAH). DESIGN: The Taiwan National Health Insurance Research Database was used to analyse all patients newly diagnosed with SAH from 2000 to 2010. The VPA users were matched for age, gender and index date in 12 ratios with randomly selected non-VPA users as a comparison group. METHODS: Multivariate Cox regression was used to identify the predictors of ARF and to compare the incidence rates of ARF among SAH patients using and not using VPA. RESULTS: The study cohort included 16 228 newly diagnosed SAH patients, from which 521 VPA users and 1042 matched non-VPA-exposed individuals were selected. In the VPA-treated cohort and the non-VPA-treated cohort, 117 and 289 patients developed ARF, respectively. Any use of VPA was associated with a 16% decreased risk of ARF requiring mechanical ventilation in 30-day tracking of the SAH patients (adjusted hazard ratio [HR], 0.840, 95% confidence interval [CI], 0.676-0.945). Age, sepsis and pneumonia were identified as independent predictors of ARF in patients with SAH. After stratification, VPA users showed a lower risk of ARF among SAH patients complicated with pneumonia compared with non-users of VPA (adjusted HR, 0.816, 95% CI, 0.652-0.921). CONCLUSIONS: Any use of VPA was associated with a reduced risk of ARF in patients with SAH. VPA may be beneficial for decreasing the risk of pneumonia-induced ARF in patients with SAH.