Nicotine replacement therapy in patients with aneurysmal subarachnoid hemorrhage: Systematic review of the literature, and survey of Canadian practice.

Tobacco smoke increases the risk of aneurysmal subarachnoid hemorrhage (SAH), as well as complications such as vasospasm. Most patients presenting with aneurysmal SAH smoke, and many survivors continue to smoke after discharge. Neurosurgeons often hesitate to use nicotine replacement therapy (NRT) during hospitalization of patients with SAH due to concerns of inducing vasospasm. We aimed to evaluate the safety and efficacy, and patterns of use of NRT in smokers hospitalized for SAH. We performed a systematic review of MEDLINE, CENTRAL, Embase, and unpublished sources of literature to October 2016 for randomized and observational studies comparing exposure to non-exposure of smoking cessation products in the acute phase of aneurysmal SAH. Additionally, we surveyed 50 Canadian vascular neurosurgeons to evaluate patterns of NRT use in SAH. Four cohort studies (n=1210) met our eligibility criteria. Three studies enrolled patients with aneurysmal SAH, and one study enrolled all neurocritically ill patients. We rated the quality of evidence as very low using the GRADE approach. We could not meta-analyze studies due to methodological heterogeneity. Individual studies reported beneficial or neutral effects of NRT on functional outcome, death, and clinical or radiographic vasospasm. None of the studies assessed long-term abstinence from tobacco. Of the 14 vascular neurosurgeons responding to our survey, most never used NRT in patients hospitalized with SAH, often citing training or standard of practice as the reason. Current evidence suggests that NRT does not induce vasospasm, and is associated with improved outcomes in smokers hospitalized for SAH. Protocol registered in PROSPERO, available at: http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42016037200.