title: Transdermal nitroglycerin in patients with subarachnoid hemorrhage.
abstract: Delayed ischemic neurological deficit (DIND) following cerebral vasospasm remains a cause for high morbidity and mortality in patients with subarachnoid hemorrhage (SAH). There is experimental and clinical evidence of positive effects of nitric oxide (NO) donors on cerebral vasospasm. We therefore analysed the effect of transdermal nitroglycerin in patients with SAH measuring transcranial Doppler velocities (TCD), cerebral blood flow (CBF) and DIND. Nitroglycerin was used in a target dose of 14 microg/kg/h. TCD assessment was performed daily. CBF measurements were done using the perfusion CT-technique. Blood pressure, volume intake and vasopressor administration, were registered. Nine patients were randomly assigned either to the nitroglycerin group (N-group) and eight patients in the control group (C-group). Mean TCD values in the extracranial portion of the internal carotid artery (ICA) were lower in the N-group (p<0.005). Mean TCD in the middle cerebral arteries (MCA) showed no difference. The Lindegaard ratio was higher in the N-group (p<0.04). CBF in the N-group was higher than in the C-group (p<0.03). Even though nitroglycerin reduces blood pressure and lowers ICA TCD-values and increases the Lindegaard ratio, a higher CBF was measured in the N-group. Thus, nitroglycerin influences the cerebral vascular tone and increases CBF. SAH therapy with nitroglycerin is possible without increasing the risk of DIND. The exact timing of onset, duration and reduction of nitroglycerin administration in respect to the appearance of vasospasm may have a strong impact on the success of such a therapy.
authors.affiliation: Department of Neurosurgery, Inselspital Bern, University of Bern, Switzerland. michael.reinert@neurochirurgie-bern.ch
authors.forename: Michael
authors.initials: M
authors.lastname: Reinert
authors.forename: Roland
authors.initials: R
authors.lastname: Wiest
authors.forename: Laurence
authors.initials: L
authors.lastname: Barth
authors.forename: Robert
authors.initials: R
authors.lastname: Andres
authors.forename: Christoph
authors.initials: C
authors.lastname: Ozdoba
authors.forename: Rolf
authors.initials: R
authors.lastname: Seiler
mesh_terms: D000279:Administration, Cutaneous; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D016009:Chi-Square Distribution; D004334:Drug Administration Schedule; D007839:Functional Laterality; D006801:Humans; D020768:Middle Cerebral Artery / Q000187:drug effects / Q000503:physiopathology; D005996:Nitroglycerin / Q000627:therapeutic use*; D018709:Statistics, Nonparametric; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D017585:Ultrasonography, Doppler, Transcranial; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin