Effect of IV Acetaminophen on Patients in the Neurocritical Care Unit

Inclusion Criteria: * \> 45 kg (amenable to adult dosing) * all traumatic brain injuries NPO for at least 12 hours * all post-operative craniotomy patients * all non-operative subarachnoid hemorrhage, intraparenchymal hemorrhage, and stroke patients * all carotid endarterectomy and carotid artery stenosis patients * all endovascular patients undergoing intracranial intervention * all post-op spine patients admitted to the NCCU Exclusion Criteria: * documented allergy to acetaminophen * documented severe hepatic impairment (Child-Pugh score \> 6) or severe hepatic disease (hepatitis) * documented severe renal impairment (CrCl \< 30 ml/min) Blood tests will be performed prior to study procedures that will ensure patients do not have renal impairment. * patients who are pregnant or breast feeding