Effects of Intravenous Acetaminophen on Body Temperature and Hemodynamic Responses in Febrile Critically Ill Adults

The purpose of this study is to compare the effects of intravenous acetaminophen to placebo on body temperature and hemodynamic (heart rate and blood pressure) responses in febrile critically ill adult patients. There are limited data to explain the variable and unpredictable antipyretic and hemodynamic response to acetaminophen in febrile ICU patients. The complex pathophysiology of critically ill patients, co-morbid conditions, the effect of multiple pharmacologic and non-pharmacologic care interventions, and/or the potential interferences with absorption of enteral or rectal formulations may be related to variations in the antipyretic response to acetaminophen. It is necessary for clinicians to have a better understanding of the therapy response and potential adverse effects of this commonly administered medication, especially the recently available IV formulation, in critically ill patients. Further research of the antipyretic response to acetaminophen in critically ill patients is warranted to inform evidence-based practice guidelines for fever management. Further randomized, placebo-controlled studies of hemodynamic responses to IV acetaminophen are also warranted. Primary Hypothesis: There is a significant reduction in time-weighted average core body temperature over 4 hours after administration of IV acetaminophen compared to placebo in febrile critically ill patients. Secondary Hypotheses: 1. There is a significant reduction in time-weighted average heart rate over 4 hours after administration of IV acetaminophen compared to placebo in febrile critically ill patients. 2. There is a significant reduction in time-weighted mean arterial pressure over 4 hours after administration of IV acetaminophen compared to placebo in febrile critically ill patients. Adult patients with fever (≥ 38.3ºCentigrade/101ºFarenheit) in the intensive care unit will be screened for eligibility and enrolled after informed consent. Patients will be randomized to receive IV acetaminophen 1 gram or normal saline 100 mLs. Body temperature, heart rate, and blood pressure will be measured at baseline and during the 4 hours post study drug administration.