Paracetamol administration is associated with hypotension in the critically ill.

An association between the administration of paracetamol and relative hypotension in critically ill intensive care patients has been reported anecdotally by nursing staff working in the Intensive Care Unit (ICU) of Prince Henry Hospital. An observational study was therefore undertaken, to determine whether there is a temporal association between the administration of paracetamol and changes in blood pressure. A dose of 1 gram of paracetamol was administered orally or by feeding tube. Blood pressure was recorded 30 minutes prior to paracetamol administration, at the time of administration and then at 15-minute intervals for the first hour and at half-hour intervals for the second hour after administration. Analysis of data from 37 individuals using a repeated measures ANOVA showed that systolic arterial pressure (SAP) and mean arterial pressure (MAP) were reduced significantly over the observation period (p < 0.0001 for both). SAP and MAP fell by an average of approximately 10 and 7 per cent respectively, with maximum falls of 36 and 34 per cent respectively. Paracetamol administration may be indicated for the control of fever in critically ill patients, thereby reducing oxygen demand. However, this must be balanced against the possibility of causing a significant fall in blood pressure.