Can intravenous paracetamol reduce opioid use in preoperative hip fracture patients?

Pain due to intra- and extracapsular hip fractures is usually treated with opioid medication. Paracetamol (acetaminophen in North America) has better bioavailability when given intravenously than orally and has been successfully used in the postoperative care of orthopedic patients. However, no study has evaluated its use in the preoperative trauma patient. Our unit conducted a prospective, consecutive cohort study to investigate the opioid-sparing effect of regularly administered intravenous paracetamol compared with oral paracetamol in preoperative hip fracture patients. The total opioid dose given, based on conversion to intravenous morphine, and the reported pain score were evaluated in 75 patients. There were 28 patients in the control group who were give routine oral paracetamol and oral opioids, with morphine for breakthrough pain. There were 47 patients in the study group who received only routine intravenous paracetamol, with opioids reserved for breakthrough pain. The patients in the 2 groups had similar characteristics. The mean preoperative oral paracetamol dose for the control group was 7.2 g compared with 6.3 g in the study group. There was a significant reduction (P<.005) in the mean total intravenous morphine with intravenous paracetamol (6.5 mg) compared with oral paracetamol (21.8 mg). There was no difference in the mean pain score between the groups, 2.1 vs 1.8 (P=.3). Intravenous paracetamol had a significant opioid-sparing effect and satisfactory pain relief in preoperative hip fracture patients.