title: Intravenous acetaminophen reduces postoperative nausea and vomiting: a systematic review and meta-analysis.
abstract: Opioids are a key risk factor for postoperative nausea and vomiting (PONV). As intravenous (i.v.) acetaminophen reduces postoperative pain and opioid requirements, one would expect i.v. acetaminophen to be associated with a lower incidence of opioid-induced side effects, including PONV. We conducted a systematic search using Medline and Cochrane databases supplemented with hand search of abstract proceedings to identify randomized-controlled trials of i.v. acetaminophen. Inclusion criteria were (a) randomized for i.v. acetaminophen vs a placebo control, (b) general anesthesia, and (c) reported or obtainable PONV outcomes. Primary outcome was postoperative nausea and secondary outcome was postoperative vomiting. We included 30 studies with 2364 patients (1223 in the acetaminophen group, 1141 in the placebo group). The relative risk (95% confidence interval) was 0.73 (0.60-0.88) for nausea and 0.63 (0.45-0.88) for vomiting. Data showed significant heterogeneity for both nausea (P=0.02, I(2)=38%) and vomiting (P=0.006, I(2)=47%), but were homogeneous when studies were grouped according to timing of first administration: i.v. acetaminophen reduced nausea when given prophylactically either before surgery, 0.54 (0.40-0.74), or before arrival in the postanesthesia care unit, 0.67 (0.55-0.83); but not when given after the onset of pain, 1.12 (0.85-1.48). When i.v. acetaminophen was given prophylactically, the reduction of nausea correlated with the reduction of pain (odds ratio 0.66, 0.47-0.93), but not with reduction in postoperative opioids (odds ratio 0.89, 0.64-1.22). Prophylactically administered i.v. acetaminophen reduced PONV, mainly mediated through superior pain control.
authors: Department of Anesthesia and Perioperative Care, UCSF Medical Center at Mt Zion, San Francisco, CA, USA Department of Epidemiology and Biostatistics, UCSF Medical Center at Mt Zion, San Francisco, CA, USA Institute of Anesthesiology and Outcomes Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA Department of Anaesthesiology, Ludwig-Maximilians-University, Munich, Germany.
authors: Christian C
authors: CC
authors: Apfel
authors: Alparslan
authors: A
authors: Turan
authors: Kimberly
authors: K
authors: Souza
authors: Joseph
authors: J
authors: Pergolizzi
authors: Cyrill
authors: C
authors: Hornuss
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000627:therapeutic use*; D000768:Anesthesia, General; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D020250:Postoperative Nausea and Vomiting / Q000188:drug therapy* / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen