Inhalation of Isopropyl Alcohol for the Management of Nausea and Vomiting: A Systematic Review

Background: The use of inhaled isopropyl alcohol (IPA) has been proposed as a therapeutic intervention for the relief of nausea in various settings. The objective of this systematic review was to evaluate the existing evidence for the use of inhaled IPA in the management of nausea and vomiting. Methods: We performed a literature search on Medline, EMBASE, Web of Science, Scopus, CINAHL, PsycInfo, and Cochrane Library databases before November 2021. The following concepts were searched using subject headings and keywords as needed “aromatherapy,” “alcohol,” “ethylic alcohol,” “ethanol,” “isopropyl alcohol,” “emesis,” “chemotherapy-induced,” “pregnancy,” “hyperemesis gravidarum,” “motion sickness,” “emetics,” “antiemetics,” “inhalation,” and “inhale.” Searches were not limited to a specific language. The bibliographies of identified articles were also manually searched. Two authors independently assessed the included studies for risk of bias. Results: Thirteen randomized controlled trials out of 158 studies identified met the inclusion criteria, with a total of 1253 participants. Twelve studies were conducted in the postoperative anesthesia care unit and two studies were performed in the emergency department setting. Four studies were double blinded, one was single blind, and eight were open label. Three studies assessed the use of inhaled IPA for prevention, whereas 10 studies evaluated its use in the treatment of nausea and vomiting. Seven studies reported IPA to be more effective, four studies reported no difference, and two studies reported IPA to be ineffective. Participant satisfaction was high overall, regardless of intervention received. No adverse effects were reported. The overall quality of evidence was low. Conclusion: There is a lack of strong evidence to support the use of inhaled IPA in the management of nausea and vomiting. Additional trials are warranted to confirm this finding and to further explore the use of inhaled IPA in various populations and settings.