Systematic Review and Meta-Analysis of Aromatherapy in Alleviating Post-Chemotherapy Nausea and Vomiting Among Cancer Patients.

Background: Chemotherapy-induced nausea and vomiting (CINV) represent prevalent and distressing adverse effects among cancer patients, substantially compromising treatment compliance and quality of life. This systematic review and meta-analysis evaluate the therapeutic efficacy of aromatherapy in managing CINV, with the objective of informing evidence-based clinical decision-making in supportive cancer care. Methods: We systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs) assessing aromatherapy's effects on CINV. Two reviewers independently screened studies, extracted data, and evaluated bias risk. Meta-analysis was performed using RevMan 5.4, with outcomes expressed as odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs). Results: Twelve RCTs (n = 1,572) were included. Aromatherapy significantly reduced acute nausea (OR = 0.46, 95% CI 0.29-0.73), acute vomiting (OR = 0.56, 95% CI 0.40-0.79), and delayed nausea (OR = 0.64, 95% CI 0.47-0.88). However, no significant effects were observed for delayed vomiting (OR = 0.72, 95% CI 0.39-1.34), VAS scores (MD = -1.30, 95% CI -2.76-0.16), or INVR scores (MD = -1.67, 95% CI -3.67-0.32). No publication bias was detected (p > 0.05). Conclusion: The existing body of evidence suggests that aromatherapy may function as a valuable adjunctive therapy in mitigating chemotherapy-induced nausea, especially during the acute phase. Nevertheless, its efficacy in managing vomiting and symptoms in the delayed phase remains uncertain. Future research efforts should focus on conducting large-scale, methodologically robust RCTs that employ standardized aromatherapy protocols and incorporate longitudinal assessments of outcomes and understanding the biological mechanisms associated with aromatherapy therapeutic effects.