Hemodynamic impact of ephedrine on hypotension during general anesthesia: a prospective cohort study on middle-aged and older patients

BACKGROUND: Ephedrine is a mixed α- and β-agonist vasopressor that is frequently used for the correction of hypotension during general anesthesia. β-responsiveness has been shown to decrease with age; therefore, this study aimed to determine whether aging would reduce the pressor effect of ephedrine on hypotension during general anesthesia. METHODS: Seventy-five patients aged ≥ 45 years were included in this study, with 25 patients allocated to each of the three age groups: 45–64 years, 65–74 years, and ≥ 75 years. All patients received propofol, remifentanil, and rocuronium for the induction of general anesthesia, followed by desflurane and remifentanil. Cardiac output (CO) was estimated using esCCO technology. Ephedrine (0.1 mg/kg) was administered for the correction of hypotension. The primary and secondary outcome measures were changes in the mean arterial pressure (MAP) and CO, respectively, at 5 min after the administration of ephedrine. RESULTS: The administration of ephedrine significantly increased MAP (p < 0.001, mean difference: 8.34 [95% confidence interval (CI), 5.95–10.75] mmHg) and CO (p < 0.001, mean difference: 7.43 [95% CI, 5.20–9.65] %) across all groups. However, analysis of variance revealed that the degree of elevation of MAP (F [2, 72] = 0.546, p = 0.581, η(2) = 0.015 [95% CI, 0.000–0.089]) and CO (F [2, 72] = 2.023, p = 0.140, η(2) = 0.053 [95% CI, 0.000–0.162]) did not differ significantly among the groups. Similarly, Spearman’s rank correlation and multiple regression analysis revealed no significant relation between age and the changes in MAP or CO after the administration of ephedrine. CONCLUSION: The administration of ephedrine significantly increased MAP and CO; however, no significant correlation with age was observed in patients aged > 45 years. These findings suggest that ephedrine is effective for the correction of hypotension during general anesthesia, even in elderly patients. TRIAL REGISTRATION: UMIN-CTR (UMIN000045038; 02/08/2021). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12871-023-02244-4.