Prophylactic infusion of norepinephrine enhances hemodynamic stability during propofol induction and early intubation period in elderly patients: a double-blind randomized placebo-controlled study
Background The induction of general anesthesia with propofol often results in hypotension, primarily attributed to decreased cardiac index (CIx) among elderly patients. Norepinephrine (NE) is typically used to manage anesthesia-induced hypotension. We hypothesized that NE attenuates the reduction in CIx while preserving blood pressure. Methods In a randomized, double-blinded trial, 60 elderly patients undergoing elective major abdominal surgery were randomly allocated to receive NE (6 µg/ml) (NE group) or saline (control [CT] group) during induction. CIx was monitored using the FloTrac/Vigileo system, and the primary outcome was the change in CIx (△CIx) (△Value = value measured at the study time point–baseline value) at 10 min post-intubation (T10). Changes in systemic vascular resistance index (△SVRI) and mean arterial pressure (△MAP) were also evaluated for comparison. Results In NE group, CIx decreased from 3.9 to 2.9 L/min/m2 at 10 min post-intubation (T10), whereas in CT group, it declined from 3.7 to 2.6 L/min/m2. After adjusting for propofol dosage per weight, the decreases in △CIx (β = 0.63, 95% confidence interval [CI] 0.18 to 1.07; P = 0.006) and △MAP (β = 11.99, 95% CI 2.05 to 21.94; P = 0.018) at T10 were significantly less in NE group compared to CT group, whereas △SVRI did not show a significant difference between the two groups. Conclusions Prophylactic infusion of NE effectively attenuated the decrease in △CIx during propofol-induced anesthesia in elderly patients while maintaining MAP.