Effects of stellate ganglion block on cardiovascular reaction and heart rate variability in elderly patients during anesthesia induction and endotracheal intubation

Study ObjectiveTo investigate the effects of stellate ganglion block (SGB) on cardiovascular response and heart rate (HR) variability in elderly patients during anesthesia induction and endotracheal intubation.DesignA randomized, double-blinded, and placebo-controlled study.SettingUniversity-affiliated teaching hospital.ParticipantsEighty elderly patients (American Society of Anesthesiologists grades I and II) receiving elective surgery during general anesthesia.InterventionsRight stellate ganglion injection (SGB) was performed in all patients using 10 mL of 1% lidocaine or normal saline.MeasurementsSystolic blood pressure (BP), diastolic BP, HR, and calculated rate pressure product. HR variability at the following time points: conscious status before induction (T0); immediately before intubation (T1); immediately after intubation (T2); and 1, 3, and 5 minutes postintubation (T3, T4, and T5).Main ResultsNo significant differences in BP and HR were observed between the 2 groups. Rate pressure product values significantly increased in the control group compared with baseline and SGB group values. Low-frequency power (LF) and LF/high-frequency power (HF) significantly increased, and HF and normalized units of HF significantly decreased in the control group compared with baseline values. LF, normalized units of LF, and LF/HF in the SGB group significantly decreased compared with those of the control group.ConclusionSGB protects the myocardium and effectively suppresses stress responses during anesthesia induction and tracheal intubation in elderly patients.