Effects of ultrasound-guided stellate ganglion block on autonomic nervous function during CO 2 -pneumoperitoneum: A randomized double-blind control trial

BackgroundCO2-pneumoperitoneum can cause sympathetic nerve activity increased and is likely to causes severe stress-related homeostatic disorders.ObjectivePatients undergoing elective laparoscopic cholecystectomy were administered type-B ultrasound-guided stellate ganglion block (SGB) to observe the effects on autonomic nervous system during CO2- pneumoperitoneum.DesignA randomized, double-blinded, and placebo-controlled study.SettingUniversity-affiliated teaching hospital.PatientsEighty patients (aged 32-75 years; weight, 45-80 kg; American Society of Anesthesiologists (ASA) physical status classification, class I or II) undergoing elective laparoscopic cholecystectomy.InterventionsThe RSGB group was administered lidocaine 1% 7 ml under ultrasound guidance.Main outcome measuresThe low frequency (LF), high frequency (HF), total power (TP) and LF/HF ratio were recorded before the block (T0), 5 min (T1) and 30 min (T2) following pneumoperitoneum, 5 min after deflation of pneumoperitoneum (T3) and after surgery (T4). The low-frequency normalized unit (LFnu) and high-frequency normalized units (HFnu) were calculated.ResultsCompared with T0, LF, LFnu and LF/HF ratio were significantly elevated at T1-4 (all P< .05 or .01). HFnu was significantly decreased at T2-4 in control group (P< .05) while HF was significantly elevated (P< .01). The LF/HF ratio was significantly decreased (P< .05) at T1-4 in RSGB group. Compared with control group, the LF, LFnu and LF/HF ratio were significantly decreased (P< .05) and HF and HFnu was significantly elevated (P< .05 or .01) at T1-4 in RSGB group.ConclusionUltrasound-guided RSGB inhibited CO2-pneumoperitoneum-induced sympathetic neural excitation, upregulated vagal nerve stimulation and maintained stable autonomic nervous function.