Effect of acupoint transcutaneous electrical nerve stimulation on early postoperative autonomic function after cardiac surgery: a randomised controlled trial
X Zhang, Z R X Luo, W T Duan, W Huang, P M YuAbstract
Background
Autonomic dysfunction frequently occurs during the early postoperative phase after cardiac surgery and may delay recovery. This randomized controlled trial evaluated the safety and efficacy of Acupoint Transcutaneous Electrical Nerve Stimulation (Acu-TENS) in modulating autonomic function and improving early postoperative outcomes.
Methods
Seventy-two adult patients undergoing cardiac surgery were randomized to receive Acu-TENS plus standard care or standard care alone. Acu-TENS was applied bilaterally at PC6 and TE5 for 45 minutes daily for three consecutive postoperative days. Heart rate variability (HRV) metrics (SDNN, rMSSD, LF, HF, and LF/HF ratio) were assessed at discharge. Multivariate analysis and covariance models adjusting for age and baseline HRV metrics were performed. Secondary outcomes included vital signs, ventilation duration, time to mobilization, ICU stay, and 6-minute walk distance (6MWD).
Results
The Acu-TENS group showed significantly higher SDNN, rMSSD, LnLF, and LnHF compared with control group (CG) (all P<0.05), with no significant difference in Ln(LF/HF+1). Multivariate analysis confirmed a significant overall effect on HRV (Pillai’s Trace=0.447, P<0.001), which remained robust after adjustment for age and HRV metrics (all P<0.001). Post-intervention HR was lower in the Acu-TENS group (P=0.010). Mechanical and non-invasive ventilation durations were shorter, and mobilization occurred earlier (all P<0.05). ICU stay and 6MWD did not differ significantly.
Conclusions
Acu-TENS is a safe and feasible non-pharmacological intervention that significantly enhances postoperative autonomic regulation and accelerates early functional recovery following cardiac surgery. These findings support its potential role as an adjunctive strategy during the critical postoperative recovery phase.