Autonomic cardiac regulation after general anesthesia in children.

Background: General anesthesia dramatically decreases the activity of the autonomic nervous system. Most of the hypnotic agents used to induce anesthesia inhibit sympathetic cardiovascular regulation and baroreflex control in a dose-dependent manner, lowering cardiac adaptability during the operation. The consequence of this effect in children during and after surgery has never been studied to date.

Aim: The aim of this study was to follow the variations in autonomic cardiac indices in children younger than 8 years old after general anesthesia (6-24 hours) in programmed surgery.

Method: A prospective descriptive monocentric study of 44 children under 8 years old who underwent scheduled surgery at our hospital center (Saint-Étienne University Hospital, France) was performed between June 1, 2016 and November 1, 2016. Heart rate variability was monitored for 24 hours using Holter-ECG devices and the resulting data were interpreted using linear and nonlinear analyses.

Results: Compared to baseline thresholds before surgery, all heart rate variability indices decreased dramatically during general anesthesia. After awakening, a slight reduction in sympathetic activity persisted 6 hours after surgery, but all measurements of sympathetic and parasympathetic activity had returned to baseline thresholds 12 hours after the operation. Twenty-four hours after surgery, some parameters had increased above the corresponding baseline levels.

Conclusion: Autonomic nervous function normalizes rapidly (within 12 hours) in prepubertal children. This study indicates that general anesthesia does not seem to increase the long-term risk of autonomic dysfunction in these patients.