Heart Rate Variability in Children Submitted to Surgery

Abstract

Objective: Heart Rate Variability (HRV) is known to reflect the sympathetic/parasympathetic interaction on several physiological and pathological conditions such as the cardiac activity responsiveness to physiological and environmental stimuli. Therefore, it has been widely used to assess nervous autonomic fluctuations and their influence on sinus node. Studies on children have demonstrated the correlation between HRV and different parameters like age, gender, physical activity and autonomic diseases whereas little evidence exists of the effects of surgery and residual anesthesic drugs on HRV. The aim of this study was to define the possible role of minor surgery in HRV in healthy children.Design: Observational prospective cohort study.Setting: Pediatric Surgery Department of a tertiary, university-affiliated hospital.Patients: 47 healthy children who were scheduled for elective minor surgery.Measurements and Main Results: HRV measurements of 10 to 15 minutes were obtained before and after surgery, using a Holter recorder and the BioSigBrowser ® software. Results showed significant differences in HRV time domain indices before and after surgery in younger patients and in frequency domain in the older ones. They also demonstrated decreased HRV indices until one hour after being submitted to surgery in both time domain and LF parameters, reflecting a parasympathetic withdrawal and sympathetic predominance. Differences were also found when analyzing other variables such as anesthetic drugs. Conclusion:This study demonstrated that surgery has impact on Autonomic Nervous System function in healthy children but, independently of anesthetic drugs, type of surgery, age and existence of pain 60 minutes after surgery no difference in HRV measures was found and autonomic homeostasis was re-established. However, further investigation in this area is required in order to a better support of the role of HRV monitoring on early prognosis prediction and risk stratification in the surgical context.