Association of Wearable Derived Pulse Rate Variability With Pediatric Appendectomy Complications

Introduction: Postoperative recovery of children is difficult to gauge by parents after hospital discharge. Consumer wearable devices (CWD) generate valid and near real-time pulse rate data, integer pulse rate variability (PRVi), that can serve as digital biomarkers for the onset of complications during post-discharge recovery. This study sought to explore whether pediatric patients with surgical complications after appendectomy exhibited a CWD-derived PRVi trajectory that differs from the normative PRVi recovery trajectory.

Methods: In this retrospective analysis, children aged 3-17 undergoing appendectomy for complicated appendicitis was invited to participate. Participants wore a Fitbit device for 21 days postoperatively. PRVi was calculated as the variance, defined as the sum of the squared differences of each value from the mean, of the heart rate in beats per minute measured over 5 consecutive minutes. The mean daily PRVi was calculated for patients recovering with and without complications.

Results: Ninety-eight patients were enrolled in the study; 60 (61 %) were ages 3-11, 54 (55 %) were female, and 57 (58 %) were Caucasian. Eleven (11 %) developed surgical complications. Those with complications experienced a slower increase in the mean PRVi over the 21-day period.

Conclusions: In this prospective observational study, it was demonstrated that PRVi derived from CWD data can be used as an objective digital biomarker to profile surgical complications. This finding provides clinicians with an additional tool for monitoring children during the postoperative period, enhancing their ability to proactively detect and address complications.

Level of evidence: IV.