Association between postsurgical pain and heart rate variability: protocol for a scoping review

Abstract

IntroductionSurgical interventions can elicit neuroendocrine responses and sympathovagal imbalance, ultimately affecting cardiac autonomic function. Cardiac complications account for 30% of postoperative complications and are the leading cause of morbidity and mortality following non-cardiac surgery. One cardiovascular parameter, heart rate variability (HRV), has been found to be predictive of postoperative morbidity and mortality. HRV is defined as variation in time intervals between heartbeats and is affected by cardiac autonomic balance. Furthermore, altered HRV has been shown to predict cardiovascular events in non-surgical settings. In multiple studies, experimentally induced pain in healthy humans leads to reduced HRV suggesting a causal relationship. In a different studies, chronic pain has been associated with altered HRV, however, in the setting of clinical pain conditions, it remains unclear how much HRV impairment is due to pain itself versus autonomic changes related to analgesia. We aim to review the available evidence describing the association between postsurgical pain and HRV alterations in the early postoperative period.Methods and analysisWe will conduct a scoping review of relevant studies using detailed searches of MEDLINE and EMBASE, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Included studies will involve participants undergoing non-cardiac surgery and investigate outcomes of (1) measures of pain intensity; (2) measures of HRV and (3) statistical assessment of association between #1 and #2. As secondary review outcomes included studies will also be examined for other cardiovascular events and for their attempts to control for analgesic treatment and presurgical HRV differences among treatment groups in the analysis. This work aims to synthesise available evidence to inform future research questions related to postsurgical pain and cardiac complications.Ethics and disseminationEthics review and approval is not required for this review. The results will be submitted for publication in peer-reviewed journals.

Heart Rate Variability and Coronary Artery Bypass Grafting: A Systematic Review

“…Decreases in HRV 6 weeks after surgery may be associated with the acute effects of the operation including: surgical manipulations, prolonged aortic cross-clamping, use of ice slush, ischemia or dysfunction of cardiac ANS regulation post-CABG [ 32 , 33 , 34 ]. Anxiety about the danger and the pain of the surgery are also likely also to contribute to the reduction in HRV [ 35 ].…”

Scoping review of the association between postsurgical pain and heart rate variability parameters

“…A flow diagram of the search results is shown in Figure 1. A detailed search of MEDLINE and EMBASE was conducted according to our published protocol 57 and yielded 230 records. No additional studies were identified in clinical trial registries or reference lists of included studies.…”

“…The review protocol has been previously published 57 and was written in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. 45…”