Effect of therapeutic suggestions during general anaesthesia on postoperative pain and opioid use: multicentre randomised controlled trial

Abstract

Objective To investigate the effect of therapeutic suggestions played to patients through earphones during surgery on postoperative pain and opioid use. Design Blinded randomised controlled study. Setting Five tertiary care hospitals in Germany. Participants 385 of 400 patients consecutively recruited from January to December 2018 who were to undergo surgery for 1-3 hours under general anaesthesia. In the per protocol analysis 191 patients were included in the intervention group and 194 patients in the control group. Intervention The intervention comprised an audiotape of background music and positive suggestions based on hypnotherapeutic principles, which was played repeatedly for 20 minutes followed by 10 minutes of silence to patients through earphones during general anaesthesia. Patients in the control group were assigned to a blank tape. Main outcome measures The main outcome was dose of opioid administered by patient controlled analgesia or nurse controlled analgesia within the first postoperative 24 hours, based on regular evaluation of pain intensity on a numerical rating scale (range 0-10, with higher scores representing more severe pain). Results Compared with the control group, the intervention group required a significantly (P=0.002) lower opioid dose within 24 hours after surgery, with a median of 4.0 mg (interquartile range 0-8) morphine equivalents versus 5.3 (2-12), and an effect size (Cohen’s d) of 0.36 (95% confidence interval 0.16 to 0.56). The number of patients who needed opioids postoperatively was significantly (P=0.001) reduced in the intervention group: 121 of 191 (63%, 95% confidence interval 45% to 70%) patients in the intervention group versus 155 of 194 (80%, 74% to 85%) in the control group. The number needed to treat to avoid postoperative opioids was 6. Pain scores were consistently and significantly lower in the intervention group within 24 hours after surgery, with an average reduction of 25%. No adverse events were reported. Conclusions Therapeutic suggestions played through earphones during general anaesthesia could provide a safe, feasible, inexpensive, and non-drug technique to reduce postoperative pain and opioid use, with the potential for more general use. Based on the finding of intraoperative perception by a considerable number of patients, surgeons and anaesthetists should be careful about background noise and conversations during surgery. Trial registration German Clinical Trial Register DRKS00013800.

Implications of nocebo in anaesthesia care

“…As many patients are in a trance-like state when under anaesthesia care, there is a concomitant increased responsiveness to suggestion associated with anterior cingulate cortex changes identified on fMRI [42,43]. This recognition and innovations in brain imaging over the last two decades have led to a resurgence of interest in the anaesthetic implications of nocebo and therapeutic suggestions in awake patients and even those undergoing general anaesthesia [44]. Patients whether paediatric [45] or adult, particularly when stressed or pregnant [46], are more likely to experience nocebo effects.…”

Review of Perioperative Music Medicine: Mechanisms of Pain and Stress Reduction Around Surgery

“…There is a large body of research on the effects of music on the ANS in healthy subjects, and findings include significant reductions in heart rate (especially when listening to soft music) (25) in both conscious and unconscious volunteers (26). There is now strong evidence that hearing is perceptive during general anesthesia (27), and auditory stimuli-including music under general anesthesia-could modulate the neurohormonal response to surgery. Cortical auditory evoked responses are not abolished by inhalational anesthetics at the concentrations used for surgery (28).…”

What Does CATS Have to Do With Cancer? The Cognitive Activation Theory of Stress (CATS) Forms the SURGE Model of Chronic Post-surgical Pain in Women With Breast Cancer

“…Of particular relevance here are effects that involve pain reduction, reduced need for medication, and shorter duration of surgery, with effect sizes indicating better clinical outcomes in patients receiving hypnosis than 89% of patients in control groups ( Montgomery et al, 2002 ). Hypnosis has further been shown to be superior to other psychological techniques (e.g., therapeutic suggestions; Kekecs et al, 2014 ) and might also provide benefits when delivered during general anesthesia ( Berlière et al, 2018 ; Lacroix et al, 2019 ; Nowak et al, 2020 ). While studies of long-term effects of hypnosis are scarce, one recent study indicates the potential for preventing CPSP with peri-operative hypnosis ( Berlière et al, 2018 ) in line with the SURGE model of CPSP.…”