In this systematic review, we summarise the effects of perioperative psychological interventions (such as cognitive-behavioural therapies, relaxation techniques, mindfulness-based interventions, hypnosis, coping strategies, and narrative medicine) on surgical pain and/or anxiety in adult patients scheduled for elective general abdominal and/or urologic surgery. Several studies suggest that psychologic/psychosocial, preoperative patient factors directly interact with the pathophysiological mechanisms involved in the surgical stress response (Mavros et al. 2011), potentially influencing wound repair, innate and adaptive immunity, inflammation, perception of pain, and mood. Here, we describe how psychological interventions can influence pain and/or anxiety in abdominal surgery patients through interaction with the pathophysiological mechanisms underlying the neuroendocrine and inflammatory response to surgical stress.
Acute and/or chronic stress, including surgery-related perioperative stress, has been demonstrated to extensively affect patients’ neuroendocrine pathways (Maduka et al. 2015). Interestingly, there is evidence to suggest that psychological therapies might modulate perioperative neuroendocrine homeostasis in patients undergoing abdominal surgery (Manyande et al. 1995). On this basis, considering in particular the neuroendocrine effects of psychological interventions on endogenous opioid response and gate control system, Roykulcharoen and colleagues designed a randomised controlled trial aimed at demonstrating the positive effect of systematic relaxation on postoperative pain in abdominal surgical patients (Roykulcharoen et al. 2004). In this study, subjective (based on VAS scores) and objective (based on 6-h opioid intake) assessment of pain revealed that patients randomised to relaxation therapy experienced less postoperative pain (Roykulcharoen et al. 2004). Using a similar approach, Good and colleagues explored the effects of relaxation therapy in a randomised controlled trial with 517 abdominal surgery patients (Good et al. 2010). The rationale for this study is the ability of relaxation therapies to enhance a natural analgesic effect via increased parasympathetic activity and endogenous inhibitory mechanisms. In this study, psychological treatments were associated with a 25% reduction in VAS scores postoperatively (Good et al. 2010).
In line with these results, most of the psychological treatments examined in this review seem to be able to increase the secretion of inhibiting hypothalamic hormones, such as somatostatin or dopamine, and decrease the secretion of releasing hormones, such as thyrotropin- and corticotropin-releasing hormones and the growth hormone-releasing factor (Jindal et al. 2013). As a consequence, cortisol levels decrease (Walton et al. 1995) whereas levels of beta-endorphins may increase (Jindal et al. 2013). All these factors may contribute to improve pain experience and reduce anxiety associated with abdominal surgical procedures. Manyande and colleagues designed a controlled trial with 51 patients undergoing general abdominal surgery to test the capability of relaxation techniques and guided imagery to increase the feeling of being able to cope with surgical stress. This study showed that patients in the interventions group had less severe pain and less frequent postoperative complications than those in the control group. In addition, cortisol levels evaluated immediately before and after surgery were lower in patients receiving psychological treatments (Manyande et al. 1995).
Psychologic/psychosocial patient factors have been demonstrated to interact with perioperative inflammation (e.g. cytokine expression (Broadbent et al. 2003)), and thus with wound repair (Glaser et al. 1999) and pain perception. On this basis, considering in particular the effects of psychological stress on leptin resistance, neuropeptide Y and inflammatory cytokines, Sockalingam and colleagues designed an observational prospective pre/post study aimed at demonstrating the positive effect of perioperative cognitive behavioural therapy in a group of abdominal surgery obese patients undergoing bariatric surgery (Sockalingam et al. 2019). The authors demonstrated the positive effect of this type of psychological therapy on postoperative depressive symptoms, anxiety, and eating psychopathology (Sockalingam et al. 2019). In an observational study, Glaser and colleagues associated the symptoms of psychological stress with an ineffective regulatory pattern for IL-1 and IL-8 production in the wound site (Glaser et al. 1999). Similar results were found in an observational study of 47 adult patients undergoing surgical repair of inguinal hernia (Broadbent et al. 2003). The authors described the relationship between psychological stress and wound healing through the tissue levels of IL-1, IL-6, and matrix metalloproteinase-9. In the same study, preoperative psychological stress significantly predicted low levels of IL-1 and matrix metalloproteinase-9 in the surgical wound, as well as severe pain, postoperative complications, and poor and slow recovery (Broadbent et al. 2003). Consistent results were obtained by the same authors in a trial with 60 patients undergoing videolaparoscopic cholecystectomy randomised to treatment with relaxation therapies (Broadbent et al. 2012). Specifically, a greater reduction in anxiety and perceived stress was observed in the relaxation group compared with the control group from pre-intervention to 7-day follow-up (p < 0.05). Interestingly, the authors observed that patients treated with perioperative relaxation therapies had higher hydroxyproline deposition in the wound (i.e. expression of tissue repair) than those in the control group (difference in means 0.35, p = 0.03).
The interactions between psychological treatments and pathophysiology of surgical stress response might explain why these treatments have been associated with reduction of perioperative pain, anxiety, and pharmacological treatment requirements.
Hizli and others designed a randomised controlled trial including 64 patients scheduled for transrectal ultrasound-guided prostate needle biopsy to investigate the effects of hypnosis on pain and anxiety. Patients were randomised to receive a 10-min presurgery hypnosis session involving suggestions for increased relaxation and decreased anxiety. Post-intervention, and before surgery, patients in the hypnosis group had significantly lower mean values of pain and anxiety, measured using visual analogic scales, Beck Anxiety Inventory, and Hamilton Anxiety Scale, respectively (Hızlı et al. 2015). Similar results were obtained by Lin and colleagues from a randomised controlled trial involving 62 patients scheduled for abdominal surgical procedures. The authors found that preoperative coping procedures (such as nursing intervention for pain) had positive effects on preoperative pain anxiety, preoperative pain attitude, and pain perception (Lin and Wang 2005).
Interestingly, most of the studies identified in this systematic review mainly relied on subjective measures of pain, such as the visual-analogic or the numeric rating scales. Only two studies (Rejeh et al. 2013; Roykulcharoen et al. 2004) assessed the effects of psychological interventions on perioperative pain through objective measurements, e.g., analgesic requirements. Although both studies show consistent results on the effects of psychological therapies in reducing analgesic requirements, only in the randomised controlled trial by Rejeh et al. were these effects statistically significant (Rejeh et al. 2013).
As far as we are aware, this is the first systematic review focusing on the effects of psychological treatments on surgical pain and anxiety in patients undergoing abdominal and/or urologic surgery. Previous systematic reviews and metanalyses aimed at assessing the effects of psychological interventions in the context of orthopaedic or cardiac surgery. Results from our review are generally consistent with those obtained from studies involving orthopaedic or cardiac surgery patients. In particular, in a systematic review of 62 relevant studies published from January 1980 to September 2016, Szeverenyi and colleagues found that psychosocial interventions significantly reduced postoperative pain (Hedges’ g = 0.31 [95% CI = 0.14, 0.48]), and pre- and postoperative anxiety (g = 0.26 [0.11, 0.42] and g = 0.4 [0.21, 0.59], respectively), while no significant effects were associated to postoperative analgesic use (g = 0.16 [95%CI = 0.01, 0.32]. Similar findings were found by Rees and colleagues in a metanalysis exploring the effects of psychological treatments in patients with coronary artery diseases undergoing cardiac surgery. Analysing results from 36 trials including 12,841 patients, the authors showed a perioperative reduction in anxiety and depression. Notably, in both studies the authors included a higher number of studies compared with our review. That can be explained considering both the different temporal limits used for literature search and the historical interest among physicians in reducing symptoms related to the most painful surgical procedures, associated with a high incidence of severe postoperative pain and anxiety (e.g. orthopaedic surgery) or to conditions where anxiety and stress may affect patients outcomes (e.g. cardiac surgery). Moreover, differently from what was observed by Szeverenyi and colleagues, we observed a reduction in postoperative pain as well as a reduction in postoperative analgesic use in patients receiving psychological therapies.
The following limitations should be acknowledged. First, studies were limited to English language. Second, in one of the selected studies the effects of perioperative psychological interventions were studied in a cohort of bariatric patients. The peculiar psychological features of this population usually differ from those observed in the majority of abdominal and/or urologic surgical patients, potentially limiting the generalisation of the results. Third, in most studies perioperative pain was assessed through subjective scales (e.g. VAS or NRS). More objective indicators of intervention success (e.g. analgesic requirements) were used only in two of the identified studies.
Finally, the treatments explored and the outcomes observed in this review are different among the selected studies. For these reasons, a synthesis of the evidence on effectiveness of psychological treatments in reducing perioperative anxiety and pain has not been provided. Nonetheless, results seem to suggest a positive effect on anxiety and pain, that certainly merits further investigation in the abdominal/urologic setting.