Efficacy of therapeutic suggestions for improved postoperative recovery presented during general anesthesia

Therapeutic Suggestion in Postoperative Pain Control: A Randomized Controlled Trial

OBJECTIVES

There is conflicting research on the effect of therapeutic suggestion in the perioperative period. This study systematically compared subjective and objective measures of postoperative pain, nausea and vomiting, urinary and bowel function, and global perception of symptomatic improvement between participants receiving perioperative therapeutic suggestion versus routine perioperative care during minimally invasive pelvic reconstructive surgery.

METHODS

This was a single-blinded, randomized controlled trial of participants undergoing vaginal hysterectomy with minimally invasive sacrocolpopexy and concomitant prolapse repairs. The intervention group received perioperative therapeutic suggestion, whereas the control group did not. Primary outcomes included postoperative pain scores and analgesic use. Secondary outcomes included a postoperative nausea and vomiting scale, the Pelvic Floor Distress Inventory Questionnaire-Short Form 20, the Patient Global Impression of Improvement scale, and time to return of bowel and bladder function.

RESULTS

Sixteen participants were randomized to each group. Final analysis included 15 intervention and 14 control participants. Overall measures of postoperative pain and analgesic use were low across all participants without a significant difference between intervention and control groups (opioid: 52.5; interquartile range [IQR], 25.5-58.9 vs 66 IQR, 7.3-125.8; morphine milligram equivalents; P = 0.64; acetaminophen: 2225 mg; IQR, 500-2600 mg vs 2800 mg; IQR, 650-4775 mg; P = 0.38). There were no statistically significant differences in secondary outcomes of urinary symptoms, bowel function, and subjective improvement of prolapse symptoms.

CONCLUSIONS

No differences in postoperative pain, analgesic use, return of bowel and bladder function, or pelvic organ prolapse symptoms were noted in participants receiving perioperative therapeutic suggestion versus routine perioperative care.

Perception of auditory stimuli during general anesthesia and its effects on patient outcomes: a systematic review and meta-analysis

Purpose

Interest in implicit memory formation and unconscious auditory stimulus perception during general anesthesia has resurfaced as perioperative music has been reported to produce beneficial effects. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating explicit and implicit memory formation during general anesthesia and its effects on postoperative patient outcomes and recovery.

Source

We performed a systematic literature search of Embase, Ovid Medline, and Cochrane Central from inception date until 15 October 2020. Eligible for inclusion were RCTs investigating intraoperative auditory stimulation in adult surgical patients under general anesthesia in which patients, healthcare staff, and outcome assessors were all blinded. We used random effects models for meta-analyses. This study adhered to the PRISMA guidelines and was registered in PROSPERO (CRD42020178087).

Principal findings

Fifty-three (4,200 patients) of 5,859 identified articles were included. There was evidence of implicit memory formation in seven out of 17 studies (41%) when assessed using perceptual priming tasks. Mixed results were observed on postoperative behavioural and motor response after intraoperative suggestions. Intraoperative music significantly reduced postoperative pain (standardized mean difference [SMD], -0.84; 95% confidence interval [CI], -1.1 to -0.57; P < 0.001; I² = 0; n = 226) and opioid requirements (SMD, -0.29; 95% CI, -0.57 to -0.015; P = 0.039; I² = 36; n = 336), while positive therapeutic suggestions did not.

Conclusion

The results of this systematic review and meta-analysis show that intraoperative auditory stimuli can be perceived and processed during clinically adequate, general anesthesia irrespective of surgical procedure severity, leading to implicit memory formation without explicit awareness. Intraoperative music can exert significant beneficial effects on postoperative pain and opioid requirements. Whether the employed intraoperative anesthesia regimen is of influence is not yet clear.

Electronic supplementary material

The online version of this article (10.1007/s12630-021-02015-0) contains supplementary material, which is available to authorized users.

Postoperative Multimodal Analgesia in Cardiac Surgery

Multimodal pain management of cardiac surgical patients is a paradigm shift in postoperative care. This promising approach features complementary medications and techniques that spare opioids and improves symptomatic and functional recovery. Although the specific elements remain to be defined, the collaboration of the health care team and patient and continuous iterative programmatic improvements are important pillars of this approach.

Mind-Body Therapies for Opioid-Treated Pain: A Systematic Review and Meta-analysis

Importance

Mind-body therapies (MBTs) are emerging as potential tools for addressing the opioid crisis. Knowing whether mind-body therapies may benefit patients treated with opioids for acute, procedural, and chronic pain conditions may be useful for prescribers, payers, policy makers, and patients.

Objective

To evaluate the association of MBTs with pain and opioid dose reduction in a diverse adult population with clinical pain.

Data Sources

For this systematic review and meta-analysis, the MEDLINE, Embase, Emcare, CINAHL, PsycINFO, and Cochrane Library databases were searched for English-language randomized clinical trials and systematic reviews from date of inception to March 2018. Search logic included (pain OR analgesia OR opioids) AND mind-body therapies. The gray literature, ClinicalTrials.gov, and relevant bibliographies were also searched.

Study Selection

Randomized clinical trials that evaluated the use of MBTs for symptom management in adults also prescribed opioids for clinical pain.

Data Extraction and Synthesis

Independent reviewers screened citations, extracted data, and assessed risk of bias. Meta-analyses were conducted using standardized mean differences in pain and opioid dose to obtain aggregate estimates of effect size with 95% CIs.

Main Outcomes and Measures

The primary outcome was pain intensity. The secondary outcomes were opioid dose, opioid misuse, opioid craving, disability, or function.

Results

Of 4212 citations reviewed, 60 reports with 6404 participants were included in the meta-analysis. Overall, MBTs were associated with pain reduction (Cohen d = -0.51; 95% CI, -0.76 to -0.26) and reduced opioid dose (Cohen d = -0.26; 95% CI, -0.44 to -0.08). Studies tested meditation (n = 5), hypnosis (n = 25), relaxation (n = 14), guided imagery (n = 7), therapeutic suggestion (n = 6), and cognitive behavioral therapy (n = 7) interventions. Moderate to large effect size improvements in pain outcomes were found for meditation (Cohen d = -0.70), hypnosis (Cohen d = -0.54), suggestion (Cohen d = -0.68), and cognitive behavioral therapy (Cohen d = -0.43) but not for other MBTs. Although most meditation (n = 4 [80%]), cognitive-behavioral therapy (n = 4 [57%]), and hypnosis (n = 12 [63%]) studies found improved opioid-related outcomes, fewer studies of suggestion, guided imagery, and relaxation reported such improvements. Most MBT studies used active or placebo controls and were judged to be at low risk of bias.

Conclusions and Relevance

The findings suggest that MBTs are associated with moderate improvements in pain and small reductions in opioid dose and may be associated with therapeutic benefits for opioid-related problems, such as opioid craving and misuse. Future studies should carefully quantify opioid dosing variables to determine the association of mind-body therapies with opioid-related outcomes.

Efficacy of therapeutic suggestions under general anesthesia: a systematic review and meta-analysis of randomized controlled trials

Background

General anesthesia does not block central nervous processing of auditive information. Therefore, positive suggestions even given during surgery might have the potential to encourage well-being and recovery of patients.

Aim of this review was to summarize the evidence on the efficacy of therapeutic suggestions under general anesthesia in adults undergoing surgery compared to an attention control (i.e. white noise).

Methods

We included randomized controlled trials that investigated therapeutic suggestions presented during general anesthesia to adult patients undergoing surgery or medical procedures. Outcomes on pain intensity, mental distress, recovery, use of medication, measured postoperatively within hospitalization were considered. Electronic searches were carried out in the following databases (last search February 23, 2015): MEDLINE, CENTRAL, Web of Science, PsycINFO, ProQuest Dissertations and Theses.

Results

Thirty-two eligible randomized controlled trials were included, comprising a total of 2102 patients. All studies used taped suggestions. Random effects meta-analyses revealed no effects on pain intensity (Hedges’ g = 0.04, CI 95% [−0.04; 0.12], number needed to treat [NNT] = 44.3) and mental distress (g = 0.03, CI 95% [−0.11; 0.16], NNT = 68.2). In contrast, we found small but significant positive effects on use of medication (g = 0.19, CI 95% [0.09; 0.29], NNT = 9.2) and on recovery (g = 0.14, CI 95% [0.03; 0.25], NNT = 13.0). All effects were homogeneous and robust.

Conclusions

Even though effects were small, our results provide indications that intraoperative suggestions can have the potential to reduce the need for medication and enhance recovery. Further high quality trials are needed to strengthen the promising evidence on the efficacy of therapeutic suggestions under general anesthesia for patients undergoing surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0292-0) contains supplementary material, which is available to authorized users.

Management of Postoperative Pain: A Clinical Practice Guideline From the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists' Committee on Regional Anesthesia, Executive Committee, and Administrative Council

Most patients who undergo surgical procedures experience acute postoperative pain, but evidence suggests that less than half report adequate postoperative pain relief. Many preoperative, intraoperative, and postoperative interventions and management strategies are available for reducing and managing postoperative pain. The American Pain Society, with input from the American Society of Anesthesiologists, commissioned an interdisciplinary expert panel to develop a clinical practice guideline to promote evidence-based, effective, and safer postoperative pain management in children and adults. The guideline was subsequently approved by the American Society for Regional Anesthesia. As part of the guideline development process, a systematic review was commissioned on various aspects related to various interventions and management strategies for postoperative pain. After a review of the evidence, the expert panel formulated recommendations that addressed various aspects of postoperative pain management, including preoperative education, perioperative pain management planning, use of different pharmacological and nonpharmacological modalities, organizational policies, and transition to outpatient care. The recommendations are based on the underlying premise that optimal management begins in the preoperative period with an assessment of the patient and development of a plan of care tailored to the individual and the surgical procedure involved. The panel found that evidence supports the use of multimodal regimens in many situations, although the exact components of effective multimodal care will vary depending on the patient, setting, and surgical procedure. Although these guidelines are based on a systematic review of the evidence on management of postoperative pain, the panel identified numerous research gaps. Of 32 recommendations, 4 were assessed as being supported by high-quality evidence, and 11 (in the areas of patient education and perioperative planning, patient assessment, organizational structures and policies, and transitioning to outpatient care) were made on the basis of low-quality evidence.

PERSPECTIVE

This guideline, on the basis of a systematic review of the evidence on postoperative pain management, provides recommendations developed by a multidisciplinary expert panel. Safe and effective postoperative pain management should be on the basis of a plan of care tailored to the individual and the surgical procedure involved, and multimodal regimens are recommended in many situations.

Anaesthetic interventions for prevention of awareness during surgery

BACKGROUND

General anaesthesia is usually associated with unconsciousness. 'Awareness' is when patients have postoperative recall of events or experiences during surgery. 'Wakefulness' is when patients become conscious during surgery, but have no postoperative recollection of the period of consciousness.

OBJECTIVES

To evaluate the efficacy of two types of anaesthetic interventions in reducing clinically significant awareness:- anaesthetic drug regimens; and- intraoperative anaesthetic depth monitors.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, ISSUE 4 2016); PubMed from 1950 to April 2016; MEDLINE from 1950 to April 2016; and Embase from 1980 to April 2016. We contacted experts to identify additional studies. We performed a handsearch of the citations in the review. We did not search trial registries.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of either anaesthetic regimens or anaesthetic depth monitors. We excluded volunteer studies, studies of patients prior to skin incision, intensive care unit studies, and studies that only randomized different word presentations for memory tests (not anaesthetic interventions).Anaesthetic drug regimens included studies of induction or maintenance, or both. Anaesthetic depth monitors included the Bispectral Index monitor, M-Entropy, Narcotrend monitor, cerebral function monitor, cerebral state monitor, patient state index, and lower oesophageal contractility monitor. The use of anaesthetic depth monitors allows the titration of anaesthetic drugs to maintain unconsciousness.

DATA COLLECTION AND ANALYSIS

At least two authors independently scanned abstracts, extracted data from the studies, and evaluated studies for risk of bias. We made attempts to contact all authors for additional clarification. We performed meta-analysis statistics in packages of the R language.

MAIN RESULTS

We included 160 studies with 54,109 enrolled participants; 53,713 participants started the studies and 50,034 completed the studies or data analysis (or both). We could not use 115 RCTs in meta-analytic comparisons because they had zero awareness events. We did not merge 27 of the remaining 45 studies because they had excessive clinical and methodological heterogeneity. We pooled the remaining 18 eligible RCTs in meta-analysis. There are 10 studies awaiting classification which we will process when we update the review.The meta-analyses included 18 trials with 36,034 participants. In the analysis of anaesthetic depth monitoring (either Bispectral Index or M-entropy) versus standard clinical and electronic monitoring, there were nine trials with 34,744 participants. The overall event rate was 0.5%. The effect favoured neither anaesthetic depth monitoring nor standard clinical and electronic monitoring, with little precision in the odds ratio (OR) estimate (OR 0.98, 95% confidence interval (CI) 0.59 to 1.62).In a five-study subset of Bispectral Index monitoring versus standard clinical and electronic monitoring, with 34,181 participants, 503 participants gave awareness reports to a blinded, expert panel who adjudicated or judged the outcome for each patient after reviewing the questionnaires: no awareness, possible awareness, or definite awareness. Experts judged 351 patient awareness reports to have no awareness, 87 to have possible awareness, and 65 to have definite awareness. The effect size favoured neither Bispectral Index monitoring nor standard clinical and electronic monitoring, with little precision in the OR estimate for the combination of definite and possible awareness (OR 0.96, 95% CI 0.35 to 2.65). The effect size favoured Bispectral Index monitoring for definite awareness, but with little precision in the OR estimate (OR 0.60, 95% CI 0.13 to 2.75).We performed three smaller meta-analyses of anaesthetic drugs. There were nine studies with 1290 participants. Wakefulness was reduced by ketamine and etomidate compared to thiopental. Wakefulness was more frequent than awareness. Benzodiazepines reduces awareness compared to thiopental, ketamine, and placebo., Also, higher doses of inhaled anaesthetics versus lower doses reduced the risk of awareness.We graded the quality of the evidence as low or very low in the 'Summary of findings' tables for the five comparisons.Most of the secondary outcomes in this review were not reported in the included RCTs.

AUTHORS' CONCLUSIONS

Anaesthetic depth monitors may have similar effects to standard clinical and electrical monitoring on the risk of awareness during surgery. In older studies comparing anaesthetics in a smaller portion of the patient sample, wakefulness occurred more frequently than awareness. Use of etomidate and ketamine lowered the risk of wakefulness compared to thiopental. Benzodiazepines compared to thiopental and ketamine, or higher doses of inhaled anaesthetics versus lower doses, reduced the risk of awareness.

Disseminating hypnosis to health care settings: Applying the RE-AIM framework

Hypnosis is a brief intervention ready for wider dissemination in medical contexts. Overall, hypnosis remains underused despite evidence supporting its beneficial clinical impact. This review will evaluate the evidence supporting hypnosis for dissemination using guidelines formulated by Glasgow and colleagues (1999). Five dissemination dimensions will be considered: Reach, Efficacy, Adoption, Implementation, and Maintenance (RE-AIM).

REACH

In medical settings, hypnosis is capable of helping a diverse range of individuals with a wide variety of problems.

EFFICACY

There is evidence supporting the use of hypnosis for chronic pain, acute pain and emotional distress arising from medical procedures and conditions, cancer treatment-related side-effects and irritable bowel syndrome.

ADOPTION

Although hypnosis is currently not a part of mainstream clinical practices, evidence suggests that patients and healthcare providers are open to trying hypnosis, and may become more so when educated about what hypnosis can do.

IMPLEMENTATION

Hypnosis is a brief intervention capable of being administered effectively by healthcare providers.

MAINTENANCE

Given the low resource needs of hypnosis, opportunities for reimbursement, and the ability of the intervention to potentially help medical settings reduce costs, the intervention has the qualities necessary to be integrated into routine care in a self-sustaining way in medical settings. In sum, hypnosis is a promising candidate for further dissemination.

Positive suggestion techniques in somatic medicine: A review of the empirical studies

INTRODUCTION

THERE IS AN EVER REOCCURRING QUESTION IN MEDICAL PRACTICE: Does the positive attitude and communication of the medical staff make any difference?

AIM

Our aim is to present a comprehensive overview of the medically relevant effects of positive suggestions by reviewing the recent literature.

METHODS

We will review the studies measuring the effects of suggestive communication of the past 20 years. In cases of studies presented in more details we quote from the suggestion scripts used in the study, too.

RESULTS

Some of the reviewed papers report that positive suggestions lead to decreased pain and use of pain medication and positively affect physiological factors like bowel motility, blood pressure and bleeding during surgery as well. However, the literature also contains studies in which only partial or no positive effects were found.

CONCLUSIONS

We emphasize further, more detailed investigation of positive suggestion techniques and its integration into the education of medical professionals.

[Positive suggestion techniques in somatic medicine]

There is a re-occurring question in medical practice: do positive attitude and communication of the medical staff make any difference?

AIM

Our aim is to present a comprehensive image of the medically relevant effects of positive suggestions by reviewing the recent literature.

METHODS

We review the studies measuring the effects of suggestive communication of the past 20 years. In cases of studies presented in more details we quote from the suggestion scripts used in the study, too.

RESULTS

Most of the reviewed papers affirm that positive suggestions lead to decreased pain and use of pain medication. But physiological factors like bowel motility, blood pressure and bleeding during surgery can be positively affected, too.

CONCLUSIONS

Suggestive communication - a yet poorly utilized tool - used appropriately can significantly affect healing and recovery of a patient. Thus we emphasize further, more detailed study of this technique and its integration into the education of medical professionals.

Factors that influence pain intensity and fentanyl requirements after a gynecologic laparotomy

The association between pain intensity and its control by intravenous patient-controlled analgesia (IV-PCA) with fentanyl after a laparotomy for cystectomy/salphingoophorectomy, myomectomy, or hysterectomy was investigated. IV fentanyl infusion was administered to patients (n = 94) at 3 μg/kg/h to provide intraoperative analgesia after induction of general anesthesia. Postoperative fentanyl requirements were quantified via IV-PCA, and the amounts of rescue fentanyl required both during and after surgery were recorded. Mean values for PCA use as well as the visual analog scores (VAS) for pain were documented for up to 24 hours. The association between postoperative fentanyl requirements and VAS were then analyzed by using Mann-Whitney or Kruskal-Wallis tests. Patients with lower midline incisions had greater degrees of pain (p < .05) during the first 16 hours after surgery but did not consume more fentanyl compared with patients with Pfannenstiel incisions. Subjects who underwent operations lasting >4 hours required more rescue fentanyl during surgery (p < .05). However, this group consumed less fentanyl during the first 4 hours after surgery (p < .05). The demand at the fourth 4-hour period was lower among subjects undergoing myomectomy compared with cystectomy/salphingoophorectomy or hysterectomy (p = .045). Only a poor correlation was observed between pain intensity and analgesic usage. Postoperative pain intensity is influenced by the type of surgical incision but not the type of gynecologic surgery nor the duration of surgery. The relationship between subjective pain ratings with analgesic consumption is weak. Prolonged intraoperative administration of continuous IV fentanyl infusion may reduce fentanyl requirements in the immediate postoperative period.

VIRTUAL REALITY HYPNOSIS

Scientific evidence for the viability of hypnosis as a treatment for pain has flourished over the past two decades (Rainville, Duncan, Price, Carrier and Bushnell, 1997; Montgomery, DuHamel and Redd, 2000; Lang and Rosen, 2002; Patterson and Jensen, 2003). However its widespread use has been limited by factors such as the advanced expertise, time and effort required by clinicians to provide hypnosis, and the cognitive effort required by patients to engage in hypnosis.The theory in developing virtual reality hypnosis was to apply three-dimensional, immersive, virtual reality technology to guide the patient through the same steps used when hypnosis is induced through an interpersonal process. Virtual reality replaces many of the stimuli that the patients have to struggle to imagine via verbal cueing from the therapist. The purpose of this paper is to explore how virtual reality may be useful in delivering hypnosis, and to summarize the scientific literature to date. We will also explore various theoretical and methodological issues that can guide future research.In spite of the encouraging scientific and clinical findings, hypnosis for analgesia is not universally used in medical centres. One reason for the slow acceptance is the extensive provider training required in order for hypnosis to be an effective pain management modality. Training in hypnosis is not commonly offered in medical schools or even psychology graduate curricula. Another reason is that hypnosis requires far more time and effort to administer than an analgesic pill or injection. Hypnosis requires training, skill and patience to deliver in medical centres that are often fast-paced and highly demanding of clinician time. Finally, the attention and cognitive effort required for hypnosis may be more than patients in an acute care setting, who may be under the influence of opiates and benzodiazepines, are able to impart. It is a challenge to make hypnosis a standard part of care in this environment.Over the past 25 years, researchers have been investigating ways to make hypnosis more standardized and accessible. There have been a handful of studies that have looked at the efficacy of using audiotapes to provide the hypnotic intervention (Johnson and Wiese, 1979; Hart, 1980; Block, Ghoneim, Sum Ping and Ali, 1991; Enqvist, Bjorklund, Engman and Jakobsson, 1997; Eberhart, Doring, Holzrichter, Roscher and Seeling, 1998; Perugini, Kirsch, Allen, et al., 1998; Forbes, MacAuley, Chiotakakou-Faliakou, 2000; Ghoneim, Block, Sarasin, Davis and Marchman, 2000). These studies have yielded mixed results. Generally, we can conclude that audio-taped hypnosis is more effective than no treatment at all, but less effective than the presence of a live hypnotherapist. Grant and Nash (1995) were the first to use computer-assisted hypnosis as a behavioural measure to assess hypnotizability. They used a digitized voice that guided subjects through a procedure and tailored software according to the subject's unique responses and reactions. However, it utilized conventional two-dimensional screen technology that required patients to focus their attention on a computer screen, making them vulnerable to any type of distraction that might enter the environment. Further, the two-dimensional technology did not present compelling visual stimuli for capturing the user's attention.

HYPNOSIS TO MANAGE DISTRESS RELATED TO MEDICAL PROCEDURES: A META-ANALYSIS

This meta-analysis evaluates the effect of hypnosis in reducing emotional distress associated with medical procedures. PsycINFO and PubMed were searched from their inception through February 2008. Randomized controlled trials of hypnosis interventions, administered in the context of clinical medical procedures, with a distress outcome, were included in the meta-analysis (26 of 61 papers initially reviewed). Information on sample size, study methodology, participant age and outcomes were abstracted independently by 2 authors using a standardized form. Disagreements were resolved by consensus. Effects from the 26 trials were based on 2342 participants. Results indicated an overall large effect size (ES) of 0.88 (95% CI = 0.57-1.19) in favour of hypnosis. Effect sizes differed significantly (p < 0.01) according to age (children benefitted to a greater extent than adults) and method of hypnosis delivery, but did not differ based on the control condition used (standard care vs. attention control).

Hypnotic analgesia

Hypnosis has been used for centuries to treat various types of pain problems. Anecdotal reports of its efficacy have been around since the early 1800 s, but only recently has sophisticated research advanced the field. This paper will summarize the theoretical and clinical foundations of hypnotic analgesia, as well as offer recommendations for increasing its efficacy and improving future research to advance the field.

Effect of communication on pain during intravenous cannulation: a randomized controlled trial

BACKGROUND

Clinicians frequently warn patients of discomfort before potentially painful procedures, despite the lack of evidence that such communications are helpful. We aimed to compare two communications (one with, and the other without, a warning of a 'sting') immediately before i.v. cannulation in order to measure differences in perceived pain by patients during the procedure.

METHODS

Randomly assigned patients awaiting elective surgery received a communication immediately before i.v. cannulation consisting of either 'I am going to apply the tourniquet and insert the needle in a few moments. It's a sharp scratch and it may sting a little' (Group S) or 'I am going to apply the tourniquet on the arm. As I do this many people find the arm becomes heavy, numb and tingly. This allows the drip to be placed more comfortably' (Group NS). Cannulation pain was measured by a 0-10 verbal numerical rating score (VNRS) and five-point Likert scale.

RESULTS

Of 101 participants, 49 were allocated to Group S and 52 to Group NS. Median VNRS pain scores with inter-quartile ranges (IQR) were 1 and 2, respectively, for both groups. Median Likert scores were 3 in Group S and 2 in Group NS with an IQR of 1 for both groups (P = 0.13). Six participants vocalized pain in Group S and none in Group NS (P = 0.01). Three participants withdrew their arm spontaneously in Group S and none in Group NS (P = 0.11).

CONCLUSIONS

Warning patients of a 'sting' before i.v. cannulation may not be helpful.

Hypnosis and surgery: past, present, and future

Hypnosis has been defined as the induction of a subjective state in which alterations of perception or memory can be elicited by suggestion. Ever since the first public demonstrations of "animal magnetism" by Mesmer in the 18th century, the use of this psychological tool has fascinated the medical community and public alike. The application of hypnosis to alter pain perception and memory dates back centuries. Yet little progress has been made to fully comprehend or appreciate its potential compared to the pharmacologic advances in anesthesiology. Recently, hypnosis has aroused interest, as hypnosis seems to complement and possibly enhance conscious sedation. Contemporary clinical investigators claim that the combination of analgesia and hypnosis is superior to conventional pharmacologic anesthesia for minor surgical cases, with patients and surgeons responding favorably. Simultaneously, basic research of pain pathways involving the nociceptive flexion reflex and positron emission tomography has yielded objective data regarding the physiologic correlates of hypnosis. In this article I review the history, basic scientific and clinical studies, and modern practical considerations of one of the oldest therapeutical tools: the power of suggestion.

The effects of prayer, relaxation technique during general anesthesia on recovery outcomes following cardiac surgery

During general anesthesia the possibility of subconscious perception of intraoperative events is a controversial subject. Some studies found that positive verbal suggestions, or music improved intraoperative relaxation and postoperative recovery. The aim of the current study was to evaluate the effect of prayer and relaxation technique applied while patients are under general anesthesia for open-heart surgery. A randomized, controlled, double-blind trial study included 78 patients who underwent cardiac surgery. During the surgery the patients used a headphone connected to a CD player. They were randomly divided into three groups. One group listened to prayer during the surgery, the other listened to relaxation technique and one, placebo. There was only one significant finding: the prayer group is less likely to believe that prayer would assist conventional medical treatments. Although not statistically significant, we discussed the length of stay (LOS) after surgery and the incidence of sternal wound infection.

Patient-controlled analgesia and intra-operative suggestion

In a double-blind randomised study, we investigated the influence of positive intra-operative suggestions, presented to anaesthetised patients undergoing total abdominal hysterectomy, on postoperative pain, nausea and vomiting. One hundred and forty patients were randomly allocated to listen to one of four tapes containing either white noise or positive suggestions. The positive suggestions related to pain, postoperative nausea and vomiting, or both. We found that the positive intra-operative suggestions had no beneficial effects in reducing postoperative pain or nausea scores, nor was the consumption of morphine or anti-emetics reduced.

Auditory evoked responses and learning and awareness during general anesthesia

BACKGROUND

There is a major distinction between conscious and unconscious learning. Monitoring the mid-latency auditory evoked responses (AER) has been proposed as a measure to ascertain the adequacy of the hypnotic state during surgery. In the present study, we investigated the presence of explicit and implicit memories after anesthesia and examined the relationships of such memories to the AER.

METHODS

We studied 180 patients scheduled for elective surgical procedures. After a thiopental induction, one of four anesthetics were studied: Opioid bolus: 7.5 microg x kg(-1) fentanyl, 70% N2O, with 2.5 microg x kg(-1) supplements as needed (n=100); Opioid infusion: Alfentanil 50 microg x kg(-1) bolus, 1-1.5 microg x kg(-1) x min(-1) infusion, 70% N2O (n=40); Isoflurane 0.3%: Fentanyl 1 microg x kg(-1), 70% N2O, isoflurane 0.3% expired (n=16); Isoflurane 0.7%: Fentanyl 1 microg x kg(-1), 70% N2O, isoflurane 0.7% expired (n=23). AER were recorded before anesthesia, 5 min after surgical incision and then every 30 min until the end of surgery. A tape of either the story of the "Three Little Pigs" or the "Wizard of Oz" was played continuously between the recordings. Explicit memory was assessed postoperatively by tests of recall and recognition, and implicit memory was assessed by the frequency of story-related free associations to target words from the stories, which were solicited twice during a structured interview.

RESULTS

Six patients showed explicit recall of intraoperative events: All received the opioid bolus regimen. About 7% of patients reported dreaming during anesthesia. The incidence of picking the correct story that had been presented during anesthesia averaged 49%, i.e., very close to chance level. Overall, priming occurred only at the second association tests for the opioid bolus regimen, for which the frequency of an association to the presented story among those not giving an association to the control story was 26%, which was double the frequency (13%) of an association to the control story among those not giving an association to the presented story. This was significant by McNemar's test, P=0.02. There were significant associations between awareness, priming and AER, e.g., recall was associated with higher Nb amplitudes during anesthesia and priming was associated with shorter wave latencies.

CONCLUSIONS

The incidence of awareness in patients anesthetized with nitrous oxide and bolus supplementation was 6%. Thus, this anesthetic technique did not reduce the risk of awareness compared with the use of nitrous oxide alone. Implicit memory occurred during nitrous oxide and bolus supplementation. Recording AER during anesthesia may help to predict awareness and implicit memory, particularly the former. The short contents of most of the dreams which were recalled could hamper future studies in this area.

Hemispheric-synchronisation during anaesthesia: a double-blind randomised trial using audiotapes for intra-operative nociception control

The possible antinociceptive effect of hemispheric-synchronised sounds, classical music and blank tape were investigated in patients undergoing surgery under general anaesthesia. The study was performed on 76 patients, ASA 1 or 2, aged 18-75 years using a double-blind randomised design. Each of the three tapes was allocated to the patients according to a computer-generated random number table. General anaesthesia was standardised and consisted of propofol, nitrous oxide 66%/oxygen 33%, isoflurane and fentanyl. Patients breathed spontaneously through a laryngeal mask and the end-tidal isoflurane concentration was maintained near to its minimum alveolar concentration value of 1.2%. Fentanyl was given intravenously sufficient to keep the intra-operative heart rate and arterial blood pressure within 20% of pre-operative baseline values and the fentanyl requirements were used as a measure of nociception control. Patients to whom hemispheric-synchronised sounds were played under general anaesthesia required significantly less fentanyl compared with patients listening to classical music or blank tape (mean values: 28 microgram, 124 microgram and 126 microg, respectively) (p < 0.001). This difference remained significant when regression analysis was used to control for the effects of age and sex.

Awareness during anesthesia and posttraumatic stress disorder

It has been estimated that approximately 30,000 patients a year suffer awareness or consciousness during anesthesia. This paper reviews existing knowledge of the psychological impact and psychiatric sequelae of awareness during anesthesia. Literature on awareness and memory during anesthesia, traumatic memory, and posttraumatic stress disorder (PTSD) was reviewed using computer searches, books, and referenced articles. Few case reports of awareness have identified the accompanying psychological trauma and resulting PTSD. Five published cases illustrating relevant material were selected for inclusion. Waking up during anesthesia, especially if the patient experienced pain, is a traumatic event which places the patient at risk for developing PTSD. Awareness-induced PTSD must be considered for patients who present for mental health treatment following surgery. The advantages of light anesthesia must be balanced against the risk of awareness-induced PTSD.

Unexpected awareness and memory in the perianesthesia setting

Unexpected awareness and memory with general anesthesia are phenomena that can occur in the intriguing interface between consciousness and unconsciousness. Studies suggest that, for some patients, cognitive processing remains active even during deep anesthesia; that is, an apparently unconscious patient still may be registering information. Although explicit memory is usually eliminated by general anesthesia, implicit or subconscious memory may remain. There is no monitor to tell where the patient lies on the continuum between consciousness and unconsciousness. "Sleeping" patients are vulnerable to overhearing inappropriate conversation that may have negative consequences. Post-traumatic stress disorder as well as medical malpractice litigation may result from awareness or memory during anesthesia. Implications for the use of opioids, benzodiazepines, and muscle relaxants in the perianesthesia setting as well as nursing interventions addressing unexpected awareness or memory are discussed.

Are non-pharmacological nursing interventions for the management of pain effective?--A meta-analysis

A meta-analysis of randomized controlled trials (RCTs) assessing the effectiveness of a non-pharmacological intervention on the management of pain was conducted. Forty-nine relevant primary studies were identified and retrieved. Individual mean pain scores from these studies were converted to standardized effect sizes and meta-analyses were conducted. Although there is evidence, in the form of primary studies, to suggest that non-pharmacological nursing interventions are effective in the management of pain, the 49 studies, pooled in this meta-analysis, were too heterogeneous to detect a difference between the treatment and control groups reliably. There is a need to rigorously test these interventions in the form of primary RCTs.

Implicit memory during anaesthesia attempt at replication

The present study investigated implicit memory during general anaesthesia in patients with elective surgery on the cervical or lumbar spine. A total of 37 patients were investigated, together with 59 healthy control subjects. The patients were divided into two groups. One group heard repeated presentations of common words (animals, flowers, countries) during anaesthesia. The other patient group heard only pink noise during anaesthesia. After surgery, all patients were asked spontaneously to name three countries, flowers, and animals. The healthy control subjects were simply asked "on the street" to spontaneously name three countries, flowers and animals. The results showed no statistically significant differences in frequency of hits for the three categories for the three groups. However, the highest hit rate was for the patient group who had heard the words during surgery (35% hits), with no difference between the other two groups (29% hits). The finding of no difference between the groups is discussed in the context of methodological issues when studying memory in anesthesia. It is, furthermore, argued that a healthy nonanesthesized control group is necessary when comparing hit rates between various anesthesized patient groups.

Awareness in anaesthesia: incidence, consequences and prevention

Awareness during anaesthesia is a state of consciousness that is revealed by explicit or implicit memory of intraoperative events. Although large clinical surveys indicate an incidence of explicit awareness of < 0.3% during anaesthesia for general surgery, this adverse effect should be a great concern, because patients may be permanently disabled by the experience of being awake during surgery. Prevention of awareness during anaesthesia starts with an appropriate preoperative visit to the patient. The anaesthetic delivery machines must be properly checked before and during anaesthesia. The anaesthetic depth should be assessed by observation of movement responses, and consequently a minimum of muscle relaxants used. Because the anaesthetic depth can be controlled by determination of endtidal drug concentration, volatile inhaled anaesthesia may be associated with a lower frequency of awareness than other anaesthetic regimens.

Positive intrasurgical suggestion fails to affect postsurgical pain

The present study explored the effect of positive intrasurgical suggestion during the anesthetic state on postsurgical pain. One-half of the patients who were undergoing elective cholecystectomy or hysterectomy received strong positive intrasurgical suggestion directed specifically towards reducing pain. The control patients received information about pain without suggestion content. There was no effect on postsurgical pain measured by the McGill Pain Questionnaire and a visual analogue scale. The lack of effect on postsurgical pain indicates that intrasurgical suggestion does not provide a therapeutic method to achieve pain control.

Neurological and psychiatric adverse effects of anaesthetics: epidemiology and treatment

The practice of anaesthesia has changed considerably over the past 20 to 30 years owing largely to technological advances in patient monitoring and an expanded and improved pharmacological repertoire. While patient safety in anaesthesia has greatly improved, the risk of neurological and psychiatric adverse effects of anaesthetics remains and is the focus of continued investigation. For example, a great deal of attention has recently been directed at intraoperative awareness. This adverse event can be caused by delivering an inappropriate amount or type of anaesthetic. Another risk of anaesthesia involves drug-induced unpleasant subjective states in patients. Those drugs most frequently associated with these states include ketamine, droperidol and scopolamine. This risk can often be attenuated by careful adjustment of drug dose and the use of adjunctive agents such as benzodiazepines which may produce amnesia of the unpleasant subjective state. While it is well established that modern anaesthetic drugs cause acute impairment of cognition and psychomotor functioning, there is little evidence that these drugs have long term impairing effects. Finally, a particular kind of surgery, cardiac surgery requiring cardiopulmonary bypass, can be associated with adverse neurological and psychiatric sequelae which, while not directly related to anaesthesia, are of intense interest to anaesthesiologists.

Non-pharmacological aspects of acute pain management

In this paper, non-pharmacological aspects of acute pain management were explored. Much of the research to date with regard to pain management, has been done, addressing the needs of chronic rather than acute pain. It is thought that misconceptions are still held by some health care professionals regarding the adequacy of pharmacology to deal totally with the problems of acute pain management, and it is of more importance to concentrate on issues associated with chronic pain. This is borne out by the relative attention paid to acute and chronic pain in the current body of research. Some aspects of non-pharmacological methods of pain management have been well researched over the last 20 to 30 years, whilst others are more recent innovations. Non-pharmacological aspects of acute pain management were examined under two headings: 1. Psychological approaches: including preoperative information giving, cognitive methods, relaxation training, distraction, guided imagery, humour, hypnosis, music and biofeedback. 2. Complementary therapies and other techniques: including both hands on and other physical therapies using equipment: massage, aromatherapy, reflex zone therapy, acupuncture, shiatsu, therapeutic touch and TENS. There is a sound body of knowledge to support the use of many of the established nonpharmacological methods in the management of acute pain. These include: appropriate preoperative information giving, preoperative relaxation, guided imagery and breathing training, cognitive reframing, distraction in both visual and auditory (music) forms, massage, acupuncture, TENS. Other methods which may be of assistance in acute pain management but are inconclusive in their effect from the current body of available research and may require further examination include: hypnosis, humour therapy, biofeedback techniques, aromatherapy, reflex zone therapy, shiatsu, Therapeutic Touch.

Subanesthetic concentrations of desflurane and isoflurane suppress explicit and implicit learning

The capacity of desflurane to suppress learning is unknown. We investigated whether a subanesthetic concentration of desflurane (0.6 minimum alevolar anesthetic concentration [MAC]) suppressed learning as much as the same concentration of isoflurane, and whether such suppression differed with increasing duration of anesthesia and intervening changes in anesthetic concentration. Using a cross-over-design study in 18-30 yr-old human volunteers, we supplied answers to Trivial Pursuit (Selchow & Righter Co., Bay Shore, NY)-like questions at 0.6 MAC desflurane and isoflurane before and after imposing a half-hour period at 1.7 MAC of each anesthetic, and behavioral directions and a category-example task at 0.6 MAC after the period at 1.7 MAC. These volunteers had a third anesthesia in which no information was supplied (control). After anesthesia, we tested whether the provision of answers during anesthesia increased the number of correct answers to Trivial Pursuit questions. We tested for the number of correct answers for information presented before versus after the 1.7-MAC period, for increased evocation of examples of categories presented during anesthesia, and for exhibition of a behavior suggested during anesthesia. We found that 0.6 MAC of both anesthetics prevented explicit and implicit learning before and after the period at 1.7 MAC.