Improved recovery and reduced postoperative stay after therapeutic suggestions during general anaesthesia

Awareness during anesthesia: how sure can we be that the patient is sleeping indeed?

Awareness during surgery is a very serious problem for the anesthetist and the patient as well. Such incidents are the cause for 2% of the legal claims against anesthetists while patients with intraoperative awareness experience describe it as the worst thing they have ever suffered from. Pain, anxiety and inability to react due to muscle paralysis often lead to the situation called posttraumatic stress disorder which demands psychiatric support. The fact that there are patients who report intraoperative experience, even several days after surgery, raises questions about the way the anesthetic drugs interfere with the mechanisms of memory and consciousness while, in bibliography, there are studies proving that even deeply anesthetized patients can be influenced by auditory stimuli without being able to recall them. Intraoperative monitoring of the anesthesia depth is important for the prevention of this problem. From all the available devices only the Bispectral Index Monitoring (BIS) has been proven to be effective for this purpose but the high cost per person and the low specificity in preventing awareness episodes do not allow its everyday use. The surgeon and especially the anesthesiologist must be aware of the risk factors, the prevention measures and the actions that must be taken after an awareness incident in order to minimize the unfortunate complications for both the patient and the doctors.

[Measurement of the depth of anaesthesia]

One of the most important mandates of the anaesthesiologist is to control the depth of anaesthesia. An unsolved problem is that a straight definition of the depth of anaesthesia does not exist. Concerning this it is rational to separate hypnosis from analgesia, from muscle relaxation and from block of cardiovascular reactions. Clinical surrogate parameters such as blood pressure and heart rate are not well-suited for a valid statement about the depth of hypnosis. To answer this question the brain has become the focus of interest as the target of anaesthesia. It is possible to visualize the brain's electrical activity from anelectroencephalogram (EEG). The validity of the spontaneous EEG as an anesthetic depth monitor is limited by the multiphasic activity, especially when anaesthesia is induced (excitation) and in deep anaesthesia (burst suppression). Recently, various commercial monitoring systems have been introduced to solve this problem. These monitoring systems use different interpretations of the EEG or auditory-evoked potentials (AEP). These derived and calculated variables have no pure physiological basis. For that reason a profound knowledge of the algorithms and a validation of the monitoring systems is an indispensable prerequisite prior to their routine clinical use. For the currently available monitoring systems various studies have been reported. At this time it is important to know that the actual available monitors can only value the sedation and not the other components of anaesthesia. For example, they cannot predict if a patient will react to a painful stimulus or not. In the future it would be desirable to develop parameters which allow an estimate of the other components of anaesthesia in addition to the presently available monitoring systems to estimate sedation and muscle relaxation. These could be sensoric-evoked potentials to estimate analgesia and AEPs for the detection of awareness.

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.

Effects of age on responsiveness to adjunct hypnotic analgesia during invasive medical procedures

OBJECTIVES

To assess the effects of age on responsiveness to self-hypnotic relaxation as an analgesic adjunct in patients undergoing invasive medical procedures.

MATERIAL AND METHODS

Secondary data analysis from a prospective trial with 241 patients randomized to receive hypnosis, attention, and standard care treatment during interventional radiological procedures. Growth curve analyses, hierarchical linear regressions, and logistic regressions using orthogonal contrasts were used for analysis. Outcome measures were Hypnotic Induction Profile scores, self-reported pain and anxiety, medication use, oxygen desaturation < or =89%, and procedure time.

RESULTS

Hypnotizability did not vary with age (p = .19). Patients receiving attention and hypnosis had greater pain reduction during the procedure (p = .02), with trends toward lower pain with hypnosis (p = .07); this did not differ by age. As age increased, patients experienced more rapid pain control with hypnosis (p = .03). There was more rapid anxiety reduction with attention and hypnosis (p = .03). Trends toward lower final anxiety were also observed with attention and hypnosis versus standard care (p = .08), and with hypnosis versus attention (p = .059); these relationships did not differ by age. Patients requested and received less medication and had less oxygen desaturation < or =89% with attention and hypnosis (p < .001); this did not differ by age. However, as age increased, oxygen desaturation was greater in standard care (p = .03). Procedure time was reduced in the attention and hypnosis groups (p = .007); this did not vary by age.

CONCLUSIONS

Older patients are hypnotizable and increasing age does not appear to mitigate the usefulness of hypnotic analgesia during invasive medical procedures.

Hypnosis in contemporary medicine

Hypnosis became popular as a treatment for medical conditions in the late 1700s when effective pharmaceutical and surgical treatment options were limited. To determine whether hypnosis has a role in contemporary medicine, relevant trials and a few case reports are reviewed. Despite substantial variation in techniques among the numerous reports, patients treated with hypnosis experienced substantial benefits for many different medical conditions. An expanded role for hypnosis and a larger study of techniques appear to be indicated.

The Effect of Music on the Neurohormonal Stress Response to Surgery Under General Anesthesia

Several pharmacological interventions reduce perioperative stress hormone release during surgery under general anesthesia. Listening to music and therapeutic suggestions were also studied, but mostly in awake patients, and these have a positive effect on postoperative recovery and the need for analgesia. In this study, we evaluated the effect of listening to music under general anesthesia on the neurohormonal response to surgical stress as measured by epinephrine, norepinephrine, cortisol, and adrenocorticotropic hormone (ACTH) blood levels. Thirty female patients scheduled for abdominal gynecological procedures were enrolled and randomly divided into two groups: group NM (no music) and group M (music). In group M, music was played from after the induction of anesthesia until the end of surgery. In the NM group, the patients wore the headphones but no music was played. We established three sample times for hormonal dosage during the procedure and one in the recovery room. Hemodynamic data were recorded at all times, and postoperative consumption of morphine in the first 24 h was noted. There was no group difference at any sample time or in the postoperative period in terms of mean arterial blood pressure, heart rate, isoflurane end-tidal concentration, time of the day at which the surgery was performed, bispectral index (BIS) value, doses of fentanyl, or consumption of postoperative morphine. There was no difference between the two groups with regard to plasmatic levels of norepinephrine, epinephrine, cortisol, or ACTH at any sample time, although the blood level of these hormones significantly increased in each group with surgical stimulation. In conclusion, we could not demonstrate a significant effect of intraoperative music on surgical stress when used under general anesthesia.

IMPLICATIONS

Listening to music under general anesthesia did not reduce perioperative stress hormone release or opioid consumption in patients undergoing gynecological surgery.

Relaxing intraoperative natural sound blunts haemodynamic change at the emergence from propofol general anaesthesia and increases the acceptability of anaesthesia to the patient

BACKGROUND

It is known that auditory input, such as comforting music or sound, blunts the human response to surgical stress in conscious patients under regional anaesthesia. As auditory perception has been demonstrated to remain active under general anaesthesia, playing comforting sounds to patients under general anaesthesia might also modulate the response of these patients to surgical stress.

METHODS

Fifty-nine patients scheduled for laparoscopic cholecystectomy were anaesthetized with propofol general anaesthesia in combination with epidural anaesthesia. Natural sounds, chosen preoperatively by each patient as being comforting, were played to 29 patients using headphones during surgery (S group) and the remainder of the patients (n = 30) were fitted with dummy open-type headphones (N group). We compared the haemodynamic change during anaesthesia and the acceptability of anaesthetic practice between the two groups in a randomized double-blind design.

RESULTS

There were no differences in haemodynamics between the S and N groups during surgery. During the emergence from anaesthesia, the mean blood pressure and heart rate gradually increased; both parameters were significantly higher in the N group than in the S group. Postoperatively, patients in the S group perceived the experience of anaesthesia as significantly more acceptable than did those in the N group.

CONCLUSION

These findings indicate that allowing patients comforting background sounds during general anaesthesia may blunt haemodynamic changes upon emergence from general anaesthesia and increase the acceptability of the experience of anaesthesia.

Brief presurgery hypnosis reduces distress and pain in excisional breast biopsy patients

Each year, hundreds of thousands of women undergo excisional breast biopsies for definitive diagnosis. Not only do these patients experience pain associated with the procedure, but they also endure distress associated with the threat of cancer. Hypnosis has been demonstrated as effective for controlling patients' pain in other surgical settings, but breast surgery patients have received little attention. To determine the impact of brief presurgical hypnosis on these patients' postsurgery pain and distress and to explore possible mediating mechanisms of these effects, 20 excisional breast biopsy patients were randomly assigned to a hypnosis or control group (standard care). Hypnosis reduced postsurgery pain and distress. Initial evidence suggested that the effects of hypnosis were mediated by presurgery expectations.

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.

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.

[Does a means exist for prevention of postoperative pain?]

Postoperative pain can be prevented through pharmacological and non pharmacological means. The influence of the interval between therapy and surgical stimulus, which corresponds to "pre-emptive analgesia" in English-speaking countries (comparison of preoperative administration with pre- and postoperative administration of the same analgesic) has been assessed by numerous studies of good methodological quality. In spite of the initial promising results, most of the results published at present are negative. In an enlarged concept of postoperative pain prevention, various trials have demonstrated the benefits of the choice of the surgical approach, as well as the psychological preparation of the patient for surgery.

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.

Monitoring depth of anaesthesia

In clinical practice, indirect and non-specific signs are used for monitoring anaesthetic adequacy. These include haemodynamic, respiratory, muscular and autonomic signs. These measures do not indicate adequacy of anaesthesia in a reliable manner. Many attempts have been made to find a more accurate monitor. Direct monitoring of anaesthetic effect should be possible by EEG measurement. EEG information can be reduced, condensed and simplified, leading to single numbers (spectral edge frequency and median frequency). These methods appear insufficient for assessing anaesthetic adequacy. The bispectral index, derived from bispectral analysis of the EEG, is a very promising tool for measuring adequacy of anaesthesia. An alternative approach is to monitor evoked potentials. Middle latency auditory evoked potentials may be helpful in assessing anaesthetic adequacy. Both techniques need further validation.

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.

Information processing during general anesthesia: evidence for unconscious memory

Memory for words presented during general anesthesia was studied in two experiments. In Experiment 1, surgical patients (n = 80) undergoing elective procedures under general anesthesia were presented shortly before and during surgery with words via headphones. At the earliest convenient time after surgery (within 5 h) and 24 h later, memory was tested by asking patients to complete auditorily presented word stems with the first word that came to mind and to leave out words they remembered having heard earlier (exclusion task). Moreover, patients were requested to perform a "yes/no" forced-choice recognition task to assess recognition memory for both the pre- and intraoperative words. Memory for the material presented during anesthesia was demonstrated immediately after surgery and 24 h later by means of both tasks. In a second similar experiment (n = 80), the results were replicated. These findings show that anesthetized patients can process information that was presented intraoperatively.

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.

Psychological and hypnotic preparation for anesthesia and surgery: an individual differences perspective

Multiple reviews indicate that psychological preparation for surgery can provide psychological, physiological, and economic benefit to the patient. Research demonstrating that hypnosis adds to this benefit is both limited and encouraging. The content and status of this literature, however, are confusing, with little coherent theoretical basis to account for the contradictions and inconsistencies across multiple studies whose methodologies often limit generalization. A model is presented regarding pertinent individual differences that include patient coping styles, prior medical experiences, and hypnotic ability, as well as differences in types of coping demanded by different surgical procedures. This model (a) helps explain some of the confusion, (b) offers a theoretical focus for patient assessment as well as development and selection of preparation strategies, and (c) clarifies future research goals.

Pavlovian fear conditioning in mice anesthetized with halothane

Pavlovian fear conditioning was employed to investigate learning during general anesthesia. Mice were given three CS-UCS presentations while anesthetized with halothane. The CS was a 10-s tone and the UCS a 0.4-mA shock delivered intramuscularly to the hindlimbs via needle electrodes. Anesthetized control groups received either CS only, UCS only, or CS followed by a 3-min delayed UCS. Strength of fear conditioning was assessed by measuring duration of suppression of drinking induced by tone presentation in a test session conducted 24 h after training. Results showed that mice trained under anesthesia exhibited a significant amount of conditioned suppression relative to the anesthetized control groups. These results show that Pavlovian fear conditioning can occur under halothane anesthesia.

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.

Therapeutic suggestion has not effect on postoperative morphine requirements

This study was designed to confirm the effect of therapeutic intraoperative auditory suggestion on recovery from anesthesia, to establish the effect of preoperative suggestion, and to assess implicit memory for intraoperative information using an indirect memory task. Sixty consenting unpremedicated patients scheduled for elective gynecologic surgery were randomly divided into three equal groups: Group 1 received a tape of therapeutic suggestions preoperatively, and the story of Robinson Crusoe intraoperatively; Group 2 heard the story of Peter Pan preoperatively and therapeutic suggestions intraoperatively; Group 3 heard the Crusoe story preoperatively and the Peter Pan story intraoperatively. A standardized anesthetic technique was used with fentanyl, propofol, isoflurane, and nitrous oxide. After surgery, all patients received patient-controlled analgesia (PCA) with a standardized regimen. In the 24 h postsurgery, morphine use was recorded every 6 h and at 24 h an indirect memory test (free association) was used to test for memory of the stories. Anxiety scores were measured before surgery and at 6 and 24 h postsurgery. There were no significant differences between groups for postoperative morphine use, pain or nausea scores, anxiety scores, or days spent in hospital after surgery. Seven of 20 patients who heard the Pan story intraoperative gave a positive association with the word "Hook," whereas 2 of 20 who did not hear the story gave such an association. Indirect memory for the Pan story was established using confidence interval (CI) analysis. (The 95% CI for difference in proportion did not include zero). No indirect memory for the Crusoe story could be demonstrated. This study did not confirm previous work which suggested that positive therapeutic auditory suggestions, played intraoperatively, reduced PCA morphine requirements. In contrast, a positive implicit memory effect was found for a story presented intraoperatively.

Subanesthetic concentrations of desflurane and propofol suppress recall of emotionally charged information

Whether anesthetized patients register emotionally charged information remains controversial. We tested this possibility using subanesthetic concentrations of propofol or desflurane. Twenty-two volunteers (selected for hypnosis susceptibility) received propofol and desflurane (on separate occasions, and in a random order) at a concentration 1.5-2 times each individual's minimum alveolar anesthetic concentration (MAC)-awake (or equivalent for propofol). We gave vecuronium, intubated the trachea of each volunteer, controlled ventilation, and then presented a neutral (control) drama or a "crisis" drama stating that the oxygen delivery system had failed, assigning crisis and control dramas in a blinded, randomized, and balanced manner. One day later, interviewers blinded to the assigned drama conducted a 2-h structured interview (including hypnosis) to determine whether the contents of the interviews after crisis and control dramas differed. In addition, messages permitting subsequent assessment of learning of matter-of-fact information (Trivial Pursuit-type question task and a behavior task) were presented at the anesthetic concentration just sufficient to prevent response to command in each volunteer. No analyses of the tasks involving matter-of-fact information revealed learning except one which correlated hypnosis susceptibility with behavior task performance. Both propofol and desflurane suppressed memory of the crisis. Consistent with previous findings for isoflurane and nitrous oxide, propofol and desflurane suppressed learning of matter-of-fact information at concentrations just above MAC-awake, except that volunteers' susceptibility to hypnosis correlated with performance of a behavior suggested during anesthesia. Propofol and desflurane suppressed learning of emotionally charged information at anesthetic concentrations 1.5-2 times MAC-awake (less than MAC), a different result from that previously reported for ether.

Implicit processing and therapeutic suggestion during balanced anaesthesia

The effect of therapeutic suggestion--implicit processing during balanced anaesthesia was studied in 70 female patients scheduled for elective breast surgery. The patients were randomly allocated to listen to a message with reassuring information focused on minimising postoperative nausea and vomiting, or just a blank tape during surgery. Occurrence of nausea and vomiting was studied during the postoperative period. No patient recalled any explicit memories during the peroperative period. No major differences were observed in the number of patients who experienced nausea or vomiting during the 24 hour observation period. The patients exposed to positive suggestion did, however, have a lower frequency of recall for nausea and vomiting compared to those just listening to the blank tape. We did not observe any major effect of peroperative suggestion for postoperative nausea and vomiting. However, we cannot rule out some implicit processing during balanced anaesthesia.

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.

Taped therapeutic suggestions and taped music as adjuncts in the care of coronary-artery-bypass patients

A randomized, single-blinded, placebo-controlled trial examined the benefits of taped therapeutic suggestions and taped music in coronary-artery-bypass patients. Sixty-six patients listened to either suggestion tapes or music tapes, intraoperatively and postoperatively; 29 patients listened to blank tapes intraoperatively and listened to no tapes postoperatively. Half the patients who listened to a tape found it helpful. There were no significant differences between groups in length of SICU or postoperative hospital stay, narcotic usage, nurse ratings of anxiety and progress, depression, activities of daily living, or cardiac symptoms. There were no significant differences in these same outcomes between the patients who were helped by the tapes and the patients not helped. These results suggest that if taped therapeutic suggestions have a measurable effect upon cardiac surgery patients, demonstrating this effect will require more detailed patient evaluations to identify subgroups of patients responsive to this type of intervention.

The incidence and severity of postoperative nausea and vomiting in patients exposed to positive intra-operative suggestions

In a double-blind study, the effects of positive intra-operative suggestions on the incidence and severity of postoperative nausea and vomiting were studied in 60 patients randomly selected to undergo routine major gynaecological surgery. Patients who received positive suggestions suffered significantly less nausea and vomiting in the 24 h after surgery.

Reducing smoking. The effect of suggestion during general anaesthesia on postoperative smoking habits

In a double-blind randomised trial, 122 female smokers undergoing elective surgery were allocated to receive one of two prerecorded messages while fully anaesthetised. The active message was designed to encourage them to give up smoking whilst the control message was the same voice counting numbers. No patient could recall hearing the tape. Patients were asked about their postoperative smoking behaviour one month later. Significantly more of those who had received the active tape had stopped or reduced their smoking (p < 0.01). This would suggest a level of preconscious processing of information.

Recall of music: a comparison between anaesthesia with propofol and isoflurane

Sixty patients undergoing laparoscopy were randomly assigned to receive total intravenous anaesthesia with propofol or inhalation anaesthesia with isoflurane. Patients in these two groups were also randomly assigned to three subgroups listening to soft music, hard rock music or no music at all. Twenty-four hours after surgery all patients were interviewed and asked if they had heard music during the operation. A tape with seven different pieces of music was also played for the patients. The music they heard during surgery was one of these. No patient had any memories or experiences from the operation. Four patients had dreams, three from the total intravenous anaesthesia group and one from the inhalation anaesthesia group. Twelve patients believed they had heard music, ten from the total intravenous anaesthesia group and two from the inhalation anaesthesia group (P < 0.05). Two patients, one from each group, picked the right melody. In conclusion, there was no difference between the two groups with respect to recall during anaesthesia. Patients in the TIVA group were significantly more inclined to state that they had been exposed to music.

Early anesthesia evaluation of the ambulatory surgical patient: does it really help?

STUDY OBJECTIVE

To evaluate whether early evaluation by the anesthesiologist is more beneficial for the ambulatory surgical patient than a day-of-surgery visit.

DESIGN

A randomized study evaluating patients with different surgical procedures.

SETTING

Ambulatory surgical outpatients at a university-affiliated integrated ambulatory surgical unit.

PATIENTS

Sixty-three ASA physical status I and II women scheduled to undergo elective dilatation and curettage or gynecologic laser surgery.

INTERVENTIONS

Approximately half of the patients received an early (1 to 7 days preoperative) anesthesia evaluation, and half received a day-of-surgery evaluation. All patients underwent the surgical procedures with a standardized general anesthetic.

MEASUREMENTS AND MAIN RESULTS

The effect of an early versus a day-of-surgery anesthesia visit was evaluated with regard to patient anxiety levels; patient satisfaction with the surgical and anesthetic experience; operating room, recovery room, and ambulatory surgery unit time; anesthetic and analgesic requirements; and frequency of postoperative problems within 72 hours at home. There were no differences between the groups in demographic characteristics, anesthesia or analgesic requirements, degree of satisfaction with the ambulatory surgical experience, time spent in recovery room, or frequency of problems on postoperative follow-up. We were unable to demonstrate any differences between those patients seen early versus those seen on the day of surgery in anxiety levels preoperatively and postoperatively.

CONCLUSIONS

Healthy ASA physical status I and II ambulatory surgical patients do not benefit from reducing preoperative anxiety by visiting the anesthesiologist prior to the day of surgery.

Awareness and information processing in general anesthesia

Although general anesthesia produces an apparent loss of consciousness, there is some reason to believe that, at least under some circumstances, surgical events may influence post-operative experience, thoughts and action as implicit memories. This paper summarizes a number of recent experiments in which adequately anesthetized patients show implicit, but not explicit, memory for surgical events. The evidence for implicit memory following general anesthesia is mixed, and the limiting conditions are not yet known. Practical and theoretical implications of these findings are explored.