By definition hypnosis relies on the participation of the hypnotized subject. Thus, literature evaluating the influence of suggestions to patients under general anesthesia is not the focus of this review (54–66).
Studies of the various aspects of the perioperative course of patients under general anesthesia are listed in Tables 1 and 2. Many of these studies are nonrandomized, and statistically significant results may be due to selection bias (67–74). In many of the pioneer studies, the investigators were also the caregivers. Therefore, some of the variables measured (e.g., pain medication administration) depended directly on the investigators (67–69). In this review results of the randomized studies will be examined more closely.
The study objectives differ among the randomized studies and the results are not always clear (75–85). van der Laan et al. (79) found no difference in postoperative pain, analgesia requirement, and nausea after preoperative and intraoperative suggestions during various gynecological procedures. A questionable benefit for the treatment interventions was noted in other studies (76,77,80). However, some studies have shown improvement of perioperative pain, anxiety, and postoperative nausea by hypnosis and suggestions (78,81,84,85).
An improvement in the recovery of postoperative gastrointestinal function after abdominal surgery was claimed by Disbrow et al. (77). Patients in the study group had less time to documented first flatus, but none of the other variables of gastrointestinal function (time to first liquid intake, time to removal of nasogastric tube) showed a significant difference among groups. The study by Ashton et al. (80) demonstrated the success of the therapeutic intervention of self-hypnosis relaxation postoperatively, with patients in the study group being more relaxed than control patients. No consequence of this treatment effect on morbidity, mortality, or intraoperative variables could be shown. Greenleaf et al. (76) analyzed the effect of preoperative hypnosis and suggestion on the postoperative course of coronary artery bypass patients. Postoperative hospital stay, time in the intensive care unit, and postoperative infusion of nitroprusside were the same among intervention and treatment groups. They did find a decrease in postoperative wound drainage for the hypnosis group (valued clinically insignificant by the surgeons), but that seems irrelevant.
Of particular interest to the anesthesiologist are the studies that focus on perioperative pain, anxiety, and nausea (78,84,85,81). Lambert (78) demonstrated reduced pain and a shorter postoperative stay among the children in a hypnosis/guided imagery group compared to an attention-control group. There was no difference in anxiety scores among the groups in this study. This contrasts with the results of a study by Calipel et al. (84) who compared the reduction of preoperative anxiety by hypnosis versus preoperative midazolam in children. Children in the hypnosis group had lower preoperative anxiety scores and less postoperative behavioral disorders than children in the midazolam group. Sadaat et al. (85) confirmed a positive effect of hypnosis on preoperative and postoperative anxiety for ambulatory surgical patients compared to an attention-control group, who received attentive listening and support, and a “standard of care” control group. Enqvist et al. (81) analyzed the positive effects of patients listening to audiotaped suggestions before breast surgery. They found a significant difference among intervention and control groups with less nausea, emesis, and analgesia requirements in the intervention group.
The effects of involving patients with hypnosis and guided imagery during procedures performed with monitored anesthesia care have been studied in a variety of clinical settings (Table 3). John and Parrino (86) used a 4-min script with hypnotic suggestions read by the surgeon prior to radial keratotomy in a nonrandomized study. The procedure was performed under regional anesthesia with sedation. No differences between study and control groups were noted intraoperatively or immediately postoperatively. In contrast, other studies have documented significant benefits of pre- and intraoperative hypnosis (13,16,17,87).
Some limits for hypnosis and sedation as the only anesthetic for surgical procedures have been demonstrated by Sefiani et al. (88). Laparoscopic cholecystectomies and hernia repairs were attempted with a combination of local anesthesia, hypnosis and sedation. Thirteen of 35 cholecystectomies and 1 of 15 hernia repairs had to be converted to general anesthesia due to the patients' discomfort.
Not every patient can be hypnotized, and not every anesthesia care provider may be willing and able to integrate hypnosis into his or her practice. Hypnotic susceptibility is a feature that describes the ability of the individual to reach a state of hypnotic trance. Patients receptive to hypnosis will reach a deeper hypnotic trance and attain a greater reduction of pain perception and operative stress than those who are less receptive to hypnosis (27,51–53). Evidence shows, however, that even patients who do not reach the stage of hypnotic trance benefit from hypnotic suggestions (or, perhaps, benefit from the closer personal attention provided by the anesthesiologist, which is also the power of suggestion) (17,89,90).
More than 200 yr have passed since Mesmer's demonstrations of animal magnetism, and more than 150 yr have passed since the first documented use of hypnosis as the sole anesthetic for general surgical cases. We now have data showing physically measurable effects of suggestion or hypnosis on the nervous system. Imaging and electrophysiologic studies have demonstrated changes in spinal and supraspinal pain pathways under the influence of hypnosis. Because suggestions and focused attention can measurably alter pain perception and pain pathways, a similar influence may be expected for the autonomous nervous system involved in modulating gastric motility, regional blood perfusion, and the humoral response to stress. Faster wound healing, earlier postoperative gastrointestinal recovery, and less nausea have been reported when hypnosis or positive suggestions were part of the perioperative management (13,14,16,91,92).
The clinician is left with the question: Do we have enough data to elevate autohypnosis and hypnosis to a clinical routine that promises benefits for patient and surgeon? Research on hypnotic techniques in the operating room has been performed by a few dedicated investigators. Only multi-institutional studies encompassing large numbers of patients could test the hypothesis that hypnosis benefits patients and health care facilities by increasing satisfaction, reducing patient morbidity, and reducing cost. A meta-analysis by Montgomery et al. (93) on the effectiveness of adjunctive hypnosis with surgical patients suggests that hypnosis improves outcome. However, the data must be interpreted with caution because of the great variability in techniques and definitions among the reports comprising the analysis.
If hypnosis and autosuggestions provide clinical benefit, they do so without the need for equipment or drugs. What other therapeutic measure appears so devoid of increased cost and demonstrable adverse effects? Personal attention to the patient, emotional support, positive suggestions, and even hypnosis are readily available, safe, inexpensive, and attractive measures that might improve the care of our patients.
The author thank Joachim S. Gravenstein, MD, Dr. med. h.c. for his support, review, and constructive criticism of the manuscript.
1. Mesmer FA. Schreiben über die Magnetkur von Herrn A. Mesmer, Doktor der Arzneygelährtheit, an einen auswärtigen Arzt. Wien: Kurzböck, 1775.
2. Riskin JD, Frankel FH. A history of medical hypnosis. Psychiatr Clin North Am 1994;17:601–9.
3. Braid J. Neurhypnology, or the rationale of nervous sleep considered in relation with animal magnetism. London: Churchill, 1843.
4. Gravitz MA. Early theories of hypnosis: a clinical perspective. In: Lynn SJ, Rhue JW, eds. Theories of hypnosis: current models and perspectives. New York: Guilford Press, 1991:19–42.
5. Gravitz MA. Etienne Felix d'Henin de Cuvillers: a founder of hypnosis. Am J Clin Hypn 1993;36:7–11.
6. Orne MT. The construct of hypnosis: implications of the definition for research and practice. Ann N Y Acad Sci 1977;296:14–33.
7. Rosen G. History of hypnosis. In: Schneck J, ed. Hypnosis in modern medicine. Springfield: Charles C Thomas, 1953;3–27.
8. Blankfield RP. Suggestion, relaxation, and hypnosis as adjuncts in the care of surgery patients: review of the literature. Am J Clin Hypn 1991;33:172–86.
9. Esdaile J. Mesmerism in India, and its practical application in surgery and medicine. New York: Arno Press, 1976 (reprint of 1846 ed. Published by Longman, London).
10. Collins VJ. Principles of anesthesiology. Philadelphia: Lea & Febiger, 1976.
11. Report of a Subcommittee appointed by the Psychological Med Group Committee of the Br Medical Association. Medical use of hypnotism. BMJ 1955;1:190–3.
12. Rosen H. Hypnosis-applications and misapplications. JAMA 1960;172:683–7.
13. Faymonville ME, Mambourg PH, Joris J, et al. Psychological approaches during conscious sedation. Hypnosis versus stress reducing strategies: a prospective randomized study. Pain 1997;73:361–7.
14. Faymonville ME, Fissette J, Mambourg PH, et al. Hypnosis as adjunct therapy in conscious sedation for plastic surgery. Reg Anesth 1995;20:145–51.
15. Meurisse M, Hamoir E, Defechereux T, et al. Bilateral neck exploration under hypnosedation. A new standard of care in primary hyperparathyroidism. Ann Surg 1999;229:401–8.
16. Defechereux T, Degauque C, Fumal I, et al. Hypnosedation, a new method of anesthesia for cervical endocrine surgery. Prospective randomized study. Ann Chir 2000;125:539–46.
17. Lang EV, Benotsch EG, Fick LJ, et al. Adjunctive non-pharmacological analgesia for invasive medical procedures: a randomised trial. Lancet 2000;355:1486–90.
18. Li CL, Ahlberg D, Landsdell M, et al. Acupuncture and hypnosis: effects on induced pain. Exp Neurol 1975;49:281–90.
19. Stern JA, Brown M, Ulett A, Sletten I. A comparison of hypnosis, acupuncture, morphine, valium, aspirin and placebo in the management of experimentally induced pain. Ann N Y Acad Sci 1977;296:175–93.
20. Moret V, Forster A, Laverrière MC, et al. Mechanism of analgesia induced by hypnosis and acupuncture: is there a difference. Pain 1991;45:135–40.
21. Meier W, Klucken M, Soyka D, Bromm B. Hypnotic hypo- and hyperalgesia: divergent effects on pain ratings and pain-related cerebral potentials. Pain 1993;53:175–81.
22. Price DD, Barber J. An analysis of factors that contribute to the efficacy of hypnotic analgesia. J Abnorm Psychol 1987;96:46–51.
23. Goldstein A, Hilgard ER. Failure of the opiate antagonist naloxone to modify hypnotic analgesia. Proc Natl Acad Sci USA 1975;72:2041–3.
24. Spiegel D, Albert LH. Naloxone fails to reverse hypnotic alleviation of chronic pain. Psychopharmacology (Berl) 1983;81:140–3.
25. Danzinger N, Fournier E, Bouhassira D, et al. Different strategies of modulation can be operative during hypnotic analgesia: a neurophysiological study. Pain 1998;75:85–92.
26. Willer JC, Bouhassira D, Le Bars D. Neurophysiological basis of the counterirritation phenomenon: diffuse control inhibitors induced by nociceptive stimulation. Neurophysiol Clin 1999; 29:379–400.
27. Sandrini G, Milanov I, Malaguti S, et al. Effects of hypnosis on diffuse noxious inhibitory controls. Physiol Behav 2000;69:295–300.
28. Ingvar M. Pain and functional imaging. Philos Trans R Soc Lond B Biol Sci 1999;354:1347–58.
29. Bushnell MC, Duncan GH, Hofbauer RK, et al. Pain perception: is there a role for primary somatosensory cortex? Proc Natl Acad Sci USA 1999;96:7705–9.
30. Kanda M, Nagamine T, Ikeda A, et al. Primary somatosensory cortex is actively involved in pain processing in human. Brain Res 2000;853:282–9.
31. Kulkarni B, Bentely DE, Elliott R, et al. Attention to pain localization and unpleasantness discriminates the functions of the medial and lateral pain systems. Eur J Neurosci 2005;21: 3133–42.
32. Hofbauer RK, Rainville P, Duncan GH, Bushnell MC. Cortical representation of the sensory dimension of pain. J Neurophysiol 2001;86:402–11.
33. Raineville P, Duncan GH, Price DD, et al. Pain affect encoded in human anterior cingulated but not somatosensory cortex. Science 1997;277:968–71.
34. Rainville P, Carrier B, Hofbauer RK, et al. Dissociation of sensory and affective dimensions of pain using hypnotic modulation. Pain 1999;82:159–71.
35. Peyron R, Garcia-Larrea L, Gregoire MC, et al. Haemodynamic brain responses to acute pain in humans: sensory and attentional networks. Brain 1999;122:1765–80.
36. Peyron R, Laurent B, Garcia-Larrea L. Functional imaging of brain responses to pain. A review and meta-analysis. Neurophysiol Clin 2000;30:263–88.
37. Tölle TR, Kaufmann T, Siessmeier T, et al. Region-specific encoding of sensory and affective components of pain in the human brain: a positron emission tomography correlation analysis. Ann Neurol 1999;45:40–7.
38. Vogt BA, Berger GR, Derbyshire SW. Structural and functional dichotomy of human midcingulate cortex. Eur J Neurosci 2003;18:3134–44.
39. Vogt BA, Derbyshire S, Jones AK. Pain processing in four regions of human cingulate cortex localized with co-registered PET and MR imaging. Eur J Neurosci 1996;8:1461–73.
40. Coghill RC, Sang CN, Maisog JM, Iadarola MJ. Pain intensity processing within the human brain: a bilateral, distributed mechanism. J Neurophysiol 1999;82:1934–43.
41. Craig AD. Pain mechanisms: labeled lines versus convergence in central processing. Annu Rev Neurosci 2003;26:1–30.
42. Brooks JC, Nurmikko TJ, Bimson WE, et al. fMRI of thermal pain: effects of stimulus laterality and attention. Neuroimage 2002;15:294–301.
43. Singer T, Seymour B, O'Doherty J, et al. Empathy for pain involves the affective but not sensory components of pain. Science 2004;303:1157–62.
44. Derbyshire SW, Jones AK, Gyulai F, et al. Pain processing during three levels of noxious stimulation produces differential patterns of central activity. Pain 1997;73:431–45.
45. Bingel U, Quante M, Knab R, et al. Single trial f MRI reveals significant contralateral bias in responses to laser pain within thalamus and somatosensory cortices. Neuroimage 2003;18: 740–8.
46. Rainville P, Duncan GH, Price DD, et al. Pain affect encoded in human anterior cingulate but not somatosensory cortex. Science 1997;277:68–71.
47. Faymonville ME, Laureys S, Degueldre C, et al. Neural mechanisms of antinociceptive effects of hypnosis. Anesthesiology 2000;92:1257–67.
48. Schulz-Stubner S, Krings T, Meister IG, et al. Clinical hypnosis modulates functional magnetic resonance imaging signal intensities and pain perception in a thermal stimulation paradigm. Reg Anesth Pain Med 2004;29:549–56.
49. Kropotov JD, Crawford HJ, Polyakov YI. Somatosensory event-related potential changes to painful stimuli during hypnotic analgesia: anterior cingulate cortex and anterior temporal cortex intracranial recordings. Int J Psychophysiol 1997;27:1–8.
50. Crawford HJ, Knebel T, Kaplan L, et al. Hypnotic analgesia: 1. Somatosensory event-related potential changes to noxious stimuli and 2. Transfer learning to reduce chronic low back pain. Int J Clin Exp Hypn 1998;46:92–132.
51. De Pascalis V, Magurano MR, Bellusci A. Pain perception, somatosensory event-related potentials and skin conductance responses to painful stimuli in high, mid, and low hypnotizable subjects: effects of differential pain reduction strategies. Pain 1999;83:499–508.
52. Zachariae R, Bjerring P. Laser-induced pain-related brain potentials and sensory pain ratings in high and low hypnotizable subjects during hypnotic suggestions of relaxation, dissociated imagery, focused analgesia, and placebo. Int J Clin Exp Hypn 1994;42:56–80.
53. Horton JE, Crawford HJ, Harrington G, Downs JH III. Increased anterior corpus callosum size associated positively with hypnotizability and the ability to control pain. Brain 2004;127:1741–7.
54. Evans C, Richardson PH. Improved recovery and reduced postoperative stay after therapeutic suggestion under general anesthesia. Lancet 1988;2:491–3.
55. Liu WH, Standen PJ, Aitkenhead AR. Therapeutic suggestions during general anaesthesia in patients undergoing hysterectomy. Br J Anaesth 1992;68:277–81.
56. Millar K. Efficacy of therapeutic suggestions presented during anaesthesia: re-analysis of conflicting results. Br J Anaesth 1993;71:597–601.
57. Nilsson U, Rawal N, Unestahl LE, et al. Improved recovery after music and therapeutic suggestions during general anaesthesia: a double-blind randomised controlled trial. Acta Anaesthesiol Scand 2001;45:812–17.
58. Dawson PR, Van Hammel C, Wilkinson D, et al. Patient-controlled analgesia and intra-operative suggestion. Anaesthesia 2001;56:1118–19.
59. Williams AR, Hind M, Sweeney BP, Fisher R. The incidence and severity of postoperative nausea and vomiting in patients exposed to positive intra-operative suggestions. Anaesthesia 1994;49:340–2.
60. Block RI, Ghoneim MM, Sum Ping ST, Ali MA. Efficacy of therapeutic suggestions for improved postoperative recovery presented during general anesthesia. Anesthesiology 1991;75:746–55.
61. Blankfield RP, Zyzanski SJ, Flocke SA, et al. Taped therapeutic suggestions and taped music as adjuncts in the care of coronary-artery-bypass patients. Am J Clin Hypn 1995;37:32–42.
62. Lebovits AH, Twersky R, McEwan B. Intraoperative therapeutic suggestions in day-case-surgery: are there benefits for postoperative outcome? Br J Anaesth 1999;82:861–6.
63. Eberhart LH, Döring HJ, Holzrichter P, et al. Therapeutic suggestions given during neurolept-anaesthesia decrease post-operative nausea and vomiting. Eur J Anaesthesiol 1998;15:446–52.
64. Jelicic M, Bonke B, Millar K. Effect of different therapeutic suggestions presented during anaesthesia on post-operative course. Eur J Anaesthesiol 1993;10:343–7.
65. Cowan GS JR, Buffington CK, Cowan GS III. Assessment of the effects of a taped cognitive behavior message on postoperative complications (therapeutic suggestions under anesthesia). Obes Surg 2001;11:589–93.
66. Pearson RE. Response to suggestions given under general anesthesia. Am J Clin Hypn 1961;4:106–14.
67. Doberneck RC, Griffen WO Jr, Papermaster AA, et al. Hypnosis as an adjunct to surgical therapy. Surgery 1959;46:299–304.
68. Bonilla KB, Quigley WF, Bowers WF. Experiences with hypnosis on a surgical service. Mil Med 1961;126:364–70.
69. Werbel EW. Use of posthypnotic suggestions to reduce pain following hemorrhoidectomies. Am J Clin Hypn 1963;66:132–6.
70. Bartlett EE. Polypharmacy versus hypnosis in surgical patients. Pac Med Surg 1966;74:109–12.
71. Surman OS, Hackett TP, Silverberg EL, Behrendt DM. Usefulness of psychiatric intervention in patients undergoing cardiac surgery. Arch Gen Psychiatry 1974;30:830–5.
72. Rapkin DA, Straubing M, Holroyd JC. Guided imagery, hypnosis and recovery from head and neck cancer surgery: an exploratory study. Int J Clin Exp Hypn 1991;39:215–26.
73. Enqvist B, von Konow L, Bystedt H. Pre- and perioperative suggestion in maxillofacial surgery: effects on blood loss and recovery. Int J Clin Exp Hypn 1995;43:284–94.
74. Mauer MH, Burnett KF, Ouellette EA, et al. Medical hypnosis and orthopedic hand surgery: pain perception, postoperative recovery, and therapeutic comfort. Int J Clin Exp Hypn 1999;47:144–61.
75. Hart RR. The influence of a taped hypnotic induction treatment procedure on the recovery of surgery patients. Int J Clin Exp Hypn 1980;28:324–32.
76. Greenleaf M, Fisher S, Miaskowski C, DuHamel K. Hypnotizability and recovery from cardiac surgery. Am J Clin Hypn 1992;35:119–28.
77. Disbrow EA, Bennett HL, Owings JT. Effect of preoperative suggestion on postoperative gastrointestinal motility. West J Med 1993;158:488–92.
78. Lambert SA. The effects of hypnosis/guided imagery on the postoperative course of children. J Dev Behav Pediatr 1996;17:307–10.
79. van der Laan WH, van Leeuwen BL, Sebel PS, et al. Therapeutic suggestion has no effect on postoperative morphine requirements. Anesth Analg 1996;82:148–52.
80. Ashton C JR, Whitworth GC, Seldomridge JA, et al. Self-hypnosis reduces anxiety following coronary artery bypass surgery. A prospective, randomized trial. J Cardiovasc Surg (Torino) 1997;38:69–75.
81. Enqvist B, Bjorklund C, Englman M, Jakobsson J. Preoperative hypnosis reduces postoperative vomiting after surgery of the breasts. A prospective, randomized and blinded study. Acta Anaesthesiol Scand 1997;41:1028–32.
82. Montgomery GH, Weltz CR, Seltz M, Bovbjerg DH. Brief presurgery hypnosis reduces distress and pain in excisional breast biopsy patients. Int J Clin Exp Hypn 2002;50:17–32.
83. de Klerk JE, du Plessis WF, Steyn HS, Botha M. Hypnotherapeutic ego strengthening with male South African coronary artery bypass patients. Am J Clin Hypn 2004;47:79–92.
84. Calipel S, Lucas-Polomeni MM, Wodey E, Ecoffey C. Premedication in children: hypnosis versus midazolam. Pediatr Anesth 2005;15:275–81.
85. Sadaat H, Drummond-Lewis J, Maranets I, et al. Hypnosis reduces preoperative anxiety in adult patients. Anesth Analg 2006;102:1394–6.
86. John ME Jr, Parrino JP. Practical hypnotic suggestion in ophthalmic surgery. Am J Opthalmol 1983;96:540–2.
87. Butler LD, Symons BK, Henderson SL, et al. Hypnosis reduces distress and duration of an invasive medical procedure for children. Pediatrics 2005;115:e77–e85.
88. Sefiani T, Uscain M, Sany JL, et al. [Laparoscopy under local anaesthesia and hypnoanaesthesia about 35 cholecystectomies and 15 inguinal hernia repair]. Ann Fr Anesth Reanim 2004;23:1093–101.
89. Spanos NP, Perlini AH, Robertson LA. Hypnosis, suggestion, and placebo in the reduction of experimental pain. J Abnorm Psychol 1989;98:285–93.
90. Egbert LD, Battit GE, Welch CE, Bartlett MK. Reduction of postoperative pain by encouragements and instruction of patients. N Engl J Med 1964;270:825–7.
91. Ginandes C, Brooks P, Sando W, et al. Can medical hypnosis accelerate post-surgical wound healing? Results of a clinical trial. Am J Clin Hypn 2003;45:333–51.
92. Moore, Lawrence E, Lawrence K. Hypnotically accelerated burn wound healing. Am J Clin Hypn 1983;26:16–19.
93. Montgomery GH, David D, Winkel G, et al. The effectiveness of adjunctive hypnosis with surgical patients: a meta-analysis. Anesth Analg 2002;94:1639–45.