Hypnosis for Acute Procedural Pain: A Critical Review
Procedural pain is a significant problem for a wide variety of surgical procedures. There is the anxiety and discomfort for patients but also substantial expenses for pain medication. In the USA, in 2002, that was estimated to be $560-$635 billion USD. Added to this problem are the side effects of pain management drugs which can include death.
Hypnosis has a long history of pain management, but the level of effectiveness and mechanisms of action are still not well studied or understood. This review paper seeks to assess the evidence for effectiveness by statistical and methodological assessment of 29 randomised controlled clinical trials.
Methodological quality was assessed using the 5-point Jadad score. In order to account for the difficulty in blinding of hypnosis practitioners, a maximum of four points were awarded: 1 point added if the study was randomised; 1 point added if the randomisation was appropriate; 1 point deducted if the randomisation was inappropriate; 1 point added if withdrawals and dropouts were explained and; 1 point added if the experimental and hospital staff were blinded to treatment assignment.
Types of medical treatment tested included, bone marrow aspiration, lumbar puncture, burn debridement and other surgical and medical procedures including abortion, venepuncture and angioplasty.
Some studies incorporated hypnotic treatment immediately prior or during surgical treatment while other commenced days before the procedure.
Pain was most often measured with a single VAS score. The reviewers complained of inadequate controls but nevertheless concluded that hypnosis seemed to at least be as effective as cognitive behavioural approaches and play therapy and was more effective than distraction techniques.
Hypnosis was shown to be beneficial in 75% of studies with medical procedures but was not shown to reduce post-operative pain.
Interventions with more than one hypnosis session reported more significant positive effects than did studies involving only one session. Applying hypnosis at least one day before the procedure was more effective.