Effects of early hypnosis on the cardiovascular and renal physiology of burn patients.

Sixteen patients with body surface area (BSA) burns of 4 per cent to 83 per cent, with whom single hypnotherapeutic interventions were attempted 5.3 +/- 3.4 h post burn, were compared to 16 matched controls. Ten physiological parameters related to fluid volume and haemodynamics were recorded on the first two post burn days. The only significant difference discovered was elevated urine output 0-48 h postburn in successfully hypnotized patients (P = 0.01). This difference was inversely related (r = -0.94, P = 0.009) to burn size from a 10 per cent BSA burn (3.9 litres/48 h) to a 35 per cent BSA burn (1.6 litres/48 h). A statistically suggestive (P = 0.13) increase in urine output occurred in patients in whom hypnotic trance induction was unsuccessfully attempted. Patients with BSA burn sizes greater than or equal to 50 per cent, who presented with significant physiological stress and hypovolemia, were found not to be susceptible to hypnotic trance induction, and derived no physiological benefit. Attempted hypnotherapeutic intervention per se, with its psychotherapeutic component, may act only to reduce affective or psychological stress and anxiety. This psychological stress reduction apparently facilitates the loss of retained fluid in patients with small burns by a mechanism which is overwhelmed by the physiological stress of a major burn injury.