Preoperative anxiety, coping, and intraoperative adjustment: Are there mediating effects of stress-induced analgesia?

There is a considerable amount of research concerning the relationship between psychological variables and the postoperative outcome of surgery. However, little attention has been paid to the potential influence of psychological factors on intra-operative variables, most notably on anaesthetic requirement. The present study investigates the influence of surgery-related trait and state anxiety as well as of dispositional and surgery-related actual coping on several indicators of intra- and postoperative adjustment. In addition, a possible mediating effect of stress-induced analgesia on the relationships between anxiety, coping, and intraoperative anaesthetic requirements was evaluated. Sixty-one patients undergoing elective lumbar nucleotomy completed questionnaires regarding anxiety and coping variables one day before surgery. Intraoperative adjustment was assessed by measuring EEG-controlled anaesthetic requirements for induction and maintenance of anaesthesia. beta -endorphin plasma concentration was collected preoperatively in the induction room. Postoperative outcome was assessed on the third day after surgery by questionnaires regarding pain experience, physical condition and emotional state. For preoperative anxiety as well as vigilant coping behaviour, there were opposite relationships with subjective measures of adjustment (e.g., self-reported postoperative pain experience), on the one side, and objective measures on the other (e.g., intraoperative anaesthetic requirement). Stress-induced analgesia was found for the subgroup of high-anxious patients. The results indicate that psychological programmes aimed at facilitating patients' perioperative adjustment should consider the different effects of anxiety and coping on subjective and objective measures.