Postsurgical pain is attenuated in men with elevated presurgical systolic blood pressure

Abstract

Previous research has demonstrated that elevated resting blood pressure is associated with a decreased perception of experimental pain. To assess this relationship in the context of clinical pain, post-surgical pain ratings were obtained from 159 men recovering from radical prostatectomy. Participants ranged in age from 46 to 75 years (Mean=61.9, SD=5.9), and on admission to the hospital had mean systolic and diastolic blood pressures of 134.2/79.9 mmHg (SD=19.2/10.2). Pain ratings were obtained at 24 h and 48 h post-surgery using the McGill Pain Questionnaire and Visual Analog Scales administered at rest and after standardized movement (VAS-M). Results of correlational analyses indicated that higher preoperative resting systolic blood pressure was associated with significantly lower VAS-M pain ratings at 24 h postsurgery and significantly lower ratings on all pain measures at 48 h postsurgery. The relationships between blood pressure and pain ratings were maintained even after controlling for individual differences in age, length of surgery and postsurgical self-administration of morphine. These results confirm and extend previous observations of decreased pain in individuals with elevated blood pressure and suggest that this effect persists despite access to morphine analgesia.