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, postsurgical 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 postsurgery 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.