Original Contribution Effect of acute arterial hypertension on morphine requirements and postsurgical pain Alejandro E. Delfino MD, MmedEd (Assistant Professor) a, ⁎ , Natalia de la Fuente MD a , Ghislaine C. Echevarría MD, MSc b , Fernando R. Altermatt MD, MSc (Associate Professor) a , Luis I. Cortinez MD (Associate Professor) a a División de Anestesiología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile b Department of Anesthesiology, New York University School of Medicine, New York, NY Received 30 August 2013; revised 17 October 2014; accepted 21 November 2014 Keywords: Hyperalgesia; Hypertension; Postoperative pain Abstract Study objective: The study objective was to establish the impact of acute hypertension on morphine's requirements after laparoscopic cholecystectomy. Design: The design was a randomized, simple blinded study. Setting: The settings were operating room, postoperative recovery area, and first postoperative day. Patients: There were 50 patients, American Society of Anesthesiologists I-II, aged 18-50 years, undergoing elective laparoscopic cholecystectomy with general anesthesia. Interventions: Anesthetic management was standardized using propofol for induction, isoflurane for bispectral index (BIS) ranging between 40 and 60, and remifentanil maintained at a constant rate of 0.4 μg kg per minute throughout surgery in all patients. Once intubated, patients were randomly allocated to 1 of 2 groups: hypertensive group: systolic arterial blood pressure was maintained with phenylephrine infusion 20%- 30% over baseline; control group: systolic arterial blood pressure was maintained 20%-30% below baseline. All surgical incisions were infiltrated with bupivacaine 0.5%, and every patient received ketorolac 60 mg intravenous. Patient-controlled analgesia with morphine intravenous was used for postoperative analgesia. Measurements: Pain visual analogue scale scores, arterial blood pressure, and hyperalgesia were assessed at recovery room every 15 minutes during the first 2 postoperative hours and then at 6, 12, and 24 postoperative hours. Cumulative morphine consumption was registered at 2 and 24 postoperative hours. Main results: The cumulative morphine consumption in the control group was around 18 mg compared with 6 mg in the hypertensive group (P = .019). During the first 75 minutes after surgery, the control group had higher visual analogue scale score pain compared with hypertensive group (P = .005). Conclusions: The intraoperative acute generation of mild hypertension with phenylephrine reduced postoperative morphine consumption and pain scores after laparoscopic cholecystectomy. © 2014 Elsevier Inc. All rights reserved. 1. Introduction A strong relationship between arterial hypertension and decreased sensitivity to painful stimuli was described in animals by Dworkin et al [1] initially and later on in humans ⁎ Corresponding author at: División de Anestesiología. Hospital Clínico UC Marcoleta 367, PO Box: 114-D, Santiago, Chile. Tel.: + 56 2 63 82 933, +56 2 63 98 766; fax: +56 2 63 27 620. E-mail addresses: aedelfin@med.puc.cl (A.E. Delfino), Natalia.delafuente@gmail.com (N. de la Fuente), gcechevarria@gmail.com (G.C. Echevarría), Fernando.altermatt@gmail.com (F.R. Altermatt), licorti@med.puc.cl (L.I. Cortinez). http://dx.doi.org/10.1016/j.jclinane.2014.11.016 0952-8180/© 2014 Elsevier Inc. All rights reserved. Journal of Clinical Anesthesia (2015) 27, 226–232