Preoperative low-dose ketamine has no preemptive analgesic effect in opioid-naïve patients undergoing colon surgery when nitrous oxide is used - a randomized study.

BACKGROUND: The analgesic properties of ketamine are associated with its non-competitive antagonism of the N-methyl-D-aspartate receptor; these receptors exhibit an excitatory function on pain transmission and this binding seems to inhibit or reverse the central sensitization of pain. In the literature, the value of this anesthetic for preemptive analgesia in the control of postoperative pain is uncertain. The objective of this study was to ascertain whether preoperative low-dose ketamine reduces postoperative pain and morphine consumption in adults undergoing colon surgery. METHODS: In a double-blind, randomized trial, 48 patients were studied. Patients in the ketamine group received 0.5 mg/kg intravenous ketamine before surgical incision, while the control group received normal saline. The postoperative analgesia was achieved with a continuous infusion of morphine at 0.015 mg∙kg-¹âˆ™h-¹ with the possibility of 0.02 mg/kg bolus every 10 min. Pain was assessed using the Visual Analog Scale (VAS), morphine consumption, and hemodynamic parameters at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively. We quantified times to rescue analgesic (Paracetamol), adverse effects and patient satisfaction. RESULTS: No significant differences were observed in VAS scores between groups (P>0.05), except at 4 hours postoperatively (P=0.040). There were no differences in cumulative consumption of morphine at any time point (P>0.05). We found no significant differences in incremental postoperative doses of morphine consumption in bolus, except at 12 h (P =0.013) and 24 h (P =0.002). The time to first required rescue analgesia was 70 ± 15.491 min in the ketamine group and 44 ± 19.494 min in the control (P>0.05). There were no differences in hemodynamic parameters or patient satisfaction (P>0.05). CONCLUSIONS: Preoperative low-dose-ketamine did not show a preemptive analgesic effect or efficacy as an adjuvant for decreasing opioid requirements for postoperative pain in patients receiving intravenous analgesia with morphine after colon surgery.

Diagnóstico y tratamiento del dolor irruptivo oncológico: recomendaciones de consenso / Diagnosis and treatment of break-through cancer pain: Consensus recommendations

INTRODUCCIÓN Y OBJETIVOS: El dolor irruptivo oncológico (DIO) es una exacerbación aguda del dolor que presenta diferentes criterios diagnósticos y de tratamiento por parte de los diferentes especialistas implicados en su manejo. Para facilitar la toma de decisiones en la práctica clínica habitual, ocho especialistas de referencia de 4 sociedades científicas implicadas en el manejo del paciente oncológico, han diseñado este documento de consenso. MÉTODOS: Tras una búsqueda bibliográfica en las publicaciones más relevantes sobre DIO, se establecieron las recomendaciones preliminares. El grupo de expertos realizó una reunión de trabajo siguiendo la metodología Metaplan(R), donde se debatieron las recomendaciones a incorporar al documento. Cada una de las afirmaciones y recomendaciones fueron clasificadas según su grado de recomendación, atendiendo a las categorías del sistema SIGN (Scottish Intercollegiate Guidelines Network). RESULTADOS: El manejo del DIO requiere de una anamnesis completa, tanto del DIO como del dolor basal, y una exploración física del paciente asociada a pruebas complementarias cuando sean precisas. Los fármacos de elección para el tratamiento del DIO deben ser aquellos que muestren una analgesia potente, con rápido inicio de acción, efectos secundarios mínimos y de fácil administración. El fentanilo administrado por vía transmucosa es actualmente el principio activo más adecuado a las necesidades analgésicas del dolor irruptivo, con independencia del opioide mayor utilizado para el control del dolor basal. CONCLUSIÓN: Este consenso puede ser una herramienta útil para la mejora de la calidad de vida del paciente con cáncer, ya que permite un mejor diagnóstico y tratamiento del DIO

INTRODUCTION OBJECTIVES: Breakthrough cancer pain (BTcP) is an acute exacerbation of baseline pain. The clinicians involved in its management have different diagnostic and therapeutic criteria. In order to facilitate decision making in usual clinical practice, 8 reference experts from 4 scientific associations involved in the management of patients with cancer pain have developed this Consensus Document. METHODS: After an initial search on the most relevant publications in BTcP literature, a set of preliminary recommendations were established. A working meeting was subsequently held with the experts, following the Metaplan(R) methodology -a structured brainstorming technique- that produced a first version of the Consensus Document which, after several review rounds, was validated by all the participants. Every statement and recommendation was sorted according to its degree of recommendation, following the categories in the SIGN (Scottish Intercollegiate Guidelines Network) system. OUTCOMES: The management of BTcP requires a full anamnesis, both of BTcP itself and of baseline pain, a physical examination and the supplementary tests that are deemed necessary. The drugs of choice for the treatment of BTcP must be those with a potent and rapid analgesic effect a short duration, minimal side effects and easy administration. Transmucosal fentanyl is currently the active ingredient most fitting to the analgesic needs of BTcP, regardless of the major opioid used for control of the baseline pain. CONCLUSION: This Consensus can be a very useful tool to improve the quality of life in cancer patients, because it guides the clinician towards a better diagnose and treatment of BTcP