Preemptive analgesia I: physiological pathways and pharmacological modalities

• Published in: Canadian journal of anesthesia Vol. 48; no. 10; pp. 1000 - 1010
• Main Authors: KELLY, Dermot J, AHMAD, Mahmood, BRULL, Sorin J
• Format: Journal Article
• Language: English
• Published: Toronto, ON Canadian Anesthesiologists' Society 01.11.2001; Springer Nature B.V
• Subjects: Adrenergic alpha-Antagonists - therapeutic use; Analgesia - methods; Analgesics; Analgesics, Opioid - therapeutic use; Anesthesia; Anesthesia, Conduction; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anti-Inflammatory Agents, Non-Steroidal - therapeutic use; Biological and medical sciences; Efferent Pathways - physiology; Humans; Local anesthesia. Pain (treatment); Medical sciences; Pain - physiopathology; Pain management; Pain, Postoperative - prevention & control; Perception; Postoperative period; Premedication; Receptors, N-Methyl-D-Aspartate - antagonists & inhibitors; Nociception; Postoperative; α2-Adrenergic receptor; Opiates; Glutamate receptor; Review; Narcotic analgesic; Non steroidal antiinflammatory agent; Prevention; Analgesia; Chemotherapy; Analgesic; Regional anesthesia; Pain; Antagonist; NMDA receptor
• ISSN: 0832-610X; 1496-8975
• DOI: 10.1007/BF03016591

This two-part review summarizes the current knowledge of physiological mechanisms, pharmacological modalities and controversial issues surrounding preemptive analgesia. Articles from 1966 to present were obtained from the MEDLINE databases. Search terms included: analgesia, preemptive; neurotransmitters; pain, postoperative; hyperalgesia; sensitization, central nervous system; pathways, nociception; anesthetic techniques; analgesics, agents. The physiological basis of preemptive analgesia is complex and involves modification of the pain pathways. The pharmacological modalities available may modify the physiological responses at various levels. Effective preemptive analgesic techniques require multi-modal interception of nociceptive input, increasing threshold for nociception, and blocking or decreasing nociceptor receptor activation. Although the literature is controversial regarding the effectiveness of preemptive analgesia, some general recommendations can be helpful in guiding clinical care. Regional anesthesia induced prior to surgical trauma and continued well into the postoperative period is effective in attenuating peripheral and central sensitization. Pharmacologic agents such as NSAIDs (non-steroidal anti-inflammatory drugs) opioids, and NMDA (N-methyl-D-aspartate) - and alpha-2-receptor antagonists, especially when used in combination, act synergistically to decrease postoperative pain. The variable patient characteristics and timing of preemptive analgesia in relation to surgical noxious input requires individualization of the technique(s) chosen. Multi-modal analgesic techniques appear most effective.