Cardiovascular Protection Conservative Effects of Esketamine Versus µ-opioid Receptor Agonists in General Anesthesia

Pain is 'a double-edged sword', disturbing daily life of the sufferers and activating the intrinsic protective mechanisms. Transient receptor potential vanilloid 1 (TRPV1), play such role as 'a double agent', transmitting the pain signals and initiating the cardio-protective mechanism via release protective neuropeptides. Surgery-related pain is mostly so severe and disturbing that must be medically treated. Unfortunately, the beneficial aspect of pain is commonly ignored in daily clinical practice. Does it matter to the patients' outcomes? We don't know yet! What we have been seeing is the shocking outcomes of patients underwent surgery, which shows about 0.8% and 7% of mortalities in the period of 48 hours and 30 days after surgery, respectively (https://www.rcplondon.ac.uk/projects/outputs/national-hip-fracture-database-annual-report-2016; Injury. 2017; 48(10): 2180-2183). What causes the disaster? Piles of evidence demonstrate that deep anesthesia or deep sedation is related to the high mortality of the patients (Anesthesiology. 2012; 116:1195-1203; Crit Care. 2014; 18(4):R156 ). What about the effect of analgesia, especially the over-analgesia, on the patients' outcome in and after surgery? Opioids are the most commonly used drugs in the treatment of moderate and sever pain including intra- and postoperative pain. The µ-opioid receptor agonists induce analgesic effect via inhibition of the transduction and the transmission of pain signals, by suppression of the release of CGRP and SP from the nerve terminals. The protective effects on cardiovascular system mediated by CGRP and SP can be inhibited, if the same effect is produced by the action of opioids in the peripheral nerve terminals innervating the heart and the vasculature. Our previous research shows that intrathecal administration of morphine or epidural administration of ropivacaine (1%, in 20 μL) significantly attenuates the increases of CGRP and its coding mRNA in ventricular myocardium and the innerv