The researches find that No study has been conducted to demonstrate the feasibility of an opioid-free anesthesia (OFA) protocol in cardiac surgery to improve patient care. The aim of the present study was to evaluate the effect of OFA on post-operative morphine consumption and the post-operative course. After retrospectively registering to (NCT03816592); they performed a retrospective matched cohort study (1:1); on cardiac surgery patients with cardiopulmonary bypass between 2018 and 2019.

Opioid-free anesthesia

Patients were divide into two groups: OFA (lidocaine, dexamethasone and ketamine) or opioid anaesthesia (OA); (sufentanil). The main outcome was the total postoperative morphine consumption in the 48 h after surgery.  Secondary outcomes Are rescue analgesic use; a major adverse event composite endpoint; and ICU and hospital length of stay (LOS). Since the 1960s, the systematic administration of opioids has been considered one of the pillars of modern anaesthesia. The use of opioid analgesics has become widespread with the development of new opioid agents.

Their use is based on their antinociceptive effects; the control of the autonomic nervous system (ANS) responses to surgical stress, and their induced hypnotic reduction. However; the principle underlying the administration of opioids during anaesthesia has only recently been called into question. Therefore Opioids have a number of adverse effects that limit their effectiveness in perioperative care, the most relevant being respiratory depression, gastrointestinal alterations, hyperalgesia, inflammation modulation, and immunologic modulation.

The autonomic nervous system

Moreover, the recent opioid epidemic, due in part to persistent use of perioperative opioids; raises questions about the systematic administration of opioids during anaesthesia and the development of new non-opioid strategies. Opioid-free anaesthesia (OFA) is a long-standing concept. It is based on the fact that a sympathetic reaction evidenced by hemodynamic changes in an anesthetised patient does not systematically reflect pain. In addition; a sleeping patient not recall pain, while hormonal stress and sympathetic and inflammatory reactions are control by therapeutic classes other than opioids.

There is an increasing body of literature on OFA, demonstrating its feasibility with a decrease of post-operative morphine consumption and improvement of postoperative well being. Several OFA protocols have also been publish. The most commonly used nonopioid agents are lidocaine; dexamethasone, and ketamine, and all have been studied separately in cardiac surgery. Murphy et al. demonstrated that the administration of dexamethasone decreased morphine consumption and the ICU length of stay. Ketamine is show to have analgesic effects and opioid-sparing effects.

Lidocaine has demonstrated analgesic and opioid-sparing effects in cardiac and non-cardiac surgery, and additional studies have found cardioprotective and/or neuroprotective effects. More specifically, the use of lidocaine has been associated with a decrease in arrhythmias and a non-constant improvement in postoperative cognitive functions. All these studies were performed with opioid anaesthesia (OA).