Anesthetic Preconditioning: Have We Found the Holy Grail of Perioperative Cardioprotection?

Role of Anaesthetic Choice in Improving Outcome after Cardiac Surgery

Clinical background

Volatile anaesthetics (VAs) have been shown to protect cardiomyocytes against ischaemia and reperfusion injury in cardiac surgery.

Clinical problems

VAs have been shown in multiple trials and meta-analyses to be associated with better outcomes when compared to intravenous anaesthesia in cardiac surgery. However, recent data from a large randomised controlled trial do not confirm the superiority of VA as compared to total intravenous anaesthesia in this population.

Review objectives

This mini review presents the VA cardioprotective effects, their clinical use in cardiac surgery and the most recent evidence that compares VA to intravenous anaesthesia for reducing perioperative morbidity. At present, there is no clear superiority of VA over intravenous anaesthesia in improving the outcome after cardiac surgery.

Disease Mechanisms of Perioperative Organ Injury

Despite substantial advances in anesthesia safety within the past decades, perioperative mortality remains a prevalent problem and can be considered among the top causes of death worldwide. Acute organ failure is a major risk factor of morbidity and mortality in surgical patients and develops primarily as a consequence of a dysregulated inflammatory response and insufficient tissue perfusion. Neurological dysfunction, myocardial ischemia, acute kidney injury, respiratory failure, intestinal dysfunction, and hepatic impairment are among the most serious complications impacting patient outcome and recovery. Pre-, intra-, and postoperative arrangements, such as enhanced recovery after surgery programs, can contribute to lowering the occurrence of organ dysfunction, and mortality rates have improved with the advent of specialized intensive care units and advances in procedures relating to extracorporeal organ support. However, no specific pharmacological therapies have proven effective in the prevention or reversal of perioperative organ injury. Therefore, understanding the underlying mechanisms of organ dysfunction is essential to identify novel treatment strategies to improve perioperative care and outcomes for surgical patients. This review focuses on recent knowledge of pathophysiological and molecular pathways leading to perioperative organ injury. Additionally, we highlight potential therapeutic targets relevant to the network of events that occur in clinical settings with organ failure.

Preconditioning strategies to prevent acute kidney injury

Acute kidney injury is a common clinical disorder resulting in significantly increased morbidity and mortality. However, despite extensive research, strategies for prevention or treatment are still lacking in routine clinical practice. Already decades ago, several preconditioning strategies (e. g. ischemic/hypoxic preconditioning and calorie restriction) have been published and their extraordinary effectiveness - especially in rodents - has raised the hope for powerful clinical tools to prevent acute kidney injury. However, the underlying mechanisms are still not completely understood and translation to the clinics has not been successful yet. In this review, the most attractive strategies and the current mechanistic concepts are introduced and discussed. Furthermore, we present clinical trials evaluating the feasibility of preconditioning in the clinical setting.