# Remote ischemic conditioning in intensive care: From bench to bedside

## TL;DR

This review explores remote ischemic conditioning, a non-invasive technique to reduce tissue damage from blood flow disruption, and its potential in critical care settings.

## Contribution

The paper provides a comprehensive review of RIC's mechanisms, clinical applications, and ongoing research to improve its effectiveness in intensive care.

## Key findings

- RIC involves controlled ischemia in a distant organ to protect against I/R injury.
- Preclinical studies show RIC's efficacy, but clinical trials have mixed results.
- Ongoing research focuses on optimizing RIC delivery and identifying suitable patient groups.

## Abstract

Ischemia/reperfusion (I/R) injury is a pathological phenomenon involving temporary blood flow restriction (ischemia) followed by a period of reperfusion. This sudden variation induces oxidative stress, inflammation, and mitochondrial dysfunction, leading to severe cellular damage. I/R is a primary driver of organ injury in critically ill patients, particularly in conditions such as myocardial infarction, stroke, cardiac arrest, trauma, cardiac surgery, and various shock states.

Remote ischemic conditioning (RIC), a non-invasive strategy involving repeated controlled episodes of ischemia and reperfusion to a distant organ (typically a limb), has emerged as a potential strategy to attenuate I/R injury through systemic protective mechanisms. RIC can be applied at various time points: i) before ischemia (pre-conditioning); ii) during ischemia (per-conditioning); iii) after reperfusion has started (post-conditioning). While preclinical models have consistently demonstrated its efficacy, clinical trials to date have shown mixed results, with limited impact on key clinical outcomes.

In this narrative review, we first provide a brief historical overview and outline the molecular and cellular mechanisms underlying RIC. Second, we examine current evidence from both animal studies and human trials on the effect of RIC across several conditions such as myocardial infarction, stroke, cardiac arrest, trauma, cardiac surgery and shock. Finally, we discuss ongoing research efforts aimed at optimizing its delivery and identifying patient populations most likely to benefit from its use.