Should the tourniquet be released every 10 minutes?

From the Guidelines

Tourniquets should not be released every 10 minutes, as this can lead to reperfusion injury and continued bleeding, and instead, they should remain in place until the patient reaches definitive medical care, typically in a hospital setting, as recommended by the most recent guidelines 1.

Rationale

The use of tourniquets has become a standard of care for severe external hemorrhage in military medicine, and several publications report their effectiveness in this specific context in adults and children 1. However, releasing a tourniquet periodically can lead to reperfusion injury, where toxins from the damaged tissue enter the circulation, potentially causing systemic complications including shock and cardiac arrest.

Key Considerations

• A properly applied tourniquet can safely remain in place for up to 2 hours with minimal risk of permanent tissue damage, as suggested by previous studies 1.
• The time of application should be clearly marked on the patient or tourniquet to inform medical personnel.
• Only trained healthcare providers in a controlled medical environment should make decisions about tourniquet release, as they can manage potential complications.
• Iterative tourniquet releases for the sake of ischemic sparing can aggravate local and systemic morbidity, as noted in recent guidelines 1.

Best Practice

This approach represents current best practice in emergency medicine and tactical combat casualty care, and is supported by the most recent and highest quality studies, including the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1.

From the Research

Tourniquet Release Interval

• The ideal interval for releasing a tourniquet is not explicitly stated in the provided studies, but we can look at the effects of tourniquet use and reperfusion injury to inform our understanding.
• A study on the effects of tourniquet application found that significant pressure loss occurs within minutes of application 2.
• The study suggests that tourniquet applications should be reassessed for arterial occlusion 5 or 10 minutes after application to be within 5mmHg or 1mmHg of maximal pressure loss.
• However, there is no direct evidence to support releasing a tourniquet every 10 minutes.

Tourniquet-Related Ischaemic Damage

• Tourniquet-related ischaemic damage can lead to the release of reactive oxygen species, resulting in injury to remote organs 3.
• Studies have investigated various interventions to reduce tourniquet-related oxidative damage, including anaesthetics, antioxidants, and ischaemic pre-conditioning 3, 4, 5.
• These interventions have shown promise in reducing biochemical oxidative stress markers, but the correlation between reduced oxidative stress and postoperative clinical outcomes requires further investigation.

Reperfusion Injury

• Reperfusion injury can occur after tourniquet release, leading to changes in glutathione metabolism and indicating oxidative stress 4.
• Mannitol has been shown to reduce skeletal muscle reperfusion injury and postischaemic compartment pressure, possibly due to its hyperosmolar property and free radical scavenging effect 5.
• Other studies have investigated the therapeutic effects of masitinib on abnormal mechanoreception in a mouse model of tourniquet-induced extremity ischemia-reperfusion, suggesting that anti-neuroinflammatory drugs may mitigate nerve damage and improve mechanoreception 6.