ICAR MEDCOM releases Experts recommendations on suspension syndrome

The authors recommend that rope work should never be conducted alone due to the risk of suspension syndrome. Patients should be laid horizontally immediately upon rescue, followed by basic and advanced life support. Authors call for an international case registry.

Suspension syndrome occurs when a person suspended vertically in, eg, a climbing harness experiences cardio-circulatory collapse. The diminished preload has been speculated to be the cause, there is no proper understanding of the syndrome and optimal treatment. People at risk include rope access technicians, cavers, height rescue workers, and sport climbers.

In a systematic review, the ICAR MEDCOM found 23 articles addressing suspension syndrome. Simon Rauch, Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy, and colleagues conducted a scoping review and then generated prevention, diagnosis, and treatment recommendations.

The key findings of the review are as follows:

• Incidence is unknown, but deaths are rare since sit harnesses were introduced in the 1970s.
• In experiments in healthy volunteers, suspension led, after minutes to hours, to a sudden drop in heart rate, blood pressure, and stroke volume, as well as presyncopal symptoms. This suggests a neurocardiogenic aetiology.
• Exacerbating factors have included pain, higher body weight, and previous exercise.
• Other effects of suspension include rhabdomyolysis, hyperkalaemia, ventricular arrhythmia, acute kidney injury, hypothermia, thrombi, and paraesthesia.
• Belt or chest harnesses without other loops are likelier to result in suspension syndrome, as are harnesses with a dorsal attachment.
• Patients who cannot be quickly rescued should be encouraged to activate leg muscles.

Based on the scoping review, discussion with the ICAR MedCom and to give guidance on the most important questions regarding the suspension syndrome, the following recommendations on prevention, diagnosis and treatment of the suspension syndrome have been developed and graded according to the Grading System of the American College of Chest Physicians.

Recommendations

• Rope work should be done only with proper equipment and knowledge of how to use it correctly. Rope work should never be conducted alone.
• Persons suspended in a harness should be rescued as soon as possible, even if the casualty is asymptomatic, as time to near or actual syncope and potentially cardiac arrest is variable and unpredictable
• While awaiting rescue, persons suspended freely on a rope should move their legs to reduce venous pooling.
• If no adjoining structures are in reach, foot loops should be used to step in and increase the activation of the muscle pump.
• If the casualty is no longer able to act and it is safe to do so, the first rescuer reaching the casualty should raise the victim’s legs to create a more horizontal position while measures are taken to lower the patient to the ground.
• Once the casualty is on the ground, the casualty should be positioned supine. Assessment and treatment should follow standard advanced life support algorithms. Reversible causes of cardiac arrest, including hyperkalaemia and pulmonary embolism, should be considered and managed appropriately.
• After prolonged hanging (> 2 h), patients are at risk of developing hyperkalaemia and acute kidney injury and should, therefore, be transported to a hospital with the capability of performing emergent renal replacement therapy.

The main limitation of the research was that there were no randomised controlled multinational studies.

Reference:

Rauch, S., Lechner, R., Strapazzon, G. et al. Suspension syndrome: a scoping review and recommendations from the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). Scand J Trauma Resusc Emerg Med 31, 95 (2023). https://doi.org/10.1186/s13049-023-01164-z