Suspension Trauma: A Clinical Review

Suspension syndrome: a scoping review and recommendations from the International Commission for Mountain Emergency Medicine (ICAR MEDCOM)

BACKGROUND

Suspension syndrome describes a multifactorial cardio-circulatory collapse during passive hanging on a rope or in a harness system in a vertical or near-vertical position. The pathophysiology is still debated controversially.

AIMS

The International Commission for Mountain Emergency Medicine (ICAR MedCom) performed a scoping review to identify all articles with original epidemiological and medical data to understand the pathophysiology of suspension syndrome and develop updated recommendations for the definition, prevention, and management of suspension syndrome.

METHODS

A literature search was performed in PubMed, Embase, Web of Science and the Cochrane library. The bibliographies of the eligible articles for this review were additionally screened.

RESULTS

The online literature search yielded 210 articles, scanning of the references yielded another 30 articles. Finally, 23 articles were included into this work.

CONCLUSIONS

Suspension Syndrome is a rare entity. A neurocardiogenic reflex may lead to bradycardia, arterial hypotension, loss of consciousness and cardiac arrest. Concomitant causes, such as pain from being suspended, traumatic injuries and accidental hypothermia may contribute to the development of the Suspension Syndrome. Preventive factors include using a well-fitting sit harness, which does not cause discomfort while being suspended, and activating the muscle pump of the legs. Expediting help to extricate the suspended person is key. In a peri-arrest situation, the person should be positioned supine and standard advanced life support should be initiated immediately. Reversible causes of cardiac arrest caused or aggravated by suspension syndrome, e.g., hyperkalaemia, pulmonary embolism, hypoxia, and hypothermia, should be considered. In the hospital, blood and further exams should assess organ injuries caused by suspension syndrome.

Fatal and non-fatal injuries due to suspension trauma syndrome: A systematic review of definition, pathophysiology, and management controversies

BACKGROUND

Suspension trauma syndrome is a life-threatening event that occurs when a person is "trapped" in a prolonged passive suspension. It is most commonly seen in people who engage in occupational or sport activities that require harness suspension. The aim of this study is to identify the predisposing factors, pathophysiology, and management of suspension trauma.

METHODS

A review and analysis of the literature published in English and Spanish from 1972 to 2020 on suspension trauma were performed. Search sources were PubMed, Medline, Cochrane Library, MeSH, UpToDate, and Google Scholar. Articles referring to suspension trauma associated with other injury mechanisms (traumatic impact injuries, drowning, asphyxiation, or bleeding), case reports, and pediatric population were excluded.

RESULTS

Forty-one articles were identified. Of these, 29 articles related to mechanism, pathophysiology, and management of individuals who suffered prolonged suspension trauma without associated traumatic injuries were included in the study. We encountered several controversies describing the putative pathophysiology, ranging from blood sequestration in the lower extremities versus accumulation of metabolic waste and hyperkalemia to dorsal hook-type harness as a trigger cause of positional asphyxia; to vascular compression of femoral vessels exerted by the harness causing decreased venous return. Pstients suspended in a full-body harness with dorsal hook showed more hemodynamic alterations in response to the compressive effect on the rib cage, causing a reduction in perfusion by presenting a decrease in pulse pressure. Management strategies varied across studies.

CONCLUSIONS

Progress has been made in individualizing the population at risk and in the management of suspension trauma. We recommend the formation of consensus definitions, larger cohort or registry studies to be conducted, and experimental animal models to better understand the mechanisms in order to develop management and life support guidelines from a trauma and emergency medicine perspective.