Suspension trauma, fact or fiction?

I’ve been involved in a lively discussion on another LinkedIn post relating to suspension trauma and thought it would be valuable to provide a summary of current expert opinion. James Hannah Ivan Korchev

For anyone that just wants the highlights:

-??????????in tests, during 50 degrees head-up tilt half of subjects near-fainted within 27 min, whereas elevation of the legs secured venous return to the heart and prevented presyncopal symptoms.

-?????????therefore, workers suspended in a rope access sit harness attached from the waist connection will not be affected nearly so quickly as a worker suspended from a fall arrest point.

-?????????the most significant risk to a rope access worker is in the event that a worker is unconscious. A casualty who is unconscious whilst suspended in a harness, should be rescued as soon as is safely possible.

-?????????no change should be made to standard first aid guidance, i.e. ABC and place the casualty into a recovery position.

For anyone who is interested in a more detailed explanation, then here’s a great starting point for authoritative research. In 2002 the late Paul Seddon was engaged by the HSE to review and evaluate the available literature, which can be read in full here CRR 451/2002 Harness suspension: review and evaluation of e... (hse.gov.uk)

Paul provided an excellent description of suspension trauma as follows ‘…blood pools in the veins (typically in the legs) due to gravity. Some venous pooling when a person is stood up is normal. Muscular action in moving the limbs, together with one-way valves in the veins, normally assists the return of blood in the veins back to the heart. If the legs are completely immobile, these “muscle pumps” do not operate and an excess of blood accumulates in the veins, which are capable of considerable expansion and, therefore, considerable capacity. Retention of blood in the venous system reduces the circulating blood volume available to the heart. Thus, the circulatory system is disturbed. During excessive venous pooling, cardiac output and arterial pressure fall, which may critically reduce the quantity and/or the quality of (oxygenated) blood flowing to the brain and precipitate syncope.’

Paul also recommended further research, and in 2009 the Health and Safety Laboratories published the following Evidence-based review of the current guidance on first aid measures for suspension trauma (hse.gov.uk)

The authors of the research were Dr A Adisesh, L Robinson, A Codling & Dr J Harris-Roberts from the Health and Safety Laboratory, and Dr C Lee & Professor K Porter from the University of Birmingham Academic Department of Traumatology Institute of Research and Development.

The main recommendations relevant to rope access workers are:

-?????????In head up suspension, elevation of the legs may prolong tolerance.

-?????????No change should be made to the standard UK first aid guidance for the post rescue recovery of a semi-conscious or unconscious person in a horizontal position, even if the subject of prior harness suspension.

-?????????No change should be made to the standard UK first aid guidance of ABC management, even if the subject of prior harness suspension.

-?????????A casualty who is experiencing pre-syncopal symptoms or who is unconscious whilst suspended in a harness, should be rescued as soon as is safely possible. If the rescuer is unable to immediately release a conscious casualty from a suspended position, elevation of the legs by the casualty or rescuers where safely possible may prolong tolerance of suspension.

The Evidence based review also referred to research carried out by Madsen et al which confirms the finding of the elevated leg semi recumbent suspension position being better tolerated. Tolerance to head-up tilt and suspension with elevated legs - PubMed (nih.gov)

This research found that 87% of subjects suffered ?within 1 h (87%; half time 27 min), but during suspension with elevated legs in only one subject (11%; p < 0.02). In presyncopal subjects the central blood volume was reduced as reflected by an elevated thoracic electrical impedance and reduced central venous and muscle oxygen saturations.

During 50 degrees head-up tilt, half of 79 subjects near-fainted within 27 min, whereas elevation of the legs secured venous return to the heart and prevented presyncopal symptoms. The high rate of near-fainting in normal subjects should be taken into account during evaluation of patients with syncope, and it emphasizes the use of a position that secures venous return during transportation.