Work at height, rescue and suspension trauma

Introduction and Legislation

Lots of work at height can be, and is, carried out safely. In many other cases, such work is not carried out safely, but people get away with it and come to no harm. However, when things do go wrong with work at height, the consequences are often severe and are sometimes fatal.

The legislative approach to work at height is relatively simple and straightforward and, unsurprisingly, is based on risk assessment. The Work at Height Regulations 2005 are concerned with working safely at heights by:

·         avoiding work at height, where it is reasonably practicable to be do so

·         preventing falls from height, where it is reasonably practicable to be do so

·         mitigating the effects of falls from height, where it is reasonably practicable to be do so

Regulation 4 of the Work at Height Regulations 2005 deals with organisation and planning:  Regulation 4(1) states that: every employer shall ensure that work at height is - 

(a) properly planned;

(b) appropriately supervised; and

(c) carried out in a manner which is so far as is reasonably practicable safe, and that its planning includes the selection of work equipment in accordance with regulation 7

Regulation 4(2) states that: Reference in paragraph (1) to planning of work includes planning for emergencies and rescue.

Avoiding and minimising the risks from work at height

Regulation 6(1) requires the employer to carry out a suitable and sufficient assessment of the risks arising from any work at heights:

“In identifying the measures required by this regulation, every employer shall take account of a risk assessment under regulation 3 of the Management Regulations.”

There will be no need for a specific risk assessment dealing with working at height if this subject has been dealt with fully and satisfactorily in the risk assessments already completed for compliance with Regulation 3 of the Management of Health and Safety at Work Regulations 1999.  For many employers, it will be necessary to revisit these assessments or to complete new “working at height” risk assessments to ensure compliance with the new regulations.

Regulation 6(2) places a duty on the employer to avoid the need for working at a height where it is reasonably practicable to do so:

“Every employer shall ensure that work is not carried out at height where it is reasonably practicable to carry out the work safely otherwise than at height.”

Work must be carried out in a manner such employees are not placed at risks of injury from falling from a height if this is reasonably practicable.  Where reasonably practicable, work should be carried out at ground level rather than at a height.  This applies to maintenance activities as well as to assembly and production activities.

The requirement for prevention of employees working at a height from falling is introduced in Regulation 6(3):

“Where work is carried out at height, every employer shall take suitable and sufficient measures to prevent, so far as is reasonably practicable, any person falling a distance liable to cause personal injury.”

Where work involves access to areas from where a person may fall, access to that area must be prevented in some way.  This may involve several solutions, such as:

• the use of suitable scaffolding systems,
• the use of mobile elevated work platforms and similar equipment,
• the construction of suitable walls or guard-rails (including intermediary guard-rails and toe-boards),
• the use of a harness and anchored lanyard that stops the person reaching the point from which they may fall (such as a 2m lanyard anchored 2.5 m from a fall, i.e. it is too short all allow the person wearing it to reach the edge over which they may fall).

Regulation 6(5) places the employer under a duty to mitigate the effects of falling from a height where it is not reasonably practicable to eliminate the risks of the employee falling.

 “Where the measures taken under paragraph (4) do not eliminate the risk of a fall occurring, every employer shall take—

(a) suitable and sufficient measures, including the provision of work equipment, to minimise—

(i) the distance and consequences; or

(ii) where it is not reasonably practicable to minimise the distance, the consequences, of a fall; and

(b) without prejudice to the generality of paragraph (3), such additional training and instruction or other additional suitable and sufficient measures to prevent, so far as is reasonably practicable, any person falling a distance liable to cause personal injury

There are several ways of mitigating the effects of a fall from a height, these include:

• the use of a suitable fall arrest system,
• the use of suitably positioned and secured safety nets
• the use of rail lock systems on vertical ladders
• the use of suitably sited, specially designed airbags
• etc.

The specific requirements relating to suitable fall arrest systems are outlined in Schedule 5 to the Working at Height Regulations.

Where a risk on a person being injured by a fall exists, the regulations require the use of suitable falls prevention measures and fall mitigation measures.  This is a case of both, not either/or.

Planning for Rescue

Employers involved in work at height operations need to make provision for rescue arrangements it is a requirement of the Work at Height Regulations 2005. Further to this, the casualty needs to be attended to and recovered promptly. This is the employer’s responsibility - not the responsibility of the emergency rescue services.  In the event of a problem developing for a worker working at height, help must be available promptly. As can be seen below (suspension trauma), the survival of an injured person may well depend on the speed of recovery and the level of suitable first aid provision.  As discussed later in this article, being suspended for any length of time may be fatal, owing to the effects of suspension trauma. It follows, therefore that it is important that there is a specific rescue plan in place and that suitable and sufficient resources are provided for each workplace where work at height is carried out. The rescue plan should be regularly reviewed and should be revised as necessary.

As well as physical resources, there should be a provision of trained rescuers on site that are familiar with the procedures, the equipment and the site.

Rescue planning must not be left to the last moment, but should form part of the risk assessment for the work at height. Rescue planning and rescue operations should give consideration to the following issues:

• the safety of the persons carrying out, or assisting with, the rescue
• the anchor points that are to be used for the rescue equipment
• the suitability of the equipment (anchor points, harnesses, attachments and connectors) that has already arrested the fall of the casualty for use during the rescue
• the method that will be used to attach the casualty to the rescue system
• the direction that the casualty needs to be moved to get them to the point of safety, i.e. up, down or sideways
• the first aid needs of the casualty (with respect to injury and also to suspension trauma)
• the possible needs of the casualty following the rescue

Checklist for rescue planning

The following is a simple checklist that employers may work through to ensure that they have considered the important elements of their rescue planning. As with a fire evacuation plan, there is no need to wait for a fire in order to find out if your procedures work – practice opf the procedures (in this case the rescue plan) will identify failings before they can havea serious effect on people.

• How will people be made aware of when someone has fallen?
• How will the suspended worker summon assistance?
• What communication systems will be used between the suspended worker and the rescue team?
• Is there an emergency contact list and other useful information for supervisory staff? 
• Is suitable rescue equipment provided on site and is it readily accessible?
• Have a sufficient number of operatives been trained in the rescue plan and in the use of rescue equipment?
• Has training been kept up to date and does it deal with the rescue equipment provided?
• Have assessments been made of anchor points to which rescue equipment will be attached?
• Has consideration been given to attaching rescue equipment to the suspended worker?
• Have the means of access to the suspended worker been considered?
• Will the rescue arrangements ensure that the suspended worker is recovered in less than five to ten minutes (to prevent suspension trauma)?
• Does the rescue plan take into account an injured (or unconscious) suspended worker?
• Are first aid personnel aware of how to treat casualties with (suspected) suspension trauma?
• Are there suitable arrangements for summoning aid from the emergency services and for liaising with them after arrival on site?
• Have the rescue operatives practiced the removal of suspended casualties using the equipment that you have provided?

Be aware of edges

The potential for a suspended worker (casualty) to be located over an edge must be considered. The rescue will be complicated in instances where edges and obstructions are involved. Recovery that involves working over an edge will:

• increase the effective load in raising operations due to additional friction
• create risks of cutting or abrasion of the anchor line
• put extra shock loading on the anchor line if (sections of) the edge collapse during the rescue
• interfere with the operation of rescue equipment

Rescue equipment that will work with, and will tolerate, the extra issues associated with edges should be selected if edges have the potential to feature in rescue operations.

Four types of rescue

 Although the immediate aim is to recover the suspended worker (or casualty) to the nearest point of safety, there are basically four options for dealing with an emergency rescue that involves an injured or incapacitated worker being recovered to safety. In order of preference these are:

• lowering a remote casualty
• raising a remote casualty
• self evacuation by descent
• rescuing another in descent

The above order is based on the premise that it is preferable that the rescuer is not involved in the descent or the suspension. When rescuing a third party, the first two options are preferable to the forth one. Generally, the first option is preferable to the second one because of the simple expedience that it is more straightforward and physically easier to lower a load than it is to raise one.

General considerations for rescue operations

The rescue system will be under tension and, as such, will be at greater risks of damage from abrasion and cutting. Consider of rescue scenarios (in the form of risk assessments) may indicate the need to use rescue equipment that is capable of coping with these situation, or it may indicate that an additional (backup) safety line may be required. The rescue plan must allow for rescue when the casualty is unconscious.  In order to reduce shock loading and jarring of the suspended worker (casualty) it is important that control is maintained at all times while operating rescue equipment.

The anchor for the rescue equipment should be in a position where the equipment can be operated easily and safely. This may mean that it is appropriate to site the equipment away from the edge to allow for its safety operation. In this situation it may be necessary to use additional equipment to redirect or align the rescue system correctly.  The potential for abrasion and cut-through means that ropes should not be run over edges which also may collapse leading to additional shock-loading of the system). If the system needs to run over an edge, then the rope and edge must be protected from each other and it should be determined that the edge can support the imposed loads.

Raising and lowering operations should be carried out in a controlled manner. The path for raising and lowering should be calculated and checked to ensure that obstacles are not encountered. The potential for some rescue equipment to operate in one direction only must also be considered so that the suspended worker is not moved into a position from which they cannot be recovered.

The general procedure for recovery of the suspended worker should give consideration to the following:

• an assessment of the rescue situation before starting the rescue operation
• arranging for the provision of appropriate medical assistance (such as by summoning the emergency services)
• determination of the appropriate position to carry out the rescue operation from
• determination of the appropriate anchor points for the rescue equipment
• identification of a suitable location (or point of safety) to move the suspended worker (casualty) to
• ensuring that all those involved in the rescue operation are aware of the procedure to be carried out and of their role within this procedure
• ensuring that all relevant employees that have been trained in the rescue procedures are competent to carry out their role
• carrying out the rescue operation in a steady and controlled manner
• ensuring that a suitable means of communication is maintained at all times during the rescue operation
• arranging a suitable process to monitor the suspended worker’s condition at all times during the rescue operation and arranging appropriate first aid and/or medical provision
• reviewing the whole operation in order to determine the lessons that can be learned to make improvements for future rescue operations

Suspension Trauma

One of the reasons why planning for rescue in work at height situations is important is suspension trauma (a special case of orthostatic intolerance and sometimes known as harness hang syndrome).  Orthostatic intolerance is a normal and natural reaction to being upright and immobile.  In such cases, a complex combination of blood pooling in the legs and cardiorespiratory restriction leads to unconsciousness. Orthostatic intolerance can occur in several sets of circumstances, such as:

• being suspended in a harness
• being trapped upright within a confined space
• being secured to a vertical stretcher or litter (such as in mountain rescue)
• many situations where people are forced to remain standing without the ability or room to move

A classic manifestation of acute orthostatic intolerance is a soldier who faints after standing rigidly at attention for an extended period of time.  Suspension trauma presents an immediate threat of death to anyone immobilised in a vertical position.

Causes of suspension trauma

When people stand upright, the heart alone cannot cope with pumping the blood around the body. In particular, it can't draw blood back up, against the force of gravity, from the legs and feet.  To aid the heart, our veins (the blood vessels that return blood to the heart) are very elastic and have a series of (non-return) valves at regular intervals. As people move around, the veins are squeezed by the muscles around them, a process that is important for helping to push blood back up towards the heart.  If people are in an upright position for a while without working their leg muscles, then the blood doesn't get pumped back up from the lower body. Instead it collects in the veins of the lower body (venous pooling), and so reduces the amount of blood available for circulation. This reduces the quantity and the quality of blood available to the brain, which can result in loss of consciousness. This loss of consciousness is an important survival mechanism in these circumstances as when people faint, they fall over.  Once they are lying down, the heart can circulate their blood quite satisfactorily, returning oxygen to the brain with no harm done.

Suspension trauma is the name given to the situation that occurs when people faint but cannot fall over, causing the body to remain upright. This is a serious problem, because if the body stays upright after losing consciousness, then the blood flow is not restored. In such circumstances, the suspended person is at serious risk as the reduced blood flow can lead to serious brain and/or kidney damage, and ultimately to death. If it is allowed to develop unchecked, it can be fatal in a very short time (a matter of minutes).

 Suspension trauma does not take long to develop

In averages cases, it takes somewhere between five and twenty minutes for the first signs of shock to be felt by the casually.  If their legs are held perfectly still (such as if they are unconscious) then the first signs of shock may be apparent after about three minutes.  If they are not rescued, a few minutes after this they the casualty will faint and shortly after this they will die.  If a suspended person is to be rescued, then the rescue must be carried out quickly, preferably within ten minutes of the start of suspension.

By their nature, rescue operations are carried out under extreme pressure.  Consideration should be given to all aspects of the rescue process. Elements to consider would include the type of equipment required, the demands placed upon the rescuer, the training the rescuer will require to carry out the rescue and how the effectiveness of the rescue system as a whole can be maintained  Following a fall and a person being suspended in a harness, it is clear that even if they are uninjured by the fall there is a relatively short time available during which to rescue them.  Following the fall, there is only a short time before the onset of shock and suspension trauma is life threatening.  It is essential, therefore, that the means of rescuing them fallen person has been planned before the event.

Even is the casualty cannot be released form suspension immediately, they can be aided by others if they can be reached safely or if they are still conscious.  If possible, lift their knees into a sitting position using a rope, sling, or other items.  If the casualty is hanging in a harness and is unable to escape, there are some things that they can do to prevent the onset of suspension trauma.  In particular, they cam wiggle their toes and move their legs. This will move the muscles in the legs and will help to squeeze the blood back up towards the heart.  This may be enough to prevent the onset suspension trauma.

First Aid for people with (suspected) suspension trauma

When somebody has been rescued from suspension, do not let them lie down and do not lay them down.  The first action of the first aider on site when the casualty is released from suspension should be to place them in a sitting position with their body upright and their legs flat, or bent at the knees. The exact angle of the knees is not critical, the important issue is that their body is upright, and the legs are no longer dangling. This posture will reduce the pooling effect of gravity, but will keep most of the pooled blood in the legs, preventing reflow and splinting (see below). The casualty should be kept in this position for at least 45 minutes.  The casualty must not be allowed to stand up, exercise, drink or eat. They should be kept calm and relaxed as this will help to reduce the effects of stress on the heart rate. The casualty should be sent to hospital, even if they are not experiencing any ill health.  The first aider must also be mindful of other injuries that have been sustained, such as spinal injuries, choking, etc.

Casualties who have developed suspension trauma may be at risk from reflow syndrome.  This is the name given to the potentially fatal situation caused when the pooled that has blood in the veins in the legs is allowed to flow back into their body.  The blood that has pooled in the veins in the legs will have the nutrients and the oxygen in it used up by the leg muscles.  Once this has been used up the leg muscles will respire anaerobically and the blood will accumulate the toxic breakdown products of this anaerobic metabolism

Another of the problems with treating suspension trauma casualties is overloading or splinting of the heart muscle. Lying the casualty down will cause about 60% of blood volume to return very quickly to the heart and may fill it with blood such that the pumping action is not possible. This overloading of the heart muscle can cause immediate death. During and after rescue, it is important that the casualty is not carried or laid horizontally or allowed to lie down.

Suspension trauma is a potential cause of death in all cases of vertical suspension.  It may result in the death of a person who has fallen and whose fall has been arrested by their fall arrest equipment and who is otherwise unhurt.  In order to prevent fatalities from suspension trauma, employers need to ensure that casualties can be rescued promptly (within ten minutes) and that the first aiders known how to deal with (suspected) suspension trauma cases.

Summary

Plan work at height carefully through a risk assessment based approach and avoid the need for work at height where this is reasonably practicable. In cases where work at height is required, prevent falls from height where reasonable practicable and mitigate the effects of any falls. As part of the planning for work at height work, plans must also be thought through (and practised) on how to conduct a rescue of a worker how falls, but whose fall is arrested and who is left suspended. Speed of the rescue is critical to the survival of the casualty, as is the training of the first aid response to workers who may have suspension trauma.

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