Suspension Trauma Prevention

Preventing suspension trauma

Without being too obvious, the best way to prevent suspension trauma is never to get into a position where it can start! Working with suspension in harnesses is perfectly OK, provided you PLAN to prevent suspension trauma. The same goes for medics and rescuers using litters, and for those who enjoy tying each other up. The risks come from failing to predict the dangers, and so allowing the casualty to develop problems without anyone else noticing, and from not knowing how to react should they suddenly faint. Almost all deaths from suspension trauma could have been prevented, had colleagues, friends and rescuers known what was going on.

Assuming you've read the Introduction you'll know how and why the condition develops, and that it's all started by blood pooling in your legs. If you're going to be held in an upright position for more than five or ten minutes, then you will be at some degree of risk. A rock climber is usually safe because he or she is using their legs all the time - but if they fall off, stop for lunch, or just get bored and 'dangle', then it's a different matter. Parachutists are never 'under canopy' for long enough to see problems until they get stuck in a tree, in which case it's too late to start asking for advice.

Prevention techniques

Preventing suspension trauma can take one of two approaches - either we stop the blood pooling in the first place, or we make sure it's pumped back out. Which you choose depends on what you're doing, and it is very important that you pick the right method. Some sources of advice, even some government publications, get this bit very wrong and you could end up very dead if you follow the wrong advice.

Plan 1 : Sitting up, chilling out

You're probably sitting in a chair reading this. You haven't moved your legs in a while, but you're not dead. It's all down to the fact your thighs are almost horizontal - they are where most of the blood pools, and so if they are kept elevated then suspension trauma is almost impossible. Think of how many times you've heard of someone fainting to death in an armchair.

For anyone suspended in a harness and who doesn't need to move about all the time, or who can't (for example someone who has fallen and is injured, tired or just lazy) then the best, most effective and easiest way to keep them safe is to lift them into a sitting position. Looping something under their knees, or sitting them on a swing-seat, is all you need to do - the person can often do that themselves if they've got something to hand. It's very important to do this as soon as possible - within a few minutes of suspension - so the blood has no time to begin pooling.

The trick is to lift the knees, and to use your legs as little as possible - the more you use them the more blood is sent down to the muscles. Sit down, relax, chill a little.

Now, there is an obvious problem with this advice, good though it is. You can only lift your knees up if you're allowed to by the design of whatever you're being suspended from. In a stretcher it's impossible. In a rock-climbing or parachute harness it's easy, and in parascending or paragliding harnesses there's an inbuilt seat precisely for the purpose. With other designs of harness you may find the angle of your torso or the way the leg loops are connected prevents you from being able to lift your knees more than a few inches. Clearly this is a stupid idea, but we're stuck with it, as many harnesses are designed to comply with standards and laws which were written long before suspension trauma was recognised.

In thse cases, you may have no option but to use the second plan below. It's not as good as plan 1 and we really would prefer you to avoid those situations at all costs, for example by changing your activity so that accidental suspension is no longer a possibility. There are however some unfortunate cases where plan 2 is going to be your only option...

Plan 2: Invisible Bicycles

Just as with a rock climber struggling up a cliff, or you when walking to the kitchen, using your legs keeps the blood flowing. Even hanging in a harness, if you are using your legs to climb about, you will be safe. The problem comes when you're in mid-air, or you're injured or tired, and that movement is a bit less forceful. Now, the pumping effect is reduced but your leg muscles are exercising, so they need blood! The arteries feeding your legs open wide, blood pours into your legs, and eventually... well you can see the result. The 'keep your legs active' plan works great if you have surfaces to kick against, like our rock climber.

So why are we saying that plan 2 is so terrible?

It's useless for anyone who physically cannot move (strapped into something, or injured), as of course it needs the casualty to exercise (and exercise very hard). If you, as a casualty, have just fallen off a cliff and smashed yourself to pulp on the way down, you won't be in a fit state to start running on the spot. If you're gently hanging there and start feeling faint, you won't be able to exercise fast enough to stop yourself fainting, as by driving more oxygen into your leg muscles you momentarily reduce the supply to your brain even more, and so you're likely to pass out anyway.

The main reason for plan 2 to rate as a stupid idea is that once you start madly pedalling that invisible bicycle in mid-air, you cannot stop. All that exercise has increased the oxygen demands of your leg muscles, and so if you get tired and stop using them, the venous pump stops instantly. Blood is still rushing into your legs to feed your muscles, and so the world goes dark around the edges.

Leg-pumping is advocated by many 'official' advice, such as from OSHA, but we simply cannot condone it - for the reasons given above. The only possible situation you should try it is if there is absolutely no other option. If you think about what 'preventing suspension trauma' is trying to do, it makes perfect sense. You're trying to get as much blood as possible to your head, and as little as possible to your legs. Lifting them and relaxing them achieves that. Using them like crazy doesn't.

We often like to remind our students of the old joke about a traffic cop who stopped a woman driving a battered old station wagon at 150mph through downtown Detroit. When asked why she was going so fast, she said

"My brakes don't work. I gotta get home fast before I have an accident!"

Unplanned suspension

If your job, hobby or personal preferences mean you're potentially at risk from suspension but in reality aren't expecting it, then being aware of the above techniques is the best single thing you can do. It would be nice to have a trained rescue team on standby, but in many cases that isn't an option - someone parachuting for sport will probably never get hung up in a tree in their lives, but if they do, a 5-minute talk from the instructor will save their lives. When the risks start increasing, you can start to take equipment with you. Military paratroopers often expect to jump into trees, and so carry ropes so they can abseil out of them. If you're going caving and there's a huge 1200ft shaft to descend, it makes sense to carry spare equipment so you're less likely to get stuck - and if possible make yourself a swing-seat from webbing so you can abseil in a safe position, or take rest stops on the way back up.

Workers who may be suspended as a result of a fall onto personal fall arrest harnesses should always plan for it happening, even if it rarely does. You should have very carefully-thought-out rescue plans for every possible scenario, including the equipment and people needed to perform the rescue. In many countries this provision is required by law - but even if it's not, it may be the only thing stopping you from attending the funeral of your best friend - or from them attending yours. Rescue plans and training are not difficult, and may be a 'business overhead' but when spread over the hours of a contract can cost less than the coffee in the canteen. Remember - you all expect an office to have a fire extinguisher, even though most of you will never be in a building that catches fire. Why not expect to be rescued from a harness?

Intentional suspension

There are many situations where prolonged suspension is intentionally planned, such as in theatrical performer flying, bondage, parascending, access into confined spaces, etc. and although it's sensible to try and adapt your activities to reduce the time spend in an at-risk position, it's not always possible.

If there is no way to avoid being suspended, you should attempt to do so with your knees raised into a sitting position. This may be by use of a climber's seat, or by using something on which you can rest your feet, but by placing your thighs horizontal the risk of suspension trauma is reduced to negligible levels. You may not be able to stay in the sitting position all the time, but if you can move into and out of it every few minutes it will help a lot.
In a sit-harness (for rock climbing, caving, rope access etc.) it's possible to swing your entire body upside-down, and although it seems (and feels) silly, doing that every few minutes will literally pour the blood out of your legs.
If you cannot adopt a sitting position then you should restrict the time in suspension to no more than five minutes at a time, and have immediate rescue in place so that the casualty can be removed from suspension instantly if they show any signs of discomfort or distress. It's important to plan for the rescue delay - if for example you are lowering a worker into a narrow shaft using a winch and harness, they may develop problems near the bottom, where it might take another three or four minutes to winch them back out again. In cases like that it can be more sensible to carry on lowering them to the bottom, so at least they're out of suspension.
A stretcher patient lifted in a vertical position is at extreme risk, especially if they already have compromised circulation due to illness or injury. It should be done only where absolutely necessary, and only for the minimum amount of time and with continual patient monitoring. Many people have been killed by vertical stretcher lifts, and some of them were just people doing training.

In summary...

So, what have we learnt so far?

Unless you're planning on moving about or are forced to stay upright for some other reason, lifting your legs into a sitting position while suspended is the best plan, and the easiest.
Try to avoid being 'upright and immobile' for more than a few minutes at a time, and if you feel ill, get out of the position straight away!
Never leave anyone alone who may be at risk of suspension trauma

Of course if it does happen, you'll want to know how to treat the victim safely!

Suspension Trauma