In 2020 the packrafting community didn’t suffer a single fatality. Also in 2020 many countries were in lockdown, access to the outdoors was limited and taking part in activities that could necessitate a Search and Rescue response was discouraged. Whilst we can take heart that there were no fatalities within packrafting, it would be foolish to discount the role that some restrictions may have played in this. However, given the easing of restrictions and the number of packrafts being sold rocketing, the aim to keep fatalities to zero in the 2021/22 season will take a more concerted effort from the community. With this in mind, Luc Mehl invited us to help contribute to the packrafting culture of safety with the aim of keeping fatal accidents to zero.
When I teach Search and Rescue teams, I’m always keen to relate key information back to our actions and behaviour. There seems little point in understanding something without context. The temptation therefore is to cut straight to the chase and teach only the parts that directly relate to our actions. For example, “when you see *this thing* happen on the river, you must respond in *this way*”. However rivers are dynamic environments that change fast and two incidents/accidents are rarely the same. The nature of managing risk often means that you’ve anticipated everything you an imagine happening…. but it’s the unexpected that catches you off guard. Having a really clear and deep understanding of what is happening, in my mind, allows you the best opportunity to act appropriately to an incident rather than depending upon a prescribed response to a prescribed situation. The same is true of hydrology, by understanding the how and why of what’s happening we can change our behaviour accordingly. Professor Nike Tipton put it far more eloquently when he said:
“The importance of understanding the physiological response to cold water immersion that can be a pre-cursor to pathophysiological problems lies in the insight it gives “the cause of the cause of death”. This will help determine it’s mitigation and the treatment of the causalities”
So whilst this is nobody’s favourite subject, lets take a bit of a look at how and why we die in/on water.
This is a large subject and best broken down into a few articles. A natural way to divide this presents itself when the physiological pathway of death in the water is examined.
Ultimately, people who die on the water will die in one of three ways. Drowning, Autonomic Conflict caused by cold water shock or Hypothermia. Whilst drowning can happen at virtually any stage during this pathway, there is a recognised progression of stages during cold water immersion made famous by Dr Giesbrecht (2010) known as the 1:10:1 rule.
1= 1 minute of cold water shock response
10= 10 minutes of meaningful movement
1= 1 hour before hyppthermia kills you
For this article we’ll cover drowning as this can realistically happen at any point of the 1:10:1 pathway. So what exactly is drowning?
Since 2002 drowning has been defined as:
“The process of experiencing respiratory impairment as a result of immersion or submersion in a liquid”
Secondary drowning, dry drowning, near drownings are not a thing. They are outdated and discouraged from being used, however they often slip passed editors or medial journals and as such they are perpetuated. The suggestion is that there are many different forms of drowning that need many different treatments which is untrue. They are all part of the same process.
The process can have three outcomes:
Morbidity (that is long lasting negative physiology effects such as brian damage)
For fatality to occur, hypoxia caused by the respiratory impairment will lead to a cessation in cardiac output eg through myocardial ischemia (the heart receives insufficient blood with oxygen and nutrients to continue to function) or arrhythmia (such as ventricular fibrillation or tachycardia). Morbidity occurs often when the brain has been deprived of oxygen for prolonged periods or the lungs have been injured and no morbidity is often the result of swift intervention and interruption to the respiratory impairment (i.e. someone pulling them out of the water and allowing them to breath again).
This respiratory impairment can be triggered by tetanic spasms whereby muscles including those around the larynx, contract to close the airway or through aspiration of water into the lungs which interrupts the interaction between alveoli and capillaries in the lungs. The aspiration itself can happen from taking a breath in as a wave breaks over us or when autonomic processes take over. Breath holding causes a build up of co2 in the body which is detected in the carotid chemoreceptors resulting in an urge to take a breath. This urge can only be consciously fought for a finite amount of time after which the urge to breath surpasses our effort to breath hold and water is inhaled and exhaled into the lungs.
The water we inhale can wash out the surfactant that surrounds the alveoli and breaks to surface tension that allows gaseous exchange to happen in the lungs. The loss of the this surfactant can make it impossible for gaseous exchange to occur and can cause alveolar collapse. This collapse can also mean that some fluid from the blood leaks directly into the lungs and out of the airway. It’s worth noting at this stage that although this is a problem that may cause morbidity, as a first responder it is not going to be something we will be able effectively reverse in the field and as such your focus should be on oxygenating your casualty. Ventilate through the foam. This is kinda gross, you might want to think about a face mask or BVM.
The lethal dose of fresh water aspirated into the lungs is around 3 litre, for sea water less than 2 litres. This is worth remembering for when we visit cold water immersion. Aspiration of water can occur at any point during the drowning process especially if our casualty has a lowered level of consciousness.
So what does this mean for us as paddle partners, responders or first on the scene? Well the cliche goes, prevention is better than cure so perhaps it goes without saying but it’s worth reiterating that becoming a better paddler and taking a course will help prevent the immersion/submersion from happening to begin with. Once the immersion/submersion has happened though, it’s back to our DrsABC. Assess the Danger, check for Response, Send for help, Airway, Breathing, Circulation.
Assessing danger is a dynamic process on the river as the situation may escalate and the risk levels rise. The only thing worse than a fatality on the river is multiple fatalities on the river and we must behave in a way that first and foremost prevents further harm from occuring. Our priorities as a rescuer are, ourselves, our team, the casualty then equipment. We should giving consideration to the least risky response initially (these responses are often quicker too which is advantageous) before resorting to riskier and more complicated responses. It’s worth noting at this stage that you may have to make the incredibly difficult decision not to intervene if life or limb of others will be compromised. This choice may in influenced by your relationship to the casualty or the role you are playing in the trip, i.e. as a first rescue team member it may be easier to arrive at this decision than if you’re watching a friend or loved one in trouble.
Protect the airway. This can mean simply pulling their head out of the water, stabilising them or taking the pressure of the flow off them. Once you’ve got an airway you can start rescue breaths. Time is critical so remember that our casualty is suffering from a lack of oxygen not a lack of dry land. Where practicable this can mean in water ventilation although this is far harder in deep water where you cannot stand. If you are in an eddy thought you may be in a position to start rescue breaths straight away rather than waiting for the assistance to pull your casualty fully out onto the bank (which can be very difficult on your own, particularly if your casualty is unconscious). Breathing is now your priority remembering to ventilate through the foam. If you can keep cardiac tissue perfused with oxygenated blood, your intervention can prevent further escalation. In severe cases your casualty might suffer from cardiac arrest secondary to the hypoxia and as such full blown CPR maybe required and you’re back to your Pre-Hospital emergency care training. If your casualty is producing foam then the best treatment is going to be Av Gas. Set off your Personal Locator Beacon and get them on a heli to hospital. You may have members of your team able to send for help as you are working to preserve the airway which is preferable.
Your casualty is almost certainly going to need hospital treatment to rule out further morbidity even if they appear to have made a full recovery.
Whether we chose to acknowledge these risks and the actions that might need to be taken in the event of a serious incident or live in blissful ignorance, there are ever present for us on the water. Prevention is absolutely key and should factor into just about every choice we make around packrafting from planning, river running, equipment purchases. Thankfully drowning is pretty high on perceived risks and almost everyone will taking actions to mitigate the risk from ever happening. There are also plenty of good Pre-hosptial emergency care courses available to brush up on your first aid skills and as ever there are packrafting specific rescue courses to hone your preventive skills and rescue responses.