Should you ever find yourself having to call in a suspected case of decompression illness, it helps to be able to recognise and convey the symptoms the diver is displaying. DR LIBBY TODD of DDRC Healthcare describes a five-minute check routine – and you don’t need to be a medic to carry it out
Whether you dive for recreational or commercial purposes, or are a diving instructor, skipper or any other member of a dive crew, you might one day find yourself in the unfortunate circumstances of caring for an unwell diver.
Also read: ‘Like tequila shots’: Deep dive sinks diver’s insurance claim
Decompression illness (DCI) can appear with a wide range of symptoms. Often, these can be neurological and present as loss of consciousness, headache, loss of vision / hearing, loss of or altered sensation anywhere in the body or weakness in one or more limbs.
Not one picture fits all, and a timely recognition of neurological symptoms is vital in getting the right help, at the right time.
When phoning through for medical assistance, you might be asked to collect and relay information about the diver’s symptoms to work out whether this could be DCI or something else entirely, such as a stroke.
The diver’s neurological system can be checked in five minutes by anyone, regardless of level of training. It should be done as early as possible, so long as the patient does not require resuscitation and is able to breathe for themselves.
The History
As when telling any story, assume that the person on the other end of the phone has no idea what has happened so far. Start with the basics:
Who are you, who is the patient and where are you currently? What are the circumstances? For example: “My name is James, I am a diving instructor working in Plymouth, and I am calling on behalf of Sally, who has just finished a dive and now can’t feel her left leg.”
If possible, be aware of the duration of symptoms and what was happening when they started (Was it during the dive, straight afterwards or nine hours later? Was it when they bent to lift something heavy, or were they lounging on a beach?).
It is also helpful to have an idea about their dive profile, including depth, duration, time of surfacing and any repetitive dives, as well as whether any unexpected events occurred, such as equipment malfunction or missed deco:
“This was Sally’s 40th dive. She dived to 20m, spent 45 minutes at the bottom, and had an uneventful ascent with a three-minute safety stop at 5m. Her symptoms started after she climbed back onto the boat.”
The Examination
AVPU is a simple scale to measure the patient’s neurological ‘status’:
A is for Alert = awake and talking
V is for Verbal = awake and responds, but only when you talk
P is for Pain = only responds when you cause discomfort, such as by squeezing their trapezius (shoulder) muscle
U is for Unresponsive = someone who does not wake up
Using AVPU is a useful way to convey urgency. If someone can talk to you, are they confused or agitated?
Inspection & Gait
If the patient is able, and it is safe to do so, encourage them to walk a few steps unaided. Are they wobbling to one side? Are they limping? Do they feel dizzy?
What happens if they stand still and shut their eyes? Do they lose their balance or fall to one side?
Cranial Nerves
Our head and neck, including senses such as vision, taste and smell, are controlled by the 12 cranial nerves. You can examine these by checking the following:
1) Eyes: Can the patient follow your finger with their eyes without any blurring, pain or double vision? Do their eyes appear unco-ordinated?
2) Face: Does their face look symmetrical? Are they able to raise both their eyebrows and smile evenly? Can they feel you touching their face, and if so, does it cause any unusual sensation or pain?
3) Ears: Is their hearing reduced in either ear? Do they feel dizzy?
4) Shoulders: Can they turn their neck without any weakness? Can they shrug their shoulders while you press down on them, or have they lost power?
Sensation
Our body interprets stimuli from the outside world such as touch, pain and temperature as signals that are sent along nerves to the brain. Any damage to the receptors identifying the signal, the nerves themselves or the area of the brain receiving the signals can result in reduced or abnormal sensation.
Light touch is relayed via different nerves to pain and temperature. Someone might have a loss of both, or just one, type of sensation. To test light touch, you can use your fingertip or a piece of cotton-wool. Ask the patient to close their eyes and say ‘yes’ every time they feel you touch their skin.
Ensure that you work systemically, and don’t miss any key areas such as hand, ankle, thigh or shoulder. Compare both sides as you go. If the patient has a numb area of skin or it feels abnormal, note the part of the body affected.
If you have the equipment and time available, you can check for pain sensation in a similar way, using something sharp such as a pin (but take care not to hurt the patient!).
Top tips:
1) Make sure the patient’s eyes are closed while you do these tests, and try not to follow an obvious pattern so that they can’t subconsciously guess!
2) Clarify with the patient whether these symptoms are new, or left over from previous injuries or illnesses.
Motor
When examining someone’s movement, we need to test the ‘power’ in each of these areas and compare one side to the other.
To do this, work from the top down, starting at the shoulders, to the elbows, wrists, fingers and thumbs and then the hips to the knees, ankles and toes.
Start by seeing if they can move these body parts independently without any help, then provide some resistance. Power can range from 0 (no movement at all) to 5 (full power).
When assessing a diver, you need to think about whether one side or one area of the body (such as the wrist or fingers), is weaker compared to the other side.
Reflexes & Tone
‘Tone’ describes the amount of rigidity in someone’s limbs.
Reduced tone = floppy and limp.
Increased tone = stiff and difficult to move.
Any obvious changes in tone could help the medical aid to determine where any possible DCI (or other pathology) has occurred.
Reflexes are the body’s subconscious reaction to an outside pressure stimulus. However, you do need a tendon hammer and a bit of practice to test reflexes so might not be able to do this.
In the arms, there is a biceps reflex (tap in the crook of the arm). In the lower limbs, there is a quadriceps reflex (tap below the knee). These can be difficult to elicit and require the limb to be totally relaxed but, if you’re able, try to understand whether the reflex is reduced or increased.
Summarising your findings
Try to hand over the examination findings in a systematic way. Be clear about your positive (abnormal) findings.
An example of a handover using the above structure would be:
AVPU: Sally is awake and orientated, so is an A on the AVPU scale.
Inspection & Gait: She is able to stand only with assistance and has a wobbly gait
Cranial Nerves: She has a normal cranial nerve examination.
Motor: She has 5/5 full power in both arms and right leg. Her left leg has 3/5 power at the hip, knee, ankle and big toe.
Sensation: She has normal light-touch sensation in both upper and lower limbs but reduced sharp / blunt sensation from her left hip downwards.
Tone & Reflexes: She has normal tone in all her limbs, and normal reflexes in both arms and her right leg. Her left leg has absent reflexes.
You could remember this order using the mnemonic: Any Illness Can Make Sailors Think & React
Conclusion
DCI symptoms are worrying and stressful for any diver and for those around them. In some cases, DCI can be life-threatening. We know that getting help quickly is the best way to improve outcomes in the long-term.
Being able to perform a quick neurological examination, regardless of who is present or where you are, could ensure that the diver gets the right help and treatment at the right time.
The summary checklist is available as a PDF from DDRC, and copies can be printed and kept in your first aid box, or with your emergency oxygen supply.
DDRC Healthcare is a Plymouth-based not-for-profit organisation and UK charity specialising in diving medicine, hyperbaric oxygen therapy and medical training.
Also on Divernet: Divers too ready to dismiss DCI symptoms, Bends breakthrough: ‘Immune system going crazy’, Preconditioning Techniques, Good Fortune After Bad