Core Skills — 19 May 2022 at 8:41 pm

Scuba Diver Emergencies – Stories From The Deep

Dr Rosie Stokes / Diving & Hyperbaric Physician / DDRC Healthcare Plymouth

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Dr Rosie Stokes specialises in diving and hyperbaric medicine at DDRC Healthcare’s hyperbaric facility in Plymouth. Here she shares some fictional cases following one of the busiest autumns at DDRC as UK scuba diving returned post lockdown. Whether they present to your Emergency Department, GP practice or on an expedition, here’s what to look out for and who to call. 

What is dive medicine? 

Most people have heard of ‘the bends’, or decompression illness. 

Decompression illness is the umbrella term for both decompression sickness (an evolved gas issue) and arterial gas embolism (an escaped gas issue):

  • Decompression sickness tends to present any time from the diver leaving the bottom to 24-72 hours later. The severity of symptoms relates to the depth and time of the dive. 
  • Arterial gas embolism presents within 20 minutes of surfacing, usually after a rapid ascent. It is unrelated to time or depth and can even occur in a swimming pool!

Presentation of decompression illness can vary, depending on the area of the body that the bubbles have affected. If you are a medic working at a dive site, near the coast (or even near an airport), it is worth having some basic knowledge of dive medicine, so that you know what symptoms to look out for. 

If in doubt, the British Hyperbaric Association emergency line is available 24/7 for advice. You can speak to a dive doctor directly and, if needed, we can arrange for assessment at the nearest hyperbaric chamber. 

Here are a few examples of some typical cases of divers that may present to DDRC. These cases are entirely fictional and any similarity to real patients are coincidental.

Case 1 – Cord Compression: Spinal Decompression Illness

A 60 year old male, JX, was on his first day of a dive trip, on a boat off the southwest coast of the UK. JX was a relatively new diver and had an enjoyable dive down to 15m. On his ascent his inflator stuck, allowing more air into his BCD (buoyancy control device). He was unable to control his ascent and rapidly arrived at the surface, in a panic. 

The boat crew got him out of the water and removed his scuba equipment. He reported feeling weak and complained of some back pain. The skipper put 100% oxygen on him and called the coastguard.

The coastguard rang the BHA who advised that the JX be taken by air ambulance to an emergency department. He had a chest x-ray to rule out a pneumothorax, which can result from a rapid ascent. He had weakness in his right leg with loss of sensation. He also had urinary retention. A urinary catheter was inserted and he was given IV fluids.

JX was transferred to the hyperbaric chamber where he had an extended treatment of over eight hours. His symptoms persisted and he returned to hospital to have an MRI spine, which did not find any other pathology. His symptoms slowly improved but it took three weeks of daily treatments before he felt back to normal. He was left with some loss of sensation in his right foot.  

Case 2 – Off Balance: Audiovestibular Decompression Illness

RS, a 50 year old man, was on the third day of his dive holiday. He had been breathing nitrox (32% oxygen) using normal open circuit scuba equipment. He had a moderate level of dive experience with 70 previous dives. The dive was uneventful, exploring a shipwreck. On returning to the boat he suddenly became very nauseous. He lay down on a bench and was unable to sit up or stand without falling. He vomited several times. 

The skipper informed the coastguard, who contacted BHA five minutes later. The boat returned to shore and was met by an ambulance. RS was transferred to the chamber for assessment on high-flow 100% oxygen.

On examination he was unable to stand and kept his eyes closed. He had horizontal nystagmus, and his extreme nausea and dizziness limited the rest of the examination. He was given anti-emetics and IV fluids and put into the recompression chamber for treatment. 

During treatment his dizziness and nausea continued and the treatment was extended to eight hours  Due to persistent severe symptoms he required two weeks of daily treatments before he could walk normally and had stopped having bouts of vertigo. 

Neurological decompression symptoms can be associated with a patent foramen ovale, and a large PFO was found on bubble echo.

Case 3 – Overloaded: Immersion Pulmonary Oedema

Decompression illness is not the only emergency that we are called about. Many things can go wrong when you are submerged underwater. We also advise on other emergencies such as immersion pulmonary oedema, barotrauma or rebreather/gas contamination issues.

TR, a very experienced 65 year old female diver, entered the water from the shore with her two dive buddies. They swam to a cluster of rocks where they had planned to dive near a kelp forest. During the surface swim she began to feel breathless, but decided it was due to lack of exercise and recent weight gain. She paused to catch her breath but couldn’t. She began to cough up a clear, frothy fluid. Her buddies noticed her struggling, so swam her back to shore and removed her scuba equipment. Her breathlessness continued and she began to look blue. A passer-by rang for an ambulance.

When the ambulance arrived she was hypoxic with oxygen saturations of 86%. She was placed on 100% oxygen and taken to hospital. On arrival she had a chest x-ray which was consistent with pulmonary oedema. She was given IV diuretics and her symptoms improved. The ED consultant rang the BHA line to discuss the incident with a dive doctor. 

This was a case of immersion pulmonary oedema, which can often be mistaken for drowning in sea swimmers and divers. Immersion in cold water causes an increase in cardiac preload, inducing pulmonary oedema. It is thought to be more common in people with uncontrolled hypertension.

This lady made a full recovery but has decided not to return to diving after a discussion with a dive doctor.

Case 4 – Under pressure: Barotrauma

GR, a 19 year old newly qualified diver, was with a group of more experienced divers. He had a bit of a runny nose but it didn’t bother him too much. During descent his right ear felt blocked and he couldn’t equalise. The divers ahead of him had almost reached the bottom, so he ignored his discomfort and continued to descend.

On reaching the reef he felt sudden relief of the pain and he forgot about his ears. The dive was uneventful with no other issues but on ascent, his right ear felt a little odd again. He surfaced without a problem. 

On the boat he noticed that he had a fullness in his right ear and noises seemed dull. His ear felt painful and sensitive and he began to worry.

GR contacted the BHA who advised him to see his GP.  He was found to have a perforated eardrum. It healed quickly and, luckily, he has no long-lasting damage to his hearing. 

Having a common cold or structural issues with your eustachian tubes can make it difficult to equalise the middle ear. Any air that is trapped in a confined space in the body has the potential to cause damage as the volume of air changes under pressure. As this diver descended the middle ear would have been squeezed, disrupting the tympanic membrane and ultimately causing a perforation. 

Who to call:

These cases illustrate the breadth of diving-related illness. It presents in multiple ways and can be tricky to identify, as it resembles so many differential diagnoses.

If you are looking after a diver in the UK then the British Hyperbaric Association emergency line is available 24/7 for advice:

  • England and Wales: 07831 151523
  • Scotland: 0345 408 6008

If you are outside of the UK then divers should be advised to speak to their nearest hyperbaric chamber or if they have DAN insurance (Divers Alert Network) they should ring +1 (919) 684-9111.

If you are providing medical cover on a dive expedition then make sure you have a thorough knowledge of the evacuation plan and access to a supply of oxygen that will last for the length of time that it takes to get the diver to the nearest medical facility or hyperbaric chamber. Hyperbaric facilities vary greatly and it is worth investigating what treatment they can provide and how accessible this is.

More advice can be found here: Diving: Managing Decompression Illness in Remote Locations.

If you want to learn more about dive and hyperbaric medicine please visit our website at: or follow us on Facebook:

If you are interested in working at DDRC we periodically advertise for junior doctors and nurses. Keep an eye out on the job section of our website: and take a look at this article by one of our previous DDRC doctors: Diving and Hyperbaric Medicine at DDRC Healthcare.