Prevent and prepare

• Be aware of and actively reduce the risk factors including deep or long dives, cold water, hard exercise at depth and rapid ascents.

Early recognition

Symptoms of decompression illnesses usually appear 15 minutes to 12 hours after surfacing, but in severe cases, may appear before surfacing or immediately afterwards.

Decompression sickness

Symptoms include the following:

• unusual fatigue
• skin itch
• pain in joints and muscles of the arms, legs or body
• dizziness, vertigo, ringing in the ears
• numbness, tingling, paralysis
• shortness of breath.

Arterial gas embolism

Symptoms include the following:

• dizziness
• chest pain
• disorientation
• bloody froth from the mouth or nose
• paralysis or weakness
• convulsions
• becoming unresponsive.

First aid steps

1. If specifically trained, administer oxygen to the person. (See Oxygen administration.)
2. Access EMS. If possible, call the Divers Alert Network +1-919-684-9111.
3. Monitor the person’s level of response, breathing and circulation until EMS arrives.

  _____________________________

NOTE

• If the person becomes unresponsive, open their airway and check for breathing. (See Unresponsiveness.)
• If the person becomes unresponsive with abnormal breathing after resurfacing, CPR should be administered with rescue breaths. See Unresponsive and abnormal breathing (baby and child) or (adolescent and adult).

______________________________

Access help

• Phone EMS immediately. They will be able to tell you what to do and arrange help.
• The Divers Alert Network is an international not-for-profit organisation with a helpline which can be reached 365 days a year, 24 hours a day, by phone: +1-919-684-9111. This network provides assistance with managing injured scuba divers, helps decide if recompression is needed, provides the location of the closest appropriate recompression facility and helps arrange transport for the person.

Context considerations

• In some countries, laws make it mandatory for professional diving operations to have oxygen readily available (e.g. diving training institutions). Therefore, the likelihood of oxygen being available is high at dive sites, and likely immediately available if called for by the first aid provider.
• Learners should be informed about any national first aid guidelines for decompression illness, including the local procedures for care in the country where they are diving.
• Programme designers should obtain information on local resources for diving emergencies and access to hyperbaric oxygen therapy facilities, to include in programmes.
• Decompression-related injuries can happen in open water as well as in deep swimming pools, so education on this topic may be applicable to learners without local access to open water.

Learner considerations

• This topic is usually targeted at professional responders (e.g., paramedics, lifeguards) who have a specific duty to respond, strong assessment skills, and access to resources such as oxygen. Consideration should be given to the technical nature of this topic and the programme designer should match the content to the skill level of the learners using appropriate terminology.

Facilitation tips

• Explain that decompression sickness is the result of rapid decompression after exposure to increased pressure. During a dive, the body tissues absorb nitrogen from the breathing gas in proportion to the surrounding pressure (which is elevated during diving). As long as the diver remains at pressure, the gas presents no problem. But if the pressure is reduced too quickly, the nitrogen comes out of solution and forms bubbles in the tissues and bloodstream. Diving tables provide scientific protocols to decompress safely, with a low chance of bubbles forming. However, decompression sickness can still occur despite following accepted guidelines.
• Explain that an arterial gas embolism happens if a scuba diver surfaces without exhaling. Air trapped in the lungs expands on the ascent and may rupture lung tissue (called pulmonary barotrauma), which releases gas bubbles into the arterial circulation. The bubbles are distributed and may impair the circulation wherever they become lodged. Because the brain receives the highest proportion of blood flow, it is the main organ where bubbles lodged in small arteries can interfere with circulation.
• Emphasise that if learners will be responding to suspected decompression illness hours after the person has resurfaced (and is presumably in a different environment), they will need to use a detailed assessment process to identify the symptoms as being related to decompression illness and not another condition.
• This topic is best suited to be covered after foundational concepts of first aid so that learners are able to draw from a range of skills and knowledge.

Facilitation tools

• National Societies may contact the Global First Aid Reference Centre for water rescue and drowning prevention first aid training programmes.
• There is an opportunity in this topic to include critical thinking and application of learning:
  >   Option 1: Explore using a scenario and role-play. This allows the learners to experience the varied roles among a team when                       responding and preparing for transport, exercise decision making, practise their communication skills, and apply first aid skills.
  >   Option 2: Explore this topic using case-based learning. Have the learners create their own case study (and then have a peer review              the case study) or solve a case which has already been developed.
  >   Using either method you can further challenge the learners by extending the scenarios or cases over time so that they are required to identify the impact of time on the ill person’s condition or add constraints which may require them to change their first aid action plan.

Learning connections

• Connect this topic to safety for the ill person and the first aid provider, assessment of the person (initial and continual), and accessing further support. (See General approach for more on each of these).
• Explore the safe administration and handling of oxygen (see Oxygen administration).
• There is the potential this condition will result in cardiac arrest (See Unresponsive and abnormal breathing (baby and child) or (adolescent and adult).