Oxygen First Aid Is Recommended for All Scuba Diving Injuries
What is the first action a rescuer should take in the event of a scuba diving injury? In addition to alerting emergency medical services, a rescuer should administer 100% oxygen to the victim of a scuba diving accident, regardless of his suspected injury
Prompt and efficient administration of 100% oxygen to a conscious or unconscious breathing diver will help to treat almost any scuba diving injury.
In the rare event that 100% oxygen is not helpful in treating an injury, it will not have any negative effects. Given the difficulty of assessing injuries and illnesses at a dive site, pure oxygen should always be administered to an ailing diver until his injury can be diagnosed by medical professionals. For this reason, responsible dive operations carry an emergency oxygen kit with them to every dive site.
Decompression sickness (DCS) is caused by bubbles of nitrogen forming in a diver’s tissues. DCS can be caused by ascending rapidly, exceeding a no-decompression limit, or by a variety of other factors.
When a diver breathes pure oxygen, the naturally occurring nitrogen in his blood plasma is replaced by oxygen. This creates an oxygen rich environment surrounding the nitrogen bubbles in his tissues.
According to gas diffusion laws, a gas will move from an area of high concentration to low concentration. Therefore, reducing the nitrogen levels surrounding a bubble by breathing pure oxygen causes nitrogen to diffuse out of the bubble and into the blood stream.
At the same time, oxygen will diffuse into the bubble. However, unlike nitrogen, oxygen is easily metabolized by the body. The size of the bubble will be reduced as the oxygen in the bubble is metabolized. This process will continue as long as the diver breathes pure oxygen.
In some cases, simply breathing pure oxygen will be enough to eliminate bubbles and alleviate symptoms. Still, in all cases of suspected decompression sickness, a diver should consult a diving physician, even if his symptoms have disappeared. It is not uncommon for bubbles to reform or expand after initial treatment with 100% oxygen.
An arterial gas embolism is a bubble of gas trapped in a diver’s artery. AGE is dangerous because it can completely block blood flow to organs and tissues, leading to organ and tissue death. In the case of a Cerebral Arterial Gas Embolism (CAGE), blood flow to the brain can be reduced or stopped, leading to brain death in a matter of minutes.
Much like the treatment of decompression sickness, breathing pure oxygen can help to eliminate or reduce an arterial gas embolism. Raising the concentration of oxygen in a diver’s blood causes nitrogen to diffuse out of the bubble and into the blood stream, where the nitrogen can be eliminated during respiration.
Again, even if a diver’s symptoms improve or disappear after treatment with 100% oxygen, the diver should still consult a physician familiar with dive medicine as additional treatment may be required.
The primary purpose for oxygen administration in scuba diving injuries is to treat decompression sickness and arterial gas embolism. However, oxygen is also recommended first aid for any injury that damages or impairs a diver’s lung function. Examples of scuba diving injuries that can impair a diver’s lung function include near-drowning, salt water aspiration syndrome, and pulmonary barotrauma.
When a diver’s lung function is impaired, his ability to oxygenate his blood and supply his organs and tissues with sufficient oxygen is reduced. Administering 100% oxygen to a diver with a lung injury helps to raise his blood oxygen levels and keep his body running.
It is important to note that field tests of blood oxygen levels are generally ineffective. A diver may have reduced blood oxygen levels but show no outward signs of this condition. Therefore, in any scuba diving accident, oxygen should be administered until emergency medical services can take over treatment of the injured diver.
Four Considerations for Oxygen Administration
Emergency oxygen kits are portable and can be carried on dive boats or in cars, making it possible to administer pure oxygen to an injured diver while he is being transported to a treatment facility. Once treatment with emergency oxygen is commenced it should continue for up to two hours or until the diver is assessed by medical professionals.
In most cases, a diver can be transported to medical professionals within a few hours, but is important to note that breathing pure oxygen on land does have the risk of pulmonary oxygen toxicity — a condition caused by breathing pure oxygen for extended periods of time. For this reason, injured divers who are treated with pure oxygen should be given “air breaks” (fifteen to thirty minutes of breathing pure air) after every few hours of treatment with pure oxygen. DAN (the Diver’s Alert Network) recommends not continuously administering oxygen for more than five hours, and other resources recommend even shorter lengths of time. In “Scuba Diving Explained” by Lawrence Martin, M.D., the author recommends giving the diver air breaks every two hours.
Pure oxygen should never be administered underwater or under hyperbaric conditions (at pressures above standard atmospheric pressure) by an untrained laymen. Doing so places the injured diver at risk of central nervous system oxygen toxicity, which is characterized by convulsions.
Finally, learning to transport, store, and administer medical oxygen requires simple training. The Diver’s Alert Network (DAN) offers an easy, half-day training class which will familiarize divers with basic principles of oxygen first aid. All divers would do well to enroll in such a course. The cost is minimal, the information is easily grasped, and the techniques and skills acquired may someday save a life.