Following an episode of decompression sickness (DCS) or other diving-related injuries, many divers harbor the desire to resume their underwater pursuits, be it for recreation, professional work, or military service. Yet, the critical question remains: when is it safe to return to diving?
Although established guidelines exist for military, government, scientific, and commercial divers, there is a noticeable absence of such recommendations for recreational divers in the United States, including dive masters and instructors.
This article delves into the intricate considerations and guidelines that divers who have experienced DCS must consider when contemplating a return to diving. It explores the criteria for the safe resumption of diving activities, emphasizes the significance of medical evaluation, and illuminates the path back into the depths of the underwater world.
Understanding DCS
DCS, colloquially known as "the bends" or caisson disease, arises due to insufficient decompression after exposure to heightened pressure. Its severity can vary from mild to potentially life-threatening. Prompt treatment significantly improves the chances of a complete recovery.
During a dive, nitrogen is absorbed by the body in proportion to pressure. Rapid pressure decrease can cause nitrogen to form bubbles in tissues and bloodstream, leading to joint pain, bodily reactions, numbness, paralysis, and cognitive disorders. Excessive bubble entry in the bloodstream can cause lung congestion and circulatory shock.
DCS Signs and Symptoms
DCS often presents with signs and symptoms ranging from subtle to severe. The most common indicators are joint pain and sensations of numbness or tingling. Muscle weakness and an inability to fully empty the bladder are the next most frequent complaints.
While severe DCS exhibits evident signs, mild cases may begin with minor joint discomfort or paresthesia (abnormal burning or tingling sensations) in an extremity.
The range of DCS symptoms can include:
- Joint pain is the most common symptom of DCS, and it typically occurs in the shoulders, elbows, knees, and ankles.
- Skin rash is another common symptom of DCS. It can appear as a blotchy rash, a rash with hives, or a rash with blisters.
- Numbness and tingling can occur in the hands, feet, or other parts of the body.
- Weakness can occur in the muscles of the arms, legs, or face.
- Fatigue is another common symptom of DCS.
- Other symptoms of DCS may include headache, dizziness, nausea, vomiting, difficulty breathing, and confusion.
Symptoms of diving illness can appear within 15 minutes to 12 hours after surfacing, but may be delayed in rare cases. These symptoms should not be ignored, as they can worsen and require prompt medical attention.
Issues of Concern for DCS Sufferers
Recurrence Risk
Divers who have previously experienced DCS, particularly those without any physiological explanation, are at a heightened risk of suffering from DCS again. The odds ratio for neurologic DCS can be as high as 8.4 in such cases, depending on factors like diving experience, a large right-to-left shunt, and failure to modify their diving practices.
- Re-injury
One major concern is the possibility of re-injury, where a diver may experience DCS again, potentially exacerbating any pre-existing residual injury.
- Risk to Fellow Diver
In the event of a DCS incident, there is also a concern for the safety of fellow divers who may need to come to the rescue of an injured dive buddy. This places the injured diver and the rescuers in an unphysiological environment for the human body, where further complications can arise.
Returning to Diving
- The timing for returning to diving after DCS depends on various factors, primarily the severity of the DCS episode.
- DCS can present along a spectrum, ranging from mild joint pain or vague symptoms to severe cases with neurological symptoms like numbness or paralysis.
- Consideration should also be given to the circumstances of the dive incident.
United States Navy (USN) Guidelines
For divers with mild DCS1 symptoms, a 7-day delay is recommended before returning to diving. DCS2 episodes with initial treatment need a mandatory 30-day delay.
If persistent neurological symptoms persist beyond initial treatment, further diving is not allowed unless a medical waiver is granted after evaluation with a neurologist.
Association of Diving Contractors International (ADCI) Guidelines
ADCI advises against diving with residual symptoms or abnormal brain MRI findings after a DCS2 episode. Divers with resolved symptoms may return, but the wait time depends on the initial symptom severity and resolution speed after treatments.
Pain-only resolution requires 72 hours, while sensory symptoms require 7 days, and motor symptoms require 4 weeks. Symptoms requiring serial treatments should be delayed 4–6 months.
Vestibular symptoms should wait 4–6 months and require a thorough evaluation by an otolaryngologist. Injury to the functioning side could result in a permanent loss of balance.
These guidelines are particularly relevant for young, healthy divers engaging in Navy-style dives.
Treatment for DCS
Immediate stabilization is crucial for severe DCS cases before transfer to a hyperbaric chamber. Early oxygen first aid is important, but it should not replace comprehensive treatment.
Contact DAN or a dive medicine specialist immediately for suspected DCS cases. Delaying treatment increases the risk of irreversible damage and decreases treatment effectiveness. Seek advice from a medical specialist before drawing conclusions about potential treatment efficacy.
How To Prevent DCS
Divers should be cautious and adopt a conservative approach to diving. Using a theoretical depth as a safety buffer is recommended, especially in cold water or physically demanding conditions.
Caution should be exercised when nearing the limits of no-decompression diving, particularly beyond the 100-foot mark. Refrain from flying or exposure to high altitudes after diving to minimize the potential for decompression sickness.
Mastering the Art of Preparing for, Identifying, and Addressing Decompression Sickness in Scuba Diving
Understanding the complexities of decompression sickness (DCS) is paramount for ensuring safety and enjoyment. Ultimately, scuba diving can be both exhilarating and secure when armed with the awareness and preparedness to handle DCS effectively, thus safeguarding the well-being of every explorer beneath the surface.
Discover the depth of knowledge and expertise in decompression sickness (DCS) with Dr. Michael B. Strauss, a seasoned diver and respected orthopedist consultant. His extensive research and papers on Decompression Science are your gateway to understanding all aspects of DCS.
Don't miss the chance to explore his latest book, "Diving Science...Revisited," and equip yourself with this invaluable source. Dive into the wisdom of Dr. Strauss today!
