It's several hours after a dive. You've got a headache, your joints are sore and you're tired. How do you know if you're experiencing decompression illness or simply ready for bed? At DAN, our 24-hour Diving Emergency Hotline receives more calls from divers confused about decompression illness (DCI) than any other topic. To safely enjoy this sport, all divers need to make sure they're well informed about the signs and symptoms of this injury so they can get proper treatment fast if it does happen. In fact, one of the most dangerous aspects of DCI is denial. Divers sometimes fail to call for help because they simply don't recognize their symptoms as possible signs of DCI, but many realize something's wrong and simply choose to ignore it because of pride or disbelief. DCI is an injury inherent to scuba diving, and there's no shame in admitting you're injured and calling for help. Seeking treatment does not mean you did something wrong, it does not mean an automatic ride in a hyperbaric chamber and it does not necessarily mean the end of your diving career. If you hurt your ankle playing basketball, you wouldn't hesitate to seek treatment, so apply that same mentality to diving. DCI can happen to anyone, and early treatment is more effective. If your symptoms turn out to be nothing, great, just make sure that diagnosis comes from a qualified medical physician, not your dive buddy.
First, let's be clear about what the term DCI means. It's actually a blanket term covering two separate injuries: decompression sickness (DCS), caused by nitrogen bubbles that form in the bloodstream, and arterial gas embolism (AGE), caused by lung over-pressurization. These two afflictions share many symptoms, and both follow the same care and treatment. So, for all intents and purposes, divers should think of them in terms of a single illness rather than try and differentiate the subtle differences.
The signs and symptoms of DCI range from mild to severe (see "DCI Symptoms," p. 86), and because symptoms generally manifest themselves only a few at a time, you should never wait until you experience all the symptoms on the list before calling for help. However, of the most common DCI symptoms, some are common ailments for people in general, and trying to determine whether something like a headache is DCI-related can confuse even the most experienced divers. Based on the questions we receive through our hotline, the following four symptoms are the most confusing. We'll explain how to evaluate them and the best course of action if you or someone you're with experiences one of these after a dive.
Along with a symptoms checklist, another way to assess a potential DCI victim in the field is with a neurological assessment. Ultimately, only medical doctors can definitively diagnose DCI, and even they can't always be 100 percent positive. However, while we would never recommend individuals diagnose other divers as a replacement for a professional evaluation, knowing what to look for can help focus your suspicions of DCI, and this may reduce the reluctance of some divers to report symptoms. Also, a well-performed neurological assessment can provide valuable information to medical professionals when they arrive on the scene, so always make sure to write down any signs and symptoms you notice when evaluating a victim. Visit scubadiving.com/field_exam to print out DAN's worksheet for performing a neurological evaluation in the field, and take it with you on your next dive trip. Even better, take DAN's On-Site Neurological Assessment for Divers class. This four-hour training program provides divers with the appropriate training for DCI first response. Visit diversalertnetwork.org/training/courses/neuro/index.asp to learn more.
These symptoms are commonly mistaken for something else:
- Itchy skin
- Joint or musculoskeletal pain
These are more dramatic and often easier to discern:
- Tingling, numbness or paralysis
- Muscle weakness
- Abnormal bladder or bowel function
- Changes in vision or hearing
- Memory loss
- Personality changes
- Collapse or unconsciousness
- Cardiac arrest