Incident Insights with the Divers Alert Network

The diver tells his story

After the third dive on the third day of our trip last year, I was alarmed when I noticed my dive computer's nitrogen-level indicator near the red but still in the yellow zone. I saw the same on my buddies' dive computers, so I was not too concerned. I did three dives that day, all on air. The second dive was to 30.6m and the third to 23m for 20 minutes, with the proper surface interval in between.
After returning to my room, I showered while washing my suit with warm water. While waiting for dinner I became very thirsty and drank several glasses of icy water. I had trouble taking a deep breath without coughing, and felt very tired. Before the food arrived, I got sick and went to my room. My dive partners came in to check on me and I remember them asking if I was OK, and then I passed out. They opened my shirt and noticed a rash on my chest. They began to administer oxygen from the resort and demanded that I go to the hospital immediately.

After a complete check at the hospital the medical staff determined that I was not having heart issues and sent me to the recompression chamber 20 minutes away. The doctors there examined me and determined that I probably had decompression sickness but that it wasn't severe enough to need any time in the chamber.
The hospital then called and informed me that based on the blood test they had done I was very dehydrated. I returned to the hospital for more observation overnight and intravenous saline infusion. I was discharged the next day mid-morning and I did not dive the remainder of the trip.

DAN’s medical expert comments

This diver's symptoms are consistent with skin manifestations of decompression sickness (DCS). With the additional coughing (the chokes) and an episode of loss of consciousness, it is very likely that a neurological component was present. His companions acted appropriately by seeking aid, providing surface-level oxygen, and transporting him for a medical evaluation. The surface oxygen helped prevent the worsening of symptoms and may have contributed to resolving them. The hospital staff were prudent to rule out any potential cardiac component, because some of the symptoms presented can be associated with cardiac issues.

There is data that indicates a warm shower soon after diving can propagate skin symptoms. The main causative factor is the inert gas tissue load; the greater the load, the greater the likelihood of developing symptoms. But in this case while it is not definite that the shower contributed to the development of symptoms it is reasonable to believe there is some connection.
The diver mentions that the laboratory tests of his blood indicated he was dehydrated. What was most likely observed was an increase in a marker known as hematocrit, which is a ratio of the solid components of blood in relation to the fluid content (plasma). The test was taken after the diver already had developed symptoms; the diver's hydration state prior to the dive is not known. Most recreational divers on a normal dietary regimen before a dive do not get dehydrated to the degree that would affect the outcome of their dive.
However, if a diver gets DCS their blood vessels will leak plasma into surrounding tissues, which is detectible as changes in the hematocrit level. This most likely accounts for a diver with DCS symptoms appearing dehydrated. An important part of treatment for DCS is fluid resuscitation which is ideally achieved with intravenous infusion. The clinical decision whether to treat a diver in the chamber ultimately rests with the evaluating physician who will rely on the condition of the patient as well as their own previous experience and expertise.
Typically, skin manifestations alone may not require hyperbaric treatment but in this case, there was the suspicion of a neurological component. At the time of the diver's evaluation by the hyperbaric physician, no evidence of neurological symptoms may have been evident so his treatment was not inappropriate. Most important, he had a positive outcome. And the diver prudently chose not to resume diving on this trip which is the best prevention of a recurrence of symptoms.

Answer provided by DAN's Marty McCafferty, EMT-P, DAN medical information specialist. https://world.dan.org/membership-coverage/asia-pacific/