This was the second day of diving from a live-aboard dive boat following five dives the previous day. The water temperature was around 80 degrees Fahrenheit (27 Celsius) and there was a strong current. I am an instructor with over 800 logged dives and I was diving with a 68 year old woman who was open water certified. She had been out of the water for a few years but did go on a refresher dive prior to this trip. She was also not very active or physically fit. During the first dive of the day to 60 fsw (18 msw), she signaled "something wrong", (later she said she had felt exhausted), so we started to ascend, separate from the group. We made a three minute safety stop and she attempted to bolt to the surface, so I tried to slow her ascent. Upon reaching the surface, she spat out her regulator and flopped onto her back, exhausted, so I towed her back to the skiff. When the captain and I positioned her upright in the water to pull her onto the boat, she coughed up about a cup to a cup-and-a-half of clear liquid and foam. After resting on the boat for four or five hours, she indicated that she wanted to dive again. We picked a calmer dive site with less current. Toward the end of this second dive to around 60 fsw (18 msw), she looked panicked and signaled to ascend. I again tried to slow her ascent and we did not do a safety stop. Upon reaching the surface, she again flopped onto her back, exhausted, and kept the regulator in her mouth. I towed her back to the skiff and during the ride back to the boat, she seemed unconscious but would respond when I asked her to. When back on the boat, the crew administered oxygen and she began a constant gulping motion. After fifteen to twenty minutes of this gulping on oxygen, she was removed from the oxygen, moved into an air conditioned room and the oxygen administration was resumed. She stopped the gulping and remained on the oxygen for another ten minutes. A doctor on board spoke with the emergency hotline at DAN about the incident and followed their recommendations. It is unknown if local emergency services were available or activated. She admitted to having previous anxiety or panic attacks while diving and a "near drowning" incident. The doctor on board also noted that she had high blood pressure following the incident. She improved over the course of the week after the incident and did not continue to dive, but did go snorkeling twice. Since the incident, her doctor cleared her for another upcoming dive vacation.
While we may never know for sure, this was most likely a case of immersion pulmonary edema (IPE). The boat crew were prudent to put the diver on oxygen, but it was not wise to let her go for a second dive after she recovered. IPE is often reoccurring and the next occurrence may prove fatal. After an episode of IPE divers should not return to diving before undergoing a thorough medical examination. After the second occurance the boat crew did recall the other divers, contacted DAN and reportedly followed DAN's instructions. IPE may occur in healthy and young people (swimmers, triathlon athletes, Navy combat divers) but it also occurs in older people with or without an identifiable underlying medical condition. Hypertension is one of the predisposing conditions. Other age related changes in heart function may contribute to IPE. The diver in question does have some risk factors including age, lack of physical fitness and exertion against a strong current while under water. Hypertension is also a risk factor for pulmonary edema but, while the diver did display hypertension following the incident, she had no history of it and was not on medication for hypertension so we cannot know if the hypertension was a cause or consequence. Pulmonary edema is characterized by fluid entering the lungs from the bloodstream into the alveoli. Symptoms include shortness of breath, cough, and sometimes frothy sputum. Whether the fluid that the diver coughed up was the result of pulmonary edema or not, DAN's recommendation would be to breathe 100% oxygen on the surface and postpone diving until the diver can be seen by a physician knowledgeable in diving medicine. It would be in the diver's best interest to be evaluated by a physician who is familiar with the stresses that SCUBA diving puts on the body and the medical conditions that are contraindications to diving before resuming any diving activity. Lastly, if any diver is unconscious or struggling to breathe, local emergency services should be activated.