Decompression Sickness (DCS) is a condition caused by the change in absorbed gas volume upon depressurization that releases gas bubbles into tissue and vasculature (1). This process can occur in divers who quickly arise from depth or who perform repetitive dives. The most common presentation of DCS in shallow dives is referred to as DCS Type 1 and is characterized by localized deep joint pain.
Extremely Late Presentation May be Unrecognized… Even in Experienced Divers
by Justin Arambasick MD, Mary Jo McMullen MD, John Carney EMT-P, DMT, Nick Jouriles MD, Peter Griffin Department of Emergency Medicine
Decompression Sickness (DCS) is a condition caused by the change in absorbed gas volume upon depressurization that releases gas bubbles into tissue and vasculature (1). This process can occur in divers who quickly arise from depth or who perform repetitive dives. The most common presentation of DCS in shallow dives is referred to as DCS Type 1 and is characterized by localized deep joint pain. DCS type I pain symptoms are most often noted in the shoulder, hip, knee, elbow or wrist (2). This pain can range from a tingling sensation to excruciating pain and it generally manifests itself within 24 hours (3). Type 2 presentations are more serious and can involve the brain, spinal cord or lungs leading to permanent disability. The initial treatment for both types of DCS is hydration and 100% oxygen until hyperbaric oxygen therapy can be delivered (4). This case report describes a late emergency department (ED) presentation of DCS that occurred 192 hours after the event. This type of presentation is rare and previously unreported in the emergency medicine literature.
The patient, a 40-year-old male, is a public safety dive specialist with a local fire department dive team. The patient’s chief complaint was left shoulder pain that radiated through the length of his left arm and up through the left side of his neck and ear. His pain was not reproducible and remained constant, ranging between a 5 to an 8 out of scale of 10. On exam and further history the patient denied any neurological symptoms. The patient stated his last two dives were eight days prior to his arrival to the emergency department. The first dive lasted forty minutes at a depth of twenty feet, with multiple controlled ascents. The second dive lasted seventy-five minutes at a depth of twenty-five feet, also with multiple controlled ascents. The patient stated he was initially asymptomatic after both dives. However, the following day he developed left shoulder pain, which he rated as a 1 out of 10 and was described as a dull non-radiating ache. His discomfort eventually accelerated to an excruciating pain with each passing day despite the use of ibuprofen and rest. Finally, on day eight the patient came to the hospital for further evaluation at the urging of his dive team and supervisor. He was treated in the hyperbaric chamber, which consisted of a table six treatment level, which is equivalent to one dive lasting five hours and three minutes at a maximum depth of sixty feet of seawater. Upon completion of the hyperbaric treatment the patient experienced complete resolution of all his symptoms.
Scuba diving is a sport that continues to grow in popularity and it is estimated that there are more than nine million divers in the United States alone who perform approximately 30 million dives per year (5). It is important that emergency physicians remain aware of DCS and its heterogeneous presentations. This case is unique not only because of the late presentation which was 192 hours after the initial dive, but also because the onset of symptoms was more than 24 hours from the last dive. DCS is a disease process in which 75% of patients notice symptoms within 1 hour, 90% within 12 hours, and few patients notice symptoms that start more the 24 hours after a dive (6). In a review of 280 delayed presentations conducted by Divers Alert Network, 50% of the patients received hyperbaric therapy within 29 hours, while 80% of patients received treatment within 96 hours (7). In this case, the patent received hyperbaric therapy over 192 hours out with complete resolution of symptoms. Failure to obtain recompression often leads to one or several residual complaints, including arthritis, paresthesia, pain and especially osteonecrosis.
In severe DCS, a permanent residual handicap may result, this can be bladder dysfunction, sexual dysfunction or muscular weakness (8). Therefore, if a patient is suspected to have DCS presenting at any time, hyperbaric therapy should be a consideration, even if their symptoms are resolved with hydration and 100% oxygen since a relapse can occur without it (9, 10).
Our patient was a dive team specialist, which is concerning since despite his knowledge in the area of DCS, he still did not recognize the symptoms. Thus posing the question: Why did this diver present so late? In the diving industry there are many reasons that may keep a diver out of the hospital. These include but are not limited to denial, ignorance, secondary (monetary) gain or simply the adverse consequences of being diagnosed with DCS. According to USN (United States Navy) guidelines Divers who received Treatment Table 5 and who have had complete relief, may return to normal diving activity 7 days after treatment. Divers who have had DCI requiring a Treatment Table 6, as in this case should not dive for at least 4 weeks and should resume diving only upon the recommendation of a Diving Medical Officer. This case is important because whatever the reason for the delay, it points out that late presentations of DCS to the emergency department could lead to devastating illness or permanent disability. A thorough history of timelines and dive frequency is needed when evaluating all DCS cases. Due to the patient’s late presentation, it may have easily been mistaken for another illness
DCS symptoms generally begin within 24 hrs. Symptoms starting later are rare. Presentation for treatment over four days is extremely uncommon and at 8 days even more so. Hyperbaric therapy should be a consideration at any point in presentation if symptomatic. Even if symptoms are resolved with hydration and 100% oxygen a relapse and possibly permanent disability can occur.
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