DAN Intern: James Cotton

James shares his experiences working on projects at DAN Headquarters.

Five days after returning from Indonesia, where I worked as a Fulbright teaching assistant, I was on a plane from my home in Colorado to Durham, N.C., ready to begin my Our World-Underwater Scholarship Society internship at DAN. While I was not entirely certain of what the experience would entail, I knew it would be an ideal way to integrate my interest and passions for diving, medicine and research.

While at DAN, I worked with my mentor, Dr. Petar Denoble in the medical research department, on a project focusing on the patent foramen ovale (PFO) and decompression sickness (DCS). Past studies have shown an association between persistent PFOs and DCS in divers. It is thought that gas in the venous system from a dive may be able to arterialize through the PFO and lead to DCS; however, no causative relation has been proven.

To reduce the risk of DCI, some divers have PFO occlusion devices implanted via trans-catheter methods. While some divers report no further neurological decompression episodes, it is difficult to be sure this represents a true reduction in risk. More information over a greater period of time is needed about the closure group's diving patterns before and after the procedure.

My role was to help conduct a prospective epidemiological study, a cost-benefit analysis looking at transcatheter PFO closure as a method to reduce the risk of DCS. We investigated whether divers with a PFO that undergo closure or divers with a PFO who continue diving without the closure are better off, taking into consideration the risks related to closure and DCS. With this data, DAN will compare the incidence of DCS before the closure with the combined incidence of DCS and subsequent adverse events related to the closure. Ultimately, the study aims to enroll 120 qualified participants and conduct annual follow-ups with each participant over five years. I was responsible for recruiting new study participants and enrolling them, collecting the necessary, accurate information. I reviewed their submissions (Informed Consent form, a relevant health and diving history questionnaire and medical documentation for the diagnosis of PFO and PFO closure, if applicable) and contacted them if there was any missing or inaccurate information. I also taught participants how to electronically collect their past dive profile information and continue recording it in a way that is beneficial to the study.

While I was working on the prospective study, I also initiated a retrospective study, taking the first 30 participants enrolled in the prospective study and investigating why some of the participants decided to undergo PFO closure while others did not. Using a literature review, we established five criteria to determine whether the PFO-positive participants with PFO closure were distinct from those that did not. I contacted participants to gather more detailed information regarding the past DCS history and PFO. After collecting sufficient information from participants, I conducted a data analysis and wrote a resear ch paper with the goal of publishing it in a peer-reviewed diving medicine journal.

In addition to my primary research endeavors at DAN, I also participated in a variety of exciting dive and medical-related activities. During my first week at DAN headquarters, I learned about DAN's many departments, which includes medical services, education, insurance, publications and research. I also attended dive trainings and lectures, which ranged from oxygen first aid for divers to dive physiology. I toured the Duke hyperbaric chamber, where I interacted with medical personnel and learned about the various experiments they conduct, including non-dive related clinical procedures conducted in the hyperbaric chambers, such as diabetic wound treatment. This experience offered greater insight into the true world of diving and hyperbaric medicine and how I might be able to incorporate it into my career.

In August and September, I volunteered for two flying after diving studies conducted by Dr. Neal Pollock in order to help develop a model for estimating decompression risk. In September, I also participated in the DAN Diver Medical Technician (DMT) course, which offered lectures presented by internationally-known faculty, hands-on practical skills and 14 hours of clinical time. The course covered topics ranging from oxygen toxicity to otoscope use; it provided yet another perspective in diving medicine and equipped me with tangible skills to become a safer, more informed diver in both the recreational and professional realm.

Overall, my experience was very positive. I conducted my own research project (which may be published), took various DAN-sponsored dive medicine courses, gained exposure to the work and experiments at the Duke University hyperbaric chamber and networked with professionals in the field of diving medicine and safety.

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