#diving research

Since 2008 DDRC Healthcare have been conducting their ongoing “Health of Divers” project which has encompassed a broad range of health issues from the use of illicit drugs to more recently, mental health.  Now in 2016 the researchers are turning their attention to “Flying after Diving”.

Since the 1980s there has been much debate about the issue of flying after diving, with workshops in 1989 and 2003.  Case reports have been discussed over the years, and recommended times to fly after diving have been debated, as well as the results of the first in-flight study of real-life dive exposures which was published last year (2015).  

Hyperbaric chambers often see and treat divers who have come back from a diving holiday and present at a chamber with possible DCI problems.  Because of this DDRC Healthcare are interested in finding out a little more about divers who fly home after a diving holiday – what type of diving were they doing, what was the actual surface interval between their last dive and when they flew home, did they experience any signs and symptoms of possible DCI during the flight, if so, did they seek any help, did any problems they may have experienced go away, what did they think was the probable cause, and so on.

The information the researchers at DDRC Healthcare hope to gather will be valuable in trying to understand a little more about the subject of flying after diving.  It would be great if as many divers as possible could complete the anonymous on-line questionnaire.  If you have been on a diving holiday for example and have taken a flight home; or maybe you have been diving at home and then take a flight to go on holiday.  Any “been diving and then caught a flight” scenario – DDRC healthcare would like you to participate.  

Please note: You do not have to have experienced any problems before/during/after a flight to take part; we would like to hear from all divers who have taken a flight after diving even if it was trouble free!

Please take part – and just to make it easier - it will be useful for you to have your log book handy when you do this survey – Thank you!

'Scuba' magazine, the official magazine of the British Sub Aqua Club (BSAC), is this month offering their readers a unique opportunity to become involved in the diving research undertaken by DDRC. 

DDRC has invited readers to put forward any exciting ideas that they may have for diving research that would be innovative, simple to conduct and would make a useful and lasting contribution to our understanding of the effects of the undersea environment on man.

All the details can be found in the April edition of 'Scuba' magazine, regarding how to propose a future diving study which readers think might be important. The competition gives readers the change to propose a research idea for consideration, which may be taken forward by the DDRC Research Team.

The ideas will be judged by a panel of internationally known researchers, and the winner with the most useful and feasible research idea will be invited to meet the DDRC Research Team to discuss the project further, and perhaps to be involved further in the project.

The DDRC are not looking for research associated with marine biology. Research ideas must be relevant to the effects of the undersea environment on people.

Questions to consider about a Research Proposal

Has your idea already been thought of or conducted before?

If yes, what were the results? Can your idea build on those results or produce better results?

If your idea has not been conducted before, then why not? What are the pitfalls in terms of practicality and quality of any potential results?

What value does your particular research proposal bring to our current knowledge? How useful will the results be? Will the results have a value to others across the diving industry - insurers, educators, equipment manufacturers, medical practitioners, or treatment chambers?

Who will be your study population? What will the sample size involved be?

How will the study be designed? Will it be retrospective / looking at past data, perhaps looking to evaluate trends, or looking at prospective, ongoing data?

What is the primary objective of your research idea and how long do you estimate it will take from start to finish to complete the study?

How to apply

All the details on how to enter this competition can be found in the April edition of Scuba magazine. Anyone can enter. The closing date is the end of May 2013.

Judges Favourite Past Research

We asked our panel of judges to name some of their favourite past pieces of research, and this is a sample of some of the diverse subjects that they came up with!

“Arne Zetterstrom showed that hydrogen mixtures are safe to breathe for deep diving. Hydrogen is non-toxic, less narcotic than nitrogen and less dense than helium, but it can explode if mixed with more than 4% of oxygen. Breathing air, Zetterstrom descended to 40 metres where 4% of oxygen has adequate partial pressure to sustain life. After flushing out excess oxygen, he introduced the hydrogen mixture and dived successfully as deep as 160 metres in open water. In 1945 he was killed in a decompression accident due to a mechanical fault and unrelated to the hydrogen mixture. Arne Zetterstrom is an inspiration to diving research, demonstrating the necessary combination of meticulous science with the personal courage to cross new boundaries. Research into the use of hydrogen continued for many years afterwards.”

“A piece of research that impressed me was done by Maurice Cross in 1984; he entered a recompression chamber for a total of 19 days. An Anglo French team tested the threshold depth for breathing a mixture of gas based on hydrogen. The trial was to test the depth reached before the onset of narcosis, being some 984 feet (300m). One sobering moment came when they were able to look out of the chamber window to see their expired air being burned off! The resulting mix of hydrogen oxygen and possibly some helium is called hydreliox, and is a very explosive mixture.”

“I will always remember at a BSAC Diving conference in the early 80’s was a presentation given by a CIA agent who first introduced us all to the condition known as Patent Foramen Ovale, as we were told that 1 in 4 could have the condition. I remember looking around at each other just like you do on Christmas Eve at a Midnight Mass wishing to give everyone a hug. Hoping it wasn’t me!”

“Ignoring decompression illness caused by obvious accidents or provocative dive profiles, there is ongoing debate as to the actual basal causes of "undeserved" bends.  A raft of physical, physiological and biochemical theories have been advanced with varying levels of acceptance.  However, one issue of interest to me is the theory that diving regularly and often provides some form of protection in subsequent dives.  Again, theories on how this could happen vary, but one involves the possibility that bubbles created in earlier dives may cause stresses in body tissues that precondition them to subsequent or repeated bubble formation.  A recent study of diving at Bikini Atoll* showed that dive guides, who were diving up to 400 times a year, were over ten times less likely to suffer decompression sickness than customers who were only undertaking 10-12 dives.  Although there were differences between the populations, the dive profiles were identical and there were no accidents.  It was, therefore, considered likely that the dive guides were exhibiting a form of acclimation to decompression stress that was being caused by near continuous diving.  The Bikini study was conducted on historical data; this area of observational study would benefit from a prospective large-scale analysis from diving groups where incidence rates of decompression sickness were compared with the number and frequency of dives conducted.”

“None of us alive today remember a time when even the most basic issues relating to gas bubble disease were not understood. As a young navy physician observing submarine escape training, in 1932, Al Behnke was the first person to formulate the idea that arterial gas embolism was different from DCS. He was the first to consider oxygen as a treatment gas during recompression which later became the standard of care. He conceived the “no-stop” decompression tables, developed the theory of nitrogen narcosis and suggested that helium gas mixtures might avoid this vexing problem. It was he who convinced the U.S. Navy to establish the Experimental Diving Unit to promote diving research. Most major leaps forward in diving medicine have been made by individuals like Admiral Behnke who retained a spirit of intellectual curiosity and were able to think creatively".