Odysseys of George

Many divers are introduced to this complication of diving during their basic open water course. However, many still are unsure of what decompression illness is all about, even those at much higher levels in their diving career. To make things worse, many medical personnel are also unprepared to handle such cases due to its rarity or assumed rarity of presentation. This assumption is however incorrect as more and more indulge into the sport of scuba diving.

Decompression illness is a disorder caused by bubbles forming in body tissues or in the blood where they should never be.

The source?

The first source is bubble formation from nitrogen that has been dissolved in tissues during the dive. This is otherwise known as DCS (Decompression Sickness)

- During descent and diving, air is breathed at increased pressure, and therefore more of the nitrogen molecules from the air can dissolve into the blood. The nitrogen enters the blood in the lung capillary bed, and is distributed to the tissues via the arteries where, nitrogen leaves the blood and diffuses into tissues.

- The deeper the dive, the faster the nitrogen is taken up from the air we breathe, and the longer the dive, the more time it has to accumulate in the tissues.

- During the ascent, pressure falls and less nitrogen can remain dissolved in the tissues and therefore, the nitrogen diffuses out of tissues and into the venous blood of the organs, back to the lungs for elimination. Ideally, this elimination process occurs fast enough to dissipate the nitrogen molecules without bubble formation.

- However, different tissues in the body have differing rates of elimination depending on their blood supply. Those with very good blood supply tend to accumulate and dissipate nitrogen fast and are called “fast” tissues. “Slower” tissues such as tendons are often not a problem after a short dive, even if it is deep, because they don’t have enough time to accumulate significant quantities of nitrogen but they become more important during long dives, or repetitive dives, when nitrogen can build up over a long time. Then there are the intermediates or “medium” tissues such as the nerves and spinal cord, where the accumulation is fast but the dissipation is slow especially if the bottom time is long or ascent is slightly faster.

- When nitrogen is not dissipated fast enough, the pressure of dissolved nitrogen will exceed the ambient (surrounding) pressure at some point during the ascent and the molecules of dissolved nitrogen will form bubbles.

- Bubbles formed in the blood (usually the venous system) are mainly filtered as it passes the lungs and rarely enters the arterial circulation except in foetus and some with a vascular heart anomaly (patent foramen ovale).

The second potential source of bubbles in DCI is the introduction of air bubbles to the arterial circulation because of lung overexpansion. This is better known as Arterial Gas Embolism(AGE)

- This has nothing to do with dissolved nitrogen, or time and depth for that matter. Indeed, this problem can arise during ascent from depths as shallow as 1 – 2 metres. The most important rule in scuba diving is “to breathe normally at all times; never hold your breath”. This is because any air trapped in the lungs during an ascent (by holding the breath for example), will expand as pressure decreases. If there is sufficient over-expansion of the lung it may rupture some of the small airways and the associated blood vessels. Such damage is referred to as pulmonary barotrauma.

- This barotrauma causes introduction of air bubbles to the lung capillary circulation which are then circulated throughout the body as air embolus. Bubbles arriving in the circulation of the brain may cause stroke-like symptoms. These arterial bubbles are therefore considered very dangerous.

Embolus = foreign particles that float and travel freely in the blood e.g air, clots
Arteries = blood vessels that carry blood from the heart to the rest of the body
Veins = blood vessels that carry blood from the body back to the heart

Taken from various reading.
( To be continued )

Recently, my diving friends called for a dive in Tioman. Surprised, I asked, ” Isn’t it monsoon still?”. “Yes, so?” was their reply. I thought about it like for less than a second and answered spontaneously, “Yes!”

During the monsoon season, there is only a single ferry trip across from Mersing to Tioman. It was a weekend dive, but due to the ferry services, we only managed two dives. Worth it? Yes!

Lizard fish

Nudibranch

another Nudi

And the Gobis

Any issues? Yes - I think the Blue Water Ferry service being the monopoly to these service is wrong as they left about 8 divers and some locals behind at the jetty 5 to 10 minutes before actual departure time. These are the same company who will make you wait an hour or two to fill up the ferry before leaving during peak time and also when there was competition to the service. Then again, this is Malaysia where healthy fair competition is never ever a trademark in service.

As I traveled home from a dive recently, I heard a friend of mine discussing about an incident that recently occurred. An experienced instructor was probably suffering from decompression sickness after doing a dive at just 18metres deep. The instructor was ill and his only hope is to get himself to a hyperbaric chamber located almost 300km up north from the incident site. The outcome depends totally on how severe the decompression sickness is and how fast they can get him into the chamber. The worst is obviously death!

As diving sport picks up pace and becomes a popular hobby, one has to realize that there are more such cases to come. Also, as diving becomes more popular, those in the industry are bound to cut corners and simplify courses in order to earn fast bucks. This then leads to more inadequately trained divers and many irresponsible trainers.

Such is the case of the above scenario. An instructor trying to cut his safety diving profile in order to earn more. This in itself reflects the attitude of the instructor and though he may be a nice individual but irresponsibility in a sport than can be fatal is totally wrong. He should be dismissed and not given the chance to train another individual.

Strangely, this was also a topic of discussion during the dive I went for. A senior diver and also an instructor noted that the syllabus for training for courses in diving has been modified so much to make it easier to attain the license. As we discussed, we realized the mark differences in the syllabus during his time, mine and a recent diver. Generally, to make diving more recreational, the diving associations have made it more relaxing. Less stress is seem to be given to the importance of safety and diving hazards and more focus given on how to dive. Maybe it is not just the associations but also the instructors who again cut corners and fear to touch the issues that may cause students to worry, and further make quick bug money. And because they, the instructors close their eyes to the importance of dive safety and hazards, those who train under them would follow and thus a string of irresponsible and inadequately trained rankings from open water to advance, rescue diver, divemasters and assistant instructors are made. Not only do they harm themselves but do not realize that they have misplaced or erased the responsibility given to them upon getting certified and place harm or possible harm on other divers they accompany.

So for those who aspire to dive, choose wisely - ask and evaluate. Assess the character of your trainer and see whether he or she holds the attitudes of a responsible trusted instructor. At the end of your training, you should be able to say that you are confident to dive safely! For those who are already diving, continue to practice safe diving. For those who train others, please have the sense of responsibility that your trainees trust you with their lives during and after training. So be responsible and dive safely!

Feed small kids small fish

Last updated: Monday, January 07, 2008

Small kids should eat only small fish to avoid building up dangerously high levels of mercury, Australian health officials warned on Sunday following research on three Asian families who fed their children a rice and fish porridge called congee.

Their children, aged 15 months to two years, who had eaten congee - known as juk in Korea and chao in Vietnam - had up to five times normal mercury levels, according to a report in the Medical Journal of Australia.
Stephen Corbett, a doctor with the Sydney West Area Health Service, told reporters that fish of the right type in the right quantity was good for children’s nutrition.

“Two to three portions a week and small fish for small fry,” he advised, warning that mercury at even relatively low levels could affect children’s development.

Fish to avoid

Dr Lisa Szabo, chief scientist of the New South Wales Food Authority, said that parents had to worry about only six types of fish: shark, broadbill, swordfish, marlin, orange roughy and catfish.

“In part it’s because they’re bigger,” she said. “But they’re also longer-lived and they’re predatory fish, which means that they eat a lot of small fish so that’s why they tend to accumulate the mercury.”

Prior to hosting the Grand Rounds last week, I was interviewed by Nicholas Genes, for the Pre-Rounds Medscape Med Students.

The interview article was actually posted on the 12th November. Please feel free to check it out.

Surgeon Dives Deep to Display Photos of the OR and the Ocean Floor

Posted 12/11/2007

Nicholas Genes, MD, PhD

What does a starfish have in common with a gallbladder? They both possess a fascinating beauty, at least when photographed by Dr. Geeverughese C. George. A surgeon and frequent traveler, Dr. George shares his photos and thoughts online at The Odysseys of George. In our recent correspondence, Dr. George discussed his background, photography, and some of the differences in Malaysian medicine.

Dr. Genes: For a surgeon, you sure seem to live life to the fullest! Is that your interpretation of your site’s motto, “Vita non est vivere sed valere”?

Dr. George: Well, living life to the fullest is something I aim for everyday. There is more to life than just work and career achievements. I enjoy travelling and thus I try to take some time away to do this. Diving was always something that interested me, but due to some reasons, I only managed to do it a few years ago — and since then I’ve never regretted it and never looked back. It has also made me indulge in photography more, as the beauty beneath the seas is awesome.

The Odysseys of George hosts Grand Rounds
December 11, 2007

Dr. Genes: What camera do you use underwater? Is it the same as what you use for your pathology and OR photography?

Dr. George: I am using a “point and shoot” camera, and have yet to invest in a dSLR. I am using a Canon G7 with Ikelite casing and a strobe for underwater lighting. I use the same camera for my land and OR shots.

Dr. Genes: Because of your travels, you may have a better idea of what medical careers are like in other lands. How is Malaysia different? You’ve mentioned that half of Malaysian men smoke, that you see a lot of complications from uncontrolled diabetes; how does that affect your practice or your work schedule?

Dr. George: Malaysia is a developing country, and therefore there aren’t as many specialists or subspecialists as in the Western community. The health awareness here is just coming around, but we are still very far from reaching good or excellent healthcare service and goals.

Dr. Genes: How long have you been a surgeon? Are you specializing?

Dr. George: I am a general surgeon with interest in upper gastrointestinal surgery. I have been a surgeon for 3 years now.

Dr. Genes: How did you discover blogging? Do your colleagues know about your online activities?

Dr. George: Blogging came as an “incidental finding” while trying to find a mode of communication with my sister, who migrated to Australia. Then, my friends helped me get the hang of it, and the rest is history. Many here know of my blog, and I am not anonymous. Blogging is common, but whether it is accepted by my hospital is yet unknown. I suppose if I breach rules, then they wouldn’t be too happy.

Dr. Genes: What are some of your favorite posts? What do your readers seem to like on your site?

Dr. George: My favorite posts are actually my medical and diving ones. I notice that most readers are not too interested in political topics — they tend to respond more to my photography, which is very encouraging.

Dr. Genes: Readers will have an opportunity to see more of the world through Dr. George’s eyes when he hosts Grand Rounds on December 11, 2007. Visit his site to see the best in online medical writing from doctors, nurses, researchers, students, and healthcare professionals, all arranged and organized by Dr. George.

Thank you!