Many people enjoy the boundless beauties of the sea. Thailand boasts some of the most extraordinary beaches in the world. It’s also one of the finest and fastest growing recreational SCUBA diving destinations. For divers, it is truly an amazing and bountiful paradise. However, the dangers encountered in the underwater world can be unexpected. While diving has become increasingly affordable and ever more popular as a sport or hobby, debilitating injury and even the potential for death resulting from a diving emergency continue to concern everyone involved

DIVING HAZARDS

The nature of human life under water differs greatly from that of our normal, natural daily life on land. Under water, our body’s systems must work differently than is usual. While submerged, the diver encounters unique limitations. The human body can easily stabilize and orient itself in this relatively weightless environment, but seeing, hearing and moving underwater pose adjustment challenges. Normal breathing, which is fairly easy on land, becomes troublesome under water. In the absence of proper, professional and certified training, these general limitations requiring adaptation can become obstacles, and in the absence of proper preparation these obstacles can potentially lead to accidental injury while diving… whenever a diver becomes injured underwater, they are exposed to the very real risk of drowning, no matter the initial cause of injury. Proper training is indispensable. The Badalveda Diving Medicine Network supports on-going Diver Education Programs through our nationwide supporting network of  Internationally Accredited, recreational dive shops…Contact us for a detailed listing of  Badalveda’s approved dive shop operators.

PRESSURE CONCERNS

INCREASED PRESSURE AND POTENTIAL INJURY (BAROTRAUMA)

The increased pressure experienced by a diver underwater has the potential to cause injury to body parts and systems which contain air, if the increase in pressure is not properly managed. Examples of these body parts and systems are the middle ear, lungs and the sinus cavities. When diving deeply into the water, the internal pressure of the body’s air spaces (or ‘cavities’) must be maintained in balance with (or equalized to) the surrounding water pressure at all times during each immersion. While we are diving deeper into the water, the quantity (volume) of air in the cavities must increase in order to equal and counter-effect the increased pressure the  water exerts upon us at that depth.

Conversely, when swimming to the surface after completing a dive, the body must release the now expanding air from these body cavities in order to match the decrease in the surrounding water pressure as we move upward into more shallow water. In this adaptive manner, when done correctly, we are able to maintain the body’s all important internal and external pressure balance. Situations where the body cannot adjust smoothly to changes in the surrounding pressure may lead to damage of the tissues in and around the air cavities affected. In diving, one of the most fragile parts of our body, the ear’s tympanic membrane, is the most commonly injured, due to tissue damage which may result from the inadequate internal and external pressure equalization of the middle ear. Improper or insufficient equalizing of the pressures affecting the ear cavity may initially cause pain. If the ascent or descent is continued without attaining the proper pressure balance, the eardrum may be damaged (barotrauma). When a pressure imbalance causes injury to the sinus cavities, one may initially experience pain in and around the sinus area, sometimes accompanied by nosebleed and severe headache. These conditions are best prevented by the pursuit of approved training, attention to that which is learned, and slow, easy ascent and descent rates in practice.

The most potentially dangerous injury caused by inadequate pressure equalization is referred to as ‘Lung Over Expansion’ injury. This condition develops when air trapped anywhere in the lungs cannot find a free path to escape or to safely expand as the pressure affecting the lungs lessens, which causes the gas volume to increase (Boyle’s Law). This may occur if a diver suddenly runs out of air, and in a state of panic, swims quickly to the surface while holding their breath. The rapidly expanding air in the lungs can be quite suddenly and explosively released into nearby blood vessels, or might forcefully enter the tissues of the lungs or chest cavity. A dangerous amount of this expanding air can potentially enter circulatory system blood vessels from the lungs in the form of bubbles, which then exhibit the potential for causing a blockage (embolus) in the arterial or venous blood supply systems in various parts of the body. In the case that a bubble of expanded air escapes from the lungs and blocks the blood circulation to the brain, it can precipitate quite serious symptoms. Fast response and professional attention are imperative to safe resolution of this potentially life threatening injury, known as ‘Arterial Gas Embolism’. (This is discussed further in : ‘Types of Decompression Illness (DCI)’)

Good training, good conditioning and good judgement minimize the possibility of these potentially dangerous conditions. Professional training, and a proper dive plan, including the knowledge of Emergency Recompression Chamber locations and what Emergency Transport Services are available is a must in dive planning. Contact The Badalveda Diving Medicine Network of Thailand for more detailed safety information when planning your dive holiday.

NITROGEN NARCOSIS

SCUBA divers use specially designed equipment, such as high pressure air cylinders, regulators and other specialized equipment which make it possible for us to breathe under water. During a typical dive, we breathe compressed (pressurized) air. We breathe higher air pressures in order to balance the increased water pressures encountered at depth. This also means we are breathing a greater volume of air on each inhalation. Air is comprised of a natural mixture of Oxygen (21%), Nitrogen(78%), and trace gases(1%). The largest constituent gas component of air is Nitrogen. Nitrogen gas forms roughly 78% of our  breathing air. On land, at surface pressures, this ‘inert’ (‘non-reactionary’—it goes into solution and comes out unchanged) gas poses no problem, is easily inhaled and exhaled. At depths approaching 30 meters (100 feet), however, the higher percentage of Nitrogen in our inspired air can induce ‘altered states’ of perception, affecting some of our higher brain functions. Referred to as ‘Nitrogen Narcosis’, and similar to feelings of alcohol intoxication, this condition affects some individuals more severely than others, is time and depth related, and is temporary… returning to  shallower depths will immediately reverse the manifestation of pressure induced Nitrogen Narcosis. None-the-less, during the onset, this condition has the potential to induce feelings of  disassociation, presenting with sensations ranging from mild discomfort to uncontrolled euphoria, including possible episodes of memory loss or causing a state of such severe confusion, that it may potentially lead to death by drowning. Recreational SCUBA diving using compressed air is sometimes limited to 30 meters (100 feet) for the novice, in respectful consideration of this potential for mishap.

As we gain in understanding and as our skill level increases, we may elect to dive with SCUBA cylinders which have been filled with specially formulated mixtures of various compressed gases. NITROX and HELIOX breathing mixtures, and specialized gas rebreathing systems all require highly technical, specially dedicated, professional training and certification. They open new diving horizons, and some allow for extended time and depth profile diving. Quality control of these gas mixtures and the pursuit of proper and qualified training is understandably of paramount concern. Feel free to contact The Badalveda Diving Medicine Network with any questions during the planning phase of your next Thailand diving holiday.

TYPES OF DECOMPRESSION ILLNESS (DCI)

A. Decompression Sickness (DCS)
Simply breathing compressed air at depth presents another potential for mishap. As well trained and experienced as we  will certainly become during our sport diving career, the potential for Decompression Illness will always exist. Many years of scientifically catalogued and collected data demonstrates that even when exactly following the various safe, conservative and internationally approved recreational dive profile tables, divers may still experience incidents of pressure related injury. Not all human bodies fit exactly to the normal standards used in the algorithmic derivation of these generally quite safe dive profiling systems.
  
We can divide into two sub-groups, this potential for pressure injury. The first of these 2 sub-groups, Decompression Sickness (DCS), can manifest as either Decompression Sickness Type I …pain only, usually in the joints or muscles, or the potentially more serious Decompression Sickness Type II…a typical diagnosis of Type II  DCS indicates that symptomatic evidence of Central Nervous System involvement is present. Decompression Sickness onset can be directly related to our return to the much lower pressure found at the surface after completion of our dive to the higher pressures encountered at depth. DCS is caused by the relatively uncontrolled release of Nitrogen gas from it’s temporary state of complete liquid solution within the blood and various body tissues. Nitrogen Gas dissolves into solution painlessly, and this occurs after prolonged breathing of compressed air under the pressures encountered during our immersion. During our dive, remember that we breathe a higher than usual concentration of Nitrogen gas, under pressure, from our SCUBA cylinder at depth. The result is pretty predictable…  the longer we breathe the compressed air at depth, the more time this ‘larger than normal’ quantity of Nitrogen gas has to dissolve into our blood and our variety of body tissues. While we are under pressure, this dissolved Nitrogen gas will stay in solution. Think in terms of a pressurized, carbonated soft drink suddenly opened to a state of lower pressure. The carbonated gas which was safely contained in a state of solution while pressurized, now fizzes (or bubbles), transformed from a state of complete liquid solution back to a gaseous state as the surrounding pressure lessens upon removal of the soft drink bottlecap.
Similar conditions give rise to the potentially unregulated release of Nitrogen from solution in our body’s blood and tissues as a return to the lower pressure at the surface allows it’s transformation once again, into a gaseous state.
This free Nitrogen gas begins as micro-bubbles, these bubbles can merge, growing larger as the pressure surrounding the diver’s body continues to lessen and as the tissues and blood surrender their gas load under the condition of decreased pressure as we return towards the surface. These expanding gas bubbles have the potential to collect, causing clotting and may obstruct nerve signal transmission, leading to the loss of feeling (DCS Type II), or again, potentially, to collect at joint sites or in muscle areas causing a steadily progressive sensation of pain or soreness  (DCS Type I).
Symptoms of DCS can manifest as long as 48 hours following a dive, although the historical data collected demonstrates that nearly 75% of DCS symptoms develop within 4 hours, post-dive. Many afflicted divers will exhibit DCS symptoms within 12-24 hours following their immersion, athough as presented above, some divers may not develop symptoms for as long as 48 hours post dive. Following precisely our dive profiles, and observing strict discipline about the importance of regulated surface intervals is a pretty dependable way to avoid DCS. But it DOES happen, even when we observe all the guidelines. No one can explain this, except by pointing out that the perfect dive time and depth profile table has not yet been formulated that would protect ALL divers under ALL conditions. Dive smart—dive safe….and be prepared.
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B. Arterial Gas Embolism, AGE
The second of the sub-groupings under ‘Types of Decompression Illness’, is a pressure caused injury condition referred to as Arterial Gas Embolism  (AGE). This condition is extremely dangerous; quick response and immediate recompression is indicated after dive medical professionals ensure there exists no evidence of  complication, involving the potential of serious lung damage.
The condition itself, known as AGE, is not unique to diving and can occur at normal atmospheric pressures too.  During normal surgical procedures, for instance, a slight amount of air inadvertently introduced into a patient’s circulatory system, can cause extremely adverse results, since it involves the introduction of a foreign element (air bubble) which can block the free circulation of blood….Diving related, pressure induced AGE is similar, and can result from a panic ascent during a dive while holding the breath after breathing as little as one breath from a compressed gas supply from a depth as shallow as 2  meters. Boyle’s law, concerning the relationship between pressure and volume, explains how air trapped in the lungs can potentially increase in volume to create an over expansion injury, leading to a possible AGE. Once the air, contained (or trapped) in the lungs, becomes expanded sufficiently to rupture it’s tissue boundaries, the bubble can enter the bloodstream and begin to travel. The potential for this bubble to block the blood supply to the brain is what makes AGE an extremely dangerous and life threatening condition, requiring skilled, prompt and professional emergency response.  Recommended treatment is always immediate recompression at the nearest hyperbaric chamber equipped facility.

TREATMENT

The Badalveda Diving Medicine Network of Thailand offers professional, world class Diagnostic and Emergency Recompression services for those in need. The majority of our network of hyperbaric chambers are situated in full service international hospital settings. Our remote-site emergency response recompression facilities are easily reached in an emergency, from even the most remote diving locations. Prompt, professional, air and surface vessel emergency evacuation services are available on 24 hour standby. We have access to large multiplace and smaller monoplace hyperbaric chambers, staffed by the best trained, specially certified and capable medical professionals in Thailand. From our Diving Medical Officers to our Certified Hyperbaric Nurses and highly skilled Chamber Operators, we are the best…. Although our marketing department needs a lot of work..

THE GOOD NEWS

Having said all this about the potential hazards we confront as SCUBA divers, It is important to point out that although it is wise to be trained and well prepared for any diving emergency, pressure related injury is fortunately, a fairly rare occurance.

CATCHY PHRASES

• PLAN YOUR DIVE…THEN DIVE YOUR PLAN.
• THERE ARE OLD DIVERS, AND THERE ARE BOLD DIVERS…BUT THERE ARE NO OLD, BOLD DIVERS.
• SAFE DIVING IS NO ACCIDENT

Underwater and Hyperbaric Medicine Society