Have you experienced pain in you legs and hands after a good session of deep sea diving? This blog explains about this particular problem which is experienced by most of the deep sea divers. A particular aspect of this problem is based on the affinity for the nitrogen by the fatty tissues. It is recommended to read the previous blog (CRACKING OF FINGERS-GOOD OR NOT) to get a clear idea on the affinity of nitrogen by the fatty tissues.
The particular problem which can affect the deep sea divers is known as decompression sickness. It can be classified as one of the forms of embolism. Embolism refers to the obstruction caused by any mass carried in the circulation. The human body is known to have a closed system of vascular system unlike cockroaches which have open type where the fluids freely flow throughout the body.
In the case of human beings, there are vessels which carry the blood throughout the body. They can be broadly classified as three namely the arteries (carry oxygenated blood), the veins (carry deoxygenated blood) and capillaries (the mix of two). A vessel is like a cylindrical tube and there are high chances for it to be obstructed. This is known as embolism and the substance causing it is known as emboli. The following list shows the various possible emboli:-
- Tumour cell
- Athermatous plaque (fat)
- Tissue fragments
- Foreign bodies
- Amniotic fluid
- Bone marrow
As a result, these substances which initially obstruct the blood vessel; slowing cover the blood vessel and finally block them. So the oxygen and nutrient rich blood cannot be delivered to the target which leads to the death of cells from lack of oxygen and nutrients (infarction in medical terminologies)
The primary concern for us is the gas/air. Air or gas embolism can occur when the air or gas is introduced into the vasculature. Air emboli is seen in common while using invasive biomedical equipment (invasive refers to penetration into the body). This can be seen while using injections, IV supplementation, catheter usage etc.
If gases enter into the body and cause embolism then it is known as gas embolism. The particular concern for the divers is decompression sickness. The decompression sickness or generalised barotrauma (baro- pressure trauma-sickness) is a medical condition which results in injuries due to release of several gas bubbles as a result of rapid decrease in the pressure in the surroundings.
The rapid decrease can occur in two cases. The first case is descending from higher altitude to normal altitude and the second case is descending from normal altitude to lower altitude. In both these cases, there is a rapid decline in the atmospheric pressure. There are two situations to analyse right here.
This occurs during the descent. As we go deep into the ocean, the pressure increases. So the gases that are present in the ocean diffuses into the blood and tissues. The primary gases which diffuse are nitrogen, oxygen and carbon-di-oxide.
This occurs when returning to original (ascent) quickly. As we go towards the surface of the ocean, the pressure decreases. So the gases which got diffused into blood, form bubbles and they are released from the blood. We already know that the fatty tissues have great affinity for nitrogen and hence they accept them. If the level of absorbed nitrogen is too much, then it can cause severe pain in the muscles and joints. Also these bubbles can block the blood vessels in any part of the body and can be fatal in areas like lung, brain etc.
The following are the consequences of the decompression sickness:-
Bends– acute pain in the skeletal muscles, joints and ligaments due to the accumulation of nitrogen bubbles
Chokes– accumulation of nitrogen bubbles in the lungs causing shortness of breath
Cerebral effects– stroke, vertigo, coma and even death
The severity of the consequences of decompression sickness depends on the following factors:-
- Depth reached
- Duration under the deep sea
- Rate of ascent/descent (quick ascent after long descent can lead to this problem)
- Condition of the individual
The chronic condition is known to as Caisson’s disease which can lead to the formation of gas emboli in the head of several bones like the tibia, femur and humerus and so on. The disease is named because it was seen primarily in deep sea divers who drill underwater tunnels. They are referred to as caissons (diving bell).
Hence it is important to understand that the decompression sickness is mostly rare but dangerous. It can become fatal if not treated soon. It is trivial that the condition arises with a quick ascent after a deep descent. The following are some of the steps that can be followed to prevent decompression sickness:-
- Take a safety stop or pauses in the ascent; this is done to make sure that there are gradual changes in the pressure
- Drinking lots of water
- Spending less time under the sea, this can reduce the concentration of nitrogen
- Avoiding air travel after diving
- keep nitroglycerin sublingual doses it can immediately cure the bends
Scuba and deep sea diving are indeed fun and interesting activities. It is recommended to enjoy and experience them at least once in a lifetime. But be aware of this problem that can occur while diving and take the precautionary measures responsively!!