Caisson's disease, also known as decompression sickness or the bends, occurs when gas bubbles form in the blood and tissues due to a rapid decrease in surrounding pressure, such as during deep sea diving or flying in a non-pressurized plane. Nitrogen dissolved in the body comes out of solution too quickly, forming bubbles that can damage tissues or block blood flow. Symptoms range from joint pain to paralysis or death. Treatment involves recompression in a hyperbaric chamber to resolve the bubbles. Following diving safety procedures can help prevent decompression sickness.

1. Caisson’s disease
Jinu Janet Varghese
Parasseril Margrace David
Group:4
Year: 5

2. Definition
• Also called Decompression sickness(DCS), also known as divers'
disease, the bends or caisson disease)
• Decompression sickness (DCS) occurs when the body is exposed to a
sudden drop in surrounding pressure. DCS occurs most frequently
during deep sea diving or when flying in a non-pressurized aircraft.

3. Causes
• DCS is caused by the formation of gas bubbles in the blood and
tissues. At normal altitudes, nitrogen and other gases are exhaled or
dissolved in the blood and tissues. However, during severe changes in
altitude and air pressure, nitrogen and other gases form gas bubbles.
These bubbles block the flow of blood. This condition can be fatal if
not treated quickly.

4. • The air we breathe is mostly a mixture of two gases, nitrogen (78%)
and oxygen (21%). Unlike oxygen, nitrogen is For this reason, most of
the nitrogen we inhale is expelled when we exhale, but some is
dissolved into the blood and other tissues. During a dive, however,
the lungs take in more nitrogen than usual. This happens because the
surrounding water pressure is greater than the air pressure at sea
level (twice as great at 33 ft [10 m], for instance). As the water
pressure increases, so does the pressure of the nitrogen in the
compressed air inhaled by the diver. Because increased pressure
causes an increase in gas density, the diver takes in more nitrogen
with each breath than he or she would at sea level.

5. • Instead of being exhaled, however, the extra nitrogen safely dissolves
into the tissues, where it remains until the diver begins his or her
return to the surface (under some circumstances the extra nitrogen
can cause nitrogen narcosis, but that condition is distinct from DCS).
On the way up, decompression occurs (in other words, the water
pressure drops), and with the change in pressure, the extra nitrogen
gradually diffuses out of the tissues and is delivered by the
bloodstream to the lungs, which expel it from the body. If the diver
surfaces too quickly, however, potentially dangerous nitrogen bubbles
can form in the tissues and cause DCS. These bubbles can compress
nerves, obstruct arteries, veins, and lymphatic vessels, and trigger
harmful chemical reactions in the blood.

6. Symptoms
• The less severe type of DCS is called DCS I. It primarily results in
inflammation of muscles, joints, and tendons, resulting in pain and
swelling. This is commonly referred to as the bends. Although pain
may occur anywhere in the body, it is most common in or near an arm
or leg joint. The pain may become more severe over time. Itching,
skin mottling, weakness, and fatigue also occur.

7. • The more severe type of DCS is called DCS II. This results in more serious
systemic effects, including neurological symptoms such as numbness and
tingling. In the most severe form, numbness may lead to paralysis and even
death. Other symptoms of DCS II include:
• Stomach pain
• Back pain
• Headache
• Dizziness
• Confusion
• Vision problems
• Vertigo
• Chest pain and severe coughing
• Shock

8. Frequency & Onset of DCS Symptoms
Symptoms Frequency
local joint pain 89%
arm symptoms 70%
leg symptoms 30%
dizziness 5.3%
paralysis 2.3%
shortness of breath 1.6%
extreme fatigue 1.3%
collapse/unconsciousness 0.5%
Time to onset Percentage of cases
within 1 hour 42%
within 3 hours 60%
within 8 hours 83%
within 24 hours 98%
within 48 hours 100%

9. Diagnosis
• Diagnosis requires taking a medical history and conducting a physical
examination.
• The diagnosis is confirmed if the symptoms are relieved by
recompression. Although MRI or CT can frequently identify bubbles in
DCS, they are not as good at determining the diagnosis as a proper
history of the event and description of the symptoms.

10. Treatment
• All cases of decompression sickness should be treated initially with
100% oxygen until hyperbaric oxygen therapy (100% oxygen delivered
in a high-pressure chamber) can be provided. Mild cases of the
"bends" and some skin symptoms may disappear during descent from
high altitude
• It is beneficial to give fluids, as this helps reduce dehydration.
• The duration of recompression treatment depends on the severity of
symptoms, the dive history, the type of recompression therapy used
and the patient's response to the treatment.

11. Prognosis
• DCS sufferers who undergo chamber treatment within a few hours of
symptom onset usually enjoy a full recovery.
• Immediate treatment with 100% oxygen, followed by recompression
in a hyperbaric chamber, will in most cases result in no long term
effects. However, permanent long-term injury from DCS is possible.

12. Prevention
• Limiting the depth and duration of deep sea dives
• Following standard diving guidelines
• Avoiding diving if you are obese, pregnant, have heart or lung
problems, or have had a recent joint or limb injury
• Avoiding excessive alcohol consumption for 24 hours before diving
• Avoiding flying for 24 hours after deep sea diving
• Avoiding repeated dives within a 12-hour period
• Taking ibuprofen to help prevent altitude sickness when hiking
• Avoiding flights in nonpressurized aircraft