1. Deep Sea Diving

2. Deep Sea Diving & Hyperbaric Condition
Atmosph = 760 mmHg
Deep into sea, at every 33 feet pressure rises by 1 atmosphere
Vol. of air compressed & pressure increased along with depth
Deep sea diver – breath high pressure air

3. PATHOPHYSIOLOGY PARAMETER DEEP SEA DIVING HIGH ALTITUDE
Barometric Pressure
Volume of Gases
Intra-thoracic Pressure
Intra-alveolar Pressure
[Compression]
[Expansion]

4. Pressure Related Problems (direct)
Descent (squeezes)
Ears
Sinuses
Mask
Thoracic
Teeth
Stomach/Intestines
Suit
Ascent (expansion)
Air embolism
Pneumothorax
Mediastinal Emphysema
Subcutaneous Emphysema

5. Pressure Related Problems (indirect)
Decompression sickness
Nitrogen partial pressures
Solubility
Nitrogen narcosis
Oxygen toxicity

6. (Dalton’s Law) 21% O2 78% N2 Partial Pressure 760 mm Hg 1% Other
760 mm Hg

7. Nitrogen Narcosis at High Nitrogen Pressure
About 4/5th of air – nitrogen
At sea level no ill effect of nitrogen but at high pressure (deep in sea) varying degree of narcosis
First symptom of narcosis joviality, at 120 feet deep, after remaining for some time
At 150 – 200 feet – Drowsy
At 200 – 250 feet – Strength wanes,
Beyond 250 feet – person can’t move

8. Nitrogen narcosis like alcohol intoxication -- impaired memory, impaired thought making
Nitrogen mech. Same as that of gas anaesthesia

9. “Rapture of the Deep” - “Martini’s Law”
Nitrogen narcosis
Nitrogen Narcosis
“Rapture of the Deep” - “Martini’s Law”
SURFACE
Thinking and
Judgment
POTENTIALLY
Affected
75-100m ft
Symptoms and Effects on
Individual Diver Vary
With Depth and Exposure.
Communication,
Motor and Mental
Tasks IMPAIRED m ft
NOT IN CONTROL
200m+

10. Nitrogen 5 time move soluble in fat than in water
At sea level 1 L of nitrogen dissolved in entire body, half in body fluids & half in fat ( though fat constitutes 15% of total body)
At 33 feet deep – 2 L of nitrogen get dissolved in body
At 100 feet deep 4 L of nitrogen
Nitrogen can not be metabolized in body
Diver ascends slowly to sea level
In case of rapid ascent → decompression sickness

11. Decompression Sickness
Decompression sickness (DCS, aka “the bends”) is the result of inadequate decompression following exposure to increased pressure

12. Decompression Sickness
If the diver ascends to quickly, the nitrogen absorbed by the diver’s body during a dive can come out of solution and form bubbles in the body’s fluids and tissues

13. Decompression Sickness
It has been common to describe decompression sickness as one of three Types, or to categorize it by the area of involvement and the severity of symptoms

14. Decompression Sickness
Type I includes skin itching or marbling; brief, mild pain called “niggles,” which resolve typically within ten minutes; joint pain; lymphatic swelling, and sometimes included extreme fatigue

15. Decompression Sickness
Type II DCS is considered to be respiratory symptoms, hypovolemic shock, cardiopulmonary problems, and central or peripheral nervous system involvement

16. Decompression Sickness
Type III includes arterial gas embolism and is also called decompression illness (DCI)

17. FACTORS INFLUENCING DCS
Exertion
Physical fitness
Temperature – cold water, hot shower
Sex – females
Age
Obesity
Dehydration
Increased carbon dioxide pressures
Alcohol intake
Physical injury
Adaptation
Dive profile
Rapid and multiple ascents
Repetitive and multi-day diving
Altitude exposure

18. Decompression Sickness
Also called bends, compressed air sickness, caisson disease, divers paralysis, dysbarism
During rapid ascent, sufficient amount of nitrogen bubbles develop in body fluids either extra or intra cellularly
Depending upon the no & size of nitrogen bubble, any area of the body can get damage
Bubble formation in brain vessels → paralysis; Around nerves → paraesthesia itching, severe pain; Around joints → severe pain in joints (called bends); In pulmonary vessels → Dyspnoea & chokes, coronary arteries → cardiac damage

19. Decompression Sickness
Categorizing DCS by area involved and severity of symptom includes:
Limb Bends
Central Nervous System (CNS) DCS
Cerebral Decompression Sickness
Pulmonary DCS
Skin Bends
Inner-Ear Decompression Sickness

20. Decompression Sickness
Limb Bends – Dull, throbbing, deep pain in the joint or tissue; usually in the elbow, shoulder, hip, or knee
Pain onset is usually gradual and slowly intensifies
In severe cases limb strength can be affected
In divers, upper limbs are affected about three times as often as lower limbs

21. Decompression Sickness
Central Nervous System (CNS) DCS – May cause muscular weakness, numbness, “pins and needles,” paralysis, loss of sensation, loss of sphincter control, and, in extreme cases, death

22. Decompression Sickness
Cerebral Decompression Sickness – May produce almost any symptom: headache, visual disturbance, dizziness, tunnel vision, tinnitus, partial deafness, confusion, disorientation, emotional or psychotic symptoms, paralysis, and unconsciousness

23. Decompression Sickness
Pulmonary DCS – aka the Chokes accounts for about 2% of DCS cases
Symptoms include: pain under the breastbone on inhalation, coughing that can become paroxysmal, and severe respiratory distress that can result in death

24. Decompression Sickness
Skin Bends – Come in two forms: harmless simple itchy skin after hyperbaric chamber exposure, or rashy marbling on the torso that may warn of serious DCS

25. Decompression Sickness
Inner-Ear Decompression Sickness – aka Vestibular DCS or Ear Bends
Signs and symptoms include vertigo, tinnitus, nausea, or vomiting

26. O2 Toxicity at High Pressure
If PO2 ↑ more than 100 mmHg → Dissolution of O2 in blood ↑ also
If someone exposed to 4 atmosphere pressure (3040 mmHg) → seizures followed by coma within minutes
Seizures may appear without warning but prove lethal
other symptoms – nausea, muscle twitching, dizziness, disturbance of vision, irritability disorientation
↑ ROS production, being lipid soluble damage the cell membrane esp; nervous tissue (as with high lipid content)

27. TREATMENT OF DECOMPRESSION SICKNESS INVOLVES IMMEDIATE RECOMPRESSION, FOLLOWED BY GRADUAL DECOMPRESSION

28. LOCALIZED PAIN IN OR AROUND A JOINT MAY SOMETIMES BE RELIEVED BY APPLICATION OF LOCAL PRESSURE, e.g FROM AN INFLATED SPHYGMOMANOMETER CUFF

29. PREVENTION
GRADED ASCENT
USE OF SCUBA
USE OF HELIUM

30. TREATMENT HYPERBARIC OXYGEN THERAPY [RECOMPRESSION THERAPY]
SUPPORTIVE THERAPY

31. Effects of Heat and Cold
Heat injuries (hyperthermia)
cramps
exhaustion
stroke
Cold injuries (hypothermia)
Decreased body functions
Decreased mental functions
Shivering, numbness
Related protection requirements

32. Temperature Injuries Heat Cold Progressive Symptoms and Effects
- Cramps
- Exhaustion
- Stroke
Profuse Sweating
Weakness
Malaise
Dry, Flushed Skin
Cool Victim
Oral Fluids
No Caffeine/Alcohol
- Hypothermia
Uncontrolled Shivering
Loss of Coord/Dexterity
Numbness
Warm Victim
No Caffeine
No Alcohol
Symptoms
Symptoms
1st Aid
1st Aid

33. Barotrauma Direct Pressure Related Problems Indirect Pressure
- Descent (Compression)
Squeezes
Ear, Sinus, Lung,
Stomach, Intestinal,
Tooth, Equipment
- Ascent (Expansion)
Lung Ruptures -
Subcutaneous and
Mediastinal Emphysema
Pneumothorax
Air Embolism
Descend and Ascend
Slowly to Minimize
Potential Problems
- Decompression Sickness
(The Bends) (DCS)
- Nitrogen Narcosis
- Oxygen Toxicity
Precautionary
Decompression Stops
(Safety Stops) Help
Reduce Bubble Formation
and Incidence of DCS
NEVER HOLD YOUR
BREATH ON SCUBA!

35. One or more tanks of compressed air or some other breathing mixture,
A first-stage "reducing" valve for reducing the very high pressure from the tanks to a low pressure level
A combination inhalation "demand" valve and exhalation valve that allows air to be pulled into the lungs with slight negative pressure of breathing and then to be exhaled into the sea at a pressure level slightly positive to the surrounding water pressure,
A mask and tube system with small "dead space."