2. MEDICINE AND PHYSIOLOGY IN UNUSUAL ENVIRONMENT
Mountain Medicine
Under-Water Medicine
Medicine on Exposure to Extremes of Temperature
Space and Aviation Medicine

3. DEEP-SEA DIVING PHYSIOLOGY
SUB AQUATIC MEDICINE
UNDER-WATER MEDICINE

4. CASE
A sailer dived in the sea upto about 100 feet depth. When he came back to the surface of sea, he was exhausted, complained of severe pain and swelling of joints [esp knee and ankle joints] and hardly could move those. Some skin rashes were visible with severe itch. He was a bit drowsy and disoriented.

5. OBJECTIVE “To have safe diving“ To Learn:- Orientation Under-Water
Pathophysiology of Under-Water Medicine
Medical Problems [Disorders] of Deep-Sea Diving
Decompression Sickness
Uses of Hyperbaric Oxygen Therapy

6. USES OF DEEP SEA DIVING
RECREATIONAL
OIL & SALVAGE
COMBAT

7. ORIENTATION UNDER WATER
VISION
HEARING
EQUILIBRIUM
RULES FOR DIVING

8. EFFECT OF SEA DEPTH ON PRESSURE AND ON GAS VOLUMES
Depth (feet) Atmosphere (s)
Sea level 1

9. FACTORS AFFECTING IN DIVING
Total Pressure [Depth]
Duration of Dive
Activity of Diver
Temp of Water
Drugs within body
Gas Mixtures
Rate of Descent/ Ascent

10. EFFECTS OF DIVING HEMATOLOGICAL Hct Platelets DLC TLC Diuresis
Weight Loss
Rise in NH4

11. RESPIRATION
CO2 Retention
Dyspnoea
Ventilation

12. CVS
Arrhythmias
Hypertrophy
Cardiac Contractility
R.V. Overload

13. RENAL
Diuresis
Resp Acidosis

14. NEURAL
Disturbed mental and motor functions
Loss of Long-term memory

15. HORMONAL
Nor-epinephrine
Epinephrine
Dopamine

16. PATHOPHYSIOLOGY OF UNDER-WATER MEDICINE
BAROMETRIC PRESSURE
VOLUME OF GASES
INTRA-THORACIC PRESSURE
INTRA-ALVEOLAR PRESSURE

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

18. MEDICAL PROBLEMS OF DEEP-SEA DIVING
Problems on Descent
Oxygen Toxicity
Lung damage
Convulsions
HPNS
Tremors
Somnolence
CO2 Toxicity
Initial excitation and later depression of respiration
Respiratory acidosis
Lethargy
Narcosis

19. MEDICAL PROBLEMS OF DEEP-SEA DIVING
Problems on Descent
Nitrogen Narcosis
Euphoria
Impaired performance
Anesthetic effects
Ear & Sinus Barotraumas

20. MEDICAL PROBLEMS OF DEEP-SEA DIVING
Problems on Ascent
Decompression Sickness
Air Embolism

21. DECOMPRESSION SICKNESSOR
BENDS
HYPER-BARISM
DIVER’S PARALYSIS

22. HISTORY 1670 : Boyles described “Decompression”
1830 : Cochrane used compressed air in
tunnels and Caissons
1937 : Behnk – discovered “N2 Narcosis”

23. DECOMPRESSION SICKNESS
Pathophysiology
Resp Gases at 1 ATA
Gaseous Pressures Outside / Inside Alveoli of Lungs
Decompression Sickness Sequence
Decompression Sickness Grading

24. Few Pictorial signs of DCS
Factors Influencing DCS
Treatment of DCS
Uses of Hyperbaric Therapy
Prevention of DCS

25. PARTIAL PRESSURES OF RESPIRATORY GASES AT 1 ATA
Sample
Gas Partial Pressure O2
[mm Hg]
CO2 N2
H2O
Total
Inspired air
158
0.3
596
5.7
760
Expired air
116 32
565 47
Alveolar air
100 40
573
Arterial blood
Venous blood 46
706
Tissues
< 30
> 50
700

26. Maximum Human Tolerance
STP = 760 mmHg
Maximum Human Tolerance
= 4 – 6 ATA for 4 hours

27. PRESSURE OUTSIDE BODY
Gaseous pressure both inside and outside the body, showing at left saturation of the body to high gas pressures when breathing air at a total pressure of mm Hg, and at right the great excess of intrabody pressure that is responsible for bubble formation in the tissues when the body is returned to the normal pressure of 760 mm Hg.

28. DECOMPRESSION SICKNESS SEQUENCE

29. DECOMPRESSION SICKNESS GRADING
Type I [Pain only]
Limb or joint pain-dysfunction
Itch
Skin rash
Localized swelling
Type II [Serious]
Central nervous system disorder
Inner ear damage
Lungs failure
Cardiac failure

30. 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

31. Skin lesions of decompression sickness
Skin lesions of decompression sickness. This diver, who had had an upper limb amputation, developed ‘bends’ pain in the phantom limb, and skin bends over the body. Both responded rapidly to recompression therapy. (Photograph by courtesy of Dr Ramsey Pearson)

32. Decompression sickness: skin lesions of isobaric counterdiffusion
Decompression sickness: skin lesions of isobaric counterdiffusion. The subject breathed a neon/oxygen mixture at 1200 feet (360 metres), while exposed to a chamber of helium/oxygen. Gross itching accompanied the intradermal bubbles. (Photograph by courtesy of Professor C. J. Lambertsen)

33. Curved and concentric lacerations of shark bite – often with teeth left in the wound. (Photograph courtesy of Dr. G. D. Campbell)

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

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

36. The value of 100% oxygen, before during and after recompression
Intravascular bubbles do not develop with oxygen breathing, [especially at 2 ATA]
Denitrogenation is maximized, reducing tissue bubbles
It reverses the development and the redevelopment of DCS

37. PREVENTION
GRADED ASCENT
USE OF SCUBA
USE OF HELIUM

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

39. USES OF HYPERBARIC [RECOMPRESSION] THERAPY
Gas Gangrene
Decompression Sickness
Arterial Gas Embolism
Severe Burns
Myocardial Infarction
Osteomyelitis
Carbon Monoxide Poisoning

40. THANK YOU,
INDEED!