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

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

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.

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

USES OF DEEP SEA DIVING RECREATIONAL OIL & SALVAGE COMBAT

ORIENTATION UNDER WATER VISION HEARING EQUILIBRIUM RULES FOR DIVING

EFFECT OF SEA DEPTH ON PRESSURE AND ON GAS VOLUMES Depth (feet) Atmosphere (s) Sea level 1 33 2 66 3 100 4 133 5 166 6 200 7 300 10 400 13 500 16

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

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

RESPIRATION CO2 Retention Dyspnoea Ventilation

CVS Arrhythmias Hypertrophy Cardiac Contractility R.V. Overload

RENAL Diuresis Resp Acidosis

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

HORMONAL Nor-epinephrine Epinephrine Dopamine

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

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

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

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

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

DECOMPRESSION SICKNESS OR BENDS HYPER-BARISM DIVER’S PARALYSIS

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

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

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

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

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

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 5000 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.

DECOMPRESSION SICKNESS SEQUENCE

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

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

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)

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)

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

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

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

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

PREVENTION GRADED ASCENT USE OF SCUBA USE OF HELIUM

TREATMENT HYPERBARIC OXYGEN THERAPY [RECOMPRESSION THERAPY] SUPPORTIVE THERAPY

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

THANK YOU, INDEED!