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•Mountain Medicine
•Under-Water Medicine
•Medicine on Exposure to Extremes of Temperature
•Space and Aviation Medicine
MEDICINE AND PHYSIOLOGY MEDICINE AND PHYSIOLOGY IN UNUSUAL ENVIRONMENTIN UNUSUAL ENVIRONMENT
•DEEP-SEA DIVING PHYSIOLOGY
•SUB AQUATIC MEDICINE
•UNDER-WATER MEDICINE
CASECASE
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.
OBJECTIVEOBJECTIVE
“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 DIVINGUSES OF DEEP SEA DIVING
•RECREATIONAL
•OIL & SALVAGE
•COMBAT
ORIENTATION UNDER ORIENTATION UNDER WATERWATER
• VISION
• HEARING
• EQUILIBRIUM
• RULES FOR DIVING
EFFECT OF SEA DEPTH ON EFFECT OF SEA DEPTH ON PRESSURE AND ON GAS PRESSURE AND ON GAS
VOLUMESVOLUMESDepth (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 FACTORS AFFECTING IN DIVINGDIVING
• Total Pressure [Depth]• Duration of Dive• Activity of Diver• Temp of Water• Drugs within body• Gas Mixtures• Rate of Descent/
Ascent
EFFECTS OF DIVINGEFFECTS OF DIVING
HEMATOLOGICAL• Hct• Platelets• DLC• TLC• Diuresis• Weight Loss• Rise in NH4
RESPIRATIONRESPIRATION
• CO2 Retention
• Dyspnoea
• Ventilation
CVSCVS
• Arrhythmias
• Hypertrophy
• Cardiac Contractility
• R.V. Overload
RENALRENAL
• Diuresis
• Resp Acidosis
NEURALNEURAL
•Disturbed mental and motor functions
•Loss of Long-term memory
HORMONALHORMONAL
• Nor-epinephrine
• Epinephrine
• Dopamine
PATHOPHYSIOLOGY OF PATHOPHYSIOLOGY OF UNDER-WATER MEDICINEUNDER-WATER MEDICINE
• BAROMETRIC PRESSURE
• VOLUME OF GASES
• INTRA-THORACIC PRESSURE
• INTRA-ALVEOLAR PRESSURE
PATHOPHYSIOLOGYPATHOPHYSIOLOGY
PARAMETER DEEP SEA DIVING
HIGH ALTITUDE
• Barometric Pressure
• Volume of Gases
• Intra-thoracic Pressure
• Intra-alveolar Pressure
[Compression]
[Expansion]
MEDICAL PROBLEMS OF MEDICAL PROBLEMS OF DEEP-SEA DIVINGDEEP-SEA DIVING
• Oxygen Toxicity– Lung damage– Convulsions
• HPNS– Tremors– Somnolence
Problems on Descent
• CO2 Toxicity – Initial excitation and later depression of
respiration– Respiratory acidosis– Lethargy– Narcosis
MEDICAL PROBLEMS OF MEDICAL PROBLEMS OF DEEP-SEA DIVINGDEEP-SEA DIVING
• Nitrogen Narcosis– Euphoria– Impaired
performance– Anesthetic effects
• Ear & Sinus Barotraumas
Problems on Descent
MEDICAL PROBLEMS OF MEDICAL PROBLEMS OF DEEP-SEA DIVINGDEEP-SEA DIVING
• Decompression Sickness
• Air Embolism
Problems on Ascent
DECOMPRESSION SICKNESSOR
BENDSOR
HYPER-BARISMOR
DIVER’S PARALYSIS
HISTORYHISTORY
1670 : Boyles described “Decompression”
1830 : Cochrane used compressed air in tunnels and Caissons
1937 : Behnk – discovered “N2 Narcosis”
DECOMPRESSION SICKNESSDECOMPRESSION 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 PARTIAL PRESSURES OF RESPIRATORY GASES AT 1 RESPIRATORY GASES AT 1
ATAATASample Gas Partial Pressure
O2
[mm Hg]
CO2
[mm Hg]
N2
[mm Hg]
H2O[mm Hg]
Total[mm Hg]
Inspired air
158 0.3 596 5.7 760
Expired air 116 32 565 47 760
Alveolar air
100 40 573 47 760
Arterial blood
100 40 573 47 760
Venous blood
40 46 573 47 706
Tissues < 30 > 50 573 47 700
STP = 760 mmHg
Maximum Human Tolerance = 4 – 6 ATA for 4 hours
PRESSURE OUTSIDE BODYPRESSURE 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 DECOMPRESSION SICKNESS SEQUENCESEQUENCE
DECOMPRESSION SICKNESS DECOMPRESSION SICKNESS GRADINGGRADING
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 DCSFACTORS 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. 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. 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
PREVENTIONPREVENTION
•GRADED ASCENT
•USE OF SCUBA
•USE OF HELIUM
TREATMENTTREATMENT
•HYPERBARIC OXYGEN THERAPY [RECOMPRESSION THERAPY]
•SUPPORTIVE THERAPY
USES OF HYPERBARIC USES OF HYPERBARIC [RECOMPRESSION] [RECOMPRESSION]
THERAPYTHERAPY•Gas Gangrene•Decompression Sickness•Arterial Gas Embolism•Severe Burns•Myocardial Infarction•Osteomyelitis •Carbon Monoxide
Poisoning