Human Factors in Aviation Physiology PDF

HUMAN FACTORS Aviation Physiology - Health factors and physical effects linked to flying 1. Dehydration 2. Hypoxia 3. Carbon monoxide poisoning 4. Hyperventilation 5. Barotrauma 6. Decompression sickness 7. Spatial Disorientation 1. Dehydration - Critical loss of water from the body Causes: • Hot Fl...

HUMAN FACTORS Aviation Physiology - Health factors and physical effects linked to flying 1. Dehydration 2. Hypoxia 3. Carbon monoxide poisoning 4. Hyperventilation 5. Barotrauma 6. Decompression sickness 7. Spatial Disorientation 1. Dehydration - Critical loss of water from the body Causes: • Hot Flight Decks • Increasing Altitude • Humidity Symptoms of Dehydration 2. Hypoxia - Not enough/reduced oxygen in the body • 4 types of Hypoxia: 1. Hypoxic hypoxia 2. Hypemic hypoxia 3. Histotoxic hypoxia 4. Stagnant hypoxia 1. Hypoxic Hypoxia – Insufficient oxygen available to the body Causes: • A blocked airway • Underwater • Being at high altitude 2. Hypemic Hypoxia – Oxygen deficiency in the blood Causes: • Physical injury resulting in blood loss • Blood Donation • Sickle Cell Anemia • Smoking • Carbon Monoxide Poisoning 1 HUMAN FACTORS 3. Histotoxic Hypoxia – The cells are unable to use the oxygen “Histo” – tissues/cells “Toxic” – poisonous Causes: • Alcohol • Drugs 4. Stagnant Hypoxia – The blood is unable to flow – Cells are starved of oxygen Causes: • Extreme cold temp. • Shock • Cardiac problems Symptoms of Hypoxia • Cyanosis (blue fingernails and lips) • Headache • Decreased reaction time • Impaired judgment • Euphoria • Visual impairment • Drowsiness • Light headed or dizzy sensation •Tingling in fingers and toes • Numbness Treatment of Hypoxia • Fly at lower altitudes • Use supplemental oxygen – 10,000ft day – 5,000ft night Time of Useful Consciousness • The maximum time a pilot has to make rational decisions 2 HUMAN FACTORS 3. Carbon Monoxide Poisoning - Caused by a faulty exhaust system or smoking - Susceptibility increases with increased altitude Symptoms of Carbon Monoxide Poisoning • Loss of muscular power • Deterioration in vision • Impaired judgment • Personality change • Impaired memory • Slower breathing rate • Cherry-red complexion • headache, dizziness and nausea Convulsions • Coma and eventually death 4. Hyperventilation - An excessive loss of Carbon Dioxide from the body Causes: • Emotional stress • Fright • Pain • Excitement Symptoms of Hyperventilation • Muscle Spasm • Tingling in fingers and toes • Visual impairment • Numbness • Unconsciousness • Hot and cold sensation • Lightheaded or dizzy sensation Treatment for Hyperventilation • Breathe normally to restore proper carbon dioxide level in the body • Breathing into a paper bag • Recovery is usually rapid 5. Barotrauma - Severe pain caused by increasing cabin altitude due to expansion of gas inside the body such as stomach, intestines, sinuses, middle ear or in decaying tooth Barotrauma of the Ear - Caused by pressure changes within the ear canal during climbs and descents • Valsalva Maneuver - This procedure forces air through the Eustachian tube into the middle ear. 3 HUMAN FACTORS Barotrauma of the Sinuses - Intense pain due to sinus block 6. Decompression Sickness - the nitrogen is forced to leave the solution too rapidly, bubbles form in different areas of the body. Symptoms: • The Bends • Skin Manifestation • Pulmonary (chokes) • Neurological Manifestation 1. The Bends - Gas dissolves out in the joints, muscles and tendons Signs & Symptoms: - Localized deep pain (mild to excruciating) - Active and passive motion of the join aggravates the pain 2. Skin Manifestation - Nitrogen dissolves out in to the skin Signs & Symptoms: - Itching - Swelling of the skin - Tiny-scar like depressions 3. Pulmonary (Chokes) – Nitrogen bubbles form in the lungs – The bubbles can block the normal flow of blood resulting in serious medical conditions Signs & Symptoms: - Burning deep chest pain - Shortness of breath - Constant Dry cough 4. Neurological Manifestation – Nitrogen bubbles can be transported to the brain, spinal cord and nerves Signs & Symptoms: - Headache - Dizziness - Confusion - Unconsciousness Decompression Sickness Prevention • Wait 12 hours after a dive which does not require a controlled ascent for flight below 8,000 feet. • Wait 24 hours after a dive which required a controlled ascent for flight below 8,000 feet. • Wait 24 hours after a dive to climb to an altitude above 8,000 feet. 4