Medical Flashcards
Three class of medical certificate
14CFR part 61
3rd class for recreational for 5y or 2y if over 40
2nd class for commercial for 1y
1st class for airline for 1y or 6mo if over 40
Hypoxia
Lack of oxygen, particularly the brain
4 different causes: hypoxic, hypemic, stagnant, histotoxic
Hypoxic hypoxia
Insufficient oxygen, Eg blocked airway, reduction of partial pressure at high altitude
Dangers of transporting dry ice
Hypemic hypoxia
Not enough in the blood
Cause: anemia or CO poisoning or blood donation
Stagnant hypoxia
Oxygen rich blood not reaching the tissues due to shock, constricted artery, or excessive Gs
Histotoxic hypoxia
Tissue can’t use oxygen due to alcohol, drugs
Drinking one ounce of alcohol = additional 2000ft of physiological altitude
Symptoms of hypoxia
Cyanosis, headache, decreased response to stimuli, increased reaction time, impaired judgement, euphoria, visual impairment, drowsiness, dizzy, tingling, numbness
Treatment of hypoxia
Flying lower altitudes
Use supplemental oxygen
Above 10000ft symptoms increase
Hyper ventilation
Excessive rate and death of respiration
Loss of carbon dioxide in the blood
Can lead to unconsciousness
Unexpected stressful situation, high altitude flying
Hyper ventilation symptoms
Similar to hypoxia
Visual impairment
Unconsciousness
Dizzy
Tingling
Hot/cold
Muscle spasms
=> breathing slowly, talking out loud, breath into bag
Middle ear and sinus issues
Due to air pressure changes during climbs and descents, equalize via Eustachian tubes, problem when clogged (cold, ear infection, sore throat)
During descent lower pressure inside, need to shut mouth, nostrils and blow gently
Same with sinuses, if sinus block reduce descent rate, meds may impair pilot
Spatial orientation body systems
Vestibular
Somatosensory
Visual
Vestibular system
Inner ear to sense movement and orientation with three semicircular canals filled with fluid and fine hair, motion transmitted via nerves to brain
Somatosensory system
Can’t distinguish between gravity and g forces
Vestibular illisions
The Leans - can’t detect rotational acceleration of 2 degrees per sec or less, leveling may feel like over correction
Coriolis - long turn ear fluids move at same speed as canal, head movement can create illusion of aircraft maneuver
Graveyard spiral - after long turn, level, illusion to turn other way, compensating and losing altitude, attempt to climb, tighten spiral
Somatogravic - rapid acceleration, feeling of nose-up attitude, pushing nose-low, rapid deceleration opposite effect
Inversion - abrupt climb-to-level, illusion of tumbling backwards, may push nose low
Elevator - updraft illusion of climb, may push nose low, abrupt downdraft opposite effect
Visual illusions
False horizon
Autokinesis
Optical illusions
When transitioning from instrument flight to visual landing
Runway width illusion
Runway and terrain slopes illusion
Featureless terrain illusion
Water refraction
Haze
Fog
Ground lighting illusions
Alcohol levels
Must be <0.04% and must wait 8hrs after drinking
Medical issues common
Motion sickness
CO poisoning
Stress
Fatigue
Exposure to chemicals
Dehydration and heats trike
Alcohol
Drugs
Scuba diving wait time
12hrs for flights up to 8000ft for dives without decompression stops
24hrs for dives with decompression stops
24hrs for flights above 8000ft
Photopic vision
Color, fine detail, needs good illumination
Mesotopic vision
During dawn and dusk, combo of rods and cones, cone sensitivity and visual acuity decreases, use off center and scanning vision
Scotopic vision
Low-light, Poor resolution of detail, color perception lost, 20/200, night blind spot
Central blind spot
Area where optical nerve connects, no rods or cones
Empty field myopia
With no visual reference, Eg clouds, eyes relax with 10-30ft focal distance
Night blind spot
Rods 10k times more sensitive than cones, responsible for peripheral vision, need to scan 5-10 degrees off center
Night vision protection
Sunglasses
Oxygen supply - rods sensitivity at 4000ft
High intensity lighting
Flightdeck lighting
Airfield precautions
Self imposed stress
Drugs
Exhaustion
Poor physical conditioning
Alcohol
Tobacco
Hypoglycemia
Distance estimation and depth perception
Motion parallax
Geometric perspective
Retinal image size
Aerial perspective
Night vision illusions
Autokinesis
False horizon
Reversible perspective illusion
Size distance illusion
Fascination
Flicker vertigo
Night landing illusions
Night vision systems
Synthetic vision system
Enhanced flight vision system
