Decompression Sickness
“The Bends”
Type 1
What Law ?
What Symptoms ?
What Law ?
- Henry’s Law
Symptoms ?
- Painful joints
- mottled skin
- pruritic (itching)
Pt may feel like ants are crawling on their skin.
Mottled skin can often look like a sunburn.
Decompression Sickness
“The bends”
Type 2
What Law ?
What Symptoms ?
What Law ?
- Henry’s Law
What Symptoms ?
- Neuologica Signs & symptoms
- Hypovolemic Shock
Arterial Gas Embolism
(AGE)
What Law ?
What Causes it ?
What Symptoms ?
What Treatment?
What Law ?
- Related to Boyle’s Law
What Causes it?
- Holding breath during ascent on a dive (causing a pneumothorax)
- Air being forced into blood vessels (causing Ischemia)
What Symptoms ?
- Stoke-like symptoms
- Altered mental status
- Syncope
- Dizziness
- Caugh
- Epistaxis
What treatment ?
- Immediate Hyperbaric treatment!
Transport by goound if possile. Air trasnport in pressurized aircraft or <1000 MSL.
Pulmonary Overpressurization
What Law ?
What Cause it ?
Effect ?
What Law ?
- Boyle’s Law
What Cause it ?
- Holding compressed air in your lungs during ascent.
Effect ?
- Lung overexpansion
- Ruptures the alveoli
- Pneumothorax
- Mediastinal emphysema
Common in inexperienced divers.
*
Atmosphere Calculations
Under water
- Every 33 feet below water = 1 ATM (atmosphere)
- Sea Level = 1 ATM
- 33 ft. under water = 2 ATM
- 66 ft. under water = 3 ATM
Atmospere Zones
- Physiologic Zone
- Physiologically Deficient Zone
- Space Equivalent Zone
Atmosphere Zones
Physiologic Zone
- Seal Level - 10,000ft MSL
Night Vision is decreased beginning at 5,000ft MSL
Atmosphere Zones
Phyiologically Deficient Zone
- 10,000 - 50,000ft MSL
- Oxygen required to survive at these altitudes
- Sign of compression loss is cooler temperatures in the cabin and windows fogging.
- If a rapid decompression occurs, TUC is cut in half.
Atmosphere Zones
Space EquivalentZone
- >50,000ft MSL
- Congratulations on becoming an astronaut!
Oxygen Adjustmen Calculation
(FiO2xP1) / P2 = FiO2 required for ascent
FiO2 = Fraction of inspired oxygen
P1 = the pressure you ae at (on the ground)
P2 = the pressure you are flying to (cruiding altitude)
Pressure (P) Values
- Sea Level = 760 torr or mmHg (1 ATM)
- 10k ft. MSL = 523 torr or mmHg
- 18k ft. MSL = 380 torr or mmHg (1/2 ATM)
- 63k ft. MSL = 0 torr or mmHg ( 0 ATM)
Types of Hypoxia
- Hypemic
- Hypoxic
- Stagnant
- Histotoxic
Types of Hypoxia
Hypemic
What is it?
- Redction in th O2 carrying capacity of blood
What causes it ?
- Anemia
- Hemorrhae
Types of Hypoxia
Histotoxic
What is it ?
- limits the use of available ocgen due to poisoning of the cytochrome oxidase system
What causes it ?
- Cyanide
- Alcohol
- Carbon Monoxide (CO)Nitroglycerin
- Sodium Nitroprusside (Nipride)
Types of Hypoxia
Hypoxic
What is it ?
- Not enough Oxygen in the air
What causes it ?
- Low PP of oxygen at altitude
- Deficiency in alveola O2 exchange
- Pneumothorax
- cardiovascular PT
types of Hypoxia
Stagnant
What is it ?
- Blood isnt moving
What causes it ?
- Reduced cardiac output
- Pooling of blood
- High G forces
- Cardiogenic shock
Stages of Hypoxia
- Indifferent
- Compensatory
- Disturbance
- Critical
Stages of Hypoxia
Indifferent Stage
0 - 10,000ft. MSL
Symptoms
- some loss of night vission at 5,000ft MSL
- Full reasonin abilities
Stages of Hypoxia
Compensatory Stage
10,000 - 15,000ft. MSL
Symptoms
- Increased HR
- Increased Ventilations
- Slowed judgment
Stages of Hypoxia
Disturbance Stage
15,000 - 20,000ft. MSL
Symptoms
- Slurred speech
- Impaired judgment
- Feeling of being drunk
Stages of Hypoxia
Critical Stage
>20,000ft. MSL
Symptoms
- Loss of consciousness
- Death
No longer able to physiologically function, death imminent
Stressors of Flight
Self Imposed
Self Imposed
(D.E.A.T.H)
- Dehydration
- Echaustion
- Alcohol
- Tobacco
- Hypoglycemia
Stressors of Flight
Inherent
Inherent
- Thermal Changes
- Decreased Humidity
- Gravitational Forces
- Fatigue
- Low PP of Oxygen
- Barometric Pressure change
- Noise
- Vibration
Altitude Effects
Barondontalgia
(Teeth)
- Occurs on ascent
- Air trapped in fillings expands due to Boyles Law
- Aso referred to as “Aerodontaligia”
