Oxygen, Gases and DCI Flashcards
What is oxygen?
How much is inhaled/exhaled as we breathe?
Colorless, odorless, tasteless gas needed for cellular metabolism
21% inhaled, 16% exhaled, 5% consumed
How is oxygen transported to body tissues?
Red blood cells - hemoglobin
What is carbon dioxide?
How is it eliminated from the body?
Waste product of metabolism
Respiration (5% CO2)
Excess leads to drowsiness, dizziness, or unconsciousness
What is nitrogen?
Carbon monoxide what and why dangerous?
Inert gas (78%) - increased levels associated with DCS Gas that interferes with oxygen uptake and delivery
Most important initial actions in responding to diving accidents?
Early recognition and providing oxygen
What is decompression illness (DCI)?
Most prevalent symptoms?
Signs and symptoms arising during or after decompression encompassing both DCS and AGE
Pain in joins or muscles, altered sensation/numbness, fatigue, general malaise, nausea, vertigo/dizziness
DCS:
primary cause
primary symptoms
Onset time of symptoms?
Decompression sickness - Inert gas not eliminated so creates bubbles in blood/tissues
Joint pain, motor or sensory dysfunctions, skin rash
After surfacing or well into ascent (extreme exposure)
Arterial gas embolism is?
Primary risk factor?
Onset time of symptoms?
Lung-overexpansion - gas enters blood
Breath-holding
Suddenly at or near the surface
Four benefits of providing a high concentration of oxygen to an injured diver?
Accelerated inert gas elimination
Reduced bubble size
Enhanced delivery to tissues
Reduced pain and swelling
What two actions of a partial pressure gas gradient help the injured diver?
Increased O2 breathing in increases inbound gradient which increases O2 uptake and delivery to injured tissues reducing pain and swelling to limit or revers hypoxic injury
What is the primary goal of emergency oxygen for injured divers?
What is the priority for oxygen delivery in remote areas?
T0 deliver the highest percentage on inspired oxygen possible to facilitate inert gas washout and improve oxygen delivery to compromised tissue
Maintaining the highest inspired fractions possible
What two critical factors affect the percentage of oxygen delivery when using a demand valve?
Mask fit and flow rate
What is the initial flow rate for constant-flow oxygen-delivery systems?
10-15 liters per min
Concerns for oxygen toxicity when delivering emergency oxygen first aid?
None but if either pulmonary before central nervous
Pulmonary toxicity - high concentrations for prolonged periods - irritation of lung tissue due to free radical build up
Five symptoms of nonfatal drowning?
Three actions a first responder should take in a nonfatal drowning?
Difficulty breathing, bluish lips, abdominal distention, chest pain, confusion, coughing pink frothy spit, irritability, unconsciousness
Monitor vital signs, provide O2, transport to medical facility
What is the fire triangle, and how is oxygen involved?
Three elements for fire - heat, fuel, oxygen
Oxygen required for fires, higher concentration = greater risk of fire and acceleration
Safety precautions to be implemented when handling oxygen equipment?
Reduce heat and oil exposures
Adequate ventilation when using
Using only proper equipment
Turn on slowly, once pressurized open 1 full turn,
Visual inspections for damage to cylinder/hoses/O rings
What grade of oxygen should be used for diving first aid?
When and how should reusable oxygen masks and removable plastic oxygen system parts be cleaned?
Aviator or medical grade
After use. Soak in bleach solution (1:9) for at least 10 mins, rinse thoroughly, allow to air dry
What documentation is required to receive an oxygen fill?
When should an oxygen unit’s components and cylinder pressure be checked?
How should an oxygen unit be stored?
Documentation of training in use of emergency O2
Check before every dive outing
Stored with valve closed and depressurized but fully assembled
What are the components of an oxygen delivery system?
Cylinder, pressure-reducing regulator, hose, face mask
What are the hydrostatic testing requirements for an oxygen cylinder?
How often and by whom should an oxygen regulator be serviced?
Same as all compressed-gas cylinders
1 - 10 year overall, 5 yrs in USA
What two factors influence what cylinder size is appropriate?
Why is a demand valve the first choice for delivering oxygen to an injured diver?
Distance to medical care/next level of response, size of cylinder
Can deliver optimal concentration with minimal waste preserving supply as long as possible - closest to 100% O2 administration
When should the oxygen provider switch to a full cylinder?
Which oxygen regulator is preferred for diving first aid?
When pressure drops below 200 psi
Multifunction regulator to service 2 divers as once (Demand value)
