Basic Dive Medicine Flashcards
- Mechanics of Breathing
- Gas Exchange
- Respiration
- O2 is diffused from the alveolar air into the alveolar capillaries due to change in pp.
- elevated ppCO2 in the plasma is driven into the lungs c/ lower ppCO2 (Daltons and Henry’s law).
- cells utilize the O2 and during metabolism, produce CO2 as a bi-product.
6 phases of respiration
- ventilation
- gas exchange from alveoli to capillaries
- transport of gases via blood
- gas exchange from blood to tissues
- gas exchange from tissue to cells
6 cells metabolize the gas
define circulatory system
closed system that delivers O2, nutrients, and hormones to cells and removes CO2, waste a, chemicals, and heat.
The most prevalent gas to in diving is…
CO2 Tox
Define CO
- colorless, oderless, tasteless gas produced from incomplete combustion.
CO:
- s/s
- why do s/s typical occur during ascent or upon RS?
- Tiny - Tightness across the head Headhunters - H/A Practice - Pounding H/A Ninja - Nausea Chicken - Confusion Voodoo - Vomitting - while @ depth the increased ppO2 allows O2 to be delivered s/ binding to hgb.
Metallic tastes
Multiple casualties
Dizziness
Unconscious
*s/s may not exist due to rapid occurring toxicity (can go straight LOC).
CO tx
remove the Pt from the environment switch to 2ndary air source 100% O2 Neuro to r/o AGE contact DMO HBO2 tx (maybe)
Hypoxia:
- define
- causes
- s/s result at ___ ppO2
- diminished O2 to tissues
- air supply failure
lost mouthpiece
airway obstruction
LARV or MK16 rebreather malfunction
depleted O2 levels
poor ventilation - < 0.16 ppO2
Hypoxia s/s
Cilli wld
Cyanosis Increase HR & BP Lack of concentration Lack of muscle control Inability to perform difficult task
Weakness
LOC
Drowsiness
Hypoxia Tx
In water EP's 100% O2 contact DMO CPR PRN Neuro r/o AGE
CO2 Tox
- define
- causes
- hypercapnia, increased CO2 levels
- skip breathing
excessive workload
over breathing dive apparatus
CO2 scrubber malfunction
CO tox:
- s/s
- ex’s usually apparent c/
- I Child
Increased Hr and RR Confusion H/A Inability to concentrate LOC (can be the 1st sx) Drowsiness
- Euphoria
- heavy work at depths >120 fsw
CO2 tox tx:
- in water
- on surface
- ventilate notify buddy decrease workload abort dive contact DMO/DMT - remove dive apparatus 100% O2 Neuro r/o AGE
N2 Narcosis define
narcotic effect on the CNS due to increased ppN2.
- it is progressive with increased pp not time @ depth, usually onset at ~4 at a (99 fsw)
N2 narcosis s/s
Clasi
Confusion Lack of concern for safety Apparent stupidity Sense of well being Impaired judgement
others: inappropriate laughter, tingling of the lips, gums, and legs.
N2 narcosis tx
work up dives to build tolerance
substitute N2 for He c/ jobs deeper than 165’
ascend above the depths of sx onset
- sx’s typically resolve c/in :01
O2 tox:
- 2 types and define
- CNS O2 tox, increased pp)2 over short periods usually encountered as low as 1.3 ata but typically onset @ 1.6 ata.
- Pulmonary O2 tox, long exposures to increased ppO2.
Risk factors that increase O2 to (5)
individual susceptibility CO2 retention exercise immersion in H2O depth
CNS O2 tox:
- s/s
- tx
- VENTTID-CVision - blurred/tunnel
Ears - tinnitus or roaring
Nausea
Twitching/Tingling - facial or extremities
Irritability - change in behavior
Dizziness - clumsiness or incoordination
Convulsions - can be 1st sx- 1st sx usually is tachycardia, not taught in dive manual, taught in civilian Chamber tech course.
- vent hat
switch air
chamber EP’s
Pulmonary O2 tox:
- s/s
- tx
- CBS coughing burning SOB/dyspnea * Ex - O2 therapy at sealevel >12hrs can cause Pulmonary O2 tox.
- ventilate off O2 Chamber EP's contact DMO Pt may have to stay on O2 even c/ sx's
An O2 hit can occur ___ to ___ mins after being off O2.
1 to 2 mins
Hypothermia
- define
- levels of insulation (3)
- when the core temp is <40 F hot water suit
- Passive Rewarming
- Active Rewarming
- why never give caffeine, alcohol, or tabacco?
- remove Pt from the environment dry clothes blankets hot soup/drink - warm bath or shower (100-110 F) place Pt in a warm space - dehydration.
Mild Hypothermia:
- s/s
- tx
- shivering
slurred speech
poor judgement - passive or active rewarming
Moderate Hypothermia:
- s/s
- tx
- apathy (sluggish, no emotion) mild confusion slurred speech uncontrollable shivering ashen skin decreased Hr - warm bath, if in shower then keep wetsuit on keep extremities out of the water rewarm till the Pt starts to sweat
Drop factor define
rewarming of the extremities causes peripheral vasodilation and dumps the cold shunted blood from the extremities into the core. Thus can cause a rapid decrease in core temp.
Severe Hypothermia:
- s/s
- tx
- cardiac arrest (handle gently) impaired motor fx's shivering stops irregular shallow hx beats LOC - passive rewarming only NPO prevent exertion Contact DMO
Hypothermia is an emergency in ….
slow motion. You have time!
Shallow water blackout:
- define
- tx
- depressed urge to breathe due to decreased CO2 levels (hyperventilation) prolonging breathe hold. As the diver ascends the ppO2 decreases creating hypoxia then causes LOC prior to feeling the urge to breathe.
- remove Pt from water
CPR PRN
100% O2
contact DMO
Transport
Near drowning:
- define
- tx
- all near drownings need to be evaluated for…
- suffocation by immersion c/ successful resuscitation.
- auscultate LS
Chest xray
100% O2
contact DMO
transport - aspiration to prevent
C/ near drownings; the possibility of ____ is the greatest risk and can develop several days after the incident.
pneumonia
Ear:
- gross anatomy (4)
- fx of each
- consist of EAC, TM, Middle ear, and inner ear
- EAC - conduit for sound
TM - transfers sound wave to conductive bones
Middle ear - conductive bones transfer sound waves to inner ear.
Inner ear - fluid transfers sound waves across cilia to the vestibulochoclear nerve.
Middle Ear Anatomy:
- define
- 3 bones
- 2 windows
- 1 tube
- gas filled space between the EAC & inner ear
- malleus, incus, stapes
- oval and round window
- eustachian tube
Eustachian tube fx
connects the middle ear to the back of the throat, which allows divers to equalize pressure in the middle ear c/ the ambient pressure.
Inner ear anatomy:
- define
- connected to the middle ear via…
- cochlea is…
- vestibular apparatus is…
- fluid filled space (paralymph, csf, and endolymph)
- the oval and round window
- organ of hearing
- organ of balance
Inner Ear physiology
the inner ear fluid moves across nerve sensors stimulating hearing and balance.
Barotrauma:
- define
- essential ingredients
- damage to body tissues due to changes in ambient pressure
- GRAVE
gas filled space
rigid walls
ambient pressure change
vascular penetration
enclosed space
Barotrauma on:
- descent
- ascent
- types of squeezes (9)
- squeeze
- reverse squeeze
-external ear middle ear inner ear sinus mask tooth lung abdomen suit
Barotrauma external ear:
- cause
- if EAC is blocked; ex wax, tight hood, ear infection, etc…
Barotrauma Middle ear:
- cause
- s/s
- tx
- occurs usually on descent due to blocked eustachian tube.
- px in ear
“fullness”
blood drainage in oral or nasal cavity
mild hearing loss - notify buddy
stop traveling
attempt to clear
DONT clear on ascent
abort dive PRN
contact DMO/DMT - most common type of barotrauma
Barotrauma Reverse squeeze:
- cause
- s/s
- tx
- blocked passage of any sinus (by mucus or edema)
- often seen with head colds
- px/pressure (in the forehead, cheeks, or molars), bloody sputum or nasal discharge.
- px in MOLARS is not a tooth squeeze!
- notify buddy
stop travel
attempt to clear
abort dive PRN
contact DMO/DMT
Vertigo:
- define
- 2 types
- false sense of spinning
- usually inner ear problem if sx’s persist
- caloric veritgo
alternobaric vertigo
Caloric Vertigo:
- define
- causes
- most common during…
- Hot or cold water that stimulates one ear to change flow of fluid in the inner ear.
- ear obstruction (tight hood, cerumen, infection).
- descent
Alternobaric Vertigo:
- define - characteristics - s/s
- pressure and balance change between middle ear space.
- most common type of vertigo and most common on ascent.
- nystagmus
tinnitus
N/V
Caloric and ABV s/s are usually transient, lasting…
<:01
POIS:
- define
- 4 types
- Pulmonary overinflation syndrome; over expansion of gas trapped in the lungs resulting in alveolar sac rupture.
- AGE
mediastinal emphysema
subcutaneous emphysema
Pneumothorax (simple then tension)
