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)
POIS tree
Alveolar sac ruptures
\/
Interstitial emphysema occurs
\/ \/ \/
Mediastinal E. Pneumothorax AGE
\/
SubQ E
AGE:
- define
- arterial gas embolism; alveolar sac ruptures, gas enters the capillaries of the lungs, travels to the chambers of the heart, then to the hearts circulation or the bodies (usually the head).
- is the most serious diving complication
AGE:
- s/s
- tx
- Transport Pt…
- Under - unconscious Water - weakness People - paralysis Need - Nausea Extremely - ears (tinnitus, roaring) Big - blurred vision Drinks - dizziness For - fatigue Partying - paresthesia - Immediate Re 'C' Neuro 100% O2 CPR PRN - lying down, all extremities straight of elevation
Mediastinal emphysema
- define
- alveolar sac ruptures, gas is forced into the loose mediastinal tissue.
Mediastinal emphysema:
- s/s
- tx
- sternal “tight”, “dull”, mild to moderate cx px
Px worse with inspiration, coughing, & dysphagia.
sx’s don’t generally get worse after onset - Neuro r/o AGE
100% O2
Transport
contact DMO
look for other POIS - LS and cx xray
Subcutaneous emphysema:
- define
- alveolar sac ruptures, mediastinal emphysema, gas then leaks from the mediastinum into the SQ tissue of the neck.
SQ Emphysema:
- s/s
- tx
- Crepitation along the neck voice change (from increase pressure on the vocal cords) same s/s as mediastinal emphysema - Neuro r/o AGE 100% O2 Transport Contact DMO look for other POIS - LS and cx xray
Pneumothroax:
- define
- 2 types
- alveolar sac ruptures, and gas leaks into pleural space.
- simple and tension
- Simple Pneumothorax define
- Tension Pneumothorax defien
- one time leakage of air
- continuous leakage of air eventually collapsing the affected lung.
- How to prevent a POIS (2)
- Unintentional ascent of ___ to ___’ can cause a POIS.
- How does having a chest cold increase the risk of a POIS?
- dont valsalva on ascent
don’t hold your breathe - 3-4’
- congested bronchioles can trap O2 in the passageway then during ascent Volume increases then POIS.
Pneumothorax:
- s/s
- tx
- cx px (sudden sharp lateral or top of shoulder) rapid shallow breathes guarding poor skin CCT - Neuro r/o AGE 100% O2 Transport Contact DMO CPR PRN Needle 'D'
Air Supply Requirements:
- Primary
- 2ndary
- How many configurations?
- enough air to press the IL once and the OL twice to 165’ and vent during on TT6A for 2 Pts and 1 IT c/ max extensions.
- enough air to press the IL and OL once to 165’ and ventilate for 1hr @ 70.4 scfm.
- 5; A,B,C,D,E pg 21-6 table 21-3
Ventilation Requirements
- Air tables (Pt and IT)
- If air supply is unlimited then…
- O2 Tables (Pt and IT)
- Pt; vent 2 acfm for ea @ rest
IT; vent 4 acfm for ea @ work - vent for comfort
- Pt; vent 12.5 acfm for ea @ rest breathing O2
IT; vent 25 acfm for ea @ work breathing O2
- Vent to keep CO2 levels below ___ SEV.
- Vent to keep O2 levels between ___ to ___ % inside the chamber.
- 1.5 SEV
- 19-25%
Neuro Exam:
- prior to Re ‘C’
- after Re ‘C’
- DCS Type I POIS (non AGE) Asymptomatic Pt after uncontrolled ascent - symptomatic omitted 'D' Diver surfaces unconscious DCS Type II AGE
How does DCS occur?
While at depth the diver’s tissues absorb N2 (or He). If the diver ascends too fast then the excess gas will separate from solution as bubbles. These bubbles can lodge into spaces causing DCS.
Predisposing Factors to DCS (6)
Excessive exercise (vasodilation, /\Hr, and /\RR)
Cold cases vasoconstriction and less off gasing
CO2 tox casuses vasodilation
AGE
Dehydration
Fatigue
~ __% of minor s/s of DCS develop into serious DCS.
30%
DCS Type I
- define
- PMS
- non lethal nor permanently crippling.
- Pain; dull and achy, commonly in joints.
Marbling; cutaneous marbling/cutis marmorata, can be itchy and create a rash.
Swelling of lymph nodes.
DCS Type I tx
Neuro r/o AGE 100% O2 Transport Contact DMO/DMT Lie Pt flat Monitor ABC's and VS Re 'C'
DCS Type II define
Any neuro sx’s after :10 upon RS and/or pain c/in the “Tanktop/UDT” region.
DCS Type II:
- s/s
- tx
- Under - unconscious Water - weakness People - paralysis Need - Nausea Extremely - ears (tinnitus, roaring) Big - blurred vision For - fatigue Partying - paresthesia - Neuro r/o AGE 100% O2 Transport Minimum TT6 contact DMO/DMT Lie Pt down & straighten extremities
Omitted ‘D’ 2 types
Symptomatic
Asymptomatic
6 parts to a Neuro Exam
Mental status Coordination Cranial Nerves Strength Sensory DTR's
Neuro conducted before Re’C’ (4)
- c/ DCS type I
- POIS sx to r/o AGE
- Asymptomatic pt after uncontrolled ascent
- During transit to RCF
Neuro not conducted before Re’C’ (3)
- symptomatic omitted ‘D’
- diver surfaces unconscious
- gross neuro deficit
7 common Re’C’ chamber systems
- Double Lock 200 psig, 425 cuft
- Double Lock 100 psig, 202 cuft
- RCF 6500
- RCF 5000
- SNDLRCS
- TRCS
- FARCC
- EEHS
- specs
- emergency evacuation hyperbaric stretcher
- allows 1 pt to 60’ while in transport. No hands on access to the pt therefore not qualified as a ready or immediate chamber.
Re’C’ chamber usage (6)
- tx DCS
- tx AGE
- SURD02
- HBO2
- dive candidate pressure test
- training
Chamber Readiness Requirements
level 1 - available c/in :05
level 2 - available c/in :60
level 3 - available c/in 6 hrs
Basic Chamber components (7)
- 02 delivery
- med lock
- ventilation
- pressure gauges (IL and OL)
- relief & gag valves
- comms
- piping
Modern Chamber components (6)
- O2/Co2 monitors
- Co2 scrubbers
- BIBS
- O2 dump systems
- ECS (environmental control systems)
- External lighting
Chamber Piping colors:
- buff
- green
- buff/green
- light gray
- light gray/green
- silver
- black
- blue/white
- red/white
- blue
- red
- He
- O2
- HeO2
- N2
- N2O2
- exhaust
- ALP, AHP
- Cold water
- Hot water
- potable water
- fire fighting
Manning requirements:
- optimum
- minimum
- emergency
- 4; dive sup, OT (driver), OT (charts), IT
- 3; dive sup, OT (driver/logs), IT
- 2; dive sup and IT
Safety precautions
- do not use oil on O2 fittings
- keep O2 tanks above 100 psi
- x2 check door dogs to fx properly
- no flammables
- no electricals unless on AMU list
- clothing:
100% cotton or 65/35 poly/cotton, no shoes - beding material must be 100% cotton.
*NEVER use wool or synthetic fibers
How many divers can the SNDL comfortably accommodate?
7; 4 IL and 3 OL
What is the size of the drilled hole in the ear pro?
1/16”
How often should USN RCF be pressure tested? (3)
- @ install or when moved
- after repairs
- @ 2yr intervals
Approved FF tools in an RCF (5)
- wetted towel
- bucket of H2O
- fire extinguisher
- hand held hose system
- sprinkler deluge system
Until a diver is “clean” he cannot ___.
eat or drink (to prevent choking)
in H2O extrication for conscious diver (4)
- assist PRN
- remove dive helmet
- check VS, tx s/s
- be urgent
in H2O extrication of unconscious diver (4)
- maintain airway
- pull pt up on decks
- check ABC’s and VS
- be urgent
in H2O extrication SCUBA conscious diver (5)
- find out the problem
- strip off dive gear
- inflate BC
- assist the pt onto boat
- use LBB and C-collar PRN
in H2O extrication SCUBA unconscious diver (4)
- maintain airway
- check ABC’s and VS
- strip gear
- extract ASAP
Dive sup roles for evacuation (4)
- Dx all s/s, tx and evacuate
- contact DMO
- direct transpo
- determine TT for s/s
Shock s/s (6)
- unusual thirst
- diaphoretic, cool, clammy ski
- N/V
- anxiety
- change in LOC
- ^ RR
Shock Tx
- elevate legs unless: LBB then tilt BB abdominal wound then flex knees chest wound then place in comfort fx leg(s) then splint unconscious then recovery position - loosen clothing
Concern for heat injuries when air temp is
> __F or H2O temp i s> __F
90 F
82 F
Heat cramps:
- s/s
- tx
- muscle cramps perspiration unusual thirst - move to shade loosen clothing slowly drink 1qt of cool H2O
Heat Exhaustion:
- s/s
- tx
- profuse sweating c/ pale, cool skin weakness dizziness/HA N/V mental confusion - move to shade loosen clothing pour H2O on and fan pt slowly drink 1qt of H2O
Heat Stroke:
- s/s
- tx
- AMS seizures H/A LOC Dizziness death weakness N/V Weak rapid pulse/respiration - initiate IV; slow drip cool pt slowly
Chillblains
- painful inflammation of small blood vessels in skin c/ sudden warming from cold temps (50 F and lower).
Immersion Syndrome “trench foot”
- non freezing peripheral cold injury due to prolonged or repetitive exposure to damp cold temps.
Frostbite:
- superficial s/s
- deep s/s
- skin freezes (usually fingers, toes, noes, ears, cheeks and chin).
red blanched, tingling, blisters - frozen, waxy solid, blisters,
Frostbite tx
- move to shelter loosen clothes remove jewelry rapid H2O warming (100-104 F) passive rewarming
Splinting reasons (2)
- prevents motion of bone fragments, bone ends, or angulated joints.
minimizes damage to muscles, nerves, and vessels.
Hazards of improper splinting (4)
- compression of nerves, tissue, and vessels
- delay in transport of life threat injuries
- too tight
- aggravating the injury
3 types of type II DCS
- Neurological
cardiopulmonary (chokes)
inner ear (staggers)
DCS type II and AGE s/s
Under - unconscious Water - weakness People - paralysis Need - N/V Extremely - ears (tinnitus, roaring) Big - blurred vision For - fatigue Partying - parasthesia
Hypercapnia s/s
I - ^ HR & RR
C - confusion H - H/A I - inability to concetrate L - LOC D - drowsiness
N2 Narcosis s/s
C - confusion L - lack of concern for safety A - apparent stupidity S - sense of well being I - impaired judgement
CO tox s/s
Tiny - tightness across the forehead Headhunters - H/A Practice - pounding temples Ninja - nausea Chicken - confusion Voodoo - vomitting
CNS O2 Tox s/s
V - vision blurred, tunneled, or impaired E - ears (tinnitus, roaring) N - nausea T - twitching (usually facial muscles) T - tingling (usually distal digits) I - irritable D - dizziness
C - convulsion (can be first sx)
Pulmonary O2 Tox s/s
C - coughing
B - burning
S - SOB
Barotrauma accronym
G - gas filled space R - rigid walls A - ambient pressure change V - vascular penetration E - enclosed space
Hypoxia s/s
C - cyanosis I - ^ Hr & BP L - lack of concetration L - lack of muscle control I - inability to perform difficult tasks
W - weakness
L - LOC
D - drowsiness
DCS Type I s/s
P - px (tank top and UDT shorts)
M - marbling/cutis marmorata
S - Swelling of lymph nodes
Trace elements:
2H’s 2 N’s MAXK
Hydrogen
Helium
Nitrous oxide
Neon
Methane
Argon
Xenon
Krypton
O2 flow:
- NC
- NRB
- Simple Face
- 4-6 lpm
- 12-15 lpm
- 12-15 lpm
