Chapter 3 US Navy Dive Manual, Rev 6

.16 ata's

.10

ABBCCIIP
1. Accumulation of fluids in lungs (Pulmonary Edema), (Chokes)
2. Blockage of Air Passageways from vomit, water, foreign objects.
3. Breathholding
4. CO poisoning
5. Collapse of lung due to Pneumothorax
6. Improper gas line up.
7. Inadequate purging of breathing bags in semi & closed circuit UBA's.
8. Paralysis of respiratory muscles from spinal cord injury.

WILLL DEAL P/H/C
1. Weakness
2. Inability to perform delicate tasks
3. Lack of Concentration
4. Lack of muscle control
5. Drowsniness
6. Euphoria
7. Agitation
8. Loss of consciousness
--Pulse and Heart rate increase
--Cyanosis (Blueness of lips and nail beds)

1. Excess of CO2 levels in compressed gases.
2. Inadequate ventilation
3. Failure of CO2 Absorbent
4. Inadequate lung ventilation i.e. skip breathing, excess dead space, breathing resistance or increased O2 pp / cold water

SIC LIED HIC B/P
1. Increased breathing rate / pulse
2. Confusion
3. Loss of consciousness
4. Inability to concentrate
5. Euphoria
6. Drowsniness
7. Headache
8. Increased Sweating
9. Headache
10. Convulsions

1. Maintain proper manifold pressure
2. Ensure absorbent is filled properly and adhering to canister limits
3. Slow work rate / Ventilate
4. Dives deeper than 150' should consider HEO2 to reduce breathing resistance.

When breathing stops and hypoxia and hypercapnia occur simultaneously

Airway obstruction
Injury to windpipe
Water inhalation
Vomit
Swallowing tongue
Spinal Cord DCS / Resp muscles paralysis

Compressor intake to close to exhaust contaminating breathing gas.
- Malfunction of compressor seals / blowing by.

Blocks hemoglobins ability to deliver 02 to cells causing cellular hypoxia and poisons cellular metabolism

210 times that of 02

Upon ascent / when the pp02 is reduced but CO takes much longer to disassociate from the red blood cells

2000 ppm / .2% / or .002 ata

1. Headache
2. Dizziness
3. Confusion
4. Vomiting / Nausea
5. Tightness across forehead
6. Pounding of temples
7. Taste of Air
8. Neurological sx
9. Mental status changes
10. rapid heart rate
11. unconsciousness
12. Death

100% 02 on surface.
- Treatment Table - 5 for mild SX
- TT-6 for severe SX

-Severe Headache
-Nuerological SX
-Mental Status changes
-Rapid heart rate

TT-6

VENTID-C
Visual - Tunnel, decrease in peripheral, blurred
Ear - Tinnitus-bells ringing, roaring, machinery like pulsing sound
Nausea - Spasmodic vomiting
Tingling - twitching of face, lips, extremities (most frequent)
Irritability - mental status change, confusion, agitation, anxiety
Dizziness - clumsiness, incoordination, unusual fatigue
Convulsions - could be 1st sign.

Tonic - Tensing / rigidity of all muscles at once.
Clonic - Violent thrashing/jerking upto :01 min or so.
Postconclusive - postictal depression - usually unconscious, then semi-conscious and restless from :15 to 1:00 hr

Fatigue
Muscle soreness
Headache

Brain SX - blindness, dizziness, paralysis, unconsciousness, convusion

Spinal SX - paralysis, decreased sensation

Inner Ear SX - Hearing loss, vertigo, loss of balance

Pulmonary (Chokes) SX - Pain in chest, coughing, shortness of breath, bloody sputum

Pain in extremities
Itching - Intense
Marbling (Cutis Mamorata)
Skin rash
Swelling and Pain in lymph nodes

Joint Pain
- deep dull ache, always present at rest, usually unaffected by movement, confined to particular area
starts gradually , difficult to to localize

98 - Cold sensations, increased 02 consumption
97 - Shivering - uncontrollable
95 - Mental confusion (could drown)
93 - Loss of Memory
91 - Hallucinations
90 - Heart Rythym irregularities
88 - Shivering Stopped, cannot recognize people
86 - Muscles Rigid
84 - Loss of Consciousness
80 - Ineffective Heartbeat
79 - Death
93 -

90 and below

Abnormal heart rythym following Bradycardia ( slow heart rate) - Caused by sudden exposure to cold water

Loosing face mask or changing out of rigs

Cold water plunge causing immediate and disabling effects of gasps / increase in respiratory rate. Diver cannot control breathing.

Dizziness
Tingling of extremities
Spasms of small muscles (hands , feet)
Blurring of vision
Headache
Weakness

Relax and Slow breathing rate Re-warm,

-High breathing rate
- Hot / uncomfortable
- Low urine output
- Confusion
- Fatigue
- Nausea
- Muscle cramps
- Increased pulse rate(sudden)
- Exhaustion
- Tremors / Seizures
- Collapse / Death

Pain experienced upon descent in shoulders, knees, wrists, hips, lower back, neck and ribs.
- Constant deep ache or sudden sharp
- Feels like popping/cracking or gritty feeling in joint

- Persistent Vertigo
- Hearing loss
- Nausea
- Vomiting
- Incoordination
- Nystagmus
- Bubbling sensation in ear

-Forceful Valsalva on descent
- Damage may not be noticed until after dive ( possibly noticed during lifting heavy weight or bowel movement)

ENT asap - Bed rest & elevation / exploratory surgery
Consult DMO for returning to diving.

Paralysis of facial muscles caused by overpressurization of middle ear.

On ascent w/ :10 to :30 of overpressure needed to occur.

Relief should return 5-10 min after pressure is relieved.

Excessive Breathing resistance.

- Flow Resistance & Static Lung Load

- Sensation of shortness of breath and labored breathing WITHOUT increase in CO2 level.

- Caused by excessive breathing resistance
(Activation of pressure and stretch receptors in airways, lungs, and chest wall)

Fluid induced asphyxia

SX
- Unconsciousness,
- Pulmonary Edema
- Increased respiratory rate

TX: ABC's, Rescue breaths, 100% 02 / Evacuate to nearest hospital
---If regains consciousness, and has no neurological sx then get diver to DMO or medical evaluate for Pulmonary Aspiration.
- Pnuemonia is classic result of Near Drowning.

Unconsciousness upon ascent (shallow water blackout)
CO2 normal while pp02 drops too low to maintain consciousness.

Breathing more than necessary to keep CO2 levels down / Diver is unaware of overbreathing. Causes Hypocapnia

-Fear
-Increased dead space
-static lung load
-excessive breathing resistance
-cold water

- Dizziness
- Tingling of extremities
- Weakness
- Headaches
- Numbness
- Faintness
- Blurring of vision

TX: Relax / Slow breathing rate

Acute episode of hypercapnia
Shortness of breath

Lead to inhaling small amounts of water causing spasms of muscles in larynx "Laryngospasm" followed by asphyxia and possible drowning.

GRAVE
- Gas filled spaces
- Ambient pressure changes
- Rigid walls
- Vascular penetration
- Enclosed space

Damage to body tissue from the mechanical effects of pressure.

Middle Ear Squeeze

-Pain - hallmark!
-Brief & violent vertigo
-Nausea & vomiting
On Surface:
Pain, Fullness in ear, hearing loss, mild vertigo, bloody nose.

Decongestants - Medical
Nothing goes into ears unless cleared by ENT.

1. Frontal - above eyes
2. Orbital - behind eyes
3. Ethmoidal - between eyes/bridge of nose & outside of eyes
4. Sphenoid - outside of cheeks
5. Maxillary - above the jaw around the back teeth

- Infected external ear (External Otitis)
- Ear plugs
- Wax impacted ear canal
- Tight fitting wetsuit

- Breathholding at deep depths
- Hose rupture with failure of non-return valve

Cochlea - Hearing sense
Vestibular Apparatus - Balance

Malleus - Connected to ear drum.
Incus - connected to Malleus
Stapes - connected to Incus and transmits sounds through oval window to the inner ear.

Narrow passage between inner ear and fluids surrounding the brain.

Hearing Loss or Vertigo
-72 hours

If in doubt-Recompress and treat.
- Keep head up
- Compress slowly if possible
- Gentle clearing / valsalva
- No +/- pressure when on BIBs

Blockage of the Infraorbital Nerve causing:
- Numbness in lower eyelid, upper lip, side of nose and cheek (on the affected side)

AGE
Pnuemothorax
Mediastinal Emphysema
Subcutaneous Emphysema

Gas trapped in lungs that cannot escape.
- Breathholding
- Excessive positive pressure
- Purging while taking breath
- FAST ascent

rupture of alveolus w/ air in lung tissue / causes no symptoms, but is beginning of other POIS.

Obstruction of blood flow caused by gas bubble/s entering the arterial circulation
- Brain and heart most vulnerable.

18 SX
- Unconsciousness, Paralysis, Numbness, Weakness, Extreme Fatigue, Parathesias, Confusion, Vertigo, Convulsions, Vision obstruction, Nausea & Vomiting, Hearing abnormalities, +Blow to chest,
Bloody sputum, Dizziness, Personality changes, Loss of bodily functions, Tremors, Death

ABC's, 100% O2 on surface, Immediate Recompression to 60' - TT-6 minimum

- Training in physics and physiology
- Correct use of equipment
- Never interrupt breathing during ascent
- Exhale continuously on emergency ascent
- Healthy divers , don't dive when sick

Gas forced through torn lung tissue into loose mediastinal tissues in middle of chest

Mild to moderate pain under breastbone
- Dull ache
- Feeling of tightness
may radiate to back or shoulder and increase upon deep inspiration, coughing, swallowing

Mediastinal that has moved up to neck area.
- Fullness around neck
- Difficulty swallowing
- Voice change
- Crepitation (rice crispies)
- Deviated trachea

Air trapped in pleural space between lung and chest wall

- Sudden sharp pain
- Shortness of breath
- Labored breathing
- Rapid heart rate
- Weak pulse
- Anxiety
Reduced chest movements on affected side and No breath sounds w/ stethescope

Pneumothorax which enlarges with each breath because gases cannot escape. Leads to Shock and Heart failure and death if not treated.

Neuro to rule out AGE
100% O2 on Surface
Get to Medical for X-rays and follow up.
Severe - Shallow recompression upon recommendation of DMO and pneumothorax has been ruled out.
100% O2, 5-10fsw for 1 hour, ascent 1fpm which is included in bottom time.

Nuero to rule out AGE
100% O2 on surface
Get to medical for X-ray

-If recompression is necessary due to AGE or DCS then prepare for tension pneumothorax upon ascent.
Have I/V catheter, chest tube with trained personnel

Narcotic effects of N2 when at depth.
- 4 ata's or 99ft begin to feel
- 130' prominent
- 200' Disabling

LALA IT
- Loss of judgement
- A false sense of well being
- Lack of concern of job safety This is the Greatest Hazard
- Inappropriate laughter
- Tingling and Numbness of lips, gums and legs.

150 ft
N2 narcosis

.5 ppO2/ata or 50% equivalent

12 hours

4 hours

TT-4, 7 & 8 or 6A w/ extensions.

Burning sensation followed by Pain on inspiration

Water - 1.3 ppO2 ata
Chamber - 2.4 ppO2 ata

- Individual Suseptibility
- CO2 retention
- Exercise/Work
- Immersion in water
-Depth / ppO2
* Intermittent exposure or interuptions will reduce risk and extend total allowable exposure.

1 to 2 minutes

2 to 3 minutes

AGE

- Observing depth time limits
- Avoiding overexhertion
- UBA is in good working order
- Taking Air breaks when required
- ensuring dead space is reduced and there is no CO2 buildup

1 liter at 1 ata or sea level

The amount of gas that will dissolve in a liquid at a given temperature is directly proportional to the partial pressure of the gas.

False.
Saturation time will be the same regardless of depth because shallower depths require more time due to less pressure (of gas) is being delivered to the tissues during each circulation cycle.

If tissue inert gas pressure never exceeds the ambient pressure by more than the "critical amount"

The critical amount.
Varies from tissue to tissue and one inert gas to another.

Bubbles forming in tissues due to a pressure difference in the inert gas and surrounding ambient pressure.

Nerve endings blocked
Stretching and tearing of tissues.
Stopping or slowing of blood flow.
Emboli in veneous or arterial circulation

Short period of time:
Recompress quickly to restore blood flow and improve gas exchange.

Body's defense mechanism to alert body of foreign body "emboli"

- Blood plasmas leak out which makes blood thick.
- Platelet system becomes active causing clotting.
- Fats released - creating more emboli
- Histamine release - causing allergic type SX's of shock and respiratory distress.

- The blood- through circulation picks up excess heat and carries to lungs.

-Transfer to surface of skin through combo of conduction, convection, and radiation

91 degrees

72 degrees

Fall more rapidly
Because movement stirs the water and heat in contact w/ the skin is carried off faster due to convection and
Increase blood flow to limbs which removes heat from the body core.

Mild - Passive and Active
Remove all wet clothing, wrap in blanket and place in protected warm area. Warm shower.

Passive only - Remove clothing, wrap in blanket and place in protected area
-Transport to nearest medical facility.

Caloric Vertigo - cold water in external ear canal
- Diving Reflex - Immediate slowing of heart (bradycardia)
- Uncontrolled Hyperventilation

Mild- remove clothing, spray w/ cool water and fanning.
Ice packs to neck armpit and groin
Oral fluid replacement

Same as mild but
Transport to Medical
Start I/V during transport

Whole body immersion in cold water or packing body in ice.
- Causes vasoconstriction which decreases skin blood flow and slows the loss of heat

Air - 90 degrees
Water - 82 degrees

Antihistimines
Aspirin

-5 consecutive days of warm water diving (work up dives).
- Exercise
* Benefits begin to disappear in 3 to 5 days after last exposure.

Nausea, Fine Tremors, Imbalance, Incoordination, Loss of dexterity, Altertness, Abdominal Cramps, Diarrhea, Vertigo, Confusion

400-500 fsw
1000 fsw

Slow compression rate - no SX may be achieved upto 1000 fsw

100fsw w/ rapid compression

Usually will appear 200-300 fsw and increase as you get deeper.
- Past 600fsw will occur even with slow compression

upset in balance of Electrolytes (sodium, potassium, and chloride)

Dehydration caused by immersion in water which causes blood to pool in trunk/chest area and causes diver to urinate more often.

Upon leaving the water when blood flow returns to legs signifigantly reducing "central blood volume" in trunk area.

Lightheadedness or faintness while getting out of water. Fatigue and less alert

Hydrate ASAP

Fluid that leaks into circulatory system into aveoli caused by "increased blood volume" while immersed in water.

- Immersion in Cold Water
- Negative pressure breathing
- Overhydration
- Heavy Exercise

Coughing, Shortness of Breath, blood tinged mucus

Chest pain is noticibly Abscent.

On the bottom, during ascent or shortly after surfacing.

100% O2 on surface, Get to hospital ASAP

Excessive pressure on the carotid artery in the neck caused by tight fitting wetsuit or neckdam

Decrease in heart rate w/ possible loss of consciousness

Negative pressure built up in the middle ear following long O2 dives.

Mild discomfort
- Hearing loss
- Pressure in ear feeling
- moist cracking sensation

Valsalva, Swallowing Yawning .
If persistent, see DMO/DMT

500 psi
Lungs and Intestinal Tract

50 psi
* Better to get diver out of water no matter what the pressure would be.

"Swimmers Ear" Infection of ear canal caused by repeated immersion.

Itching, wet feeling, local pain, swelling of lymph nodes, painful jaw movement.

Stop diving
External Ear prophylaxis (Dombory Solution) (morning, evening and after every dive) :05 min each side
- Get ear wax cleaned out.

Abnormal low blood sugar level
- Missing meals or underlying medical condition/s

Unusual hunger, Excessive sweating, numbness, chills, headache, trembling, dizziness, confusion, anxiety, loss of consciousness

Give sugar by mouth or I/V to an unconscious diver

Brain and spinal cord

Nerves originating in brain and spinal cord.
Crainial Nerves, Spinal Nerves and Sympathetic Nervous System

Low O2 blood enters:
- Superior Vena Cava
- Inferior Vena Cava

Pumped to: Left & Right Pulmonary Artery
Through the lungs and back through Right and Left Pulmonary Vein then enters
Left Atrium - Left Ventrical and to Aorta

5 liters

Ventilation & pulmonary gas exchange

1. Ventilation-fresh air
2. Exchange of gases between blood and air in lungs
3. Transport of gas by blood
4. Exchange of gases between blood and tissues
5. Exchange of gases between tissue fluids and cells
6. use and production of gas by cells

Nose, Nasal Cavity, Frontal Sinus, Maxilary Sinus, Larynx, Trachea

-Carries air, filters, moistens, warms during inhalation

Left & Right Bronchi - Bronchioles - alveolar ducts- alveolar sacs - alveoli

850 sqft

One complete breath inspiration, expiration and pause.

# of cycles per minute / normally 12-16 pm

Total volume of air lungs can hold / Normally 5-6 liters

Volume that can be exhaled after a full inspiration

Volume moved in or out during single respiratory cycle
1/2 liter at rest
3 liters at heavy work

Total air moved in :01 minute.
6-10 liters p/m
100 liters p/m at heavy work

Maximum Inspiratory Flow Rate & Max Expiratory Flow Rate

Ratio of CO2 produced to amount of O2 consumed

.7-1.0
.9 used for calculations.
Closed circuit operations and canister duration versus O2 supply.

Central and Peripheral - Activates breathing control

- Carotid Artery-on neck Activated by CO2
- Aorta - near heart / Activated by CO2 and O2