Barotrauma

Question 1

what is the % breakdown of air?

Answer 1

21% oxygen
79% nitrogen (and others) - nitrogen is inert

Question 2

What is Dalton’s law?

Answer 2

The pressure of a gas mixture is equal to the sum of the partial pressures of its component gases

Question 3

What is the equation for Dalton’s law?

Answer 3

Ptotal = PO2 +PN2 + PX

Ptotal - total pressure
PO2 - partial pressure of oxygen
PN2 - PArtial pressure of nitrogen
Px - partial pressure of remaining gases

Question 4

Define Boyles Law

Answer 4

• at a constant temperature, the volume of a given mass of gas is inversely proportional to its pressure

Question 5

What is an example of a complication that arises when we interfere with Daltons Law?

Answer 5

Hypoxia

Question 6

What is an example of a complication that can arise that is directly tied to Boyles Law?

Answer 6

• pneumothorax
• air embolism

Question 7

Define Henrys Law

Answer 7

The quantity of gas dissolved in a liquid is proportional to the partial pressure of the gas in contact with liquid

Question 8

What is the patho of Henrys law

Answer 8

decrease in atmospheric pressure, decreased pressure at alveolar level therefore less oxygen dissolving in blood

Question 9

What are signs and symptoms of barotrauma of descent (aka the squeeze)

Answer 9

• pain (in small caviites)
• bleeding from nose or ears
• sensation of fullness
• HA disorientation
• tinnitus

Question 10

What are some causes of pulmonary barotrauma

Answer 10

• breath holding during ascent or ascending too quickly

Question 11

What does POPS stand for?

Answer 11

Pulmonary Over-Pressurization Syndrome.

Question 12

What are some symptoms of POPS

Answer 12

• pneumothorax
• subcutaneous emphysema
• alveolar rupture
• air embolism

Question 13

What is general prehospital care for barotrauma of ascent?

Answer 13

administer high flow O2
possible needle decompression or hyperbaric chamber

Question 14

What is the patho of an air embolism

Answer 14

1. Expanding air disrupts tissues
2. Air forced into circulatory system
3. Air passes through left side of heart
4. enters systemic circulation which may
   - block cerebral, coronary and other small arterioles
   - block distal circulation

Question 15

Signs and symptoms of an air embolism

Answer 15

• blood tinged sputum
• paralysis or sensory change
• aphasia
• confusion
• blindness
• seizures
• LOC

Question 16

Prehospital care ofr air embolism

Answer 16

• ABCs - high flow O2
• transport left lateral position
• consideration for ACP
• air transport in pressurized cabin or low altitude
• hyperbaric chamner

Question 17

Define Decompression Sickness

Answer 17

Nitrogen in compressed air converts from solution to gas, which forms bubbles in tissues and blood

Question 18

Signs and Symptoms of decompression sickness

Answer 18

MSK
- joint pain (shoulders, elbows, knees)
- crepitus
Cutaneous
- itch, rash
Neurologic
weakness, fatigue, vertigo, paresthesia, seizures, LOC
Pulmonary
- Dyspnea

Question 19

Prehospital Care for decompression sickness

Answer 19

• support vital function
• high concentration O2
• fluid resuscitation
• rapid transport to hyperbaric chamber if local bypass exists

Question 20

Define Nitrogen Narcosis

Answer 20

Occurs when divers remain at depth for a prolonged period breathing compressed gas (too much nitrogen dissolved in blood)

Question 21

Signs and Symptoms of Nitrogen Narcosis

Answer 21

• altered LOC
• impaired judgement
• slowed motor response
• euphoria
• potential memory loss
• severe cases can lead to hallucinations, coma or death

Question 22

Treatment for Nitrogen narcosis

Answer 22

• early identification
• supportive care
• usually symptoms will reverse upon ascent
• transport

Question 23

Define Acute Mountain Sickness

Answer 23

• happens above 8000 ft above sea level
• reduced atmospheric pressure
• hypobaric hypoxia
• associated with rapid ascent of unacclimatized person to high altitudes

Question 24

Symptoms of Acute Mountain Sickness

Answer 24

• onset 4-6 hours after reaching altitude
• maximally symptoms within 24-48 hours
• subsides on 3rd or 4th day
• HA, tiredness, nausea, dizziness, SOB, ataxia, altered LOC

Question 25

Prehospital treatment for Acute Mountain Sickness

Answer 25

- O2 therapy - descent

Question 26

What is the patho of a hgih altitude pulmonary edema? (HAPE)

Answer 26

- Pulmonary hypertension develops in response to hypoxia - Increased SNS response and vasoconstriction - increased capillary stress resulting in increased vessel permeability - leakage of fluid into extravascular spaces - occurs 24-72 hours after reaching high altitudes

Question 27

Symptoms of high Altitude Pulmonary Edema

Answer 27

- SOB on exertion or at rest - Crackles - cough (may have blood tinged sputum) - lethargic, weak

Question 28

Emergency care for High altitude pulmonary edema

Answer 28

- oxygen/respiratory support - descent

Question 29

Define High Altitude Cerebral Edema (HACE)

Answer 29

- severe acute high-altitude illness - related to increased intracranial pressure from cerebral edema (HA, ataxia, disorientation, n/v, lethargy, decreased LOC

Question 30

How do you differentiate between High Altitude Cerebral Edema and Acute Mountain Sickness

Answer 30

- mild AMS to unconcious with HACE can occur within 12 hours - urgent management is needed to prevent coma or death