Aeromedivac

Question 1

Clinical Considerations for Air medical transport

Answer 1

1) Temperature fluctuations
2) Dehydration
3) Noise
4) Vibration
5) Risk of ascent injuries: conversion of simple pneumothorax into tension, rupture of hollow viscus due to expansion of intestinal gas
6) Alterations in IV flow rates, pressure in air splits/ETT cuffs

Question 2

Types of Air Medical missions

Answer 2

1) Primary responses: aircraft serves as the sole means of patient transport to a receiving facility
2) Secondary responses: aircraft transports patients from outlying hospitals to facilities offering higher levels of care

Question 3

Boyle’s Law

Answer 3

Volume of a unit of gas is inversely proportional to the pressure on it
-as altitude increases (& atmospheric pressure ↓) the volume of the gas expands
PV= k; V α 1/P
where: P denotes the pressure of the system
V is the volume of the gas, k is a constant value representative of the pressure and volume of the system.

Question 4

Squeeze injuries (barotitis/barosinusitis)

Answer 4

-Occur on descent due to contraction of air trapped within the sinus/middle ear cavities, which cannot be equalized with ambient pressure, resulting mucosal and neurovascular tissue being pulled inward

Question 5

Reverse squeeze

Answer 5

-Injuries occur on ascent due to ↑ air volume in trapped spaces with ↓ in barometric pressure causing the exertion of pressure on adjacent bony, neurovascular, or parencymal structures

Question 6

Charles’ Law

Answer 6

-As the temperature ↑ the volume of a gas ↑ V1= V2; V α T T1T2

Question 7

Dalton’s Law

Answer 7

-Total barometric pressure at any given altitude equals the sum of partial pressures of gases in the mixture Pt= P1+ P2+ P3+. . .+ Pn

Question 8

Clinical aspect of Dalton’s Law

Answer 8

-Manifested as a ↓ in partial arterial oxygen tension with ↑ altitude (O2 still constitutes 21% of atmospheric pressure but since ↑ altitude= ↓ pressure each breath brings fewer O2 molecules to the lungs

Question 9

Henry’s Law

Answer 9

• Mass of gas absorbed by a liquid is directly proportional to the partial pressure of the gas above the liquid
• sudden decompression at high altitude may result in dysbarism

Question 10

Transport by Helicopters (Rotor-Wing Aircraft)

Answer 10

-Generally 1000-3500 ft above ground

Question 11

5 Advantages of Helos:

Answer 11

1) Travel “as the crow flies” reducing travel times by 75% vs ground transport
2) Large service area
3) Can access locations that may be inaccessible to other modes of travel
4) Avoids traffic delays and ground obstacles
5) Does not require an airport to land

Question 12

5 Disadvantages of Helos:

Answer 12

1) Noise
2) Turbulence (interference with pt evaluation/monitoring/mgmt)
3) Weather may limit availability (pilots should be blinded to the nature of the call during mission planning)
4) Cramped patient compartments (may compromise optimal care)
5) Weight limitations

Question 13

List 5 Safety Precautions/Rules for Rotor-wing transport

Answer 13

1) Aircraft should always be approached from the front where the pilot can see approaching personnel
2) When rotors are turning, non-flight team personnel should approach the aircraft only with escort from a flight team member
3) Never approach from the rear as the tail rotor is virtually invisible
4) Landing zone should be at least 100 x 100ft
5) Ground personnel should be well clear during landings/takeoffs

Question 14

5 Advantages of Fixed Wing:

Answer 14

1) Increased range abilities
2) Greater speed than rotor-wing/ground transport
3) Increased capacity for patient/crew/equipment compared to rotor-wing
4) Less cabin noise and turbulence than rotor-wing
5) Pressurization of cabin can combat the impact of physiologic gas laws

Question 15

4 Disadvantages of Fixed Wing:

Answer 15

1) Requires an airport to land
2) Runway must be of appropriate length or condition
3) Requires refueling facilities
4) Transports require multiple vehicles (also requires ground transport from airport to hospital)

Question 16

Role of the Air Medical Director

Answer 16

1) Supervising air medical services (final authority over all clinical aspects): off-line and on-line
2) Ensuring all personnel have adequate training and qualifications
3) Ensure appropriate equipment/supplies are available
4) Ensure the correct vehicle selected or transports
5) Evaluating air medical transport teams
6) Quality assurance

Question 17

List Criteria for Air Medical Transport

Answer 17

1) Distance to the closest appropriate facility is too great for safe and timely transport by ground ambulance
2) Patient’s clinical condition requires that the time spent in transport be as short as possible
3) Pt’s condition is time critical, requiring specific or timely treatment not available at the referring hospital
4) Potential for transport delay associated with ground transport is likely to worsen the patient’s clinical condition
5) Patient requires critical care life support during transport that was not available from the local ground ambulance service
6) Patient is located in an area inaccessible to regular ground traffic, impending ambulance egress or access
7) Local ground units are not available for long-distance transport
8) Use of local ground transport services would leave the local area with out adequate EMS coverage