Transfer - transfer course

Question 1

Effect of acceleration in an ambulance

Assuming patient supine, head towards direction of travel

Answer 1

60% circulatory volume is contained within venous (capacitance) system.

Acceleration -> blood moves towards feet, decreasing venous return and cardiac output
-> loss of peripheral vision, loss of vision with consciousness maintained (black-out), complete loss of consciousness.
-> risk of seizures on return of blood supply to brain when acceleration stops

Question 2

Effect of deceleration in an ambulance

Assuming patient supine, head towards direction of travel

Answer 2

Venous blood moves towards head-> (Note compensatory baroreceptor and vasoconstrictor reflexes are often obtunded or absent in the critically ill due to illness or drug therapy)

**Cardiovascular instability: **
Bradycardia (reflex)
Hypotension or hypertension depending on fluid status and cardiac function
Cardiac dysrhythmias
Pulmonary oedema
Cardiac arrest

Increase in ICP, seizures
Gastric contents spilling upwards into oropharynx -> aspiration pneumonia

Question 3

Positioning of patient for transfer

Answer 3

Avoid rapid deceleration if possible
Neuroprotective strategies: 30 degree head up, avoid tight ETT ties
Blocks and tape commonly used to achieve secure immobilisation of head

Question 4

Oxygen requirement for transfer in mechanically ventilated patients

Answer 4

Oxygen requirement = oxygen consumption * journey time * safety margin

Oxygen consumption = (MV * FiO2) + vent driving requirement
Vent driving requirement is usually 1L/min O2 for portable ventilators

Journey time = driving time + 30 mins (15 mins for transfers to/from ambulance either end)
Safety margin = 2

Question 5

Oxygen requirement for transfer in spontaneously ventilating patients

Answer 5

Oxygen requirement = oxygen consumption * journey time * safety margin

Oxygen consumption = L/min from wall oxygen flow metre
Journey time = driving time + 30 mins (15 mins for transfers to/from ambulance either end)
Safety margin = 2

Question 6

CD oxygen cylinder

Answer 6

Used for portable oxygen
460L

Question 7

C oxygen cylinder

Answer 7

170L
Portable oxygen

Question 8

ZD oxygen cylinder

Answer 8

Portable - standard in LAS (looks identical to CD)
605L

Question 9

E oxygen cylinder

Answer 9

Used in anaesthetic machines
680L

Question 10

F oxygen cylinder

Answer 10

Used in A+E. Ambulances usually have 2x
1360L