Non-terrestrial Basic Life Support Simon N Evetts PhD

Thais Russomano MD PhD

John Ernsting MBBS PhD

Subhajit Sarkar MRCS

Lisa Evetts RGN

João Castro MD

Microgravity Laboratory, PUCRS, Porto Alegre, Brazil.

Human Physiology and Aerospace Medicine Group, King’s College London.

CPR in MicrogravitySimon N Evetts PhD

Non-terrestrial Basic Life SupportSimon N Evetts PhD

Introduction Non-terrestrial as opposed to microgravity.


Basic Life Support;


Basic Life Support;

– Cardiopulmonary Resuscitation without equipment

or other resources.


Basic Life Support;


or other resources.

Single rescuer, not multiple care-giver.


Basic Life Support;


or other resources.

Single rescuer, not multiple care-giver.

Emphasis on chest compression, mouth-to-

mouth ventilation secondary consideration.

The Space Environment Space exploration is inherently dangerous.

Significant Space Related Medical Occurrences

Year Mission Nation Event

1967 Soyuz 1 USSR Spacecraft crashed – 1 death

1967 Apollo 1 US Command module fire – 3 deaths

1969 Apollo 11 US Type 1 decompression sickness

1970 Apollo 13 US Urinary tract infection

1971 Soyuz 11 USSR Depressurization – 3 deaths

1971 Apollo 15 US Arrhythmia during lunar EVA

1975 Apollo 18 US Nitrogen tetroxide pneumonitis

1985 Salyut 7 USSR Prostatis and sepsis

1985 Salyut 7 USSR Hypothermia

1986 Challenger US Spacecraft exploded - 7 deaths

1987 Mir Russia Arrhythmia requiring evacuation

1997 Mir Russia Depressurization after collision

1997 Mir Russia Toxic atmosphere after fire

2003 Columbia US Spacecraft disintegrated – 7 deaths

Pulseless victim The Space Medicine Configuration Control Board of NASA

has approved a list of 442 medical conditions (the Patient

Condition Database) that appear possible during long

duration spaceflight on the ISS.





Of these conditions 106 (24 %) are classified as “critical”

requiring use of critical care procedures.







…including cardiac conditions (e.g. myocardial infarction,

ventricular fibrillation, ventricular tachycardia, and asystole),







…including cardiac conditions (e.g. myocardial infarction,

ventricular fibrillation, ventricular tachycardia, and asystole),

…and respiratory conditions (e.g. acute airway obstruction,

laryngeal oedema from anaphylaxis and inhalation injuries).

Pulseless victim It has been estimated that the risk to an ISS crew member of

developing a serious medical condition requiring medical

evacuation is 6% per year*,

* Johnston, S. L., Marshburn, T. H., and Lindgren, K., 2000. Predicted Incidence of Evacuation-Level Illness/Injury During Space Station Operation. 71st Annual Scientific Meeting of the Aerospace Medical Association, Houston, Texas. May 2000.




… and 1% per year risk of a life-threatening condition*.





… and 1% per year risk of a life-threatening condition*.

A figure of 0.15%/yr of CAD related event occurring in 35-

45 yr old flight personnel has been cited**.


** Ball, C.G., Hamilton, D.R. and Kirkpatrick, A. 2004. Primary prevention approach to mitigating cardiac risk in astronauts. 75th Annual Scientific Meeting of the Aerospace Medical Association, Houston, Anchorage. May 2004.

Pulseless victim As has the figure of 0.06 persons/year with regards to the risk

of a healthy astronaut receiving a significant injury or

developing a significant medical condition in space*.

* Mukai, C. and Charles, J. B. 2004. Psychological and medical challenges for Mars crew composition as considered against similar challenges faced by the Lewis and Clark Expedition. 75th Annual Scientific Meeting of the Aerospace Medical Association, Houston, Anchorage. May 2004.

Pulseless victim As has the figure of 0.06 persons/year with regards to the risk

of a healthy astronaut receiving a significant injury or

developing a significant medical condition in space*.

The potential for a serious medical incident resulting in a

pulseless apneic state requiring intervention, therefore is real.

* Mukai, C. and Charles, J. B. 2004. Psychological and medical challenges for Mars crew composition as considered against similar challenges faced by the Lewis and Clark Expedition. 75th Annual Scientific Meeting of the Aerospace Medical Association, Houston, Anchorage. May 2004.

Recent and current CPR guidelines (+1Gz)

European Resuscitation Council 1998:– Mouth-to-mouth ventilation requiring tidal volumes of

400 – 600 ml.

– Chest compression depth of 40 – 50 mm.

– Chest compression rate of ~ 100 compressions.min-1.

Recent and current CPR guidelines (+1Gz)

European Resuscitation Council 1998:– Mouth-to-mouth ventilation requiring tidal volumes of

400 – 600 ml.


– Chest compression rate of ~ 100 compressions.min-1.

European Resuscitation Council 2001:– Tidal volumes of 700 – 1000 ml.


– Chest compression rate in excess of 100 min-1.

+1Gz - Earth

Earth Gravity (9.8 ms-2)

7.0

6.1

4.1

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9 10 11

Compression depth (cm)

Fo

rce

(N)

Minimum required depth (3.8 cm)

Mean β +1 s.d.,

γ +1 s.d.

β +2 s.d.,

γ +2 s.d.β -1 s.d.,

γ -1 s.d.

β -2 s.d.,

γ -2 s.d.

93 kg person

76 kg person

Chest Compression Depth According to Rescuer Body Weight

Min required depth

Big patient/low compliance chest

Small patient/high compliance chest

41 kg person

For

ce (

N)

Compression Depth (cm)

Average compliance chest

Earth Gravity

9.8 m.s-1

+0.16 Gz - The Moon

Lunar Gravity (1.62 ms-2)

1.0

2.01.7

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9 10 11


Fo

rce (

N)

β +1 s.d., γ +1 s.d.

β +2 s.d., γ +2 s.d.

β -1 s.d., γ -1 s.d.

β -2 s.d., γ -2 s.d.

Mean

Minimum required depth (3.8 cm) 93 kg

76 kg41 kg

Lunar Gravity


For

ce (

N)




+0.38 Gz - Mars

+0.38 Gz - MarsSpaceman Spiff wrestles with his Galactic Mk 3 Mars Lander, but

what with muscle wastage, deconditioning and Martian death rays, the landing wasn’t looking

too good!!

+0.38 Gz - Mars

Mars Gravity (3.71 ms-2)

3.73.2

2.0

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9 10 11


Fo

rce (

N)

Minimum required depth

β +1 s.d., γ +1 s.d. Mean

β +2 s.d., γ +2 s.d.

β -1 s.d., γ -1 s.d..

β -2 s.d., γ -2 s.d..

93 kg76 kg

41 kg

Mars Gravity


For

ce (

N)




76 kg provider - Mean compliance chest - Different gravities

1.7

3.2

6.1

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9 10 11


Fo

rce

(N

)

Minimum required depth (3.8 cm)

On Earth

On Mars

On Moon


For

ce (

N)

Mean Mass Rescuer – Mean Chest Compliance Patient

76 kg Rescuer

What can be done about off planet BLS?

Assisted CPR.– Using a restraint system.

Assisted CPR.– Using a restraint system.


Assisted CPR.– Using a restraint system.– Using assistance devices.


Assisted CPR.– Using a restraint system.– Using assistance devices.– Multiple person CPR.


Technique of compression

Equipment Description

Standard Nil Normal terrestrial CPR method.

Heimlich CPR Method

Nil Rescuer behind patient, chest compression by elbow flexion.

Abdominal compression

Nil Abdomen compressed to utilize pure abdominal pump mechanism.

Mass momentum method

Nil Dropping from a height provides potential energy. The force may be applied by the hands or the feet.





Heimlich CPR Method(RBH)










Heimlich CPR Method







ER Method Nil Patient thorax encircled by rescuer legs to enable additional force application through hip/knee flexion.

Added mass Weights Standard method with added masses (e.g. on a weight belt).

Assist device Elastic compression assist device

Large ‘elastic band’ placed around the patient’s back and over the rescuer’s shoulders/back provides additional force.

Modified Hand-stand Method (HS)

Opposing ‘walls’ approx 2m apart.

Modification of the microgravity hand-stand method.


ER Method Nil Patient thorax encircled by rescuer legs to enable additional force application through hip/knee flexion

Added mass Weights Standard method with added masses (e.g. on a weight belt).

Assist device Elastic compression assist device

Large ‘elastic band’ placed around the patient’s back and over the rescuer’s shoulders/back provides additional force.

Modified Hand-stand Method (HS)

Opposing ‘walls’ approx 2m apart.

Modification of the microgravity hand-stand method.


N.B.

• A major limitation of all microgravity BLS methods is the lack of back/neck/head support!

N.B.

• A major limitation of all microgravity BLS methods is the lack of back/neck/head support!

• A decision will need to be made as whether a potential back/neck injury poses a greater risk than not receiving adequate CPR.

Lets Walk Before We Can Run

Can Cardiopulmonary Resuscitation be performed by anyone, anywhere when off planet?

(Fly before we bound)



Current unrestrained Basic Life Support methods.



Current unrestrained Basic Life Support methods.– Hand stand method

Hand Stand method




– Reverse bear-hug (Heimlich).

Reverse Bear-hug (Modified Heimlich).





Limitations.





Limitations.

Can a method of CPR (with fewer limitations than current methods) be performed by anyone, anywhere when off planet?

King’s/PUCRS CPR in Microgravity Study

ER CPR method – chest compression potential.

ER method – ventilation potential.

Manikin trials.

Results

Measure +1GZ MicrogravityChest Compressions Depth (mm) 43.6 ± 0.59 41.3 ± 1.03 Range (min-max, mm) 40.4 – 47.1 27.6 – 51.2 Rate (compressions.min-1) 97.1 ± 3.0 80.2 ± 3.4 Percent correct (depth) 90% 60% n 225 672Tidal Volume Volume (ml) 507.6 ± 11.5 491 ± 50.4 Range (min-max, ml) 423 – 570 284 - 891 Percent correct 87% 69% n 30 32

Results

Measure +1GZ MicrogravityChest Compressions Depth (mm) 43.6 ± 0.59 41.3 ± 1.03 Range (min-max, mm) 40.4 – 47.1 27.6 – 51.2 Rate (compressions.min-1) 97.1 ± 3.0 * 80.2 ± 3.4 * Percent correct (depth) 90% 60% n 225 672Tidal Volume Volume (ml) 507.6 ± 11.5 491 ± 50.4 Range (min-max, ml) 423 – 570 284 - 891 Percent correct 87% 69% n 30 32

* P < 0.05

Results

Measure +1GZ MicrogravityChest Compressions Depth (mm) 43.6 ± 0.59 41.3 ± 1.03 Range (min-max, mm) 40.4 – 47.1 27.6 – 51.2 Rate (compressions.min-1) 97.1 ± 3.0 * 80.2 ± 3.4 * Percent correct (depth) 90% 60% n 225 672Tidal Volume Volume (ml) 507.6 ± 11.5 491 ± 50.4 Range (min-max, ml) 423 – 570 284 - 891 Percent correct 87% 69% n 30 32

Discussion

Reasons for insufficient rate of chest compression and greater variation of measures in microgravity.

Discussion

Reasons for insufficient rate of chest compression and greater variation of measures in microgravity.– Novelty of environment.

Discussion

Reasons for insufficient rate of chest compression and greater variation of measures in microgravity.– Novelty of environment.– Variable acceleration forces and shortness of

microgravity exposure.

Discussion

Reasons for insufficient rate of chest compression and greater variation of measures in microgravity.– Novelty of environment.– Variable acceleration forces and shortness of

microgravity exposure.– Use of +1Gz manikin (albeit adapted for

microgravity use).

ER compared to other methods of performing CPR in microgravity.

Discussion

Measure ER Hand Stand

Rev Bear Hug

ERC 98 Guidelines

Chest Comp Depth (mm)

41.3 ± 1.03 40.1 ± 0.51 36.8 ± 0.64

40 – 50

Chest Comp Rate (per min)

80.2 ± 3.4 98.3 ± 6.3 89.3 ± 4.1

~ 100

Tidal Volume (ml)

491 ± 50.4 - - 400 - 600

• Jay, Lee, Goldsmith, Battat, Maurer and Suner, 2003. CPR effectiveness in microgravity: Comparisons of thee positions and a mechanical device. Aviat Space Environ Med, 74(11): 1183-9

Discussion


Rev Bear Hug

ERC 98 Guidelines


41.3 ± 1.03 40.1 ± 0.51 36.8 ± 0.64

40 – 50


80.2 ± 3.4 98.3 ± 6.3 89.3 ± 4.1

~ 100

Tidal Volume (ml)

491 ± 50.4 - - 400 - 600

Discussion


Rev Bear Hug

ERC 98 Guidelines


41.3 ± 1.03 40.1 ± 0.51 36.8 ± 0.64

40 – 50


80.2 ± 3.4 98.3 ± 6.3 89.3 ± 4.1

~ 100

Tidal Volume (ml)

491 ± 50.4 - - 400 - 600

Effectiveness of the ER method for all populations will need to be ascertained before it can be considered a viable method for universal use.

Discussion

Effectiveness of the ER method for all populations will need to be ascertained before it can be considered a viable method for universal use.

Discussion

– Strength

– Anthropometric indices

– Cardiovascular fitness

Effectiveness of the ER method for all populations will need to be ascertained before it can be considered a viable method for universal use.– Strength– Anthropometric indices– Cardiovascular fitness

Indications are that ER CPR should be possible for almost anyone, anywhere off planet.

Discussion

Non-terrestrial CPR - will one size fit all?

Conclusion

Non-terrestrial CPR - will one size fit all?– Off planet (no artificial gravity).

Conclusion


• Large habitat, no immediate access to equipment and requirement to conduct CPR for mins not secs.

Conclusion

ER CPR



Conclusion

ER CPR

• Large habitat, access to appropriate equipment e.g. CPR assist band, compression assist device.

Assisted methods



Conclusion

ER CPR

• Small habitat, no immediate access to equipment and requirement to conduct CPR for hours not mins.

HS CPR

• Large habitat, access to appropriate equipment e.g. CPR assist band, compression assist device.

Assisted methods

Non-terrestrial CPR - will one size fit all?– Off planet (no artificial gravity).– On planet (within habitat).

Conclusion


• Gravity greater than +0.5Gz.

Conclusion

Conventional CPR ?



Conclusion

Conventional CPR ?

• Gravity less than +0.5Gz, large habitat, no immediate access to equipment. ER CPR



Conclusion

Conventional CPR ?

• Gravity less than +0.5Gz, large habitat, no immediate access to equipment.

Assisted methods

ER CPR

• Gravity less than +0.5Gz, large habitat, access to appropriate equipment.



Conclusion

Conventional CPR ?

• Gravity less than +0.5Gz, small habitat, no immediate access to equipment, CPR required for hours not mins.

• Gravity less than +0.5Gz, large habitat, no immediate access to equipment.

Assisted methods

ER CPR

HS CPR

• Gravity less than +0.5Gz, large habitat, access to appropriate equipment.

Train in multiple CPR techniques?

Conclusion

Conventional CPR

Assisted methodsER CPR HS CPR

Train in multiple CPR techniques? Mission oriented training.

Conclusion

Conventional CPR



– CPR techniques appropriate for habitat and risks according to mission tasks.

Conclusion

Conventional CPR



– CPR techniques appropriate for habitat and risks according to mission tasks.

Foreseeable future will probably require 1 or 2 methods to be learnt for each mission.

Conclusion

Conventional CPR


Thank you for your time

Any questions?

E-mail address

[email protected]

Non-terrestrial Basic Life Support Simon N Evetts PhD

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