Three methods of manual external chest compressions during microgravity simulation.

Area of Science:

• Space Medicine
• Emergency Medicine
• Physiology

Background:

• Cardiopulmonary resuscitation (CPR) in microgravity presents unique challenges.
• Three single-person CPR techniques exist for microgravity: Evetts-Russomano (ER), Handstand (HS), and Reverse Bear Hug (RBH).
• Previous evaluations focused on parabolic flights, with ER showing effectiveness in prolonged simulations; however, all methods require assessment against current 2010 guidelines.

Purpose of the Study:

• To evaluate the effectiveness of three single-person CPR techniques (ER, HS, RBH) in simulated microgravity against the 2010 CPR guidelines.
• To measure true depth (D(T)), compression rate, and oxygen consumption (Vo2) for each technique.

Main Methods:

• Twenty-three male subjects performed simulated terrestrial CPR (+1 G(z)) and the three microgravity CPR techniques.
• A body suspension device (BSD) and trolley system were used to simulate microgravity.
• Measurements included true depth (D(T)), external chest compression (ECC) rate, and oxygen consumption (Vo2).

Main Results:

• The ER and RBH methods yielded significantly lower D(T) than +1 G(z) CPR but met the ECC rate guidelines.
• The HS method achieved superior D(T) but a lower ECC rate.
• Oxygen consumption was higher for ER and HS compared to +1 G(z) CPR, but not for RBH.

Conclusions:

• All three microgravity CPR techniques show potential, with ER and RBH offering adequate ECC rates and HS providing adequate D(T).
• None of the evaluated methods fully satisfied all criteria of the 2010 CPR guidelines.
• Further research is necessary to determine the most effective CPR method for microgravity environments.