Minimum oxygen flow needed for vital support during simulated post-cardiorespiratory arrest resuscitation

Area of Science:

• Cardiology
• Critical Care Medicine
• Biomedical Engineering

Background:

• European Resuscitation Council (ERC) and American Heart Association (AHA) guidelines recommend titrating Fraction of Inspired Oxygen (FiO2) to achieve an oxygen saturation (O2Sat) of ≥ 94% in post-cardiac arrest care.
• Determining the optimal oxygen delivery parameters is crucial for effective resuscitation and patient outcomes.

Purpose of the Study:

• To evaluate the minimum oxygen flow and ventilation time required to achieve specific FiO2 levels (0.32 and 0.80) using different resuscitator devices in a simulated post-cardiac arrest scenario.

Main Methods:

• An experimental setup simulating post-cardiac arrest care was used with an artificial lung.
• Four resuscitator devices (Mark IV, SPUR II, Revivator Res-Q, O-TWO) were tested at various oxygen flow rates (2, 5, 10, 15 lpm).
• Statistical analysis included Bonferroni and Mann-Whitney U tests to compare device performance.

Main Results:

• All tested resuscitators and oxygen flows achieved an FiO2 of ≥ 0.32 within 35 seconds.
• The Mark IV was the only device to reach an FiO2 of 0.80 at lower flows (2 or 5 lpm) within 75 seconds.
• At 15 lpm, Mark IV and Revivator Res-Q reached FiO2 ≥ 0.80 in 35 seconds, significantly faster than SPUR II (50 seconds).

Conclusions:

• For achieving an FiO2 of 0.32, any resuscitator with 2 lpm oxygen flow is adequate, though O-TWO may be slower initially.
• To reach an FiO2 of 0.80, 10 lpm oxygen flow is sufficient, with Mark IV and Revivator Res-Q being the preferred devices.
• Revivator Res-Q and Mark IV are recommended over O-TWO and SPUR II for optimal FiO2 delivery in post-cardiac arrest care.