Final answer:
The appropriate oxygen concentration for PPV during chest compressions in CPR is not specified in exact terms by current guidelines, but high-quality chest compressions are emphasized, and oxygen should be administered to maintain adequate alveolar Po₂. Emergency services often use 100% oxygen to compensate for lower alveolar partial pressure.
Step-by-step explanation:
The question involves determining the appropriate oxygen concentration to be used during positive pressure ventilation (PPV) while performing chest compressions in cardiopulmonary resuscitation (CPR). The goal of PPV is to maintain adequate oxygenation and ventilation during cardiac arrest. The current CPR guidelines emphasize the importance of uninterrupted, high-quality chest compressions. While the guidelines don't specify a precise oxygen concentration during chest compressions, it is vital to ensure that breathable air administered has an appropriate level of oxygen to support the patient's circulatory and pulmonary systems.
When considering the partial pressure of oxygen, breathable air at sea level has an atmospheric pressure where oxygen makes up approximately 21%. The partial pressure of oxygen in inhaled air is around 150 mm Hg. Considering that alveolar partial pressure of oxygen (alveolar Po₂) is lower due to mixing with residual air, the administered oxygen concentration should compensate for this to maintain the appropriate alveolar Po₂, which typically is around 100 mm Hg. Emergency services often use a high-concentration oxygen mask or an advanced airway with 100% oxygen during CPR to achieve this. However, the specifics can depend on local protocols and the clinical presentation of the patient.