Which ventilation technique is not recommended for a lone rescuer during CPR?

Bag-mask ventilation is not recommended for a lone rescuer during CPR due to the complexity and skill required to effectively use this technique. While it can be an effective way to provide positive pressure ventilation when performed correctly, it typically requires the assistance of a second rescuer to maintain a proper seal and manage the airway effectively.

When a rescuer is alone, the priority should be on continuous chest compressions, as this is the most critical component in maintaining blood circulation and enhancing the chances of resuscitation. Rescue breathing can still be performed, but it is generally more feasible to provide compressions rather than attempt bag-mask ventilation single-handedly, especially under time pressure.

The head-tilt maneuver is often used as a simple method to open the airway but does not involve the complexities of managing a bag and mask effectively without assistance. Therefore, in a lone rescuer scenario, chest compressions combined with rescue breathing if needed, is preferred over trying to use equipment that requires more than one person.