In which situation is positive pressure ventilation indicated?

Positive pressure ventilation is indicated in situations where a patient is unable to maintain adequate oxygenation or ventilation on their own. In this scenario, the patient being lethargic with a pulse oximeter reading of 90% signifies that their blood oxygen levels are below the normal range, which is typically considered to be 92% or higher. This low oxygen saturation suggests that the patient is at risk for hypoxia, meaning their body may not be receiving enough oxygen to meet its needs.

Utilizing positive pressure ventilation can help deliver oxygen directly into the lungs, thereby increasing the amount of oxygen available to the bloodstream and improving overall oxygen saturation levels. This intervention is crucial for supporting patients who are not breathing adequately due to decreased consciousness or other respiratory compromise.

In other situations listed, such as the patient with a respiratory rate of 20 who is alert and breathing adequately without distress, they do not demonstrate signs of respiratory failure or significant hypoxia, thus active intervention like positive pressure ventilation is not necessary. The patient experiencing chest pain with normal breath sounds may require evaluation and management, but if their breathing is adequate, they too do not require positive pressure ventilation.