Which sign indicates respiratory failure that may require PPV through LMA or ET?

The indication of respiratory failure that may require positive pressure ventilation (PPV) through a laryngeal mask airway (LMA) or endotracheal tube (ET) is characterized by mod-severe retractions. Retractions occur when the muscles between the ribs are used to help pull air into the lungs, which indicates that the patient is struggling to breathe effectively. This is often a sign that the airway is compromised or that there is significant respiratory distress, leading to inadequate ventilation.

In cases of moderate to severe retractions, the body is working excessively hard to maintain adequate airflow, suggesting that oxygenation and ventilation may be insufficient. This situation necessitates intervention to ensure the patient can breathe adequately. Proper management may include the use of PPV to alleviate the work of breathing and improve oxygenation.

Other signs, such as stable oxygen saturation and effective oxygenation, would generally suggest that the patient is maintaining adequate respiratory function, while an increased heart rate could be a non-specific response to stress or distress rather than a direct indication of respiratory failure. Thus, it is the presence of mod-severe retractions that directly correlates with the need for advanced airway support.