Which factor is most likely to lead to oxygen toxicity in patients undergoing oxygen therapy?

High concentrations of oxygen for prolonged periods are indeed the most significant factor associated with the risk of oxygen toxicity during oxygen therapy. At elevated levels, oxygen can generate reactive oxygen species (ROS), which can lead to cellular damage, particularly in the lungs. This condition, known as oxygen toxicity, can cause symptoms such as coughing, chest pain, difficulty breathing, and in severe cases, lung damage and respiratory failure.

In clinical practice, oxygen therapy is carefully monitored, especially when administering high concentrations of oxygen (greater than 60% oxygen or above) over extended periods. This precaution is essential to avoid complications such as pulmonary edema and atelectasis, which can arise from the damaging effects of oxygen at such concentrations.

Factors like low respiratory rates, inadequate humidification, or the method of delivery—such as using nasal cannulas—do not directly contribute to the risk of oxygen toxicity in the same way that prolonged exposure to high concentrations of oxygen does. While these factors can influence the efficacy and comfort of oxygen therapy, they do not present the same risk of toxicity. Therefore, understanding the impact of oxygen concentration on potential toxicity is crucial for the safe administration of oxygen therapy.