What is a potential risk associated with high concentrations of inspired oxygen on a ventilator?

High concentrations of inspired oxygen, especially when administered over prolonged periods, can lead to pulmonary fibrosis due to oxygen toxicity. When oxygen levels exceed certain thresholds, free radicals can be generated in the lung tissue, causing inflammation and damage to the alveoli and leading to fibrotic changes. This alteration in lung architecture can result in a decreased ability to exchange gases effectively and can contribute to chronic lung conditions.

In contrast, barotrauma, atelectasis, and hypercapnia involve different mechanisms. Barotrauma is primarily related to over-distension of the lungs due to increased pressure rather than oxygen concentration. Atelectasis refers to the collapse of lung tissue, which can occur due to hypoventilation or lack of surfactant but is not directly caused by high oxygen exposure. Hypercapnia results from inadequate ventilation rather than oxygen toxicity, as it involves the accumulation of carbon dioxide when respiratory effort is insufficient to eliminate it.

Understanding these concepts helps clarify the specific risks associated with oxygen therapy and illustrates the importance of monitoring oxygen levels to prevent complications in mechanically ventilated patients.