Final answer:
The sources of increased imposed work of breathing in intubated patients are the endotracheal tube, the ventilator circuit, and auto-PEEP, making the answer D) I, II, and III.
Step-by-step explanation:
In intubated patients, sources of increased imposed work of breathing can include several factors. These factors can impose an additional burden on a patient's respiratory muscles as they try to ventilate effectively. The sources of increased work of breathing in this context include:
- Endotracheal tube (ETT): The presence of the tube itself can add resistance to airflow because of its narrower lumen compared to the natural airway, and the length of the tube can increase the effort required to move air in and out.
- Ventilator circuit: The patient must also overcome resistance from the ventilator circuit, which includes the tubing, filters, and any valves or bends.
- Auto-PEEP (positive end-expiratory pressure): This occurs when a patient's exhalations are incomplete, leading to a buildup of air pressure in the lungs, making it more difficult to initiate the next breath.
Hence, the answer to the question would be D) I, II, and III, as the endotracheal tube, ventilator circuit, and auto-PEEP all contribute to the increased work of breathing in intubated patients.