Final answer:
A safe level of FiO2 for prolonged intubation is typically 40% to minimize the risk of oxygen toxicity, while ensuring adequate oxygenation, which can also be monitored using a pulse oximeter and blood gas analysis.
Step-by-step explanation:
The level of FiO2 (fraction of inspired oxygen) used for prolonged intubation needs to be carefully managed to ensure adequate oxygenation while minimizing the risk of oxygen toxicity. Option (b) FiO2 of 0.4 (40%) is typically considered a safe level for prolonged delivery. Using FiO2 of 1.0 (100%) for a prolonged period can increase the risk of lung damage and other complications due to oxygen toxicity. Monitoring oxygenation can be done using a pulse oximeter, which measures percent saturation of hemoglobin, and blood gases can be checked by an arterial stick to measure partial pressure of oxygen (PO2).