Final answer:
To optimize Pao2 in a patient with ARDS, PEEP will most likely be used as it improves oxygenation by keeping alveoli open, increasing the functional residual capacity, and in turn, the alveolar oxygen pressure without raising the Fio2.
Step-by-step explanation:
To improve the Pao2 (partial pressure of oxygen) in a patient with ARDS (Acute Respiratory Distress Syndrome) who is already intubated and on mechanical ventilation with a high fraction of inspired oxygen (Fio2 of 1.0), the patient will most likely be placed on PEEP (Positive End-Expiratory Pressure). PEEP helps to keep the alveoli open during the expiratory phase of the breathing cycle, thereby preventing alveolar collapse and improving alveolar ventilation. This improves oxygenation by increasing the functional residual capacity and can enhance the partial pressure of oxygen in the alveoli without increasing Fio2. The alveolar Po2 can be calculated by subtracting the product of the respiratory quotient (RQ), which is typically around 0.8, and the alveolar carbon dioxide pressure (Pco2) which is typically around 40 mm Hg from the inspired Po2. Since the goal is to optimize oxygenation without raising Fio2 due to the risk of oxygen toxicity, PEEP is an effective intervention for patients with ARDS.
ARDS stands for Acute Respiratory Distress Syndrome. When a patient with ARDS is intubated and placed on mechanical ventilation, their Pao2 level (partial pressure of oxygen in arterial blood) may be low. To improve the Pao2 without increasing the Fio2 (fraction of inspired oxygen), the patient will most likely be placed on PEEP (Positive End-Expiratory Pressure). PEEP helps to keep the alveoli open during expiration, allowing for better oxygenation of the blood.