Which physiological changes indicate a need for increased PEEP?

Which physiological changes indicate a need for increased PEEP?

• A. Increased lung compliance and decreased work of breathing
• B. Decreased lung compliance, shunting, and increased work of breathing
• C. Stable lung function and oxygen saturation
• D. Improved oxygenation and decreased shunting

Answer: (B)

The correct choice highlights the physiological changes that suggest a need for increased Positive End-Expiratory Pressure (PEEP). When there is decreased lung compliance, shunting, and increased work of breathing, it signals that the lungs are less effective at oxygen exchange. Decreased lung compliance suggests that the lung tissue is stiffer or less expandable, which can occur in conditions like acute respiratory distress syndrome (ARDS) or pneumonia. This reduced ability to expand the lungs efficiently means more effort is required to ventilate the patient, hence the increased work of breathing. Furthermore, shunting, where blood bypasses the alveoli and does not get oxygenated, exacerbates the situation by preventing adequate oxygenation despite the effort. Increasing PEEP can help recruit collapsed or under-inflated alveoli, enhancing ventilation-perfusion matching, improving oxygenation, and decreasing shunting. The application of higher PEEP helps to recruit collapsed alveoli and maintains them open at the end of expiration, thus providing more surface area for gas exchange and potentially reducing the shunting effect. In contrast, scenarios like increased lung compliance and decreased work of breathing indicate that lungs are functioning well, while stable lung function and oxygen saturation show no urgent need for changes in ventilatory support. Improved oxygen

The correct choice highlights the physiological changes that suggest a need for increased Positive End-Expiratory Pressure (PEEP). When there is decreased lung compliance, shunting, and increased work of breathing, it signals that the lungs are less effective at oxygen exchange. Decreased lung compliance suggests that the lung tissue is stiffer or less expandable, which can occur in conditions like acute respiratory distress syndrome (ARDS) or pneumonia. This reduced ability to expand the lungs efficiently means more effort is required to ventilate the patient, hence the increased work of breathing.

Furthermore, shunting, where blood bypasses the alveoli and does not get oxygenated, exacerbates the situation by preventing adequate oxygenation despite the effort. Increasing PEEP can help recruit collapsed or under-inflated alveoli, enhancing ventilation-perfusion matching, improving oxygenation, and decreasing shunting. The application of higher PEEP helps to recruit collapsed alveoli and maintains them open at the end of expiration, thus providing more surface area for gas exchange and potentially reducing the shunting effect.

In contrast, scenarios like increased lung compliance and decreased work of breathing indicate that lungs are functioning well, while stable lung function and oxygen saturation show no urgent need for changes in ventilatory support. Improved oxygen