Which of the following is a sign of poor lung compliance after endotracheal intubation?

Poor lung compliance refers to the reduced ability of the lungs to expand during inhalation. After endotracheal intubation, this can manifest in several ways, but one key sign is hypercapnia, which is an elevated level of carbon dioxide (CO2) in the blood.

When lung compliance is poor, the ventilation-perfusion ratio can become impaired, making it difficult for oxygen to diffuse into the blood and CO2 to be expelled effectively. As a result, CO2 accumulates in the bloodstream, leading to hypercapnia. This accumulation arises because even though the airway may be patent due to intubation, the lung tissues may not be able to expand adequately to allow for sufficient gas exchange.

The presence of hypercapnia indicates inadequate ventilation and can lead to respiratory acidosis, which can have further systemic effects. Recognizing hypercapnia as a sign of poor lung compliance is crucial for identifying patients who may be experiencing difficulties with their respiratory function despite having a secured airway.