What signs could suggest a patient is in respiratory failure?

A decreased level of consciousness and inadequate respiratory effort are critical indicators of respiratory failure. In respiratory failure, the body's ability to exchange gases effectively is compromised, which often leads to hypoxia (lack of oxygen) and hypercapnia (excess CO2). A decreased level of consciousness can signify inadequate oxygen supply to the brain, while inadequate respiratory effort suggests that the patient is not breathing effectively or sufficiently, which could lead to further complications if not addressed promptly.

The other options do not accurately reflect signs of respiratory failure. Increased respiratory rate and high blood pressure could indicate distress but are not definitive signs of respiratory failure on their own. Clear lung sounds and normal oxygen saturation levels suggest functioning respiratory status, which would not be consistent with respiratory failure. Shortness of breath and wheezing sounds may indicate respiratory distress but do not necessarily confirm failure without other significant findings like those mentioned in the correct answer.