Which of the following indicates a patient is in respiratory failure?

A patient is considered to be in respiratory failure when they are unable to maintain adequate gas exchange, which is reflected in low oxygen saturation levels. This condition occurs when the lungs do not efficiently transfer oxygen into the bloodstream or remove carbon dioxide from it, leading to decreased oxygen levels in the blood.

Low oxygen saturation levels, typically measured by a pulse oximeter, indicate that the body is not receiving enough oxygen, which can result from various underlying issues such as respiratory diseases, airway obstruction, or central nervous system problems. Recognizing low oxygen saturation levels is critical, as it prompts immediate medical intervention to restore proper respiratory function and ensure adequate oxygen delivery to the tissues.

High blood pressure readings, rapid heart rate, or clear lung sounds on auscultation do not directly indicate respiratory failure. High blood pressure may suggest other cardiovascular issues, while a rapid heart rate could arise from numerous causes, including anxiety or shock. Clear lung sounds imply no significant obstruction or fluid in the lungs, making them less relevant in diagnosing respiratory failure.