If a patient with a chest injury only inhales and is unable to exhale, what is the most likely consequence?

• A. The lungs will collapse due to lack of air entry.
• B. Oxygen levels in the blood will continuously increase without any negative effects.
• C. The heart will immediately stop beating due to lack of oxygen.
• D. Carbon dioxide will accumulate in the blood, leading to respiratory acidosis.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the mechanics of breathing. Breathing involves two main processes: inhalation (air enters the lungs) and exhalation (air exits the lungs). Exhalation is crucial for removing carbon dioxide (CO2), a waste product of cellular metabolism.
2. Step 2: Recognize the role of carbon dioxide in the blood. CO2 is transported in the blood and must be expelled through exhalation. If CO2 accumulates, it reacts with water in the blood to form carbonic acid (H2CO3), which dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3−). This process lowers blood pH, leading to respiratory acidosis.
3. Step 3: Analyze the consequences of impaired exhalation. If a patient cannot exhale, CO2 builds up in the bloodstream. This disrupts the acid-base balance, causing the blood to become more acidic. The body relies on exhalation to maintain homeostasis and prevent acidosis.
4. Step 4: Connect the physiological effects of respiratory acidosis. Acidosis can impair enzyme function, disrupt cellular processes, and lead to symptoms such as confusion, fatigue, and shortness of breath. Severe acidosis can be life-threatening if not corrected.
5. Step 5: Conclude that the inability to exhale results in CO2 accumulation, which leads to respiratory acidosis. This is the most likely consequence of the described chest injury, as the body cannot effectively remove CO2 from the bloodstream.