A nurse is teaching a group of nursing students about spinal cord injuries in clients who are aged 65 years and older. Which of the following should the nurse identify as the most common cause of spinal cord injuries for this age group?

Choice A Reason:

Hypoxemia due to dead space is not appropriate. Dead space refers to areas of the lung where ventilation occurs but no perfusion takes place. In ARDS, hypoxemia typically occurs due to ventilation-perfusion (V/Q) mismatch and shunting rather than dead space.

Choice B Reason:

Impaired carbon dioxide elimination due to shunting is not appropriate. Shunting occurs when blood bypasses ventilated alveoli, leading to inadequate gas exchange. In ARDS, shunting contributes to hypoxemia, but it doesn't directly impair carbon dioxide elimination.

Choice C Reason:

Decreased pulmonary arterial pressure due to ventilation-perfusion (V/Q) mismatch is incorrect. V/Q mismatch occurs when ventilation and perfusion are mismatched in different areas of the lung. This leads to areas of low ventilation (dead space) and areas of low perfusion (shunting). V/Q mismatch contributes to hypoxemia in ARDS but does not typically lead to decreased pulmonary arterial pressure.

Choice D Reason:

Decreased pulmonary compliance due to stiffness is correct. This is a characteristic feature of ARDS. The inflammation and damage to the alveoli cause them to become stiff, reducing pulmonary compliance and impairing lung expansion during ventilation.

Choice A Reason:

A client with a decreased potassium level is incorrect. Hypokalemia (decreased potassium level) can cause various neurological symptoms, but it doesn't directly lead to osmotic cerebral edema.

Choice B Reason:

When plasma glucose levels are rapidly lowered, an osmotic gradient develops between the brain and plasma, which can lead to cerebral edema.Brain cells pull water from the plasma, resulting in widespread edema.

Choice C Reason:

While HbA1c is an important marker of diabetes control and may indicate poor long-term management, it does not directly relate to the acute metabolic derangements (e.g., rapid osmotic shifts, severity of acidosis) that predispose to cerebral edema in DKA.

Choice D Reason:

A client with an increased creatinine level is incorrect. Elevated creatinine levels typically indicate kidney dysfunction or dehydration, but they don't directly cause osmotic cerebral edema.