Olivia

M. Garfield is an anxious nursing student who is very nervous about taking her midterm exams.

She thinks about how her entire future happiness all rests on the results of this one exam.

As she creatively imagines all the terrible things that will happen to her if she fails, she starts to hyperventilate and passes out in her seat.

The instructor obtains an ABG on the student and the results are as follows: pH 7.40, PaCO2 40, HCO3 of 24. What do these ABG results show?

Choice A rationale

Respiratory acidosis is characterized by a low pH and an elevated PaCO2. The patient's pH is elevated (7.61), indicating alkalosis, and the PaCO2 is low (22 mmHg). These findings are the opposite of what would be seen in respiratory acidosis.

Choice B rationale

The pH of 7.61 is significantly elevated, indicating alkalosis. The PaCO2 of 22 mmHg is markedly decreased below the normal range (35-45 mmHg). This decrease in carbon dioxide, a potent acid, directly causes the alkalosis. The bicarbonate (HCO3) level of 25 mEq/L is within the normal range (22-26 mEq/L), indicating that the renal system has not yet initiated any compensatory response. Therefore, this pattern is consistent with uncompensated respiratory alkalosis, primarily driven by hyperventilation.

Choice C rationale

Metabolic alkalosis would present with an elevated pH and an elevated bicarbonate level. While the pH is elevated, the bicarbonate (25 mEq/L) is within the normal range, and the PaCO2 is low, which is inconsistent with metabolic alkalosis as the primary imbalance.

Choice D rationale

Metabolic acidosis is characterized by a low pH and a low bicarbonate level. The patient's pH is high (alkalotic) and the bicarbonate is normal. This contradicts the diagnostic criteria for metabolic acidosis.

Choice A rationale

While establishing IV access and fluid replacement are crucial in trauma, they are secondary to ensuring cervical spine stabilization in a patient who is unresponsive after a head-on motor vehicle crash. Uncontrolled movement of an unstable cervical spine can lead to irreversible spinal cord injury, exacerbating neurological deficits or causing paralysis.

Choice B rationale

Monitoring pulse and blood pressure frequently is an important ongoing assessment in a trauma patient to identify shock or other systemic issues. However, in the immediate post-crash scenario with an unresponsive patient, the primary concern is preventing further neurological damage from potential spinal cord injury, making stabilization a higher priority.

Choice C rationale

Inserting a nasogastric tube for decompression might be necessary later in the management of a trauma patient to prevent aspiration or gastric distension. However, it is not the immediate priority action in an unresponsive patient following a head-on collision, where airway, breathing, circulation, and most importantly, cervical spine protection are paramount.

Choice D rationale

In an unresponsive client following a head-on motor vehicle crash, cervical spine injury must be presumed until ruled out. Any movement of the head or neck could further compromise the spinal cord, leading to permanent neurological deficits or even death. Therefore, keeping the neck stabilized using a cervical collar and backboard is the absolute priority to prevent further injury.