Correct Answer: B

Rationale: The correct answer is B: Respiratory alkalosis. Hyperventilation leads to excessive elimination of carbon dioxide, causing a decrease in PaCO2 levels, resulting in respiratory alkalosis. This is the most common cause of hyperventilation. Respiratory acidosis (choice A) occurs when there is retention of carbon dioxide. Increased PaCO2 (choice C) is a consequence of respiratory acidosis, not alkalosis. CNS disturbances (choice D) can lead to abnormal breathing patterns but are not the most common cause of hyperventilation.

Correct Answer: C

Rationale: The correct answer is C: Metabolic alkalosis. Pyloric stenosis can lead to vomiting, causing loss of gastric acid and chloride ions, leading to metabolic alkalosis. Low potassium levels are common in metabolic alkalosis due to potassium shifting into cells to compensate for the alkalosis. Hypercalcemia (choice A) is not associated with pyloric stenosis. Metabolic acidosis (choice B) typically presents with low pH and bicarbonate levels. Respiratory acidosis (choice D) is caused by impaired gas exchange in the lungs, not related to pyloric stenosis.

Correct Answer: B

Rationale: The correct answer is B: Ensure an x-ray is completed to confirm placement. This is crucial to prevent complications such as pneumothorax or incorrect placement. X-ray confirmation is the gold standard to verify the central line's proper positioning before initiating any infusions. Option A is incorrect because starting the infusion without confirming placement can lead to serious complications. Option C is unnecessary for central line insertion. Option D is important but not the immediate next step as confirming placement takes precedence for patient safety.

Correct Answer: A

Rationale: The correct answer is A: Cardiac rate and rhythm. In an acid-base imbalance, the pH is below the normal range indicating acidosis. The nurse should assess the cardiac rate and rhythm first because acidosis can have negative effects on the cardiovascular system. Acidosis can lead to arrhythmias and decreased cardiac output. Monitoring the cardiac rate and rhythm is crucial to detect any cardiac complications early. Choices B, C, and D are not the priority in this situation as they are not directly impacted by acid-base imbalances.

Correct Answer: D

Rationale: The correct answer is D: Excessive administration of chloride. Normal anion gap acidosis is commonly caused by an excessive intake of chloride-containing solutions like normal saline during treatment. This leads to an increase in the plasma chloride concentration, causing a decrease in the anion gap. Metastases (A) are not typically associated with normal anion gap acidosis. Excessive potassium intake (B) would not lead to normal anion gap acidosis but rather hyperkalemia. Water intoxication (C) can lead to dilutional hyponatremia but not normal anion gap acidosis.