What laboratory finding is expected when a person has chronic renal failure?

A. Opiate drugs cause respiratory acidosis by depressing the central nervous system, specifically the respiratory centers in the brainstem, leading to reduced ventilation and accumulation of carbon dioxide. This increases arterial PCO2, lowering blood pH. The patient’s exposure to opiates aligns with this mechanism, as it impairs the physiological need for adequate respiration, a key component of Maslow’s hierarchy.

B. Atelectasis results in respiratory acidosis due to collapsed alveoli, which reduces effective gas exchange and causes carbon dioxide retention. This elevates PCO2, decreasing pH. The patient’s condition of atelectasis directly contributes to hypoventilation, supporting this classification.

C. Hypoventilation leads to respiratory acidosis by decreasing alveolar ventilation, causing carbon dioxide buildup. Elevated PCO2 lowers blood pH. The patient’s hypoventilation directly correlates with this mechanism, as it disrupts the respiratory system’s ability to maintain acid-base balance.

D. Renal failure causes metabolic acidosis by impairing the kidneys’ ability to excrete hydrogen ions and reabsorb bicarbonate, leading to acid accumulation and reduced serum bicarbonate. This aligns with the patient’s renal failure, as it disrupts the renal regulation of acid-base homeostasis, a critical physiological need.

E. Airway obstruction results in respiratory acidosis by preventing adequate ventilation, leading to carbon dioxide retention and increased PCO2, which lowers pH. The patient’s airway obstruction directly causes this imbalance, impairing respiratory function.

F. Diarrhea causes metabolic acidosis due to excessive loss of bicarbonate-rich intestinal fluids, reducing serum bicarbonate and lowering pH. The patient’s diarrhea aligns with this mechanism, as it leads to a direct loss of base, disrupting acid-base equilibrium.

Choice A reason: Diarrhea is not a typical feature of autonomic dysreflexia, which involves sympathetic overactivity causing vasoconstriction. Bowel dysfunction may occur in spinal cord injury, but it is not specific to dysreflexia, making this incorrect.

Choice B reason: Tachycardia can occur in autonomic dysreflexia due to sympathetic stimulation, but it is less specific than headache, which is a hallmark symptom from severe hypertension, making this choice incorrect.

Choice C reason: Autonomic dysreflexia, often triggered by stimuli below the injury level, causes severe hypertension, leading to a pounding headache due to increased intracranial pressure. This is a hallmark symptom, making this the correct choice.

Choice D reason: Hypotension is not associated with autonomic dysreflexia, which causes hypertension from unopposed sympathetic responses. Hypotension may occur in spinal shock, not dysreflexia, making this choice incorrect.