A nurse is reviewing the arterial blood gas results for a client in the ICU who has pneumonia and acute tubular necrosis (ATN). The nurse determines that the client has metabolic acidosis. Which of the following findings should the nurse expect?

Choice A rationale Metabolic acidosis involves an accumulation of hydrogen ions or a loss of bicarbonate, resulting in a serum pH below 7.35. This acidosis affects cardiac conduction by slowing the electrical impulses through the ventricles. Consequently, the nurse should expect to see widened QRS complexes on the electrocardiogram. Severe acidosis interferes with normal myocardial contractility and predisposes the client to dangerous arrhythmias, reflecting the profound impact of the low pH on cellular electrolyte exchange and cardiac excitability. Choice B rationale In metabolic acidosis, the body often compensates through peripheral vasodilation rather than vasoconstriction. Therefore, the skin is more likely to be warm, flushed, and dry rather than cool, pale, or cyanotic. Cool and pale skin is more characteristic of compensatory mechanisms seen in shock or hypovolemia where the body shunts blood to the vital organs. The nurse should focus on monitoring for flushing and warmth as the cardiovascular system reacts to the decreased systemic pH levels. Choice C rationale Metabolic acidosis typically leads to a decrease in cardiac output and systemic vascular resistance due to the inhibitory effect of hydrogen ions on the heart. This results in weak, thready peripheral pulses rather than bounding ones. Bounding pulses are more commonly associated with fluid volume overload or early stages of septic shock. In a client with pneumonia and acute tubular necrosis, the acidotic state impairs the strength of ventricular contraction, leading to diminished peripheral pulse volume and intensity. Choice D rationale High levels of hydrogen ions in metabolic acidosis generally depress the central nervous system and neuromuscular irritability. This leads to findings such as muscle weakness, flaccid paralysis, and diminished or absent deep tendon reflexes. Hyperactive deep tendon reflexes are more indicative of respiratory alkalosis or metabolic alkalosis, where decreased ionized calcium levels increase neuromuscular excitability. In acidosis, the systemic depression of the nervous system results in a sluggish response to reflex testing during the physical assessment.