A client is brought to the emergency department by emergency medical responders. Exhibits The nurse reviews the client's laboratory results. Complete the following sentences by choosing from the lists of options. The nurse interprets the client's arterial blood gas results and knows the client is most likely experiencing dropdown. The nurse anticipates dropdown of the client.

ABGs are essential for evaluating acid–base balance, oxygenation, and ventilation status in critically ill patients. Burn and inhalation injuries often lead to impaired oxygen delivery, tissue hypoperfusion, and lactic acid buildup. Correct interpretation of pH, PaCO₂, and HCO₃⁻ is necessary to determine the primary acid–base disorder and guide ongoing management. Rationale for correct choices: • Metabolic acidosis: The ABG shows a low pH (7.26), indicating acidemia, with a decreased bicarbonate level (HCO₃⁻ 18 mEq/L), which is the primary abnormality. This pattern is consistent with metabolic acidosis, commonly caused in burn and smoke inhalation patients by tissue hypoxia and lactic acid accumulation due to impaired oxygen delivery. Although PaCO₂ is slightly elevated, this represents partial respiratory compensation. The underlying disorder remains metabolic in origin. • Serial ABG monitoring: In a client with burn injury and suspected inhalation injury, acid–base status can change rapidly due to evolving hypoxia, shock, and fluid shifts. Serial ABGs are necessary to monitor progression of metabolic acidosis and evaluate the effectiveness of oxygen therapy and resuscitation. Ongoing monitoring helps guide escalation of respiratory support and detect deterioration early. Therefore, repeated ABG assessment is the appropriate management plan. Rationale for incorrect choice: • Respiratory acidosis: Respiratory acidosis is characterized by elevated PaCO₂ as the primary disturbance, typically due to hypoventilation. Although this client has a mildly elevated PaCO₂ (45 mmHg), the primary abnormality is a low bicarbonate level, indicating a metabolic process rather than respiratory failure as the primary cause. Therefore, respiratory acidosis is not the best interpretation of these ABG results. • Metabolic alkalosis: Metabolic alkalosis is associated with elevated pH and increased bicarbonate levels, often due to vomiting, diuretic use, or excessive bicarbonate intake. This client instead has a low pH and decreased bicarbonate, indicating acid accumulation rather than base excess. The ABG findings clearly contradict alkalosis. • Administer oral bicarbonate: Oral bicarbonate is not appropriate in acute burn or inhalation injury-related metabolic acidosis. The underlying cause is tissue hypoxia and lactic acid production, which must be corrected by improving oxygenation and perfusion rather than buffering acid directly. Additionally, oral administration is inappropriate in a critically ill, potentially drowsy patient. • Discontinue oxygen: Oxygen therapy is essential in this client due to suspected smoke inhalation and hypoxia risk. The client initially had an oxygen saturation of 86% and continues to show respiratory compromise. Discontinuing oxygen would worsen tissue hypoxia and exacerbate metabolic acidosis. Therefore, this action is unsafe and contraindicated.