A male client with a massive pulmonary embolus is tachycardic, hypotensive, and has audible bilateral pulmonary crackles. His arterial blood gas (ABG) results are: pH 7.0: PaCO, 66 mm Fig; HCO3- 24 mEq/L (24 mmol/L); PaO, 60 mm Hg. Based on these findings, this client is at greatest risk for which pathophysiological condition? Reference Ranges: pH [7.35 to 7.45] PaCO, [35 to 45 mm Hg] HCO3- [21 to 28 mEq/L (21 to 28 mmol/L)] PaO, [80 to 100 mm Hg]

The ABG results indicate respiratory acidosis (pH 7.0, PaCO2 66 mmHg) with compensatory metabolic alkalosis (HCO3- 24 mEq/L). The low PaO2 (60 mmHg) suggests hypoxemia. pH 7.0: The pH is below the normal range (7.35 to 7.45), indicating acidosis. PaCO2 66 mmHg: The PaCO2 is elevated above the normal range (35 to 45 mmHg), indicating respiratory acidosis. HCO3- 24 mEq/L: The bicarbonate level is within the normal range (21 to 28 mEq/L), indicating compensatory metabolic alkalosis. PaO2 60 mmHg: The PaO2 is decreased below the normal range (80 to 100 mmHg), indicating hypoxemia. These findings suggest that the client is experiencing respiratory failure, which is characterized by inadequate gas exchange resulting in hypoxemia and hypercapnia. In this case, the massive pulmonary embolus is causing ventilation-perfusion (V/Q) mismatch, leading to impaired gas exchange and respiratory compromise. Tachycardia, hypotension, and audible bilateral pulmonary crackles further support the diagnosis of respiratory failure in the context of a massive pulmonary embolus.