PULMONARY-EMBOLISM IN THE PATIENT WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE - A DIAGNOSTIC DILEMMA

It is often difficult to distinguish pulmonary embolism from worsening underlying disease in the setting of severe chronic obstructive lung disease [COPD]. Patients (3) with severe COPD and angiographically documented pulmonary embolus are described. Standard clinical and radioisotopic studies were of little value in establishing a diagnosis. All patients had acute increases in alveolar ventilation immediately following the embolus with a reduction in previously elevated levels of PaCO2 [arterial CO2 pressure], and hypoxemia. Such changes in arterial blood gases in the patient with severe COPD should suggest pulmonary embolus rather than increased obstruction.