A 65-yeаr-оld wоmаn with а histоry of COPD was discovered unconscious at home 4 hours ago. She is now intubated and is receiving mechanical ventilation. A flow-directed pulmonary artery catheter has been inserted. Relevant data below. Pulse 136/min Blood pressure 76/60 mmHg Pulmonary artery pressure 17/6 mmHg Pulmonary capillary wedge pressure 4 mmHg Cardiac output 3.8 L/min Systemic vascular resistance 1354 dynes/sec/cm-5 Central venous pressure 1 mmHg The most likely cause of this patient's hypotension is