Question of the Week

For November 12, 2019

An 82-year-old man is brought to the emergency department with a 3-day history of increasing dyspnea, wheezing, purulent sputum, and cough. He also has a history of severe chronic obstructive pulmonary disease, congestive heart failure, and chronic kidney disease.

On examination, the patient is afebrile, his blood pressure is 145/80 mm Hg, his heart rate is 115 beats per minute, his respiratory rate is 40 breaths per minute, and his oxygen saturation is 88% while receiving 3 liters of oxygen by nasal cannula. He is in respiratory distress, speaking in 1- to 2-word sentences and using accessory muscles and pursed lips to breathe. He has tachycardia with a regular rhythm, and his jugular venous pressure is not elevated. His breath sounds are diminished bilaterally with scattered expiratory wheezes.

An arterial blood gas sample reveals a pH of 7.15, a partial pressure of carbon dioxide of 100 mm Hg (reference range, 35–45) and a partial pressure of oxygen of 60 mm Hg (80–100).

The patient is intubated with initial ventilator settings of volume control with a respiratory rate of 25 breaths per minute, tidal volume of 6 mL/kg ideal body weight, positive end-expiratory pressure of 5 cm of water, and fraction of inspired oxygen of 100%.

Chest radiography after intubation reveals hyperinflated lungs with adequate endotracheal-tube position and no focal consolidation. On arrival to the intensive care unit 20 minutes later, the patient’s blood pressure is 74/43 mm Hg.

What is the best next step for this patient?

Decrease the inspiratory flow rate
Temporarily disconnect the patient from the mechanical ventilator and manually ventilate him
Change the mode of ventilation to pressure-support ventilation
Increase the respiratory rate to 30 breaths per minute
Increase the positive end-expiratory pressure to match the intrinsic positive end-expiratory pressure