Quantitation of oxygen-induced hypercapnia in respiratory pump failure

To determine the likelihood that clinicians know carbon dioxide levels before administering supplemental oxygen to patients with neuromuscular disorders, to quantitate the effect of oxygen therapy on carbon dioxide retention, and to explore hypercapnia contributing to the need to intubate and use of continuous noninvasive ventilatory support to avert it.

A retrospective chart review for patients with neuromuscular disorders intubated or having intubation averted by using continuous noninvasive ventilatory support with carbon dioxide known pre- and during oxygen administration.

For only 2 of 316 patients who were intubated did clinicians know carbon dioxide levels prior to administering oxygen. For four cases, intubation was averted by continuous noninvasive ventilatory support and mechanical insufflation-exsufflation despite severe hypercapnia and acidosis. After initiating oxygen therapy, patients' carbon dioxide partial pressures increased 52.1±42.0mmHg in over as little as 20min.

Clinicians should attempt to use continuous noninvasive ventilatory support and mechanical insufflation-exsufflation rather than supplemental oxygen to normalize blood gases for neuromuscular ventilatory failure and should be prepared to intubate hypercapnic patients for whom oxygen is administered.