Figure 2.

Indirect calorimetry. Oxygen (O₂) extraction and carbon dioxide (CO₂) removal rates were calculated from the product of the breath-to-breath changes in inspired and expired O₂ and CO₂ and the minute volume (corrected for dry weight). Bubble continuous positive airway pressure (CPAP) animals extracted O₂ more efficiently than constant pressure CPAP animals (p = 0.041). The significantly higher respiratory quotient (RQ) of the constant pressure CPAP group is suggestive of respiratory failure (p = 0.005).