The effect of neuromuscular blockade on oxygen supply, consumption, and total chest compliance in patients with high oxygen requirements undergoing mechanical ventilation

Abstract

We investigated the effects of neuromuscular blockade with atracurium on oxygen consumption, oxygen delivery and total chest compliance in 20 sedated intensive care patients who required mechanical ventilation with an inspired oxygen fraction of at least 0.6. The reverse Fick method was used to measure oxygen consumption. Total chest compliance was measured from the ventilator pneumotachograph and pressure transducer. Measurements were made before neuromuscular blockade, at a standard level of neuromuscular blockade, and after demonstrated recovery of neuromuscular function. There was no statistical difference in any of the parameters measured. However there were large changes in oxygen consumption (range -35% to +17%) and total chest compliance (range -19.7% to + 9.7%) in individuals. We conclude that in the setting of critical oxygenation, neuromuscular blockade cannot be assumed to reduce oxygen requirements or improve total lung compliance. If, however, neuromuscular blockade is selected as an adjunct to therapy, we recommend that the indices of oxygenation are calculated.