After tracheal extubation, upper and total airway resistances may frequently be increased resulting in an increase in inspiratory effort to breathe. We tested whether breathing a helium-oxygen mixture (HeO2) would reduce inspiratory effort in the period after extubation. Eighteen consecutive patients with no chronic obstructive pulmonary disease who had received mechanical ventilation (> 48 h) were successively studied immediately after extubation (N2O2), 15 min after breathing HeO2, and after return to N2O2. Effort to breathe, assessed by the transdiaphragmatic pressure swings (ΔPdi) and the pressure-time index of the diaphragm (PTI), comfort, and gas exchange, were the main end points. The mean reduction of the transdiaphragmatic pressure under HeO2 was 19 ± 5%. All but three patients presented a decrease in transdiaphragmatic pressure under HeO2, ranging from - 4 to - 55%, and a significant reduction in ΔPdi was observed between HeO2 and N2O2 (10.2 ± 0.7 versus 8.6 ± 1.1 versus 10.0 ± 0.8 cm H2O for the three consecutive periods; p <0.05). PTI also differed significantly between HeO2 and N2O2 (197 ± 19 versus 166 ± 22 versus 201 ± 23 cm H2O/s/min for the three periods; p <0.05). Breathing HeO2 significantly improved comfort, whereas gas exchange was not modified. We conclude that the use of HeO2 in the immediate postextubation period decreases inspiratory effort and improves comfort.
|Number of pages||5|
|Journal||American Journal of Respiratory and Critical Care Medicine|
|Publication status||Published - Aug 15 2001|
- Work of breathing
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine