Objective: To evaluate the application of sequential noninvasive following invasive mechanical ventilation in chronic obstructive pulmonary disease (COPD) patients with severe respiratory failure by investigating the appearance of pulmonary-infection-control-window.
Methods: From November 2001 to October 2004, 76 case of COPD patients with severe respiratory failure due to pulmonary infection were intubated and recruited in the study. When the pulmonary infection was significantly controlled (the time of pulmonary infection control was called PIC window) by the antibiotic and comprehensive therapy, all cases were randomized into noninvasive veatiation group (NIV) and control group. The early extubation was conducted and followed by noninvasive mechanical ventilation via facial mask with bilevel positive airway pressure mode immediately in the NIV group. Conventional invasive synchronized intermittent mandatory ventilation (SIMV) plus pressure support ventilation (PSV) was used as the weaning technique in the control group.
Results: Thirty eight cases among 76 patients were in the NIV group, and the rest in the control group. The NIV group and the control group had similar age, sex, APACHE scores, RR, HR, MAP, PaO2 and PaCO2 at the time of commencement and PIC window (P > 0.05). The time of PIC window was (7.5 +/- 1.9) d in the NIV group, and (8.0 +/- 2.5) d in the control group (P > 0.05). In the NIV group, the durations of invasive mechanical ventilation (MV) and total MV were (7.5 +/- 1.9) d and (12.5 +/- 4.0) d respectively, while the durations were (23.5 +/- 9.5) d in the control group (P < 0.05). The durations of RICU stay and hospital stay were shorter than that in the control group. The incidence of ventilation associated pneumonia (VAP) was 18.4% (7/38) in the NIV group, 39.5% (15/38) in the control group respectively (P < 0.05). The incidence of reintubation was 13.2% (5/38) in the NIV group, 34.2% (13/38) in the control group respectively (P < 0.05). Hospital mortality was 7.9% (3/38) in the NIV group, and 28.9% (11/38) in the control group (P < 0.05).
Conclusion: In those COPD patients requiring intubation and mechanical ventilantion who have severe respiratory failure due to pulmonary infection, sequential noninvasive following invasive mechanical ventilation at the appearance of PIC window can significantly reduce the MV duration, the length of RICU stay and hospital stay, and decrease the occurrence of VAP, reintubation and hospital mortality as well. So it is an efficient strategy to be generalized.