Treatment of acute exacerbations of chronic respiratory failure: integrated use of negative pressure ventilation and noninvasive positive pressure ventilation.

STUDY OBJECTIVES Acute respiratory failure (ARF) can be treated with either invasive mechanical ventilation (IMV) or noninvasive mechanical ventilation (NIMV), which can spare the complications of artificial airways. To evaluate the efficacy of an integrated approach using negative pressure ventilation (NPV) with iron lung and noninvasive positive pressure ventilation (NPPV), we performed a prospective study in a group of patients admitted to our respiratory ICU (RICU) for ARF due to exacerbation of chronic respiratory failure (CRF). SETTING RICU at "R. Silvestrini" Hospital in Perugia, Italy. PATIENTS AND METHODS One hundred fifty-two consecutive patients were included in the study and treated with iron lung as first choice or, when contraindicated or not tolerated, with NPPV using a nasal or facial mask. After 2 h of noninvasive mechanical ventilation (NIMV), the patients were reevaluated; in case of clinical deterioration, patients receiving NPV were switched to NPPV. When NPPV as a first or second line of treatment failed the patients were intubated. MEASUREMENTS AND RESULTS One hundred fifty-two patients received NIMV, 97 with iron lung as the first choice of treatment, and 55 with NPPV. Six patients treated with NPV were switched to NPPV during the first 2 h of treatment. Twenty-five patients required IMV. The success rate of the integrated use of NIMV (NPV plus NPPV) was 81.6%, compared to that of NPV (83.5%) and NPPV (70.5%). Twenty-one patients (13.8%) required tracheostomy; the duration of hospital stay was significantly lower in patients treated with NIMV only. Thirty patients required mechanical ventilation at home. Few severe complications were observed in patients receiving IMV. CONCLUSIONS The integrated use of two NIMV techniques is effective in patients with acute exacerbation of CRF. In most cases intubation and tracheostomy were avoided, thus reducing the complication rate of mechanical ventilation.