ACUTE EXACERBATIONS IN PATIENTS WITH COPD - PREDICTORS OF NEED FOR MECHANICAL VENTILATION

Predictive factors in mechanically-ventilated patients with acute exac erbations of chronic obstructive pulmonary disease (COPD) have been ex tensively studied but not in spontaneously breathing patients. The aim of this retrospective study was to evaluate the contribution of param eters of respiratory mechanics, clinical and nutritional status in pre dicting the need for mechanical ventilation (MV) in COPD patients trea ted with medical therapy for an acute exacerbation. Anthropometric dat a,Acute Physiology and Chronic Health Evaluation (APACHE) II score, be dside spirometry, breathing pattern, respiratory mechanics and blood g ases were measured in 39 COPD patients upon hospital admission for exa cerbation of their disease, Fourteen patients in whom MV was necessary were compared with 25 patients in whom medical therapy was enough for a good outcome. The discriminant analysis showed, with decreasing ord er of power, that nutritional prognostic index (NPI), APACHE II score, forced expiratory volume in one second/forced vital capacity (FEV1/FV C) ratio, vital capacity (VC) (% predicted) and FVC (% pred) provided a significant distinction between the two groups, The discriminant equ ation considering NPI, and FVC (% pred) could correctly predict the su ccess in 76% of the patients, A multiparametric stepwise regression an alysis showed that APACHE II score was significantly correlated with N PI, VC (% pred), pressure time index (PTI) and duty cycle, i.e. fracti on of inspiration to duration of total breathing cycle (tI/ttot). In c onclusion, underlying general conditions as assessed by malnutrition a nd APACHE II score were shown to be unfavourable indices of outcome fo r chronic obstructive pulmonary disease patients who experienced an ex acerbation of their disease and were treated with medical therapy, Flo w limitation data as assessed by the forced expiratory manoeuvre may p rovide additional information.