RESUMO
INTRODUCTION: With the ventilatory mechanical attendance has been prolonged the life of the preterm newborn (PTNB) critically sick and during that lapse many occasions it is necessary reintubation to PTNB in two or more times with the subsequent damage that makes enter to the patient to a vicious circle with more damage during the same reintubated. The objective of this study was to determine the factors that predict the extubation failure among PTNB from 28 to 36 weeks of gestational age in two or more times. MATERIAL AND METHODS: It was considered extubation failure when in the first 72 hours of being had extubated the patient; there was reintubation necessity, independent of the cause that originated it. For the second extubation or more took the same approach. During the period of September to December of the 2004 were included in retrospective study to all PTNB that were interned in one hospital of third level that fulfilled the inclusion approaches (one study published where we take account the first extubation failure) and in retrolective study to the patients of the same hospital of January to October of the 2006. They were formed two groups, group A of cases (who failed in extubation two or more times) and the B of controls (who failed in extubation for the first time). The descriptive statistic and the inferential through of Student t test or Mann-Whitney U or rank sum test Wilcoxon, in suitable case; Chi-square or Fisher's exact test was used. Odds ratio (OR) and multivariate analysis for to study predictors factors for the extubation failure was employed. Statistical significance was considered at p < 0.05. RESULTS: The group A it was conformed by 21 patients and the group B for 20 patients. In the multivariate analysis it was association like predictive factor for fail of the second extubation to the presence of postextubation atelectasis with an OR 19.2 with IC to 95% of 3.1-117 (P = 0.001) and preextubation oxygenation index (IO2) >2, OR 5.3, IC to 95% of 1.3-21.4 (P = 0.02). In the bronchoscopy study they were some anatomical alterations that they explained the extubation failure in the second time. CONCLUSIONS: We conclude that it is important to plan an extubation in the PTNB, when there has already been a previous failure, and to avoid the well-known predictors factors for extubation failure as much as possible in the extubation in the PTNB, and that according to that found in this study non to extubate with an IO2 >2, and to manage the atelectasis postextubation intensively. Later to the pursuit of those limits and after a second extubation failure, be probably necessary to pass to bronchoscopy if the patient's conditions allow it.