Valor preditivo da raz？o entre espa？o morto e volume corrente fisiológicos no processo de desmame da ventila？？o mecanica em crian？as

objective: to evaluate the physiological deadspace/tidal volume ratio (vd/vt) as a predictor of extubation failure in 42 ventilated children (median age: 4.75 years). method: extubation readiness was determined using the criteria proposed by the 6th international consensus conference on intensive care medicine adapted to children. results: non-invasive ventilation (niv) was used in four patients who developed respiratory failure after extubation; none was reintubated. children who needed niv to avoid reintubation had a significantly higher vd/vt ratio than those who were extubated without niv (p < 0.001). the cut-off value of vd/vt ratio was 0.55 and the area under the receiver operating characteristic curve was 0.86. conclusion: our findings confirm the good predictive value of weaning success/failure of the vd/vt ratio and suggest its role for predicting the need for niv after extubation.