The Clinical Research On Predicting Outcome Of The Difficult-to-wean By Central Venous Oxygen Saturation

Objective To evaluate the value of central venous oxygen saturation(Scv02) in predicting weaning outcome in difficult-to-wean patients.Methods184patients had taken214cases of weaning, the cases were divided into weaning success group and weaning failure group according to weaning outcome in this study, and also stratified as cardiac dysfunction group and non-cardiac dysfunction group according to whether the patients with cardiac dysfunction when they were transferred to ICU. Patients’age, admission APACHE II score, death risk factors, oxygenation index before weaning were recorded. Patients’heart rate, respiratory rate, blood pressure and oxygen saturation were recorded at the moment of disconnecting the ventilator, peripheral arterial blood and central venous blood were taken to check blood gas, then we got arterial oxygen saturation and central venous oxygen saturation. Repeat above mentioned operating sequence at the30t hmin of spontaneous breathing trail(SBT), make the ScvO2at the moment of disconnecting the ventilator subtracting the ScvO2at the30th min of SBT, the difference value we got was recorded as ΔScvO2. Analysed the differences between these parameters in weaning success group and weaning failure group, determine which indicators to influence the result of weaning.Result (1)Among the214cases of weaning, there was difference in ScvO2at the30th min of SBT and in ΔScvO2between weaning success group and weaning failure group(74.6±6.6VS71.4±5.5, p<0.05and2.76±4.16VS4.63±3.71, p<0.05), and there was no difference of the rest of the parameters in weaning success group and weaning failure group. The cut off value of ΔScvO2to predicting weaning failure was3.65%, the sensitivity was73.3%and the specificity was60.3%.(2) Stratified analysis showed:only the ScvO2at the30th min of SBT and ΔScvO2had difference between weaning success group and weaning failure group of cardiac dysfunction patients(73.6±5.2VS70.4±5.2, p<0.05and2.61±3.13VS5.08±2.38, p<0.01), there was no difference in cardiac dysfunction group and non-cardiac dysfunction group of the remaining parameters. The cut off value of ΔScvO2to predicting cardiac dysfunction patients’ weaning failure was4.0%, the sensitivity was85.0%and the specificity was73.6%.Conclusions The ScvO2at the30th min and ΔScvO2could predict weaning outcome of difficult-to-wean patients; stratified analysis showed that ScvO2at the30th min of SBT and ΔScvO2could have predictive value for weaning failure only in patients with cardiac dysfunction; ΔScvO2≥4.0%could be regarded as a predictive factor of weaning failure in patients with cardiac dysfunction.