A study published in critical care journal investigated the predictive ability of various tests for successful weaning from mechanical ventilation and extubation in a prospective, multicenter observational study involving 367 adult patients across four intensive care units. Researchers focused on the cuff leak test, rate of rapid and shallow breathing, cough intensity (0 to 3), and diaphragmatic contraction velocity (DCV) to determine their utility in forecasting the outcome of spontaneous breathing trials (SBT) and extubation.
Key findings include:
Out of 456 SBTs performed, the success rate was 76.5%.
An equation for predicting SBT success was developed, combining cough intensity and DCV. With a cutoff point of ≥0.83, the prediction had a high sensitivity of 91.5% but a low specificity of 22.1%, with an overall accuracy of 76.2%. The area under the receiver operating characteristic (ROC) curve was modest at 0.63.
(0.56 × Cough) − (0.13 × DCV) + 0.25
Another equation to predict extubation success was also created, which factored in SBT results, cough intensity, and DCV. This had a cutoff point of ≥1.25 and yielded a high sensitivity of 96.8% and specificity of 78.4%, with an overall accuracy of 91.5%. The area under the ROC curve for this model was high at 0.91, indicating excellent discriminative capacity.
(5.7 × SBT) + (0.75 × Cough) − (0.25 × DCV) − 4.5
The study concludes that objective measurements of cough intensity and DCV are useful predictors for the success of SBT, and the developed equation incorporating these measurements along with SBT results is a strong predictor of successful extubation.