Utilization of spontaneous breathing trial, objective cough test, and diaphragmatic ultrasound results to predict extubation success: COBRE-US trial

Abstract

Background: The results of clinical and weaning readiness tests and the spontaneous breathing trial (SBT) are used to predict the success of the weaning process and extubation.

Methods: We evaluated the capacity of the cuff leak test, rate of rapid and shallow breathing, cough intensity, and diaphragmatic contraction velocity (DCV) to predict the success of the SBT and extubation in a prospective, multicenter observational study with consecutive adult patients admitted to four intensive care units. We used receiver operating characteristic (ROC) curves to assess the tests' predictive capacity and built predictive models using logistic regression.

Results: We recruited 367 subjects who were receiving invasive mechanical ventilation and on whom 456 SBTs were performed, with a success rate of 76.5%. To predict the success of the SBT, we derived the following equation: (0.56 × Cough) - (0.13 × DCV) + 0.25. When the cutoff point was ≥ 0.83, the sensitivity was 91.5%, the specificity was 22.1%, and the overall accuracy was 76.2%. The area under the ROC curve (AUC-ROC) was 0.63. To predict extubation success, we derived the following equation: (5.7 × SBT) + (0.75 × Cough) - (0.25 × DCV) - 4.5. When the cutoff point was ≥ 1.25, the sensitivity was 96.8%, the specificity was 78.4%, and the overall accuracy was 91.5%. The AUC-ROC of this model was 0.91.

Conclusion: Objective measurement of cough and diaphragmatic contraction velocity could be used to predict SBT success. The equation for predicting successful extubation, which includes SBT, cough, and diaphragmatic contraction velocity values, showed excellent discriminative capacity.

Keywords: Airway extubation; Cough; Diaphragm; Mechanical ventilation.

Fig. 1

Criteria for initiating the weaning process. SBP systolic blood pressure, HR heart rate, Hb, hemoglobin, ICU intensive care unit, CAM-ICU confusion Assessment method for the ICU, SaO2 oxygen saturation, FiO2 Fraction of Inspired Oxygen, PaO2/FiO2 ratio of partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen concentration, PEEP Positive End-Expiratory Pressure, RSBI rapid shallow breathing index

Fig. 2

Violin plot of the objective cough measurement by spontaneous breathing test (SBT) success. Violin plot illustrating objective cough measurement data distribution within successful and unsuccessful Spontaneous Breathing Test (SBT) groups. The density curves visually represent data point frequency across the distribution range. In this figure, the width of each curve is proportionate to the approximate frequency of data points within the corresponding region. Red lines represent median values for each group, while green lines denote the 25th and 75th percentiles

Fig. 3

ROC curve of the successful extubation and successful breathing trial prediction model. SE successful extubation, SBT spontaneous breathing trial success, AUC-ROC area under the ROC curve

Fig. 4

Violin plot of the objective cough measurement by extubation success. Violin plot illustrating objective cough measurement data distribution within successful and unsuccessful extubation groups. The density curves visually represent data point frequency across the distribution range. In this figure, the width of each curve is proportionate to the approximate frequency of data points within the corresponding region. Red lines represent median values for each group, while green lines denote the 25th and 75th percentiles