Transthoracic Echocardiography with Doppler Tissue Imaging predicts weaning failure from mechanical ventilation: evolution of the left ventricle relaxation rate during a spontaneous breathing trial is the key factor in weaning outcome

Abstract

IntroductionThere is growing evidence to suggest that transthoracic echocardiography (TTE) should be used to identify the cardiac origin of respiratory weaning failure. The aims of our study were: first, to evaluate the ability of transthoracic echocardiography, with mitral Doppler inflow E velocity to annular tissue Doppler Ea wave velocity (E/Ea) ratio measurement, to predict weaning failure from mechanical ventilation in patients, including those with atrial fibrillation; and second, to determine whether the depressed left ejection fraction and/or diastolic dysfunction participate in weaning outcome.MethodsThe sample included patients on mechanical ventilation for over 48 hours. A complete echocardiography was performed just before the spontaneous breathing trial (SBT) and 10 minutes after starting the SBT. Systolic dysfunction was defined by a left ventricle ejection fraction under 50% and relaxation impairment by a protodiastolic annulus mitral velocity Ea under or equal to 8 cm/second.ResultsA total of 68 patients were included. Twenty failed the weaning process and the other 48 patients succeeded. Before the SBT, the E/Ea ratio was higher in the failed group than in the successful group. The E/Ea measured during the SBT was also higher in the failed group. The cut-off value, obtained from receiver operating characteristics (ROC) curve analysis, to predict weaning failure gave an E/Ea ratio during the SBT of 14.5 with a sensitivity of 75% and a specificity of 95.8%. The left ventricular ejection fraction did not differ between the two groups whereas Ea was lower in the failed group. Ea increased during SBT in the successful group while no change occurred in the failed group.ConclusionsMeasurement of the E/Ea ratio with TTE could predict weaning failure. Diastolic dysfunction with relaxation impairment is strongly associated with weaning failure. Moreover, the impossibility of enhancing the left ventricle relaxation rate during the SBT seems to be the key factor of weaning failure. In contrast, the systolic dysfunction was not associated with weaning outcome.

Ventilator Liberation for High-Risk-for-Failure Patients: Improving Value of the Spontaneous Breathing Trial

“…50 In a small study of mechanically ventilated subjects, an E/EЈ cutoff value of 14.5 during an SBT trial had a sensitivity of 75% and specificity of 95.8% in predicting failure of extubation (4/20 subjects) or failure of SBT (16/20 subjects). 53 Further studies with focus on HRFF patients could establish ultrasound as a very useful tool during the SBT assessment.…”

Tracheal ExtubationDiscussion

“…39,40 Echocardiography and serum brain natriuretic peptide levels have been used to assess cardiac dysfunction as a cause of weaning failure. 41,42 Strategies for treatment include afterload reduction with vasodilators, preload reduction with diuretics, and CPAP.…”

Tei Index versus Pro BNP as Predictors of Weaning Failure in Mechanically Ventilated Chronic Obstructive Pulmonary Disease Patients

“…Additionally, the impossibility of enhancing the left ventricle relaxation rate during the SBT seemed to be the key factor of weaning failure. In contrast, the systolic dysfunction was not associated with weaning outcome [16]. Papanikolaou et al evaluated 50 patients with Doppler echocardiography to predict outcome of weaning trials.…”