Ultrasonography of Diaphragm to Predict Extubation Outcome

Background and objectives An intensivist's decision, when it comes to weaning off a patient from mechanical ventilation and extubation, is based on many criteria. Problems can be associated with both prolonged ventilation and early extubation. Therefore, for optimal functioning of the diaphragm, the primary inspiratory muscle, it is important to resume spontaneous ventilation after extubation irrespective of the cause of respiratory failure. Thus, diaphragmatic parameters can prove useful in predicting the rate of success of extubation. However, till date in our institute, extubation has been done using only the standard parameters; hence, in this study, diaphragmatic parameters obtained by ultrasonography-diaphragmatic thickening fraction (dTF) and diaphragmatic excursion (DE) have been studied to predict extubation outcome. The objectives of this study are to (1) measure the diaphragmatic thickening fraction (dTF) in % and diaphragmatic excursion (DE) in cm before and after the spontaneous breathing trial (SBT) and (2) compare dTF and DE with standard extubation parameters in order to predict extubation outcome. Materials and methods This is a prospective, double-blind, observational study. The number of patients involved was 41. After obtaining ethical committee clearance, informed consent was taken from the patients' attendants. In this study, we divided doctors into the treating team and the research team. The treating team comprised the primary doctors working in the intensive care unit (ICU), and they evaluated the patients' readiness for pressure support ventilation. The research team performed diaphragmatic ultrasonography on those patients who met the inclusion criteria. The treating team was blinded to the dTF and DE results obtained by the research team. Prior to extubation, all the patients had to satisfy the standard extubation criteria followed at R. L. Jalappa Hospital and Research Centre (RLJH), Kolar Results We observed that 68.29 (%) of the patients with normal dTF and DE values and 21.95(%) with slightly lower dTF and DE values were extubated successfully, and 7.31 (%) with normal dTF and DE values were reintubated; 2.43 (%) were extubated onto non-invasive ventilation (NIV). Conclusion From our study, we have concluded that bedside ultrasonography of the diaphragm, that is the measurement of diaphragm for dTF and DE always compliments the standard criteria for extubation and can be used for weaning the patients from mechanical ventilation, as bedside ultrasonography is not only easy and convenient but also a reliable parameter in predicting the outcome of weaning, however, it cannot be used as a sole criteria.