Abstract
Background and Objectives: Several indices have been widely used with high sensitivity but lack specificity to predict weaning outcome. Electrical activity of diaphragm (Edi) represents a neural input from brain directly, increased in Edi amplitude is proportional to inspiratory effort. This study was designed to identify the Edi as a weaning parameter.
Methods: Prospective observational study. Fifty-two patients in adult ICU who were on ventilator with pressure support less than 8 cmH2O. Routine patient's readiness for weaning (rapid shallow breathing index, negative inspiratory pressure, vital capacity) were measured. An electrical diaphragmatic activity catheter was inserted. Edi at end-expiratory (min Edi) and at inspiratory phase (max Edi) were recorded during quiet breathing. Patients were instructed to make a full inspiration, peak Edi was measured over 3 trials, with the largest being recorded. Spontaneous breathing trial was started by primary doctors who were blinded to the Edi values. Successful weaning was defined by patient who can maintain spontaneous breathing more than 24 hours after discontinuation of mechanical ventilator.
Results: Forty-two patients (80.2%) were successful weaning. Difference between peak Edi and max Edi was significant higher in the successful weaning 18.33 (12.53-27.17) µV than the weaning failure 8.32 (4.03-13.83) µV. The ROC analysis showed AUC=0.786 (p=0.013), and delta Edi at the cut-off point of 16.6 µV had a sensitivity of 69.7%, a specificity of 87.5%.
Conclusions: Patients who can generate a higher difference of diaphragmatic activity from tidal breathing to full inspiration may have better preserved diaphragmatic function and better weaning outcome.
- Copyright ©the authors 2016
