Ultrasonographic Monitoring of the Diaphragm during Mechanical Ventilation: The Vital Pump Is Vivid, Plastic, and Vulnerable

Diaphragmatic Ultrasonography, a Novel Approach in Critical Care: A Proposal for a New Weaning Index

The evaluation of the diaphragm in critically ill patients is simple and noninvasive and has shown good repeatability. The aim of the study was to generate a predictive index for successful weaning (ULDIMex) from invasive mechanical ventilation (IMV) based on an ultrasonographic diaphragmatic assessment before performing a spontaneous breathing test. We recruited patients who required IMV and who were candidates for weaning from ventilation. The measurement of diaphragmatic excursion and time during inspiration and expiration was obtained with a 3- to 5-MHz probe in the M mode. Using the formula (a + b)c/2, the value for the ULDIMex was obtained to evaluate its impact on predicting the successful weaning of IMV, where a is the time during the inspiratory phase, b is the time during expiration, and c is the diaphragmatic excursion during the inspiratory phase, which corresponds to the highest point of the curve from the baseline. We recruited 114 patients, of whom 86 (76%) were successfully weaned from IMV. The patients who were successfully weaned from the IMV had a cutoff value greater than 4.06 cm/s for the ULDIMex index, with a sensitivity of 92.8% (95% confidence interval, 76.5-99.1), specificity of 63.9% (95% confidence interval, 52.9-74.0), positive predictive value of 45.6%, and negative predictive value of 96.5%. The ULDIMex index demonstrated a good level of discrimination for successful weaning prediction. Considering the excellent negative likelihood ratio of the ULDIMex index of greater than 4.06, this index may be considered before performing an spontaneous breathing test to identify critically ill adult patients who will extubate successfully.

Update in Critical Care 2015

This review documents important progress made in 2015 in the field of critical care. Significant advances in 2015 included further evidence for early implementation of low tidal volume ventilation as well as new insights into the role of open lung biopsy, diaphragmatic dysfunction, and a potential mechanism for ventilator-induced fibroproliferation. New therapies, including a novel low-flow extracorporeal CO2 removal technique and mesenchymal stem cell-derived microparticles, have also been studied. Several studies examining the role of improved diagnosis and prevention of ventilator-associated pneumonia also showed relevant results. This review examines articles published in the American Journal of Respiratory and Critical Care Medicine and other major journals that have made significant advances in the field of critical care in 2015.