The Observation on Risk of Ventilator Failure Weaning by Ultrasound bedside Monitoring of Inferior Vena Cava and Lung B Line

Objective: This study was designed to investigate risk of ventilator weaning by ultrasound bedside monitoring of the width of inferior vena cava (IVC) and the number of lung B-lines (B-lines). Methods: This study was conducted on 106 patients from January 2019 to January 2020 who had mechanical ventilation for more than 48 hours in an emergency care unit. They were clinically stable and had the criteria for weaning from the ventilator. Before Spontaneous Breathing Test (SBT) and 30 min or 120 min after SBT, the width of IVC and the number of B-lines in patients were monitored via bedside ultrasound. There were 87 cases of successful weaning as a control group and 19 cases of ventilator failure weaning as a study group. Changes of the width of IVC and the number of B-lines were compared in the different stages of SBT. Results: A total of 106 patients were included in this study. There were 87 cases of ventilator successful weaning and 19 cases failure weaning. The weaning success rate was 82.08%. The width of IVC and the number of B-lines in the study group were higher than those in the control group in same stage of SBT, the difference was statistically significant (P < 0.05), and which increased significantly with time. There was no significant difference in the width of IVC and the number of B-lines on the different stage of SBT in the control group (P > 0.05), and significant difference in the study group. Conclusion: The width of IVC and the number of B-lines monitored by bedside ultrasound can assess the risk of ventilator weaning, it may be caused by cardiopulmonary interaction.