Exploring the Use of Pulse Tissue Doppler in Predicting Extubation Success in Mechanically Ventilated Patients

Predicting Extubation Outcomes in Mechanically Ventilated Patients Using PW-TDI Diaphragmatic Kinematics and Traditional Ventilation Parameters: A Prospective Study

Determining the appropriate extubation timing for mechanically ventilated patients is a critical issue in the Intensive Care Unit (ICU). Early or delayed extubation may prolong mechanical ventilation and ICU stay, leading to an increased mortality rate. Currently, extubation timing relies solely on the Spontaneous Breathing Trial (SBT), but its reliability is relatively low, with a extubation failure rate ranging from 10% to 40%. Therefore, accurately predicting potential post-extubation issues and early identification of reasons for SBT trial failure are crucial for improving patient outcomes. Commonly used parameters for assessing readiness for extubation do not fully reflect organ dysfunction, and the investigators plan to utilize comprehensive techniques, including bedside lung and diaphragm ultrasound parameters, to enhance the accuracy of predicting extubation outcomes in patients who pass the SBT trial.

All patients included in the study underwent a spontaneous breathing trial (SBT) using pressure support ventilation (PSV) strategy. This strategy employed pressure support(PS)≤9 cmH2O and positive end-expiratory pressure (PEEP)≤5 cmH2O. The duration of the trial was 30 minutes, and the FiO2 level was set at the same level (≤0.5) used during mechanical ventilation. After successful completion of the spontaneous breathing trial (SBT), ultrasound images were promptly acquired, and the Rapid Shallow Breathing Index (RSBI) was calculated based on the values displayed by the ventilator . Simultaneously, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score was computed and recorded. The decision to extubate, made by the attending physician (unaware of the ultrasound examination parameters), was based on clinical judgment. The primary endpoint event was extubation failure, defined as successful completion of SBT but an inability to sustain spontaneous breathing for more than 48 hours without noninvasive or invasive ventilation support.

Inclusion Criteria:

• Patients were enrolled if participants had been intubated and mechanically ventilated for more than 24 hours and were ready for participants first SBT according to ICU weaning criteria.

Exclusion Criteria:

• paralytic drugs taken within 24 hours prior to the trial;
• diagnosis of diaphragmatic paralysis or paradoxical movement of the hemidiaphragm detected by ultrasound or poor imaging quality;
• Pregnancy;
• Ascites;
• age<18years;
• Post-thoracotomy;
• Existence of pneumothorax;
• presence of large pleural effusion, subcutaneous emphysema, flail chest or right-sided rib fractures;
• presence of neuromuscular diseases.