Background: Cardiac dysfunction can prevent successful discontinuation of mechanical ventilation. An estimated 9% to 37% of all mechanically ventilated patients exhibit significant difficulty during the transition from positive pressure to spontaneous ventilation or weaning. This study aims to describe and compare hemodynamic parameters between baseline mechanical ventilation and pressure support mode weaning trial. Methods: One hundred thirty – Two patients were involved in this study and received mechanical ventilation and divided into two groups according to the success of spontaneous breathing trial. Hemodynamics data was recorded by connection to the monitoring system, cental line was inserted and cardiac output was evaluated by transthoracic echo at the following time points: Baseline during the last 6 hours of mechanical ventilation before the weaning trial, Half an Hour, One Hour after the start of the weaning trial and End of the Trial 2-hour from weaning trial. Results: In the fourth assessment after extubation, the group with successful spontaneous ventilation exhibited significantly better outcomes compared to the unsuccessful group.This highlights the importance of these hemodynamic parameters in predicting weaning success. Conclusion:During the fourth assessment after extubation, there were significantly superior outcomes across multiple hemodynamic parameters. Specifically, marked improvements in heart rate, blood pressure (both systolic and diastolic), oxygen saturation, and cardiac index in Group 1 compared to Group 2. These findings suggested the important role of these hemodynamic parameters in delineating successful transitions from mechanical ventilation to spontaneous breathing.