The aim of the study is to compare end expiratory occlusion test to passive leg raising test for prediction of fluid responsiveness in post cardiac surgery mechanically ventilated patients.

Circulatory hypervolemia and hypovolemia are both associated with worse outcomes.Intravenous fluids are similar to drugs, with serious adverse effects and changeful efficacy. Fluids should be administered only if indicated. Passive leg raising test transiently increase venous return which can be used to evaluate fluid responsiveness.There is growing evidence that the End expiratory occlusion (EEO) test reliably detects fluid responsiveness. In patients under mechanical ventilation, the inspiration increases intra-thoracic pressure and decreases venous return. The expiratory hold augments the cardiac preload which, in case of preload responsiveness, leads to a significant increase of cardiac output (CO).EEO prevents any variation in intra-thoracic pressure leading to an increase in venous return, cardiac preload and stroke volume in preload-responsive patients. There're no studies comparing EEO with passive leg raising test in cardiac surgery patients. So, this is the target of the study.

Inclusion Criteria:

• Age group: 21-60years old
• Sex: eligible both sexes
• Post cardiac surgery
• Sedated intubated mechanically ventilated patients (Controlled ventilation with no respiratory effort)

Exclusion Criteria:

• Patients refusal
• Pregnancy or any medical condition that may affect the intra abdominal pressure.
• Lower limb deep venous thrombosis Open chest conditions impaired left-ventricular ejection fraction (<45%), arrhythmias, inter-ventricular shunt, severe peripheral arterial occlusive disease and the need for intra-aortic balloon counter pulsation