Correlation Between Internal Jugular Vein Ultrasound and Electrical Cardiometry

Inclusion Criteria: * Adult patients (above 18 years old to be able to provide advanced informed consent Planned for elective CABG surgery) both male and female will be included in the study Exclusion Criteria: * Severely reduced preoperative left ventricular ejection fraction (\< 40 %). * Patients who will develop any complication after fluid infusion as pulmonary edema and heart failure will be excluded from the study. * Significant cardiac arrhythmia. * Significant valvular heart disease. * Clinically evident pulmonary disease. * Bilaterally inserted venous catheters (jugular or subclavian vein). * History of radiotherapy or surgery of the neck region. * Inability to obtain interpretable ultrasound images due to a difficult acoustic window.