Internal Jugular Venous Distensibility Index and Innominate Venous Flow Patterns As Predictors of Fluid Responsiveness

Inclusion criteria

• Utilizing intraoperative mechanical ventilation with a tidal volume of 8 ml/kg (PBW).
• ASA physical status 1-3.
• Mongoloid ethnicity.
• Willing to participate in the research and sign the informed consent.

Exclusion criteria

• Patients with symptoms and signs of fluid overload, such as pulmonary edema, pleural effusion, ascites, and peripheral edema.
• Patients with chronic or acute kidney dysfunction, renal replacement therapy history, and/or oliguria (urine output <0.5 ml/kg/hour).
• Patients with cardiovascular diseases, including heart failure, cardiac arrhythmias, moderate-to-severe valvular abnormalities, a history of angina/myocardial infarction, pulmonary hypertension, and peripheral artery disease.
• Patients with anatomical abnormalities in the neck and chest region that make it impractical to perform jugular vein ultrasound and transthoracic echocardiography.
• Jugular vein thrombosis.
• Superior vena cava syndrome.
• Placement of jugular vein catheter.
• Body mass index (BMI) greater than 30.0 kg/m2.
• Patients with contraindications to the use of muscle relaxants.
• Patients with lung hyperinflation and pleural effusion.

Drop out criteria:

• Patients who wish to withdraw from the study.
• Post-anesthesia induction complications and emergencies.
• Transthoracic echocardiography provides a less representative image due to difficult acoustic window.