Ultrasound of the Inferior Vena Cava in the Prevention of Hypotension After Induction of General Anesthesia

Inclusion criteria

• Elderly patients undergoing elective non-cardiac surgery under general anesthesia;
• Age 65-85 years old;
• Body mass index (BMI) 18-28 kg/m2;
• American society of anesthesiologists (ASA) class I-III.

Exclusion criteria

• Patient refusal or lack of cooperation;
• Inability to communicate properly;
• Severe sinus bradycardia, pacemaker implantation, atrioventricular block, and atrial fibrillation;
• Presence of severe hepatic and renal function abnormalities;
• Preoperative cardiac ultrasound suggesting LVEF <50%;
• Tricuspid valve displacement <16 mm by preoperative cardiac ultrasound;
• Chronic obstructive pulmonary disease;
• Pulmonary hypertension;
• Administration of drugs that inhibit the renin-angiotensin-aldosterone system;
• Possibility of a difficult airway.