The correlation between internal jugular vein variability during deep inhalation and the decrease in blood pressure during propofol induction.

1. Ultrasound records at least one quiet breathing cycle and one deep inhalation cycle to calculate IJVV
2. Propofol was infused target-controlled at 4 μg/ml, and changes in arterial blood pressure within 3 minutes of propofol induction were observed.
3. Aim to conduct a prospective observational study to evaluate the correlation between internal jugular vein variability during deep inhalation and the decrease in blood pressure during propofol induction.

Inclusion Criteria:

• age over 60 years
• American Society of Anesthesiology (ASA) status Ⅱ-Ⅲ
• Surgery with radial artery puncture
• Propofol induction

Exclusion Criteria:

• BMI≥30kg/m2
• People with short necks;
• Previous hypotension (systolic blood pressure <90mmHg or mean arterial pressure <65mmHg)
• Previous poorly controlled hypertension
• Cardiac insufficiency , EF value<50%
• Upper limb deep vein thrombosis
• History of radiotherapy or neck surgery
• Inability to maintain a supine position for necessary measurements
• Mechanical ventilation status or inability to take deep breaths patients
• gastrointestinal surgery
• patients allergic to propofol.

Patients undergoing intravenous general anesthesia surgery at Jiaxing First Hospital