Although induced hypertension decreased SVV and PPV,the influences of stroke volume variation and pulse pressure variation caused by phenylephrine,dopamine and ephedrine were unknown.

Pulse pressure variation (PPV) and stroke volume variation (SVV) during mechanical ventilation have been shown to be effective parameters to predict preload responsiveness. Although induced hypertension decreases PPV and SVV, the influences of phenylephrine, dopamine and ephedrine on PPV and SVV are unknown.

Inclusion Criteria:

• Their American Society of Anesthesiologists (ASA) physical status was 1 or 2
• Body mass index (BMI) ranged from 18 to 26
• None of the patients had known diabetes mellitus, hypertension, cardiovascular, pulmonary, endocrinological, neurological diseases, or diseases that influenced intravascular fluid volume or balance
• All patients had a preoperative fast for at least 8 h and routine atropine intramuscular injection

Exclusion Criteria:

• Persistent arrhythmias
• Intraoperative application of vasoactive drugs except phenylephrine, dopamine and ephedrine