Effects of Phenylephrine on Cardiac Preload

In consecutive patients scheduled for laparoscopic sigmoidectomy, all hemodynamic and respiratory variables are recorded electronically for subsequent offline analysis.

All patients are ventilated in volume control mode with a tidal volume of 8 ml/kg ideal body weight.

During steady-state Target Controlled Infusion (TCI) propofol/remifentanil anesthesia, when the Mean Arterial Blood Pressure (MAP) dropped below 80% of the awake state for at least 5 minutes, a phenylephrine bolus of 2 μg/kg is administered. If necessary this is repeated, or a continuous administration of phenylephrine is started at a rate of 10-30 μg/kg/u.

All patient manipulations during the procedure are electronically recorded and time stamped for subsequent off-line data analysis.

The first episode in each patient where phenylephrine is administered and in a period of at least 10 minutes when minimal or absent patient manipulation occurred, the hemodynamic variables are analysed to describe the effects of phenylephrine administration on the dynamic preload parameters and macro-hemodynamics.

Inclusion criteria

• Adult
• necessity for arterial blood pressure monitoring
• necessity for central venous blood pressure monitoring

Exclusion criteria

• unwilling or unable to grant written informed consent
• cardiac arrythmia
• contra-indication for phenylephrine
• contra-indications for atropine
• contra-indication for Total Intravenous Anesthesia