Effects of Phenylephrine on Cardiac Preload
The Dynamic Effects of Phenylephrine on Preload and Cardiac Output in Patients Under General Anaesthesia
  • Phase

    Phase 4
  • Study Type

  • Status

    Completed No Results Posted
  • Study Participants

In patients under general anesthesia, episodes of hypotension are often treated with phenylephrine. The effect of phenylephrine is conventionally attributed to afterload increase.

The aim of the study is to describe the time course of the effects of phenylephrine on the cardiac preload and cardiac output, and to evaluate whether phenylephrine, as an exclusive alpha-mimetic, could be beneficial for preload optimisation.
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.
Study Started
Feb 29
Primary Completion
Jul 31
Study Completion
Sep 30
Last Update
Dec 09

Drug Phenylephrine

Intravenous administration

  • Other names: Phenyl

Patient receiving phenylephrine 2ug/kg Other

phenylephrine 2ug/kg in case of hypotension


Inclusion Criteria:

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
No Results Posted