Effect of Phenylephrine Versus Norepinephrine on Venous Return

Algemeen Ziekenhuis Maria Middelares

Status and phase: Unknown; Phase 4

Conditions: Arterial Hypotension

Treatments: Drug: Phenylephrine; Drug: Norepinephrine

Study type: Interventional

Funder types: Other

Identifiers

NCT03872570

MMS.2019.008

Details and patient eligibility

About

Induction of general anesthesia often induces a decrease in the mean arterial blood pressure (MAP) caused by arterial and venous dilatation. Fluid administration is conventionally used to increase the patient's total blood volume, but is often associated with multiple adverse events such as postoperative edema.

Arterial hypotension can also be treated by vasopressor agents such as norepinephrine and phenylephrine which mainly increase the blood pressure by arterial vasoconstriction.

Compared to phenylephrine, norepinephrine has a shorter half-life (2 - 3 minutes) and improves the MAP by increase in cardiac contractility. In a recent study at our department it was demonstrated that besides arterial vasoconstriction, phenylephrine also improves venous return and cardiac output by venous vasoconstriction.

The aim of this study is to compare the hemodynamic effects of both vasopressor agents in patients undergoing deep inferior epigastric perforators (DIEP) flap surgery. If significant differences between both agents are demonstrated, these findings can provide an important basis for future recommendations.

Full description

In consecutive patients scheduled for DIEP flap surgery, all hemodynamic and respiratory variables are recorded electronically for subsequent off line analysis.

A systolic blood pressure of minimal 100 mmHg will be maintained during surgery by optimization of the cardiac preload and titrated norepinephrine (1.5 µg/kg/h) or phenylephrine (15 µg/kg/h) administration. Cardiac preload optimization will be based on pulse pressure variation (PPV) measurement, which is calculated by pulse contour analysis of the radial arterial pressure curve. Following the international goal-directed fluid therapy guidelines, plasmalyte will be administrated if the PPV>11%.

The tricuspid annular plane systolic excursion (TAPSE) will be measured by transthoracic echocardiography (TTE) to evaluate the inotropic effect of norepinephrine and phenylephrine. In addition, TTE will be used to measure the cardiac output to calibrate the PPV measurements.

Enrollment: 40 estimated patients

Sex: Female

Ages: 18 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult
• patients scheduled for DIEP flap surgery

Exclusion criteria

• unwilling or unable to grant written informed consent
• contra-indications for phenylephrine or norepinephrine
• cardiac arrhythmia
• no necessity for pharmacological blood pressure management

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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40 participants in 2 patient groups

phenylephrine

Active Comparator group

Description:

starts at 15 µg/kg/h phenylephrine and titrated to main a minimal systolic blood pressure of 100 mmHg

Treatment:

Drug: Phenylephrine

norepinephrine

Active Comparator group

Description:

starts at 1.5 µg/kg/h phenylephrine and titrated to main a minimal systolic blood pressure of 100 mmHg

Treatment:

Drug: Norepinephrine