Inotropic Effects of Vasopressin Versus Noradrenaline In Patients With Vasoplegic Syndrome After Cardiac Surgery

Summary

This is a randomized, double-blind clinical trial designed to compare the inotropic effects of vasopressin versus norepinephrine in patients who develop vasoplegic syndrome in the immediate postoperative period following cardiac surgery.

Vasoplegic syndrome is characterized by severe hypotension due to systemic vasodilation, despite adequate fluid resuscitation and preserved or elevated cardiac output. Vasopressors are essential in restoring hemodynamic stability in this context; however, their impact on myocardial performance remains uncertain. While norepinephrine is the standard first-line agent, vasopressin has shown potential benefits, including reduced catecholamine exposure and fewer adverse cardiovascular effects.

This study aims to assess changes in cardiac output and other echocardiographic and hemodynamic parameters after administration of either vasopressin or norepinephrine. The findings are expected to contribute to optimizing vasopressor selection in vasoplegic patients after cardiac surgery and improving clinical outcomes.

Conditions

• Vasoplegic Syndrome of Cardiac Surgery

Interventions

DRUG

Vasopressin intravenous infusion

Vasopressin will be administered intravenously in a blinded 250 mL bag of 5% glucose solution, at a final concentration of 0.12 U/mL. The infusion will begin at 5 mL/h and be increased by 2.5 mL/h every 10 minutes during the first hour, up to a maximum rate of 30 mL/h (equivalent to doses from 0.01 to 0.06 U/min). The target is to reach and maintain mean arterial pressure (MAP) ≥65 mmHg. If this is not achieved, open-label norepinephrine may be added. Hemodynamic and echocardiographic parameters will be measured before and after the target MAP is reached.

DRUG

Norepinephrine intravenous infusion

Norepinephrine will be administered intravenously in a blinded 250 mL bag of 5% glucose solution, at a final concentration of 120 µg/mL. The infusion will begin at 5 mL/h and be increased by 2.5 mL/h every 10 minutes during the first hour, up to a maximum rate of 30 mL/h (equivalent to doses from 10 to 60 µg/min). The goal is to reach and maintain MAP ≥65 mmHg. If the MAP target is not reached, open-label norepinephrine may be initiated. Clinical and hemodynamic parameters will be collected at baseline and after MAP stabilization.

Sponsors & Collaborators

• Hospital Universitário Cassiano Antônio de Moraes/HUCAM

  collaborator UNKNOWN

• Hospital Santa Casa de Misericórdia de Vitória

  collaborator UNKNOWN

• University of Sao Paulo

  lead OTHER

Principal Investigators

• Ludhmila A Hajjar, Full Professor · University of Sao Paulo

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-04-01

Primary Completion

2025-07-30

Completion

2025-07-30

Countries

• Brazil

Study Locations