Cardiac Output and Central Venous Oxygen Saturation Monitoring Using the Vigileo FloTrac Sensor Versus Conventional Thermodilution Method Using the Pulmonary Artery Catheter: A Prospective Study

Cardiac Output and Central Venous Oxygen Saturation Monitoring Using the Vigileo FloTrac Sensor Versus Conventional Thermodilution Method Using the Pulmonary Artery Catheter: A Prospective Study

OBJECTIVE: To study the role of Vigileo monitor using the FloTrac sensor to measure cardiac output using the pulse contour analysis as well as central venous oxygen saturation monitoring as a guide for tissue perfusion. The accuracy of the Vigileo monitoring was compared with the conventional thermodilution method for measuring cardiac output using the pulmonary artery catheter and mixed venous oxygen saturation for assessing global tissue perfusion.

DESIGN: A prospective clinical study conducted at the cardiothoracic operating theatre and the cardiothoracic intensive care unit of Sultanah Aminah Hospital Johor Bahru.

PARTICIPANTS: 60 patients from the time of induction of anaesthesia to post operative Day 1 in the cardiothoracic intensive care unit.

INTERVENTIONS: Simultaneous cardiac output measurements using the Vigileo FloTrac sensor and thermodilution method using the PAC will be obtained at the following intervals: Post Induction( T0), Pre CPB( T1), Post CPB( T2), 1 hour post ICU admission( T3), 4 hours post ICU admission( T4), 1 hour post extubation( T5) and post operative Day 1 at 0700(T6). Central venous oxygen saturation measurements and mixed venous oxygen saturation using the PAC was also obtained at similar interval times as above. Low central venous oxygen saturation is defined as less than 70% while low mixed venous oxygen saturation was fixed as less than 65% for appropriate interventions to be instituted to improve oxygen delivery. Arterial blood gases will also be done at the scheduled interval to validate whether the presence of metabolic acidosis can be used to correlate with central or mixed venous oxygen saturation measurements.