Masimo Announces Continuous Noninvasive Functional Hemodynamic Monitoring With Plethysmograph Variability Index (PVI)

Symposium presentation during the 2007 European Society of Anaesthesia Congress in Munich, Germany cites independent research showing the potential value of this new noninvasive diagnostic tool

Irvine, California June 20, 2007 - Masimo, the inventor of Pulse CO-Oximetry and Read-Through Motion and Low Perfusion pulse oximetry, reported that new independent studies presented at a symposium during the European Society of Anaesthesia in Munich, Germany last week indicated that Masimo's Plethysmograph Variability Index (PVI), a noninvasive measurement that quantifies changes in the plethysmographic waveform derived from pulse oximetry, can provide clinicians with a noninvasive way to monitor functional hemodynamics in their patients.

Clinicians who have evaluated PVI believe this technology will prove to be a valuable clinical tool with significant advantages over currently available indicators of changes in functional hemodynamics that are invasive, operator dependent, often inaccurate, and expensive. PVI displays a numeric representation of the changes to the pleth waveform on the pulse oximeter and allows clinicians to track and trend these changes over time as well as a Diagnostic Plethysmograph that maintains the morphology of the true pleth for clinicians to view.

In his presentation in Munich, Maxime Cannesson, MD from the Claude Bernard University and Louis Pradel Hospital in Lyon, France cited research he co-authored entitled Ability of a Novel Algorithm for Noninvasive Automatic Estimation of the Respiratory Variations in the Pulse Oximeter Waveform to Detect Changes in Ventricular Preload scheduled for publication in the journal Anesthesiology later this year that indicates Masimo's PVI method of quantifying changes in ventricular preload, and therefore the ability of the heart to pump adequate blood to the tissues, correlated well with invasive methods.1

Dr. Cannesson said the authors had demonstrated in an earlier study that a change in the beat to beat amplitude of the oximeter waveform of greater than 15% predicted whether a patient was able to adapt to fluid restoration with an appropriate physiological response.2

Dr. Cannesson said that it was his belief that "Pleth Variability Index can automatically and noninvasively detect changes in ventricular preload in mechanically ventilated patients in the operating room. PVI shows great promise for use in perioperative fluid optimization which will have both clinical and economical impact. Other clinical applications for PVI are in the areas of fluid depletion/restriction, mechanical ventilator settings/adjustments, detection of changes in myocardial contractility."

Other clinicians have concurred with these observations and feel that the ability of Masimo Rainbow SET oximeters to display PVI may provide them with a useful clinical data point in the management of their patients.

Dr. Mitchell Goldstein of Loma Linda University Children's Hospital said "Trending of PVI may be useful in monitoring critical care and surgical patients, both intraoperatively and postoperatively, for appropriate hydration and ventilation status."

Dr. Dan Redford of the University of Arizona, University Medical Center added "PVI may be useful in monitoring surgical patients, for appropriate intravascular volume status. For example, a rising PVI may indicate developing hypovolemia, and a falling PVI post-fluid resuscitation is evidence of an appropriate fluid responsiveness, and important measure in the critical care/OR environment."

About Masimo
Masimo develops innovative monitoring technologies that significantly improve patient care-helping solve "unsolvable" problems. In 1995, the company debuted Read-Through Motion and Low Perfusion pulse oximetry, known as SET and with it virtually eliminated false alarms and increased pulse oximetry's ability to detect life-threatening events. More than 100 independent clinical studies have confirmed that Masimo SET technology allows clinicians to accurately monitor blood oxygen saturation in critical care situations-establishing the technology as the "gold standard" pulse oximetry and substantially contributing to improved patient outcomes. In 2005 Masimo introduced Masimo Rainbow SET Pulse CO-Oximetry, which, for the first time, noninvasively monitors the level of carbon monoxide and methemoglobin in the blood, allowing early detection and treatment of potentially life-threatening conditions. Masimo, founded in 1989, has the mission of "Improving Patient Outcomes and Reducing Cost of Care by Taking Noninvasive Monitoring to New Sites and Applications." Additional information about Masimo and its products may be found at www.masimo.com.

1 "Ability of a Novel Algorithm for Noninvasive Automatic Estimation of the Respiratory Variations in the Pulse Oximeter Waveform to Detect Changes in Ventricular Preload", Maxime Cannesson, Bertrand Delannoy, Antoine Morand, Pascal Rosamel, Jean-Jacques Lehot. Anesthesiology 2007 (In Press).
2 "Relation Between Respiratory Variations in Pulse Oximetry Plethysmographic Waveform Amplitude and Arterial Pulse Pressure in Ventilated Patients", Maxime Cannesson, Cyril Besard, Pierre G. Durand, Julien Bohe, and Didier Jacques. Critical Care 2005.