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New Published Study Finds Noninvasive Masimo PVI Accurately Predicts Fluid Responsiveness in Intensive Care Patients

PVI Predictive Ability Similar to Invasive Pulse Pressure Variation and Superior to Cardiac Output

IRVINE, Calif., Feb. 1, 2011 /PRNewswire via COMTEX/ -- Masimo (Nasdaq: MASI) announced today that a new study published in the peer-reviewed journal Critical Care Medicine demonstrates that noninvasive, continuous monitoring of Masimo Pleth Variability Index (PVI®) predicts fluid responsiveness with high sensitivity (95%) and specificity (91%) in mechanically-ventilated patients in the Intensive Care Unit (ICU).(1) Multiple previous studies have shown that PVI predicts fluid responsiveness in surgical patients--helping clinicians improve fluid management to reduce patient risk,(2, 3, 4) but this is the first published study demonstrating its effectiveness in predicting fluid responsiveness in critically-ill ICU patients.

Hemodynamic instability is a common problem for critically-ill patients, but the decision to administer fluid in an attempt to improve cardiac output is challenging. When necessary, fluid administration is critical to optimizing patient status and enabling end organ preservation, but unnecessary fluid administration is associated with increased morbidity and mortality. However, other dynamic indicators for assessing intravascular fluid volume are either invasive, operator dependent, costly, or unreliable predictors of whether a patient will benefit from fluid administration.

Citing numerous prospective studies showing that "only half of critically-ill patients respond to fluid boluses deemed necessary by attending physicians," researchers from CHU de Poitiers (France) acknowledged the "need for simple, noninvasive, and continuous bedside monitoring capable of detecting fluid responsiveness early in virtually all ICU patients, including those without an arterial catheter" in undertaking the current study. PVI provides clinicians with a noninvasive, continuous, and cost-effective measure for assessing whether patients will benefit from fluid administration--enabling clinicians to provide personalized and goal-directed fluid therapy(1, 2, 3, 4).

To evaluate the predictive ability of fluid responsiveness indicators, study researchers compared three indices in 40 mechanically-ventilated patients with circulatory insufficiency in the ICU. The indices ranged in level of difficulty to perform--from automatic (PVI, noninvasively obtained via the Masimo Radical-7 Pulse CO-Oximeter) to invasive (DeltaPP, respiratory variations in arterial pulse pressure obtained via arterial catheter) to operator-dependent (CO, cardiac output obtained via echocardiography). Each of the indices was recorded before and after fluid challenge, which consisted of either 500mL of 130/0.4 hydroxyethyl-starch (fluid) infused over 10 minutes with the patient in a semi-recumbent position (head at 45 degrees) or passive leg raising (PLR) if DeltaPP <13%--indicating that the patient would be unlikely to respond to fluid administration.

Results showed 21 patients (19 fluid, 2 PLR) were responders--defined as an increase in cardiac output of >15% after fluid or PLR--and 19 patients (2 fluid, 17 PLR) were non-responders. A threshold value of 17% for PVI allowed discrimination between responders and non-responders at 95% sensitivity and 91% specificity and a DeltaPP threshold value of 10% allowed discrimination between responders and non-responders at 100% sensitivity and 95% specificity. However, cardiac output (CO) was unable to reliably predict responders vs. non-responders. Additionally, responders had significantly higher average values vs. non-responders for PVI (28% vs. 11%) and DeltaPP (22% vs. 5%) and both PVI (r=0.72, p<.0001) and DeltaPP (r=0.77, p<.0001) correlated with the percentage change in CO induced by the fluid challenge--suggesting that "the higher PVI or DeltaPP is at baseline, the higher the beneficial effect of volume expansion."

Finding that the "performance of PVI to predict fluid responsiveness was similar to that of DeltaPP," researchers concluded that Masimo PVI "can predict fluid responsiveness in intensive care unit patients under mechanical ventilations." Researchers also noted the implications of using such dynamic fluid responsiveness predictors, commenting that "optimizing the patient's hemodynamic state with DeltaPP or PVI monitoring has potential to decrease duration of hospital stay and mechanical ventilation, postoperative morbidity, and costs in patients undergoing high-risk surgery."

PVI is available as part of Masimo rainbow® SET platform--the first-and-only technology to noninvasively and continuously measure total hemoglobin (SpHb®), oxygen content (SpOC(TM)), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), Pleth Variability Index (PVI®), perfusion index (PI), and acoustic respiration rate (RRa(TM)), in addition to the 'gold standard' Measure-Through Motion and Low Perfusion performance of Masimo SET® oxyhemoglobin (SpO2), and pulse rate (PR).


About Masimo

Masimo (NASDAQ: MASI) is the global leader in innovative noninvasive monitoring technologies that significantly improve patient care--helping solve "unsolvable" problems. In 1995, the company debuted Measure-Through Motion and Low Perfusion pulse oximetry, known as Masimo SET®, which virtually eliminated false alarms and increased pulse oximetry's ability to detect life-threatening events. More than 100 independent and objective studies demonstrate Masimo SET provides the most reliable SpO2 and pulse rate measurements even under the most challenging clinical conditions, including patient motion and low peripheral perfusion. In 2005, Masimo introduced rainbow® SET Pulse CO-Oximetry(TM) technology, allowing noninvasive and continuous monitoring of blood constituents that previously required invasive procedures, including total hemoglobin (SpHb®), oxygen content (SpOC(TM)), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), and Pleth Variability Index (PVI®), in addition to SpO2, pulse rate, and perfusion index (PI). In 2008, Masimo introduced Patient SafetyNet(TM), a remote monitoring and wireless clinician notification system designed to help hospitals avoid preventable deaths and injuries associated with failure to rescue events. In 2009, Masimo introduced rainbow Acoustic Monitoring(TM), the first-ever noninvasive and continuous monitoring of acoustic respiration rate (RRa(TM)). Masimo's rainbow SET technology platform offers a breakthrough in patient safety by helping clinicians detect life-threatening conditions and helping guide treatment options. In 2010, Masimo acquired SEDLine®, a pioneer in the development of innovative brain function monitoring technology and devices. Masimo SET and Masimo rainbow SET technologies can be also found in over 100 multiparameter patient monitors from over 50 medical device manufacturers around the world. Founded in 1989, Masimo has the mission of "Improving Patient Outcome 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

Forward-Looking Statements

This press release includes forward-looking statements as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, in connection with the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based on current expectations about future events affecting us and are subject to risks and uncertainties, all of which are difficult to predict and many of which are beyond our control and could cause our actual results to differ materially and adversely from those expressed in our forward-looking statements as a result of various risk factors, including, but not limited to: risks related to our assumptions regarding the repeatability of clinical results, risks related to our belief that Masimo PVI is capable of detecting fluid responsiveness in virtually all ICU patients, and risks related to our assumptions that Masimo PVI monitoring has the potential to decrease hospital stay, mechanical ventilation, postoperative morbidity, and costs in patients undergoing high-risk surgery, as well as other factors discussed in the "Risk Factors" section of our most recent reports filed with the Securities and Exchange Commission ("SEC"), which may be obtained for free at the SEC's website at Although we believe that the expectations reflected in our forward-looking statements are reasonable, we do not know whether our expectations will prove correct. All forward-looking statements included in this press release are expressly qualified in their entirety by the foregoing cautionary statements. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of today's date. We do not undertake any obligation to update, amend or clarify these statements or the "Risk Factors" contained in our most recent reports filed with the SEC, whether as a result of new information, future events or otherwise, except as may be required under the applicable securities laws.

Masimo, SET, Signal Extraction Technology, Improving Patient Outcome and Reducing Cost of Taking Noninvasive Monitoring to New Sites and Applications, rainbow, SpHb, SpOC, SpCO, SpMet, PVI, rainbow Acoustic Monitoring, RRa, Radical-7, Rad-87, Rad-57, Rad-8, Rad-5, Pulse CO-Oximetry, Pulse CO-Oximeter, and SEDLine are trademarks or registered trademarks of Masimo Corporation.

Media Contacts:
Dana Banks
Phone: (949) 297-7348


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