Masimo's Noninvasive Pleth Variability Index as Accurate as Invasive Stroke Volume Variation for Fluid Responsiveness Assessment in Cardiac Surgery

August 7, 2012

IRVINE, Calif., Aug. 7, 2012 /PRNewswire via COMTEX/ --Masimo (NASDAQ: MASI) announced today a new study in the Journal of Anesthesia demonstrates that for fluid responsiveness assessment, Masimo's noninvasive Pleth Variability Index (PVI®) is as accurate as invasive stroke volume variation (SVV) in patients undergoing cardiopulmonary bypass surgery.1 In the study conducted at the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, researchers evaluated 18 patients who underwent elective cardiopulmonary bypass surgery. All patients had a central venous catheter as well as a femoral arterial catheter monitored with the PiCCO monitor (PiCCO2; Pulsion Medical Systems) for continuous measurement of SVV and intermittent assessment of cardiac index. PVI was measured using the Masimo Radical-7® monitor.

Fluid responsiveness was defined as a >10% increase in cardiac index after fluid administration and non-responsiveness was defined as <10% increase in cardiac index after fluid administration. Out of 22 fluid challenges, four resulted in a significant increase in cardiac index, while 18 did not. The optimal threshold value for fluid responsiveness was >11% for SVV and >16% for PVI. Both PVI and SVV correctly identified each of the four responders (100% sensitivity), while PVI identified 16 of 18 non-responders (89% sensitivity) and SVV identified 13 of 18 non-responders (72% sensitivity). Receiver operator characteristic curve analysis, which takes into account both sensitivity and specificity, showed a 0.95 area under the curve (AUC) for PVI and 0.87 AUC for SVV (p=0.31 for difference between PVI and SVV). Central venous pressure was a poor predictor of fluid responsiveness, with an AUC of 0.19.

The authors stated that both PVI and SVV are "much more valuable for prediction of volume responsiveness than CVP" and that PVI "is of high value, especially regarding sensitivity and negative predictive value. Thus, volume responsiveness is not to be expected when PVI is low."

Fluid administration is usually the first intervention in hemodynamically unstable patients to improve status and enable end organ preservation.2 Fluid is given to increase a patient's cardiac output, but only about half of critically ill patients actually increase cardiac output after fluid administration.3 Unnecessary fluid administration should be avoided because it's associated with increased morbidity and mortality.3 Clinical decision making is challenging using traditional invasive measurements such as central venous pressure, stroke volume/index, cardiac output/index, and pulmonary capillary wedge pressure, as they have not been shown to predict fluid responsiveness.5 Newer, dynamic indices such as SVV and pulse pressure variation can accurately predict fluid responsiveness and improve outcomes,6 but are invasive and/or complex and have a high procedural cost, estimated to be about $225 with an SVV monitoring system in one cost analysis.7 PVI is also a dynamic measurement of changes over respiratory variations, but does so with the Masimo SET plethysmograph waveform instead of the arterial waveform. In contrast to other available methods, PVI is noninvasive, easy to use, and has no incremental procedural cost because pulse oximetry monitoring is already performed on all surgical and intensive care patients. No other pulse oximetry technology provides a parameter like PVI. Once Masimo SET® pulse oximetry or rainbow® Pulse CO-Oximetry(TM) with PVI is available in a hospital, it can be utilized in all patients.

Previously, PVI has been shown to help clinicians assess fluid responsiveness in adult surgical and intensive care patients under mechanical ventilation.8,9,10 In addition to the present study comparing PVI to SVV from the PiCCO invasive catheter from Pulsion, two previous studies have compared PVI to SVV from the FloTrac invasive catheter from Edwards Lifesciences and showed similar results.11,12 Masimo PVI has also been shown to help clinicians improve surgical fluid management to decrease patient risk in a randomized controlled trial.13

The United Kingdom's National Health Service advises hospitals to use Intraoperative Fluid Management Technologies to improve patient outcomes and decrease costs. In June 2012, the NHS included PVI in its new Intra Operative Fluid Management pack, which serves as a guide for hospitals wishing to implement fluid responsiveness monitoring.14

Michael O'Reilly, MD, Chief Medical Officer of Masimo, stated: "Masimo is indeed improving patient outcome and reducing cost of care with its breakthrough measurements, such as PVI. Masimo is the only pulse oximetry technology to offer automated assessment of fluid responsiveness with PVI, along with other breakthrough measurements available with rainbow® technology such as noninvasive and continuous hemoglobin (SpHb®) to help clinicians reduce unnecessary blood transfusions."

1 Haas S., Trepte C., Hinteregger M., Fahje R., Sill B., Herich L., Reuter D.; "Prediction of volume responsiveness using pleth variability index in patients undergoing cardiac surgery after cardiopulmonary bypass." J Anesth. 2012 May; DOI 10.1007/s00540-012-1410-x.
2 Dellinger RP, Levy MM, Carlet JM, et al. Surviving sepsis campaign: International guidelines for management of severe sepsis and septic shock: 2008. Crit Care Med 2008;
3 Brandstrup B, Tonnesen H, Beier-Holgersen R, et al: Effects of intravenous fluid restriction on postoperative complications: comparison of two perioperative fluid regimens: A randomized assessor-blinded multicenter trial. Ann Surg 2003; 238:641-648
4 Michard F, Teboul JL: Predicting fluid responsiveness in ICU patients: A critical analysis of the evidence. Chest 2002; 121:2000-2008
5 Marik PE, Cavallazzi R, Vasu T, Hirani A. Dynamic changes in arterial waveform derived variables and fluid responsiveness in mechanically ventilated patients: A systematic review of the literature. Crit Care Med 2009; 37:2642-2647.
6 Bundgaard-Nielsen M et al. Acta Anaesthesiol Scand. 2007; 51(3):331-40
7 Manecke G. Edwards FloTrac(TM) sensor and Vigileo(TM) monitor: easy, accurate, reliable cardiac output assessment using the arterial pulse wave. Expert Rev Med Devices. 2005;2(5):523-527.
8 Cannesson M., Desebbe O., Rosamel P., Delannoy B., Robin J., Bastien O., Lehot JJ. "Pleth variability Index to Monitor the Respiratory Variations in the Pulse Oximeter Plethysmographic Waveform Amplitude and Predict Fluid Responsiveness in the Operating Theatre." British Journal of Anaesthesia August 2008; 101(2):200-6. Available online here.
9 Loupec T., Nanadoumgar H., Frasca D., Petitpas F., Laksiri L., Baudouin D., Debaene B., Dahyot-Fizelier C., Mimoz O. "Pleth Variability Index Predicts Fluid Responsiveness in Critically Ill Patients." Crit Care Med. 2011 Feb;39(2):294-9.
10 Hood J.A., Jonathan R., Wilson T. Anesth. Analg. Pleth Variability Index to Predict Fluid Responsiveness in Colorectal Surgery. 2011;113:1058-63.
11 Zimmerman M., Feibicke T., Keyl C., Prasser C., Moritz S., Graf B., and Wiesenack C. "Accuracy of Stroke Volume Variation Compared with Pleth Variability Index to Predict Fluid Responsiveness in Mechanically-ventilated Patients Undergoing Major Surgery." European Journal of Anaesthesiology June 2010; 27(6):555-61. Available online here.
12 Fu Q., Mi WD., Zhang H. "Stroke Volume Variation and Pleth Variability Index to Predict Fluid Responsiveness During Resection of Primary Retroperitoneal Tumors in Hans Chinese." BioScience Trends. 2012; 6(1):38-43 DOI: 10.5582/bst.2012.v6.1.38. Available online here.
13 Forget P, Lois F, De Kock M. "Goal-Directed Fluid Management Based on the Pulse Oximeter-Derived Pleth Variability Index Reduces Lactate Levels and Improves Fluid Management." Anesthesia & Analgesia. 2010 Oct;111(4):910-4. Published online here.

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 have shown that Masimo SET® outperforms all other pulse oximetry technologies, 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, the company introduced Masimo 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 also be 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

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Masimo, SET, Signal Extraction Technology, Improving Patient Outcome and Reducing Cost of Care... by 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, Adaptive Threshold Alarm, and SEDLine are trademarks or registered trademarks of Masimo Corporation. The use of the trademarks Patient SafetyNet and PSN are under license from University HealthSystem Consortium.

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