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New Study Evaluates the Utility of Masimo SpHb® Monitoring During Liver Transplantation


IRVINE, Calif.--(BUSINESS WIRE)--Mar. 13, 2017-- Masimo (NASDAQ:MASI) announced today the publication of a recent study conducted on adult patients undergoing liver transplantation (LT), in which researchers assessed the accuracy and trending ability of noninvasive Masimo SpHb® (total hemoglobin) measurement, as compared to conventional laboratory hemoglobin (HbL) measurements. The researchers found that SpHb had “clinically acceptable accuracy of hemoglobin measurement [compared] with a standard laboratory device when used during LT” and that “[t]his technology can be useful as a trend monitor during all surgical phases of LT and can supplement HbL to optimize transfusion decisions or to detect occult bleeding.”1

Monitoring a patient’s hemoglobin (Hb) levels is essential during LT because, as the researchers point out, “a serious loss of blood and fluid shift causes great variations [in] the Hb level, and delayed blood transfusion may cause graft dysfunction because of hypo-perfusion and tissue hypoxia. Morever, more importantly, over-transfusion is associated with end organ damage and graft dysfunction.” Recognizing that the “benefits and clinical advantages of noninvasive, rapid, and accurate determination of Hb in the operating room are obvious,” Dr. Kayhan and colleagues sought to evaluate the accuracy and trending ability of Masimo SpHb during LT by comparing its measurements to those of a standard laboratory hematology analyzer.

To this end, the investigators enrolled fifty-five adult patients undergoing orthotopic LT in the study. The patients’ Hb levels were analyzed using a Beckman Coulter LH 780 Hematology Analyzer, with each patient’s arterial blood being sampled six times, twice during each of the three phases of the surgery: pre-anhepatic, anhepatic, and neohepatic. SpHb values were recorded within 10 seconds of each blood sample using a Masimo Radical-7® Pulse CO-Oximeter® (software version and Masimo rainbow® ReSposable R2-25r and R2-25a sensors. A total of 282 paired measurements were collected and analyzed. HbL values ranged from 5.4 to 17.1 g/dL (mean 10.58) and SpHb values ranged from 6.9 to 17.7 g/dL (mean 11.44).

To compare the accuracies of the two methods, the researchers used a Bland-Altman plot and calculated absolute bias (the differences between SpHb and HbL) of 0.86 (95% CI = 0.50-1.21), precision (one standard deviation of the bias) of 1.58, and limits of agreement of -2.25 to 3.96. Using Pearson’s correlation analysis, the researchers found that the correlation between the two sets of values was “highly significant”: Pearson’s correlation coefficient r=0.73; 95% confidence interval = 0.67-0.78, R2=0.53, p < 0.001.

The researchers concluded that “[t]he results of this study show that SpHb has clinically acceptable accuracy of Hb measurement as compared with a standard laboratory device when used during LT. This technology may provide more timely information on Hb status than intermittent blood sample analysis and thus has the potential to improve blood management during LT. The trending accuracy may not only detect occult bleeding but can also prevent overtransfusion after bleeding; at least this method has the potential to supplement detection of changes. Nevertheless, due to underestimation in the lower Hb values, clinicians should be cautious when making decisions based on SpHb alone. Instead of focusing on a single value, SpHb may be considered an early warning system and a trend monitor. Future studies should evaluate the utility of SpHb in terms of overall clinical outcomes of transfusion decision.”

“In prior studies using SpHb monitoring, reductions in blood transfusion were observed,2,3,4 and when used with PVi®, another Masimo noninvasive measurement, a reduction in 30-day mortality was observed5,” stated Joe Kiani, Founder and CEO of Masimo. “Dr. Kayhan’s study adds to the evidence that SpHb may be a useful tool during procedures such as liver transplantation.”

SpHb monitoring may provide additional insight to the directional trend of hemoglobin between invasive blood samples. SpHb monitoring is intended to supplement, not replace, laboratory measurements. Blood samples should be analyzed by laboratory instruments when possible prior to clinical decision making.

@MasimoInnovates | #Masimo


1. Kayhan et al. Accuracy of Noninvasive Hemoglobin Monitoring by Pulse CO-Oximeter During Liver Transplantation. Minerva Anestesiologica. 2017 Jan 20. DOI: 10.23736/S0375-9393.17.11652-4

2. Ehrenfeld JM et al. Continuous Non-invasive Hemoglobin Monitoring during Orthopedia Surgery: A Randomized Trial. J Blood Disorders Transf. 2014. 5:9. 2.

3. Awada WN et al. Continuous and noninvasive hemoglobin monitoring reduces red blood cell transfusion during neurosurgery: a prospective cohort study. J Clin Monit Comput. 2015 Feb 4.

4. Imaizumi et al. Continuous and noninvasive hemoglobin monitoring may reduce excessive intraoperative RBC transfusion. Proceedings from the 16th World Congress of Anaesthesiologists, Hong Kong, 2016. Abstract #PR607.

5. Nathan N et al. Impact of Continuous Perioperative SpHb Monitoring. Proceedings from the 2016 ASA Annual Meeting, Chicago. Abstract #A1103.

About Masimo

Masimo (NASDAQ: MASI) is a global leader in innovative noninvasive monitoring technologies. Our mission is to improve patient outcomes and reduce the cost of care by taking noninvasive monitoring to new sites and applications. In 1995, the company debuted Masimo SET® Measure-through Motion and Low Perfusion™ pulse oximetry, which has been shown in multiple studies to significantly reduce false alarms and accurately monitor for true alarms. Masimo SET® has also been shown to help clinicians reduce severe retinopathy of prematurity in neonates,1 improve CCHD screening in newborns,2 and, when used for continuous monitoring in post-surgical wards, reduce rapid response activations and costs.3,4,5 Masimo SET® is estimated to be used on more than 100 million patients in leading hospitals and other healthcare settings around the world. In 2005, Masimo introduced rainbow® Pulse CO-Oximetry technology, allowing noninvasive and continuous monitoring of blood constituents that previously could only be measured invasively, including total hemoglobin (SpHb®), oxygen content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), and more recently, Pleth Variability Index (PVi®) and Oxygen Reserve Index (ORi™), in addition to SpO2, pulse rate, and perfusion index (PI). In studies with SpHb, reductions in blood transfusion* were observed,6,7 and when used with PVi, a reduction in 30-day mortality was observed.8 In 2014, Masimo introduced Root®, an intuitive patient monitoring and connectivity platform with the Masimo Open Connect™ (MOC-9™) interface, enabling other companies to augment Root with new features and measurement capabilities. Masimo is also taking an active leadership role in mHealth with products such as the Radius-7™ wearable patient monitor, iSpO2® pulse oximeter for smartphones, and the MightySat™ fingertip pulse oximeter. Additional information about Masimo and its products may be found at Published clinical studies on Masimo products can be found at

*Clinical decisions regarding red blood cell transfusions should be based on the clinician’s judgment considering, among other factors: patient condition, continuous SpHb monitoring, and laboratory diagnostic tests using blood samples.


1. Castillo A et al. Prevention of Retinopathy of Prematurity in Preterm Infants through Changes in Clinical Practice and SpO2 Technology. Acta Paediatr. 2011 Feb;100(2):188-92.

2. de-Wahl Granelli A et al. Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns. BMJ. 2009;338.

3. Taenzer AH et al. Impact of Pulse Oximetry Surveillance on Rescue Events and Intensive Care Unit Transfers: A Before-And-After Concurrence Study. Anesthesiology. 2010; 112(2):282-287.

4. Taenzer AH et al. Postoperative Monitoring – The Dartmouth Experience. Anesthesia Patient Safety Foundation Newsletter. Spring-Summer 2012.

5. McGrath SP et al. Surveillance Monitoring Management for General Care Units: Strategy, Design, and Implementation. The Joint Commission Journal on Quality and Patient Safety. 2016 Jul;42(7):293-302.

6. Ehrenfeld JM et al. Continuous Non-invasive Hemoglobin Monitoring during Orthopedia Surgery: A Randomized Trial. J Blood Disorders Transf. 2014. 5:9. 2.

7. Awada WN et al. Continuous and noninvasive hemoglobin monitoring reduces red blood cell transfusion during neurosurgery: a prospective cohort study. J Clin Monit Comput. 2015 Feb 4.

8. Nathan N et al. Impact of Continuous Perioperative SpHb Monitoring. Proceedings from the 2016 ASA Annual Meeting, Chicago. Abstract #A1103.

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 include, among others, statements regarding the potential effectiveness of Masimo SpHb®. 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's unique noninvasive measurement technologies, including Masimo SpHb, contribute to positive clinical outcomes and patient safety; 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.

Source: Masimo

Evan Lamb, 949-396-3376

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