Study Investigates the Ability of Continuous Noninvasive Hemoglobin Monitoring with Masimo SpHb® to Reflect Acute Hemodilution During Incremental Fluid Administration

NEUCHATEL, Switzerland--(BUSINESS WIRE)--Masimo (NASDAQ: MASI) announced today that in a study recently published in Anesthesia & Analgesia, researchers evaluated the ability of noninvasive and continuous hemoglobin monitoring with Masimo SpHb^® to detect the development of acute hemodilution after graded fluid administration, by comparing it to invasively measured laboratory hemoglobin (BHb), on patients undergoing major surgery.¹

In the study, Dr. Şerban Bubenek-Turconi and colleagues at the Carol Davila University of Medicine and Pharmacy and the Prof. C.C. Iliescu Institute for Cardiovascular Diseases in Bucharest, Romania, and Sheba Medical Center in Tel Aviv, Israel, examined the effects of incremental fluid loading (as part of perioperative goal-directed therapy (GDT)) on oxygen delivery and whether noninvasive SpHb monitoring could reliably track the development of acute hemodilution (which can necessitate blood transfusions that might otherwise be avoided). They analyzed data from 40 adult patients undergoing major gastrointestinal or vascular surgery. SpHb was continuously measured using Masimo Root^® with the Radical-7^® Pulse CO-Oximeter^®. BHb and partial pressure of oxygen (PaO₂) were intermittently, invasively measured using a Radiometer ABL800 blood gas analyzer. Cardiac output (CO) and stroke volume (SV) were also obtained through invasive modalities. Oxygen delivery (DO₂) was calculated as: CO*((Hb*1.38*SpO₂)+PaO₂*0.0031)). Parameter values were recorded after the induction of general anesthesia and before the start of surgery (T0) and 5 minutes after successive 250 ml colloid fluid challenges (FC) (T1, T2, and T3). Patients were given the second and third fluid challenges if at each stage SV increased by at least 10%. 40 patients received the first FC, 32 received the second, and 20 received the third, for a total of 92 administered FCs.

The researchers found that, “Compared to their baseline values (T0), BHb and SpHb decreased by a mean of 5.3% ± 4.9% and 4.4% ± 5.2%, respectively, after the first FC (T1; n = 40), by 9.7% ± 8.4% and 7.9% ± 6.9% after the second FC (T2; n = 32), and by 14.5% ± 6.2% and 14.6% ± 5.7% after the third FC (T3; n = 20).” Using Bland-Altman analysis of all 132 paired SpHb and BHb values, the researchers found mean bias and precision values of -0.3 ± 1.5 g/dL and limits of agreement of -2.7 to 3.3 g/dL. They also found that concordance rates between changes in SpHb and in BHb after the administration of the 250, 500, and 750 mL of fluid were 83%, 90%, and 100%, respectively. They noted that results showed “excellent” concordance after 750 mL, despite the limited absolute accuracy, which may have been negatively affected by the “well-recognized inherent variability of the laboratory Hb device that served as our reference method.”

The researchers concluded, “In summary, our study shows that acute iatrogenic hemodilution does invariably occur after fluid administration, that it may lead to paradoxical decrease in DO₂ especially in ‘nonresponders’ and that its development is made visible by the continuous monitoring of SpHb when >500 mL of colloids are being administered. Further studies are needed to examine the potential clinical benefit of SpHb monitoring in identifying acute hemodilution.”

SpHb is not intended to replace laboratory blood testing. 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.

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About Masimo

Masimo (NASDAQ: MASI) is a global medical technology company that develops and produces a wide array of industry-leading monitoring technologies, including innovative measurements, sensors, patient monitors, and automation and connectivity solutions. Our mission is to improve patient outcomes and reduce the cost of care. Masimo SET^® Measure-through Motion and Low Perfusion™ pulse oximetry, introduced in 1995, has been shown in over 100 independent and objective studies to outperform other pulse oximetry technologies.² Masimo SET^® has also been shown to help clinicians reduce severe retinopathy of prematurity in neonates,³ improve CCHD screening in newborns,⁴ and, when used for continuous monitoring with Masimo Patient SafetyNet™ in post-surgical wards, reduce rapid response team activations, ICU transfers, and costs.^5-7 Masimo SET^® is estimated to be used on more than 100 million patients in leading hospitals and other healthcare settings around the world,⁸ and is the primary pulse oximetry at 9 of the top 10 hospitals listed in the 2018-19 U.S. News and World Report Best Hospitals Honor Roll.⁹ Masimo continues to refine SET^® and in 2018, announced that SpO₂ accuracy on RD SET™ sensors during conditions of motion has been significantly improved, providing clinicians with even greater confidence that the SpO₂ values they rely on accurately reflect a patient’s physiological status. 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^®), Pleth Variability Index (PVi^®), RPVi™ (rainbow^® PVi), and Oxygen Reserve Index (ORi™). In 2013, Masimo introduced the Root^® Patient Monitoring and Connectivity Platform, built from the ground up to be as flexible and expandable as possible to facilitate the addition of other Masimo and third-party monitoring technologies; key Masimo additions include Next Generation SedLine^® Brain Function Monitoring, O3^® Regional Oximetry, and ISA™ Capnography with NomoLine^® sampling lines. Masimo’s family of continuous and spot-check monitoring Pulse CO-Oximeters^® includes devices designed for use in a variety of clinical and non-clinical scenarios, including tetherless, wearable technology, such as Radius-7^® and Radius™ PPG, portable devices like Rad-67™, fingertip pulse oximeters like MightySat^® Rx, and devices available for use both in the hospital and at home, such as Rad-97™. Masimo hospital automation and connectivity solutions are centered around the Iris^® platform, and include Iris Gateway™, Patient SafetyNet, Replica™, Halo ION™, UniView™, and Doctella™. Additional information about Masimo and its products may be found at www.masimo.com. Published clinical studies on Masimo products can be found at www.masimo.com/evidence/featured-studies/feature/.

ORi and RPVi have not received FDA 510(k) clearance and are not available for sale in the United States. The use of the trademark Patient SafetyNet is under license from University HealthSystem Consortium.

References

1. Bubenek-Turconi S, Văleanu L, Popescu M, Panaitescu E, Tomescu D, Cacoveanu M, and Perel A. Continuous Noninvasive Hemoglobin Monitoring Reflects the Development of Acute Hemodilution After Consecutive Fluid Challenges. Anesth Analg. 2019. DOI: 10.1213/ANE.0000000000004323.
2. Published clinical studies on pulse oximetry and the benefits of Masimo SET^® can be found on our website at http://www.masimo.com. Comparative studies include independent and objective studies which are comprised of abstracts presented at scientific meetings and peer-reviewed journal articles.
3. 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.
4. 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;Jan 8;338.
5. 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.
6. Taenzer A et al. Postoperative Monitoring – The Dartmouth Experience. Anesthesia Patient Safety Foundation Newsletter. Spring-Summer 2012.
7. 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.
8. Estimate: Masimo data on file.
9. http://health.usnews.com/health-care/best-hospitals/articles/best-hospitals-honor-roll-and-overview.

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; risks related to our belief that Masimo noninvasive medical breakthroughs provide cost-effective solutions and unique advantages; 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 www.sec.gov. 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.