Study Shows Noninvasive SpCO® Can Help Rapidly Detect Carbon Monoxide Poisoning in the Emergency Department

May 21, 2013

IRVINE, Calif., May 21, 2013 /PRNewswire/ -- Masimo (NASDAQ: MASI) announced today that a new clinical study posted online in Respiratory Care confirms the clinical utility of Masimo's noninvasive carboxyhemoglobin (SpCO®) from rainbow® Pulse CO-Oximetry™ as a first-line assessment tool in helping clinicians rapidly detect carbon monoxide (CO) poisoning.1

CO poisoning accounts for an estimated 50,000 emergency department (ED) visits in the U.S. annually and is the leading cause of accidental poisoning death.2 Symptoms of CO poisoning include headache, dizziness, nausea/vomiting, confusion, fatigue, chest pain, shortness of breath, and loss of consciousness, but are often attributed to other illnesses such as the flu. Failure to diagnose CO poisoning can have disastrous consequences for patients and potentially other family members of the affected household.3 Unfortunately, only about half (50%) of U.S. acute care hospitals have laboratory CO-oximetry capabilities enabling confirmation of CO poisoning in the blood,4 likely due to the expense of the instrumentation. Additional delays occur if a patient needs hyperbaric oxygen therapy, which often requires transfer to yet another medical center with hyperbaric capability.

Previous studies have shown that SpCO can help clinicians increase CO poisoning detection by as much as 39%5 and is associated with a shorter time to initiation of treatment (4.4 vs. 5.3 hours) with hyperbaric oxygen.6 These data have previously led to suggestions that SpCO could be used as a tool to help determine whether an invasive blood measurement of carboxyhemoglobin (COHb) should be performed to confirm CO intoxication.7

Researchers at Departement des urgencies, Centre Hospitalier Regional Universitaire Lapeyronie in Montpellier, France, studied 93 consecutive patients suspected of CO exposure presenting to an urban-based university hospital ED. Patients were tested noninvasively with a Masimo Rad-57™ Pulse CO-Oximeter®, while simultaneous blood samples were taken for laboratory COHb analysis and comparison.

Diagnosis of CO poisoning was determined for 26 (28%) patients. Compared to laboratory COHb values, the bias and standard deviation of SpCO over all patients was -0.2% +/- 3.3%. In six subjects with very high COHb values (greater than 15%), the bias and standard deviation of SpCO was 1.2% +/- 2.2%. The area under the curve for SpCO's ability to detect CO poisoning, which takes into account both sensitivity and specificity, was 0.83 for non-smokers and 0.98 for smokers, with an optimal SpCO threshold of 6% for non-smokers and 9% for smokers.

Researchers concluded "noninvasive Pulse CO-Oximetry could be useful as a first-line screening test, enabling rapid detection and management of CO-poisoned patients in the ED."

1 Sebbane M, Claret PG, Mercier G, Lefebvre S, Thery R, Dumont R, et al. "Emergency Department Management of Suspected Carbon Monoxide Poisoning: Role of Pulse Co-Oximetry." Respir Care. Published online ahead of print Mar 19, 2013. Available here

2 Hampson N., Weaver L. "Carbon Monoxide Poisoning: A New Incidence for an Old Disease." Undersea Hyperb Med 2007;34:163-168. Available online here

3 Hampson N., Piantadosi C., Thom S., Weaver L. "Practice Recommendations in the Diagnosis, Management, and Prevention of Carbon Monoxide Poisoning," American Journal of Respiratory and Critical Care Medicine, Vol. 186, No. 11 (2012), pp. 1095-1101. Available online here

4 Hampson NB, Scott KL, Zmaeff JL. "Carboxyhemoglobin measurement by hospitals: Implications for the diagnosis of carbon monoxide poisoning." J Emerg Med 2006;31(1):13-6. Available online here

5 Suner S, Partridge R, Sucov A, et al. "Noninvasive Pulse CO-Oximetry Screening in the Emergency Department Identifies Occult Carbon Monoxide Toxicity." J. Emerg Med. 2008; 34(4): 441-450.

6 Hampson N. "Noninvasive pulse CO-oximetry expedites evaluation and management of patients with carbon monoxide poisoning." The American Journal of Emergency Medicine 2012 (10.1016/j.ajem.2012.03.026) Available online here

7 Zaouter C, Zavorsky G. "The measurement of carboxyhemoglobin and methemoglobin using a noninvasive pulse CO-oximeter." Respiratory Physiology & Neurobiology July 2012. Available 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 help clinicians detect life-threatening events. More than 100 independent and objective studies have shown that Masimo SET® outperforms other pulse oximetry technologies, even under the most challenging clinical conditions, including patient motion and low peripheral perfusion. In 2005, Masimo introduced rainbow ® Pulse CO-Oximetry™ technology, allowing noninvasive and continuous monitoring of blood constituents that previously required invasive procedures; total hemoglobin (SpHb®), oxygen content (SpOC), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), PVI®, and perfusion index (PI), in addition to measure-through motion SpO2, and pulse rate. In 2008, Masimo introduced Patient SafetyNet™, 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, the first-ever commercially available noninvasive and continuous monitoring of acoustic respiration rate (RRa™). Masimo SET® and Masimo rainbow® technologies also can 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 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 SpCO will provide an accurate and effective noninvasive method of screening for CO poisoning, risks related to our belief that SpCO offers an effective front-line tool for first responders and emergency departments, 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.

Media Contact:
Mike Drummond
Masimo Corporation
Phone: (949) 297-7434

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