Masimo (Nasdaq: MASI), the inventor of Pulse CO-Oximetry(TM) and Measure-Through Motion and Low Perfusion pulse oximetry, announced today that new clinical studies presented this week at the American Society of Anesthesiology (ASA) Annual Meeting in New Orleans, Louisiana, show Masimo noninvasive and continuous hemoglobin (SpHb(TM)) technology is reliable and accurate compared to invasive blood tests for both healthy subjects and hospitalized patients. Another study presented found Masimo PVI to be an accurate, reliable automatic noninvasive indicator of a patient's ability to respond to fluid.
Clinical Study Highlights
Accuracy of Noninvasive Hemoglobin Measurements by Pulse CO-Oximetry in Hemodilution Subjects (A184), a clinical study led by Dr. Martin W. Allard at Loma Linda University in Loma Linda, California, compared SpHb measurements to 165 invasive laboratory measurements in 20 healthy adult patients undergoing hemodilution. All 20 patients had one unit of blood drawn through an arterial line while isolyte intravenous fluid was given (to compensate for the decrease in intravascular volume) until they reached a 30% reduction in hemoglobin or a maximum of 30 ml/kg of fluid. Blood samples were drawn after each 500 ml of fluid administered and analyzed for total hemoglobin by laboratory CO-Oximeter. Masimo SpHb had a bias of 0.15 g/dL and precision of 0.92 g/dL, leading researchers to conclude that SpHb "measurement accuracy was unaffected by perfusion index levels" and offers an "acceptable alternative to invasive hemoglobin tests in many clinical scenarios."
Validation of a New Noninvasive Hemoglobin Algorithm in Patients Undergoing Liver Transplantation (A751), a clinical study led by Dr. Klaus D. Torp at the Mayo Clinic in Jacksonville, Florida, compared SpHb measurements to 55 invasive laboratory measurements in five patients undergoing liver transplantation and found significant agreement between the two methods. The study showed that SpHb--using the new Masimo ReSposable(TM) Sensor that helps to reduce medical waste and costs----had a bias of 0.2 g/dL and precision of 0.8 g/dL. Researchers concluded that "the accuracy of noninvasive SpHb measurements obtained by the Pulse CO-Oximeter with new ReSposable sensors was high."
Additionally, two studies presented at the ASA highlight the importance of understanding the variation in invasive arterial and venous hemoglobin measurements. A study (A937) of 471 paired invasive hemoglobin measurements from 33 patients on two different invasive laboratory devices (Beckman Coulter® hematology analyzer and Nova Biomedical® CO-Oximeter) showed a bias of -0.97 g/dL and a precision of 0.58 g/dL. The authors noted that "different devices using different principles of operation can produce consistent differences in the absolute value of measurement." Another study (A1294) comparing hemoglobin measurements in 107 subjects from time-matched arterial and venous blood samples on the same invasive laboratory device found average differences as high as 0.5 g/dL and noted that "arterial and venous hemoglobin values from the same individual are not interchangeable."