Masimo Corporation is bent on destroying CVP as a fluid status monitor. The company’s latest line of pulse oximeters is so advanced that the devices use twelve separate wavelengths to provide analysis more nuanced than traditional systems. A study just presented at the International Anesthesia Research Society (IARS) 83rd Scientific Congress on March 14th in San Diego, California has shown that Masimo’s Radical-7 Pulse CO-Oximeters can be used as a viable option for intravascular fluid volume monitoring during surgery, thanks to a proprietary Pleth Variability Index (PVI) function, which is a measure of the dynamic changes in perfusion index (PI) that occur during the respiratory cycle. The study was conducted on patients undergoing liver transplants, no less!
In the study, Errol P. Lobo, M.D., PhD, at UCSF in San Francisco, Calif., and colleagues used Masimo Radical-7 Pulse CO-Oximeters to noninvasively measure and continuously track PVI, perfusion index (PI) and pulse rate (PR) data during 16 consecutive liver transplant operations. Researchers extracted and analyzed the noninvasive data at three critical points where preload changes occur rapidly: 1) immediately before clamping, 2) during clamping, and 3) immediately after clamping of the inferior vena cava (IVC), and found that PVI changed rapidly and significantly in response to known acute changes in preload (clamping and unclamping of IVC) in 100% of the cases.
The study results showed that PVI increased in response to IVC clamping (from 11.4, +/- 4.3, to 25.2, +/- 4.4; p<0.0001) and decreased after unclamping (from 25.2, +/- 4.4, to 8.9, +/- 3.8; p<0.0001) in all 16 transplant patients. Researchers concluded that this study data demonstrates that PVI may have "a role in monitoring intravascular volume in mechanically ventilated patients."
PVI is available as part of Masimo Rainbow SET Pulse CO-Oximetry—a revolutionary noninvasive patient monitoring platform that measures multiple blood constituents and helps to predict fluid responsiveness in patients previously requiring invasive procedures. The first-and-only upgradable noninvasive blood constituent monitoring technology platform capable of continuously and noninvasively measuring total hemoglobin (SpHb™), oxygen content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), and pleth variability index (PVI™), in addition to oxyhemoglobin (SpO2), pulse rate (PR), and perfusion index (PI), Masimo Rainbow SET has the potential to facilitate faster, easier and safer health decisions.
Press release: New Clinical Study Finds Masimo Rainbow SET® Pulse CO-Oximetry™ Accurate in the Noninvasive Monitoring of Fluid Status During Surgery
Product page: Masimo Rainbow SET…
White paper from Masimo: Clinical Applications of Perfusion Index (.pdf)…
Abstract: EFFECT OF PRELOAD CHANGES ON PLETH VARIABILITY INDEX DURING LIVER TRANSPLANTS