Masimo Corporation announced that three new independent studies demonstrating the clinical accuracy and utility of Masimo PVI as a noninvasive and continuous measure of patient fluid status and responsiveness were presented this week at the European Society of Anaesthesiology (ESA) Annual Congress in Milan, Italy.
Although fluid administration is critical to optimizing patient status and enabling end organ preservation, unnecessary fluid administration is associated with increased morbidity and mortality. Traditional invasive measurements such as central venous pressure are not reliable to predict whether a patient will benefit from fluid administration, and newer more reliable methods to predict fluid responsiveness are also invasive and costly. Multiple recent studies have shown that Masimo PVI provides a simple and cost-effective method for accurate, noninvasive, and continuous monitoring of fluid responsiveness. The three studies presented at the ESA reinforce the accuracy of PVI compared to invasive measures and highlight its value for before, during, and after anesthesia.
Does the Pleth Variability Index correlate with stroke volume variation?
Researchers in the Department of Anesthesiology at the Hamamatsu University School of Medicine in Hamamatsu-City, Japan, compared the accuracy of Masimo PVI measurements with Stroke Volume Variation (SVV) obtained via an invasive catheter (Flo Trac) in 13 patients. After analyzing data recorded at five points—in the supine position, lateral position, start and end of one-lung ventilation, and in the supine position again—researchers found a significant correlation between PVI and SVV (r = 0.75; p = 0.02). The study concluded that Our results suggest that an accurate prediction of fluid responsiveness can be obtained non-invasively using the PVI.
The Change of Upper Limbs PVI in Spinal Block (Comparison in High Spinal Block and Non-High Spinal Block)
At the Tokai University School of Medicine in Tokyo, Japan, researchers examined how PVI in the upper limbs of patients undergoing caesarean procedures for hernia surgery changed in response to the level of spinal block reached. PVI was recorded in all patients before and every two minutes after spinal block was performed. In patients reaching the anesthetic level C-area—identified as the high spinal block group—PVI decreased. In patients who did not reach the C-area—identified as the non-high spinal block group—PVI of the upper limbs did not change significantly. Researchers summarized that high spinal block dilates vessels and increases blood flow in the upper limbs, which in turn, is shown by decreased PVI.
Perfusion Index and Pleth Variability Index After Administration of General Anesthetic Agents
In this study, anesthesiologists at the Teikyo University School of Medicine in Tokyo, Japan, analyzed changes in PVI and Masimo perfusion index (PI) in 21 surgical patients before and after administration of general anesthetic agents. After administration of general anesthetic agents and 10ml/kg/hr of fluid during induction, PVI significantly decreased from 22.9±8.1 to 17.1±7.2 (p<0.05) and PI significantly increased from 2.1±1.7 to 3.8±2.3 (p<0.001), leading researchers to conclude that an increase in peripheral perfusion and improvement of fluid status and preload occurred after administration of general anesthetic agents and intravenous fluid administration during anesthesia induction.
Michael O’Reilly, MD, EVP of Medical Affairs at Masimo, stated; These studies confirm what previous results have shown—that PVI’s accuracy at predicting fluid responsiveness is better than traditional measurements and similar to the newer invasive monitoring techniques at fraction of the cost and complexity. Because PVI is noninvasive and is available from the same sensor used with Masimo Rainbow SET® Pulse CO-Oximeters, it has the strong potential to expand and improve fluid monitoring and management in patients who would otherwise not be monitored with the newer invasive techniques.
PVI is available as part of Masimo Rainbow SET Pulse CO-Oximetry—the first-and-only technology platform to noninvasively measure blood constituents and fluid responsiveness that previously required invasive procedures, including: noninvasive and continuous total hemoglobin (SpHb), oxygen content (SpOC), carboxyhemoglobin (SpCO), methemoglobin (SpMet), and PVI, in addition to the ‘gold standard’ Measure-Through Motion and Low-Perfusion performance of Masimo SET oxyhemoglobin (SpO2), pulse rate (PR), and perfusion index (PI).