Masimo (Nasdaq: MASI) announced that a new randomized controlled trial published in Anesthesia & Analgesia shows that clinicians using Masimo Pleth Variability Index (PVI®) significantly improved fluid management and reduced lactate levels in patients during and after surgery, compared to patients managed by standard care without PVI(1). Multiple previous studies(2,3,4) have shown that PVI predicts fluid responsiveness, defined as a significant increase in cardiac output after fluid administration, but this is the first published study to show that the use of PVI can improve patient management compared to a group of patients not managed with PVI.

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 (CVP) are not reliable in predicting whether a patient will benefit from fluid administration, and newer methods of predicting fluid responsiveness are invasive and/or costly. Masimo PVI provides clinicians with a noninvasive, continuous, and cost-effective measure in assessing whether patients will benefit from fluid administration to enable more personalized and targeted fluid therapy.

In the current study, researchers from the University Catholique de Louvain, St. Luc Hospital in Brussels, Belgium, randomized 82 patients undergoing abdominal surgery into two groups, a control group where fluid management was guided by standard care through CVP and clinician assessment, and the PVI group where fluid management was guided by standard care and PVI values from a Masimo Radical-7® Pulse CO-Oximeter®. In the PVI group, 500mL of crystalloids were infused at induction, followed by 2mL per kg per hour continuous infusion. A 250mL bolus of colloid was added if the PVI exceeded 13% for more than 5 minutes. In the control group, 500mL of crystalloids were infused at induction, followed by continuous infusion of crystalloids (4 to 8mL per kg per hour) and a 250mL bolus of colloids was given to compensate acute blood losses (>50mL), maintain mean arterial pressure above 65mmHg and the central venous pressure above 6mmHg.

The results showed that the PVI group received significantly lower amounts of intraoperative crystalloids (P=0.004) and total volume infused (P=0.049), and lactate levels were significantly lower during surgery (1.2 mmol/L +/- 0.6 vs 1.6 +/- 1.2, P=0.04), 24-hours post-operatively (1.4 +/- 0.3 vs 1.8 +/- 1.0, P=0.02), and 48-hour post-operatively (1.2 +/- 0.3 vs 1.4 +/- 0.4, P=0.03). The researchers concluded that "PVI-based goal directed fluid management reduced the volume of intraoperative fluid infused and reduced both intraoperative and postoperative lactate levels." Study authors also noted that the reduction in lactate levels for PVI-guided patients suggests that "PVI-guided fluid management may lead to fluid administration that is tailored to each individual patient's needs."

PVI is available as part of Masimo rainbow® SET platform the first-and-only technology to noninvasively and continuously measure total hemoglobin (SpHb®), oxygen content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), Pleth Variability Index (PVI®), perfusion index (PI), and acoustic respiration rate (RRa™), in addition to the 'gold standard' Measure-Through Motion and Low Perfusion performance of Masimo SET® oxyhemoglobin (SpO2), and pulse rate (PR).

"The clinical merit of using a dynamic index like PVI to guide fluid administration relates to a timing issue," stated William E. Johnston, MD, Professor and Associate Chair, Vice Chair of Academic Affairs in the Department of Anesthesiology at Scott & White Memorial Hospital in Temple, Texas. "What's so unique about PVI is that it allows the medical team to rapidly fine tune fluid administration using a Masimo Radical-7 Pulse CO-Oximeter in the operating room before global hypovolemia and hypoperfusion occur. Consequently, an appropriate amount of fluid can be administered at the most opportune time."

Masimo, SET, Signal Extraction Technology, Improving Patient Outcome and Reducing Cost of Care... by Taking Noninvasive Monitoring to New Sites and Applications, rainbow, SpHb, SpOC, SpCO, SpMet, PVI, rainbow Acoustic Monitoring, RRa, Radical-7, Rad-87, Rad-57,Rad-8, Rad-5,Pulse CO-Oximetry, Pulse CO-Oximeter, and SEDLine are trademarks or registered trademarks of Masimo Corporation.

References

(1) Forget, Patrice; Lois, Fernande; De Kock, Marc. "Goal-Directed Fluid Management Based on the Pulse Oximeter-Derived Pleth Variability Index Reduces Lactate Levels and Improves Fluid Management." Anesthesia & Analgesia. August 2010. Published online ahead of print here.

(2) Cannesson M, Desebbe O, Rosamel P, Delannoy B, Robin J, Bastien O, Lehot JJ. "Pleth variability Index to Monitor the Respiratory Variations in the Pulse Oximeter Plethysmographic Waveform Amplitude and Predict Fluid Responsiveness in the Operating Theatre." British Journal of Anaesthesia August 2008; 101(2):200-6. Available online here.

(3) Markus Zimmerman, Thomas Feibicke, Cornelius Keyl, Christopher Prasser, Stefan Moritz, Bernhard M. Graf, and Christoph Wiesenack. "Accuracy of Stroke Volume Variation Compared with Pleth Variability Index to Predict Fluid Responsiveness in Mechanically-ventilated Patients Undergoing Major Surgery." European Journal of Anaesthesiology June 2010; 27(6):555-61.

(4) M. Feissel, R. Kalakhy, J. Badie, G. Robles, J. Faller, JL. Teboul. "Plethysmography Variability Index: A New Fluid Responsiveness Parameter." Presented at the 29th International Symposium on Intensive Care and Emergency Medicine (ISICEM) Annual Meeting, March 25, 2009, Brussels, Belgium.

Source: Masimo Corporation