Masimo LogoMasimo has declared that new clinical studies demonstrate that the Masimo noninvasive and continuous hemoglobin technology is dependable and precise as opposed to invasive blood tests for both healthy subjects and hospitalized patients. Another study apparently discovered Masimo PVI to be an exact, consistent automatic noninvasive pointer of a patient’s capability to react to fluid.

Precision of Noninvasive Hemoglobin Measurements by Pulse CO-Oximetry in Hemodilution Subjects (A184)1, a clinical study headed by Dr. Martin W. Allard at Loma Linda University in Loma Linda, California, evaluated SpHb measurements to 165 invasive laboratory measurements in about 20 healthy adult patients going through hemodilution. All 20 patients apparently had one unit of blood taken through an arterial line while isolyte intravenous fluid was received by them until they arrived at a 30% decrease in hemoglobin or a maximum of 30ml/kg of fluid. Blood samples were taken after each 500ml of fluid administered and examined for total hemoglobin by laboratory CO-Oximeter. Masimo SpHb had a bias of 0.15g/dL and accuracy of 0.92g/dL.

The authors mentioned, “SpHB measurement accuracy was unaffected by perfusion index levels and offers an acceptable alternative to invasive hemoglobin tests in many clinical scenarios.”

Corroboration of a New Noninvasive Hemoglobin Algorithm in patients going through liver transplantation (A751)2, a clinical study led by Dr. Klaus D. Torp at the Mayo Clinic in Jacksonville, Florida, assessed SpHb measurements to 55 invasive laboratory measurements in around five patients experiencing liver transplantation and apparently discovered considerable agreement between the two techniques. The study illustrated that SpHb, using the new Masimo ReSposable Sensor assists to decrease medical waste and costs. It was seen that they had a bias of 0.2g/dL and accuracy of 0.8g/dL.

The authors commented, “The accuracy of noninvasive SpHb measurements obtained by the Pulse CO-Oximeter with new ReSposable sensors was high.”

Moreover, two studies presented at the ASA emphasize the significance of understanding the difference in invasive arterial and venous hemoglobin measurements. A study of 471 paired invasive hemoglobin measurements from around 33 patients on two diverse invasive laboratory devices displayed a bias of -0.97g/dL and an accuracy of 0.58g/dL.

The authors observed, “Different devices using different principles of operation can produce consistent differences in the absolute value of measurement.”

Another study evaluates hemoglobin measurements in around 107 participants from time-matched arterial and venous blood samples on similar invasive laboratory device found average distinctions as high as 0.5g/dL.

A clinical study led by Dr. Olivier Desebbe at the Hospices Civils de Lyon in Lyon, France, examined the finger, forehead, and ear as measurement sites for PVI and discovered that all three sites let bias between fluid responders and non-responders. Researchers gauged hemodynamic data in around 12 patients under common anesthesia via pulmonary artery catheter and Masimo PVI prior to and post volume expansion of around 500ml of hetastarch 6%. Fluid responders were described as patients presenting >15% increase in cardiac index (CI) following VE.

The authors remarked, “Study results showed that a PVI >17% for the forehead and ear, and a PVI >13% for the finger before volume expansion allowed discrimination between responders and non-responders with a sensitivity and specificity of 100 and 83% for the forehead, 83 and 100% for the ear, and 100 and 67% for the finger.”

This shows that PVI seems to be a precise and dependable automatic noninvasive pointer of a patient’s aptitude to react to fluid and that clinicians ought to take site measurement into account when using PVI to forecast fluid responsiveness.

This work was presented at the Americal Society of Anesthesiology (ASA) Annual Meeting in New Orleans, Louisiana.