Market Overview

New Study Compares Two Methods of Guiding Goal-Directed Fluid Therapy, Noninvasive Masimo PVi® and Invasive Esophageal Doppler


Masimo (NASDAQ: MASI) announced today the findings of a study recently published in BMC
in which researchers at University Hospital
Linköping, Sweden, compared the performance of goal-directed fluid
therapy (GDFT) using invasive esophageal Doppler to GDFT using Masimo PVi®
(pleth variability index, measured noninvasively and continuously using
SET® pulse oximetry sensors) in patients undergoing major
abdominal surgery.1

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Masimo Radical-7® with PVi® (Photo: Business Wire)

Masimo Radical-7® with PVi® (Photo: Business Wire)

Noting the value of GDFT in aiming to determine "the optimal amount of
fluid for an individual patient," Dr. Hans Bahlmann and colleagues
sought to compare the effects of two methods of GDFT, stroke volume
optimization guided by invasive esophageal Doppler (control group) and
fluid optimization guided by noninvasive PVi (intervention group), on
patients who were scheduled for open abdominal surgery lasting two or
more hours. The effects compared were incidence of complications and
length of hospital stay.

The researchers collected data from 146 patients who had surgery between
November 2011 and January 2015, who were randomly divided into the two
groups. In the intervention group, PVi was noninvasively and
continuously measured with a Masimo Radical-7® Pulse
CO-Oximeter® with software version and SET®
sensors. After an initial fluid bolus (given to all patients
irrespective of PVi value), a fluid bolus was given if PVi was ≥ 10%,
repeated at 5 minute intervals until PVi fell below 10% or did not
decrease at all. In the control group, esophageal Doppler measurements
were performed using a Deltex Medical CardioQ apparatus. After an
initial fluid bolus, Doppler measurement was performed after 5 minutes
and fluid boluses were repeated until stroke volume did not increase by
10%, in accordance with published protocols.

Observers blinded to each patient's group assessed complications for 30
postoperative days using a pre-specified list of complications, as well
as length of hospital stay. The researchers found that noninvasive PVi
and invasive Doppler performed with no statistical difference, with
similar incidences of complications and lengths of stay between the two
groups. In the intervention/PVi group, there were 64 complications
(corresponding to 51% of patients), with a median length of stay of 8.0
days (interquartile range [IQR] 8.0 days). In the control/Doppler group,
there were 70 complications (corresponding to 49% of patients), with a
median length of stay of 8.0 days (IQR 9.5).

The researchers concluded, "No difference in clinical outcome, as
defined by number of postoperative complications, and length of hospital
stay, was found when goal-directed fluid therapy was applied using PVi
as an alternative to esophageal Doppler. PVi appears to be an acceptable
alternative to esophageal Doppler for goal-directed fluid therapy during
major open abdominal surgery."

In discussing other PVi-related clinical studies, the researchers also
noted that "Based on these reports and our findings, a clinician wishing
to pursue GDFT can choose PVi over esophageal Doppler in the large
majority of patients undergoing major open abdominal surgery. PVi, in
contrast to esophageal Doppler, is not sensitive to interference from
diathermy and does not require frequent access to the patient's head for
probe repositioning. Also, PVi can be measured without single-use
equipment, avoiding the cost for single-use esophageal probes (USD 130
in our setting). However, as illustrated by the request for Doppler data
in two PVi patients, the clinician might still want to have access to a
reliable method for measuring intraoperative cardiac output to increase
the amount of hemodynamic information during unusually complex
situations or in cases of known vascular and/or myocardial dysfunction."

As a study limitation, the researchers noted the absence of a control
group with neither PVi nor Doppler guiding fluid therapy, and therefore
"it is not possible to tell whether PVi and Doppler both result in
similar improvements in outcome, or whether neither method improves
outcome when compared to treatment without GDFT." They also noted that
because of determining sample size using a 10% difference in the number
of complications at 30 days, "the study was not powered to detect
smaller albeit still significant differences in postoperative outcome."

PVi has not been cleared by the FDA to assess fluid responsiveness.

@MasimoInnovates |


  1. Bahlmann H, Hahn R, and Nilsson L. Pleth variability index or stroke
    volume optimization during open abdominal surgery: a randomized
    controlled trial. BMC Anesthesiology. (2018) 18:115.

About Masimo

Masimo (NASDAQ:MASI) is a global leader in innovative noninvasive
monitoring technologies. Our mission is to improve patient outcomes and
reduce the cost of care. In 1995, the company debuted Masimo SET®
Measure-through Motion and Low Perfusion™ pulse oximetry, which has been
shown in multiple studies to significantly reduce false alarms and
accurately monitor for true alarms. Masimo SET® has also been
shown to help clinicians reduce severe retinopathy of prematurity in
neonates,1 improve CCHD screening in newborns,2
and, when used for continuous monitoring with Masimo Patient SafetyNet™
in post-surgical wards, reduce rapid response activations and costs.3,4,5
Masimo SET® is estimated to be used on more than 100 million
patients in leading hospitals and other healthcare settings around the
world,6 and is the primary pulse oximetry at 9 of the top 10
hospitals listed in the 2018-19 U.S. News and World Report Best
Hospitals Honor Roll.7 In 2005, Masimo introduced rainbow®
Pulse CO-Oximetry technology, allowing noninvasive and continuous
monitoring of blood constituents that previously could only be measured
invasively, including total hemoglobin (SpHb®), oxygen
content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin
(SpMet®), Pleth Variability Index (PVi®), and more
recently, Oxygen Reserve Index (ORi™), in addition to SpO2,
pulse rate, and perfusion index (Pi). In 2014, Masimo introduced Root®,
an intuitive patient monitoring and connectivity platform with the
Masimo Open Connect® (MOC-9®) interface, enabling
other companies to augment Root with new features and measurement
capabilities. Masimo is also taking an active leadership role in mHealth
with products such as the Radius-7® wearable patient monitor,
iSpO2® pulse oximeter for smartphones, and the
MightySat™ fingertip pulse oximeter. Additional information about Masimo
and its products may be found at
Published clinical studies on Masimo products can be found at

ORi has not received FDA 510(k) clearance and is not available for sale
in the United States.

The use of the trademark Patient SafetyNet is under license from
University HealthSystem Consortium.


  1. Castillo A et al. Prevention of Retinopathy of Prematurity in Preterm
    Infants through Changes in Clinical Practice and SpO2
    Technology. Acta Paediatr. 2011 Feb;100(2):188-92.
  2. de-Wahl Granelli A et al. Impact of pulse oximetry screening on the
    detection of duct dependent congenital heart disease: a Swedish
    prospective screening study in 39,821 newborns. BMJ. 2009;Jan
  3. Taenzer AH et al. Impact of Pulse Oximetry Surveillance on Rescue
    Events and Intensive Care Unit Transfers: A Before-And-After
    Concurrence Study. Anesthesiology. 2010; 112(2):282-287.
  4. Taenzer AH et al. Postoperative Monitoring – The Dartmouth Experience. Anesthesia
    Patient Safety Foundation Newsletter
    . Spring-Summer 2012.
  5. McGrath SP et al. Surveillance Monitoring Management for General Care
    Units: Strategy, Design, and Implementation. The Joint Commission
    Journal on Quality and Patient Safety
    . 2016 Jul;42(7):293-302.
  6. Estimate: Masimo data on file.

Forward-Looking Statements

This press release includes forward-looking statements as defined in
Section 27A of the Securities Act of 1933 and Section 21E of the
Securities Exchange Act of 1934, in connection with the Private
Securities Litigation Reform Act of 1995. These forward-looking
statements include, among others, statements regarding the potential
effectiveness of Masimo PVi®. These forward-looking
statements are based on current expectations about future events
affecting us and are subject to risks and uncertainties, all of which
are difficult to predict and many of which are beyond our control and
could cause our actual results to differ materially and adversely from
those expressed in our forward-looking statements as a result of various
risk factors, including, but not limited to: risks related to our
assumptions regarding the repeatability of clinical results; risks
related to our belief that Masimo's unique noninvasive measurement
technologies, including Masimo PVi, contribute to positive clinical
outcomes and patient safety; risks related to our belief that Masimo
noninvasive medical breakthroughs provide cost-effective solutions and
unique advantages; as well as other factors discussed in the "Risk
Factors" section of our most recent reports filed with the Securities
and Exchange Commission ("SEC"), which may be obtained for free at the
SEC's website at
Although we believe that the expectations reflected in our
forward-looking statements are reasonable, we do not know whether our
expectations will prove correct. All forward-looking statements included
in this press release are expressly qualified in their entirety by the
foregoing cautionary statements. You are cautioned not to place undue
reliance on these forward-looking statements, which speak only as of
today's date. We do not undertake any obligation to update, amend or
clarify these statements or the "Risk Factors" contained in our most
recent reports filed with the SEC, whether as a result of new
information, future events or otherwise, except as may be required under
the applicable securities laws.

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