Open Journal of Nursing, 2012, 2, 332-335 OJN
http://dx.doi.org/10.4236/ojn.2012.223048 Published Online November 2012 (http://www.SciRP.org/journal/ojn/)
Emerging technology in acute resuscitation monitoring
Matthew Tichauer, Jonathan McCoy
Department of Emergency Medicine, Robert Wood Johnson Medical School, New Brunswick, USA
Email: email@example.com, firstname.lastname@example.org
Received 16 September 2102; revised 17 October 2012; accepted 28 October 2012
Fluid optimization in the resuscitation of shock be-
came the mainstay of treatment following the advent
of Early Goal-Directed Therapy (EGDT) by Rivers et
al. in 2001 . Patients presenting in shock require
prompt optimization of volume status and cardiac out-
put to ensure adequate perfusion. Poor optimization
may be associated with prolonged hospital and inten-
sive care unit stays. The prior gold standard, pulmo-
nary artery catheterization, is rarely available in the
emergency department setting and its invasive nature
has led to recent re-evaluation of its clinical utility.
However, there are new monitoring technologies that
are being studied in the intensive care unit setting
that may soon be available in emergency departments
to aid in nursing and physician decision making to
improve acute resuscitation.
Keywords: Critical Care; Monitoring;
In 1870, Adolf Fick proposed a method to determine
cardiac output utilizing the relationship between rate of
oxygen uptake and consumption in an organ by calculat-
ing the difference in oxyg en content of ar terial blood and
mixed venous blood . However, Fick’s model was
rarely used at the time due to the difficulty and danger of
obtaining mixed venous blood samples; it was only
tested on animals initially. It would not be until more
than half of a century following his publication, that
Werner Forssmann, in 1922, would demonstrate the first
recorded cardiac catheterization in humans . In an ef-
fort to elucidate the benefits of direct cardiac administra-
tion of medications as well as study the metabolic me-
chanisms of the human body, Forssmann would self-
catheterize with a ureteral catheter without complication.
Though already being performed in animals, human car-
diac catheterization op ened a world of possibilities in the
realm of hemodynamic monitoring, particularly applica-
tion of the direct Fick princi ple.
A century after Fick’s description of cardiac output, an
article in the New England Journal of Medicine de-
scribed catheterization of the heart with a balloon-tipped
catheter . Advancements since the time of hemody-
namic monitoring via cardiac catheterization have led to
several hemodynamic minimally invasive techniques that
have become available providing continuous CO mea-
surement, with or without the utilization of invasive cali-
2. CURRENT NEEDS
Hemodynamic monitoring to confirm diagnosis or as a
guide for therap eutic intervention in critically ill patients
in the emergency department currently requires invasive
methods such as pulmonary artery catheterization (PAC),
central venous catheterization, and arterial lines. The
former has lost its role as the first choice of hemody-
namic monitoring and optimization in the intensive care
unit (ICU) and is rarely used in the emergency depart-
ment due to complications and the availability of less
invasive devices to measure cardiac output (CO) . Ad-
verse events associated with placement of the PAC range
from local pain, infection, or hemorrhage at the insertio n
site, to death [6-11]. These complications can be expec-
ted to occur more frequently in non-ideal settings, par-
ticularly during emergent placement . It is with this
understanding that application of the minimally-invasive
methods of hemodynamic monitoring should be review-
ed in the emergency setting.
3. NEW TOOLS
A number of systems are now available that are less in-
vasive than pulmonary artery catheterization. They also
provide beat to beat stroke volume measurement and
other parameters based on pulse contour and stroke vol-
ume analysis when heart rhythms and respiratory status
are stable. The systems more directly estimate volume
status with different assumptions than pressure meas-
urements such as central venous pressure that intend to
estimate left ventricular end diastolic pressure in lieu of
left ventricular end diastolic volume.
Stroke volume variation may more accurately identify
M. Tichauer, J. McCoy / Open Journal of Nursing 2 (2012) 332-335 333
patients who are preload responsive, in other words,
those patients who will have additional increase in car-
diac output with the administration of further volume.
This is a key parameter that clinicians struggle with par-
ticularly during early resuscitation as they attempt to
optimize volume status without the causing pulmonary
edema. Many of the other tools used to estimate this pa-
rameter, such as central venous pressure, serial vena cava
index ultrasound, esophageal Doppler, and pulmonary
artery catheterization, have logistic, invasive, and other
limitations on their u se in the emergent setting. Therefore,
further examination of these newly available technolo-
gies is warranted.
Arterial pulse-wave analysis PiCCO (PiCCO Plus;
Pulsion Medical Systems, Munich, Germany) and Li-
DCO (LiDCO Plus; LiDCO, Cambridge, UK) systems
are validated by numerous studies and have shown over-
all good correlation compared with the pulmonary artery
thermodilution technique [12-14]. They can be manually
calibrated by transpulmonary thermodilution (PiCCO),
lithium dilution (LiDCO), or previous measurement of
the aortic diameter, to compensate for inter-individual
differences in arterial compliance [15,16].
The PiCCO system requires central venous access and
the cannulation of a large arterial vessel for transpul-
monary thermodilution calibration. Typical parameters
followed are cardiac output, end diastolic volume, sys-
temic vascular resistance, and stroke volume variation. In
addition to using stroke volume variation to predict vol-
ume responsiveness, a new parameter, pulmonary vascu-
lar permeability index is available. This is suggested to
differentiate inflammatory induced capillary leak from
congestive cardiac edema although further testing is need-
The LiDCO system allows minimally invasive calibrated,
continuous, real-time m onit oring of cardi ac out put t hrough
a bolus indicator dilution method and pulse contour
analysis. The transpulmonary bolus indicator dilution ca-
libration is similar to transpulmonary thermodilution, how-
ever, only a peripheral (brachial) intravenous and pe-
ripheral (radial) arterial line are required [19-21]. The
LiDCO system requires a peripheral venous catheter as
well as an arterial line. A nonreactive Lithium chloride
(0.15 mmol) bolus is injected into the peripheral venous
line and detection of the indicator in the arterial blood by
the lithium-sensitive electrode produces a lithium con-
centration-time curve . A robust number of parame-
ters that includes cardiac output, end diastolic volume,
systemic vascular resistance, and stroke volume variation
can be evaluated on a beat-to-beat basis.
The recently introduced, 3rd generation FloTrac/Vigileo
(Edwards Lifesciences, Irvine, CA), calculates continu-
ous CO from arterial pressure waveform characteristics
utilizing an expanded patient algorithm database includ-
ing height, weight, age and sex, and real-time arterial
pressure waveform analysis, rather than requiring exter-
nal calibration. It automatically calculates key flow pa-
rameters every 20 seconds as well as recognizes and ad-
justs for hyperdynamic, and vasodilated patient condi-
tions allowing for volume or cardiovascular intervention
(preload, afterload, and contractility). The direct propor-
tionality between arterial pulsatility and the stroke vol-
ume in conjunction with heart rate is used to calculate
CO. Sex, age, and the body surface area are used to cor-
rect for interindividual differences in arterial compliance
based on the model described by Langewouters et al.
. In addition to CO (index), the FloTrac/Vigileo cal-
culates stroke volume variation (SVV). Systemic vascu-
lar resistance and the systemic vascular resistance index
are calculated if central venous pressure is available.
Continuous central venous oxygen saturation can be ob-
tained and displayed as well with implementatio n of spe-
cialized central venous catheterization. Please see Table
With the emergence of noninvasive and less invasive
hemodynamic monitoring and their documented suc-
Table 1. Arterial flow continuous cardiac output monitoring systems.
Device Continuous CO
monitoring BP monitoringRequires central
venous access Calibration
LiDCO Yes Yes Yes Yes** Arterial flo w signal quality. Rapid changes
in vascular motor tone
PiCCO Yes Yes Yes Yes
Arterial flow signal quality. Rapid changes
in vascular motor tone
FloTrac/Vigileo Yes Yes Yes* No
Impaired accuracy due to changes in
vascular motor tone without calibration
For contin uous ScvO2 monitoring. **Rapid; ca l available but not required.
Copyright © 2012 SciRes. OPEN ACCESS
M. Tichauer, J. McCoy / Open Journal of Nursing 2 (2012) 332-335
cess in the critically ill patient, it is appropriate to
question the lack of studies of these devices in the em-
ergency department, and the potential benefits to cri-
tically ill patients it affords therein. Continuous cardiac
output monitoring that informs optimal preload and after-
load can guide the timing of fluid, vasopressor, and ino-
trope therapies. Such goal directed or quantitative re-
suscitation efforts can be associated with improved out-
comes, decreased length of stay, and reduced compli-
cations . The advanced available technology and the
increasingly complex patients presenting to emergency
departments requiring acute resuscitation increases the
likelihood that tod ay’s nurses will begin to see these n ew
systems deployed to the emergency department environ-
ment to pro- vide critical monitoring.
Special thanks to Stephen Trzeciak and Kathy Zavotsky.
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