Determining Correlation between IVC-CI and CVP in Hypotensive and Intubated
Patients with Central Lines
David Price, M.D., Nicholas Stollenwerk, M.D.
University of California, Davis Medical Center; Sacramento, CA
BACKGROUND



DISCUSSION

Figure 2. Correlation between
IVC-CI and CVP
Figure 1. Linear Trendline with
Increased CVP

80
70
60
50
r
IVC-CI

Assessing fluid status in ICU patients is challenging
1996 Connors shows mortality associated with routine use of
pulmonary artery catheters
IVC-CI determined by ultrasound offers a non-invasive
alternative to assess fluid status
CVP is an imprecise tool to assess fluid status
Ultrasound is a cumbersome tool for routine use in the ICU
The goal of this study is to assess correlation between IVC-CI
and CVP in hypotensive and intubated patients to find range of
CVP with maximal correlation to preclude need for ultrasound
IVC-CI (%)


RESULTS
40

30
20
STUDY DESIGN
10
0
0
5
10
15
20
25
30
> 12
8-12
<8
CVP
CVP
Patient identified by EMR search, talking to primary team, or while
caring for ICU patients

IMAGES
CVP recorded at
beginning of ultrasound
evaluation
Ultrasound evaluation
performed by study
authors
Figure 3. Sub-Costal View of IVC
Entering Right Atrium
Figure 4. M-Mode View Showing
IVC Max and Min Diameter
AREAS FOR FUTURE STUDY

Study authors review
ultrasound images
together within 24 hours
to assess for image
quality, correct
anatomical structures,
and measurement
confirmation
Pearson correlation
coefficient used to
determine correlation
between CVP and
IVC-CI
Our study demonstrated a weak correlation between IVC-CI
and CVP in hypotensive patients on mechanical ventilation
with a CVP < 8
Strengths of Study:
 Literature on using ultrasound evaluation of IVC in this
patient population is sparse.
 Study performed by intensivist and resident, not
experienced echocardiographer, making results
generalizable to MDs willing to learn ultrasound
Weaknesses of Study:
 Sample size small
 Does not control for other variables such as mean
airway pressure, PEEP, and cause of hypotension
 Intensivist and resident performing exams not certified
in echocardiography
Conclusion: As IVC-CI is a validated measurement of fluid
status, our data shows that in hypotensive and intubated
patients, clinician can trust their CVP more when the value
is less than 8, but that in general CVP is an inaccurate tool
for fluid assessment in this patient population.

Future of this study
 Collect data on 74 patients
 Multivariable analysis accounting for effect of mean
airway pressure, PEEP, and type of mechanical
ventilation
 Calculate success rate of novice echocardiographers in
obtaining adequate view to assess volume status.
Does IVC-CI accurately predict volume responsiveness in
septic patients throughout their hospital course?
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