Radiologic determination of intravascular volume status using portable, digital chest radiography: a prospective investigation in 100 patients.
OBJECTIVE
To answer the following questions: Can the digital chest roentgenogram (CXR) be used to differentiate patients' volume status? Do clinical data alter radiologists' accuracy in interpreting the digital CXR?


METHODS
Prospective cohort study.


METHODS
Nine adult intensive care units of a tertiary care medical center.


METHODS
One hundred thirty-five consecutive patients with pulmonary artery catheters, of whom 35 were excluded because of unacceptable pulmonary artery occlusion pressure (PAOP) tracings.


METHODS
Each patient had a portable, anteroposterior, supine digital CXR. Clinicians evaluated volume status and then measured hemodynamic data within 1 hr of the CXR. Digital CXRs were independently interpreted on two separate occasions (with and without clinical information) by three experienced chest radiologists, and these interpretations were compared with hemodynamic data.


RESULTS
Of the 100 patients, 39 had PAOP >18 mm Hg, whereas 61 had PAOP <18 mm Hg. Radiologists' accuracy in differentiating volume status increased with incorporation of clinical data (56% without vs. 65% with clinical data, p =.009). Using objective receiver operating characteristic-derived cutoffs of 70 mm for vascular pedicle width and 0.55 for cardiothoracic ratio, radiologists' accuracy in differentiating PAOP >18 mm Hg from PAOP <18 mm Hg was 70%. The intrareader and the inter-reader correlation coefficients were very high. The likelihood ratio of the CXR in determining volume status using the objective vascular pedicle width and cardiothoracic ratio measures was 3.1 (95% confidence interval, 1.9-6.0), significantly higher than subjective CXR interpretations with and without clinical data (p <.001).


CONCLUSIONS
Differentiating intravascular volume status with portable, supine, digital CXRs may be improved by using objective cutoffs of vascular pedicle width >70 mm and cardiothoracic ratio >0.55 or by incorporating clinical data.
Ely
E W
EW
Department of Internal Medicine, Division of Allergy/Pulmonary/Critical Care Medicine, Vanderbilt University Medical Center, 6th Floor Medical Center East, Nashville, TN 37232-8300, USA. wes.ely@mcmail.vanderbilt.edu
Smith
A C
AC
Chiles
C
C
Aquino
S L
SL
Harle
T S
TS
Evans
G W
GW
Haponik
E F
EF
D000328:Adult; D002407:Catheterization, Swan-Ganz; D015633:Extravascular Lung Water / Q000000981:diagnostic imaging*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D013902:Radiography, Thoracic