Factors influencing the estimation of extravascular lung water by transpulmonary thermodilution in critically ill patients.
OBJECTIVE
To investigate factors that may influence the estimation of extravascular lung water (EVLW) with a single (cold) indicator compared with assessment using two indicators (thermo-dye dilution).


METHODS
Post hoc analysis of an electronic hemodynamic database.


METHODS
Surgical intensive care unit of a university hospital.


METHODS
Forty-eight critically ill patients monitored by the thermo-dye dilution technique in the postoperative period.


METHODS
None.


RESULTS
The EVLW was simultaneously assessed by the thermo-dye dilution technique (EVLWref) and estimated by transpulmonary thermodilution (EVLWest). EVLWref index ranged between 1 and 40 mL/kg (mean 10 +/- 7 mL/kg) and EVLWest between 2 and 39 mL/kg (mean 9 +/- 6 mL/kg). EVLWref was closely correlated (r = .96) with EVLWest. The mean difference (bias) between EVLWref and EVLWest was -0.5 +/- 1.9 mL/kg. The bias was not influenced by the weight, height, body surface area, body mass index, Pao2, intrathoracic blood volume, cardiac output, or dosage of vasoactive agents. In contrast, the bias was slightly but significantly influenced by EVLWref, Pao2/Fio2 ratio, tidal volume, and level of positive end-expiratory pressure.


CONCLUSIONS
In our surgical intensive care unit population, the estimation of EVLW by transpulmonary thermodilution was influenced by the amount of EVLW, the Pao2/Fio2 ratio, the tidal volume, and the level of positive end-expiratory pressure. However, compared with the double indicator method, transpulmonary thermodilution estimation remained clinically acceptable even in patients with severe lung disease.
Michard
Frédéric
F
Department of Anesthesia and Critical Care, Massachusetts General Hospital-Harvard Medical School, Boston, MA, USA. michard.frederic@free.fr
Schachtrupp
Alexander
A
Toens
Christian
C
D000368:Aged; D004396:Coloring Agents; D015633:Extravascular Lung Water; D006439:Hemodynamics; D006801:Humans; D007208:Indocyanine Green; D007362:Intensive Care Units; D016014:Linear Models; D008297:Male; D011175:Positive-Pressure Respiration; D011654:Pulmonary Edema / Q000175:diagnosis*; D015656:Respiratory Mechanics; D013815:Thermodilution
D004396:Coloring Agents; D007208:Indocyanine Green