Study objectives: A transpulmonary thermal-dye dilution
(TDD) technique using cold indocyanine green dye was utilized to
monitor cardiac index (CI) and preload in patients after heart
transplantation. Preload, determined by intrathoracic blood volume
index (ITBVI) and global end-diastolic volume index (GEDVI), was
compared to central venous pressure (CVP) and pulmonary artery
occlusion pressure (PAOP) and was correlated with stroke volume index
Design: Prospective study.
Setting: Cardiac surgery ICU at a university hospital.
Patients: Forty patients (34 men, 6 women) with a mean
(± SD) age of 54.4 ± 8.5 years after orthotopic heart
Measurements and results: CI and
preload measurements were performed with TDD and pulmonary artery
catheters in the ICU at 3, 6, 12, 24, 36, 48, and 72 h
postoperatively. The femoral artery CI was compared with the pulmonary
artery CI. Changes in the ITBVI, GEDVI, CVP, and PAOP were correlated
with changes in the SVI. No difference was found between the femoral
and pulmonary arterial CIs (r = 0.98 [bias, 0.35
L/min/m2]; p < 0.01). There was no statistically
significant correlation between changes in the SVI and changes in CVP
(r = −0.23,) and PAOP (r = −0.06).
However, the ITBVI (r = 0.65; p < 0.01) and the
GEDVI (r = 0.73; p < 0.01) were significantly
correlated to changes in the SVI. Changes in the same direction
occurred between the SVI and the GEDVI as well as between the SVI and
the ITBVI in 76.3% and 71.9% of patients, respectively, while CVP and
PAOP also changed in the same direction as SVI in only 35.1% and
36.9% of patients, respectively.
and GEDVI are more reliable preload parameters than CVP and PAOP. Even
in denervated hearts, ITBVI and GEDVI show significant correlations
with SVI. The transpulmonary indicator dilution technique is promising
and should be investigated further.