Published in:
01-07-2006 | Original
Cardiac response is greater for colloid than saline fluid loading after cardiac or vascular surgery
Published in: Intensive Care Medicine | Issue 7/2006
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Objective
To study the effects on volume expansion and myocardial function of colloids
or crystalloids in the treatment of hypovolaemic hypotension after cardiac
and major vascular surgery.
Design and setting
A single-centre, single-blinded, randomized clinical trial at the intensive
care unit of a university hospital.
Patients and methods
Patients (n = 67) were subjected to a 90-min filling pressure-guided
fluid challenge with saline 0.9% or the colloids gelatin 4%,
hydroxyethyl starch 6% or albumin 5%. Biochemical variables and
haemodynamics (transpulmonary thermodilution) were measured.
Results
An amount of 1800 (1300–1800) ml of saline or 1600 (750–1800) ml of
colloid solution (P< 0.005) was infused. Colloid osmotic pressure (COP)
decreased in the saline group and increased in the colloid groups
(P< 0.001). Plasma volume increased by 3.0% (–18 to 24) in the saline
versus 19% (–11 to 50) in the colloid groups (P< 0.001). Cardiac index
increased by median 13% (ns) in the saline group and by 22% in the
colloid groups (P< 0.005). The rise in left ventricular stroke work index was
greater in the colloid than in the saline groups. The different colloids
were equally effective. The rise in cardiac index related to the rise in
plasma volume and global end-diastolic volume, confirming plasma volume and
preload augmentation by the fluid loading.
Conclusion
After cardiac or major vascular surgery, the pressure- and time-guided fluid
response is dependent on the type of fluid used. Colloid fluid loading leads
to a greater increase in preload-recruitable cardiac and left ventricular
stroke work indices than that with saline, because of greater plasma volume
expansion following an increase in plasma COP.