CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 8, September 2012
428
AFRICA
Cardiovascular Topics
Comparison of the effects of gelatin, Ringer’s solution
and a modern hydroxyl ethyl starch solution after
coronary artery bypass graft surgery
SM ALAVI, B BAHARVAND AHMADI, B BAHARESTANI, T BABAEI
Abstract
Objective:
The aim of this study was to compare the effect
of 6% hydroxyl ethyl starch solution with 4% gelatin
and Ringer’s solutions on the haemodynamic stability of
patients after coronary artery bypass graft (CABG) surgery
and immediately after discontinuation of cardiopulmonary
bypass (CPB).
Methods:
This was a randomised, double-blind clinical trial
of 92 patients who were candidates for on-pump CABG.
After discontinuation of CPB, all patients were transferred to
the intensive care unit (ICU) and divided randomly into three
groups. The first group received Ringer’s solution, the second
group 4% gelatin, and the third 6% hydroxyl ethyl starch
(
HES) solution (Voluven). Haemodynamic parameters such
as heart rate, mean arterial pressure, systolic blood pressure,
diastolic blood pressure, central venous pressure, cardiac
output and the presence of arrhythmias were documented.
Results:
The volume needed for maintaining normal blood
pressure and central venous pressure in the range of 10–14
mmHg was less in the HES group than in the other groups.
The volume was similar however in the gelatin and Ringer’s
groups in the first 24 hours after surgery. Urinary output in
the first four and 24 hours after surgery were significantly
higher in the HES group than in the other two groups. Mean
creatinine levels were significantly lower in the HES group.
Conclusion:
HES (6%) had a better volume-expanding effect
than gelatin (4%) and Ringer’s solutions, and its short-term
effects on renal function were also better than gelatin and
Ringer’s solutions.
Keywords:
CABG, haemodynamic stability
Submitted 7/4/10, accepted 13/3/12
Cardiovasc J Afr
2012;
23
: 428–431
DOI: 10.5830/CVJA-2012-026
Immediately after coronary artery bypass graft (CABG) surgery,
patients are haemodynamically unstable and need fluid support.
1
The purpose of using volume expanders after cardiac bypass
surgery is to maintain stable haemodynamics.
2
Applying an
appropriate fluid with enough volume at this stage may prevent
systemic hypoperfusion and cellular hypoxia, which lead to
systemic lactic acidosis.
3
Furthermore, after cardiopulmonary
bypass patients experience systemic inflammatory responses
and endothelial damage, which lead to fluid extravasations and
interstitial oedema. Therefore correct volume administration is
recommended in this situation.
4
There is controversy regarding the different types of solutions
used after CABG, and various researchers have used materials
such as crystalloid solutions or colloids, including albumin and
gelatin, or other agents such as hydroxyl ethyl starch solutions.
Volume expansion is an important aspect of these solutions,
however, side effects, such as inflammatory responses, and
effects on endothelial integrity and on organs such as the kidney
should also be considered during their administration.
4
Gelatins are polydispersed polypeptides produced by
degradation of bovine collagen. Three types of modified gelatin
products are now available: cross-linked or oxypolygelatins
(
e.g. Gelofundiol
®
),
urea cross-linked (e.g. Haemacel
®
)
and
succinylated or modified fluid gelatins (e.g. Gelofusine
®
).
Their
molecular weight (MW) ranges from 5 000–50 000 Da, with an
average of 30 000–35 000 Da. The various gelatin solutions have
comparable volume-expanding powers and all are said to be safe
with regard to coagulation and organ function (including kidney
function).
2
Hydroxyl ethyl starch (HES) is a widely used plasma substitute
for correcting hypovolaemia in cardiac surgery patients. HES
preparations vary with regard to concentration, mean MW, molar
concentration, C
2
:
C
2
ratio, and solvent. HES solutions with a low
MW and a low molar concentration are thought to be safe with
regard to coagulation, and increased bleeding tendency no longer
appears to be a problem (Valoven, HES 6%), even when higher
doses are given.
3
Some authors believe that albumin has a better volume-
expanding effect than HES.
5
Rehm
et al
.
have shown that
HES and albumin solutions caused mild systemic acidosis in
patients undergoing normovolaemic haemodilution after cardiac
surgery.
6
Others maintain that a short time of infusion of a
rapidly degradable HES solution after cardiac surgery produces
impairment in fibrin formation and clot strength in thrombo-
elastometry tracings. In this clinical setting, human albumin does
Department of Anaesthesiology and Intensive Care
Medicine, Rajaei Heart Centre, Tehran University of Medical
Sciences, Tehran, Iran
SM ALAVI, MD
T BABAEI, MD
Department of Cardiovascular Surgery, Rajaei Heart Centre,
Tehran University of Medical Sciences, Tehran, Iran
B BAHARVAND AHMADI, MD,
B BAHARESTANI, MD
