CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 2, March/April 2014
AFRICA
67
Effects of topical hypothermia on postoperative
inflammatory markers in patients undergoing coronary
artery bypass surgery
Murat Kadan, Gokhan Erol, Bilgehan Savas Oz, Mehmet Arslan
Abstract
Background:
We aimed to examine the effects of topical
hypothermia on inflammatory markers in patients undergoing
coronary artery bypass surgery.
Methods:
Fifty patients undergoing isolated coronary artery
bypass surgery were included the study. They were randomised
to two groups. Mild hypothermic cardiopulmonary bypass
(28–32°C) was performed on both groups using standardised
anaesthesiology and surgical techniques. Furthermore, topical
cooling with 4°C saline was performed on patients in group
I. We recorded peri-operative and intra-operative results of
blood samples, pre-operative and postoperative outcomes of
electrocardiography and echocardiography, diaphragm levels
on X-ray, and the necessity of positive inotropic medication
and intra-aortic balloon pump (IABP).
Results:
Time-dependent changes in blood samples were
compared between the two groups. The changes on comple-
ment 3 (C3) and TNF-
α
levels were more significant in
group I than group II (
p
<
0.05 and
p
<
0.001, respectively).
Spontaneous restoration rate of sinus rhythm was higher in
group II than group I (80 vs 32%,
p
<
0.01). Atrial fibrillation
was seen in six patients in group I and one patient in group
II (
p
<
0.05). IABP was performed on four patients (16%)
in group I (
p
<
0.05). Diaphragmatic paralysis was seen in
seven patients in group I but not in group II (
p
<
0.01). Partial
pericardiotomy rates were compared within the groups but
there was no statistically significant difference (
p
>
0.05).
One patient in group I died on the 18th postoperative day,
but operative mortality rate was not statistically significant
between the two groups (
p
>
0.05).
Conclusions:
Topical hypothermia had a negative impact on
inflammatory markers and postoperative morbidities.
Keywords:
cardiopulmonary bypass, hypothermia, topical cool-
ing, diaphragmatic paralysis, postoperative atrial fibrillation
Submitted 13/11/13, accepted 11/2/14
Cardiovasc J Afr
2014;
25
: 67–72
DOI: 10.5830/CVJA-2014-005
Since Frey and Gruber’s theory in 1885 of circulating blood
through a machine in order to pump and oxygenate it,
cardiopulmonary bypass (CPB) has improved dramatically and
has become almost indispensable in cardiac surgery today.
1
However, there are many consequences such as inflammation and
thrombosis.
2
The notion that by changing the body temperature
we could decrease inflammatory activity and thus mortality and
morbidity rates has intrigued cardiac surgeons over time.
Topical and systemic hypothermia is applied in many centres
today but there is little data on the advantages and disadvantages
of topical cooling. We aimed to investigate the effects of
topical hypothermia on postoperative cardiac function in patients
undergoing coronary artery bypass surgery.
Methods
This study was approved by the ethics committee of Gulhane
Military Academy of Medicine. Informed consent was obtained
from all patients involved.
Fifty-four patients diagnosed with coronary artery disease
using coronary angiography (CAG) and who were not suitable
for percutaneous or minimally invasive treatment techniques
were included. The exclusion criteria included previous heart
or pulmonary surgery, emergency revascularisation (within
the first 24 hours after CAG), concomitant cardiac surgical
procedures (valve repair or replacement, atrial or ventricular
septal repair, aneurysmectomy, coronary endarterectomy etc.),
left ventricular aneurysm diagnosed by echocardiography or
angiography, myocardial infarction within the last two weeks,
low ejection fraction (EF) (
<
35%), and the necessity for
pre-operative intra-aortic balloon pump (IABP), temporary or
permanent pacemaker, and positive inotropic pharmacological
drugs. Four patients who had ungraftable coronary arteries intra-
operatively were also excluded from the study in order to obtain
optimum standardisation.
The remaining 50 patients were randomised into two groups.
Group I patients included those undergoing surgery using
4°C saline for topical hypothermia and mild hypothermic
CPB (28–32°C) (
n
=
25). Group II patients were to undergo
surgery without topical hypothermia but mild hypothermic CPB
(28–32°C) (
n
=
25).
A median sternotomy was performed on all patients after
general anaesthesia. Standard right atrial cannulation with
two-staged venous cannula and aortic cannulation was performed
after left internal mammarian artery (LIMA) harvesting (if it
was to be used). A roller pump (Ann Arbor, Michigan, USA)
and membrane oxygenator (Dideco Evo adult fiber oxygenator,
Dideco, Mirandola, Italy) were used with mild hypothermia
(28–32°C). The patient’s body temperature was measured with a
rectal probe. Anticoagulation was provided at a dosage of 300 U/
Department of Cardiovascular Surgery, Gulhane Military
Academy of Medicine, Etlik, Ankara, Turkey
Murat Kadan, MD,
Gokhan Erol, MD
Bilgehan Savas Oz, MD
Mehmet Arslan, MD
