CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 4, May 2013
122
AFRICA
(haematocrit
<
40.5%), low ejection fraction (EF) (30%), pre-
and postoperative infection, patients who underwent emergency
operations and operations other than CABG surgery. Patients
with re-operations and revisions were excluded from the study.
All patients were operated on under general anaesthesia
using a midline sternotomy and cardiopulmonary bypass, with
membrane oxygenators and a crystalloid priming solution. A left
internal mammary artery graft was used in all patients.
In group 1, autologous bloods were prepared via a central
venous catheter that was inserted into the right internal jugular
vein in all patients, using the isovolumetric replacement
technique. The protocol for blood conservation in elective
coronary surgery was as follows: cessation of antiplatelet drugs
seven days before the surgery; removal of autologous blood
before bypass for re-transfusion after bypass; intra-operative
re-transfusion of the oxygenator and tubing contents with the
help of a leukocyte filter; and adequate rewarming of patients
and control of systemic blood pressure. In group 2, homologous
bloods were used.
The primary outcome was postoperative in-hospital mortality
and mortality at 30 days. Secondary outcomes included the length
of hospital and intensive care unit (ICU) stay, time for extubation,
re-intubations, pulmonary infections, pneumothorax, pleural
effusions, atrial fibrillation, other arrhythmias, renal disease,
allergic reactions, mediastinitis and sternal dehiscence, need for
inotropic support, and low cardiac-output syndrome (LCOS).
Pulmonary infections included pneumonia and bronchitis.
Pneumonia was defined by radiological evidence of new
infiltration, consolidation or cavity, and antibiotic use in the
presence of one of the three following criteria: purulent sputum,
positive blood culture or positive bronchial secretion culture.
Bronchitis was defined by the presence of purulent sputum
production and antibiotic use. Pleural effusion was included in
the analysis only if it required drainage during hospitalisation.
Arrhythmias other than atrial fibrillation included
supraventricular arrhythmias, atrio-ventricular block requiring
pacemaker, ventricular tachycardia, ventricular fibrillation and
asystole. LCOS was considered when postoperative inotropic
support was used for more than 24 hours. Renal failure was
defined as an abnormal increase in serum creatinine levels and a
decrease in urinary output.
Statistical analysis
Statistical analysis was performed with SPSS 15.0 for Windows.
Continuous data were presented as mean
±
SD. Nominal data
were presented as frequencies and percentages. Differences
were analysed with the Levene’s test, Fischer’s exact test, Mann–
Whitney
U
-test and chi-square test.
Results
There was no difference between the two groups with regard
to co-morbidities and other surgical risk factors. Patient
characteristics are summarised in Table 1. Mean pre-operative
haematocrit levels in groups 1 and 2 were 42.2
±
3.9 and 41.7
±
4.1%, respectively.
There was no in-hospital or 30-day mortality in either group.
There were no significant differences between the two groups
related to intra-operative parameters such as cross-clamping time
and cardiopulmonary bypass time. There was also no statistically
significant difference in postoperative haematocrit level between
the groups. However the mean extubation time, ICU and
hospital stays were significantly shorter in group 1. Furthermore,
postoperative drainage amounts were less in group 1 (375.8
±
114.2 vs 543.7
±
268.4 ml, respectively). Intra-operative and
postoperative data are summarised in Table 2.
There were significant differences in postoperative
morbidities. Significantly fewer patients had postoperative
pulmonary complications, pneumonia, atrial fibrillation and
renal disease. The number of patients who needed postoperative
inotropic support and those with low cardiac output were also
significantly lower in group 1. Data related to postoperative
morbidities are detailed in Table 3.
Discussion
Blood donation is problematic globally, largely due to donor-
related factors, which may differ from country to country. In
a study by Kubio
et al
.,
7
among donors from Ghana, positive
rates for infectious disease markers were 7.5% for hepatitis B
surface antigen, 6.1% for hepatitis C virus, 3.9% for human
immunodeficiency virus and 4.7% for syphilis. This amounted
to 22.2% of the available donors being rejected due to infectious
TABLE 1. PATIENTS’ CHARACTERISTICS
Variable
Group 1
(
n
=
163)
Group 2
(
n
=
160)
p
-value
Age (years)
64.2
±
10.3
61.5
±
11.6
0.034
BMI (kg/m
2
)
25.7
±
3.3
27.6
±
3.0
0.045
Gender
Male
125
130
0.033
Female
38
30
NYHA class
2.0
±
0.3
2.1
±
0.3
0.062
Hypertension
65
80
0.068
Diabetes
23
45
0.002
Hyperlipidaemia
20
9
0.037
COPD
7
8
0.764
Smoking
54
50
0.718
BMI: body mass index, NYHA: NewYork Heart Association, COPD:
chronic obstructive pulmonary disease.
TABLE 2. INTRA- AND POSTOPERATIVE DATA
Variable
Group 1
(
n
=
163)
Group 2
(
n
=
160)
p
-value
Cross-clamp time (min)
63.6
±
21.4 64.8
±
27.1 0.084
CPB time (min)
102.3
±
32.0 116.3
±
25.2 0.062
Extubation time (h)
5.6
±
1.1 6.34
±
1.4
<
0.01
Drainage (ml)
375.8
±
114.2 543.7
±
268.4
<
0.01
ICU stay (h)
23.0
±
0.9 32.4
±
20.2
<
0.01
Blood transfusion (intra-opera-
tive) (units)
0.3
±
0.4
1.1
±
0.6 0.025
Blood transfusion (postoperative)
(units)
1.7
±
0.7
2.1
±
0.9 0.018
Hospital stay (days)
7.0
±
1.1
8.7
±
3.1
<
0.01
Preoperative haematocrit (%)
42.2
±
3.9 41.7
±
4.1 0.628
Discharge haematocrit (%)
33.8
±
2.9 31.8
±
2.3 0.002
CPB: cardiopulmonary bypass.
