Cardiovascular Journal of Africa: Vol 24 No 6 (July 2013) - page 33

CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 6, July 2013 AFRICA 227
and returned to baseline levels (p < 0.001). In the V group, IL-10
levels were increased following induction of anaesthesia, peaked
at one hour after discontinuation of CPB, and decreased soon
after (p < 0.001). When the two groups were compared, only
IL-10 levels were higher immediately after discontinuation of
CPB in the NV group than in the V group (p = 0.001) (Table 2,
Fig. 3).
Pulmonary function
Lactate release was significantly increased after the induction
of anaesthesia in both groups; it peaked at one hour after
discontinuation of CPB in the NV group and decreased at six
hours, but remained higher than baseline levels ( p < 0.001). In
the ventilated group, levels of lactate progressively increased
with time (p < 0.001) (Table 2, Fig. 4). However, in each time
period there was no significant difference in lactate levels
between the groups.
The alveolar–arterial oxygen gradient widened after the
induction of anaesthesia, peaked at one hour after discontinuation
of CPB, and decreased at six hours, but remained higher than
baseline levels in both groups (p < 0.001). When the two groups
were compared, the gradient was higher in the non-ventilated
group after induction, and immediately after and at one hour
after discontinuation of CPB (p < 0.001) (Table 2, Fig. 5).
In the ICU, the intubation time for the NV group was 9.67
± 3.29 h and 9.27 ± 2.86 h in the V group (p = 0.61) (Table 3).
Prolonged intubation was not required in any patient.
Clinical parameters
Length of stay in ICU and postoperative hospital length of
stay were not statistically different in both groups. There was
no significant difference when amount of drainage, amount of
blood and blood products used, and incidence of postoperative
exploration for haemorrhage were compared. Renal failure was
defined as peak creatinine value ≥ 1.5 times the pre-operative
value and there was no significant difference between the groups
(Table 3).
When postoperative AF was studied, there were six patients
(20.7%) with AF in the NV group, and three (10.0%) in the V
group (p = 0.29). Normal sinus rhythm was maintained in all
patients except one in the V group. There was no statistically
significant difference when maintenance of sinus rhythm was
compared. There was no postoperative stroke and mortality
noted throughout the study.
Discussion
The inflammatory response to CPB is acute, complex and
can lead to significant morbidity and mortality. It involves the
release of cytokines, which may have an impact on postoperative
Fig. 2. Serum IL-8 levels.
50
40
30
20
10
0
NV V
Group
95% CI (pg/ml)
IL-80 IL-82 IL-81 IL-83
Fig. 3. Serum IL-10 levels.
200
150
100
50
0
NV V
Group
95% CI (pg/ml)
IL-100 IL-102 IL-101 IL-103
Fig. 4. Serum lactate levels.
6
5
4
3
2
1
NV V
Group
95% CI (mmol/l)
Lactate 0 Lactate 2 Lactate 1 Lactate 3
Fig. 5. Alveolar–arterial oxygen gradient measurements.
30
25
20
15
10
5
NV V
Group
95% CI (kPa)
Aa0 Aa2 Aa1 Aa3