CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 5, June 2013
AFRICA
185
Global Initiative for Chronic Obstructive Lung Disease (GOLD)
spirometric criteria,
4
on early surgical outcomes in patients
undergoing primary isolated non-emergency CABG.
Methods
Between January 2008 andApril 2012, 1 737 consecutive patients
underwent an isolated CABG operation in the Department
of Cardiovascular Surgery of Gulhane Military Academy
of Medicine. Patients were identified from a prospectively
maintained surgical database, and medical charts were reviewed
retrospectively. Of these 1 737 patients, 127 with a diagnosis of
moderate-risk COPD were operated on. Of these 127 patients,
only 104 with available pulmonary function tests and no
missing data were included in the study. Exclusion criteria were
significant valve disease, emergency operation, and approaches
other than median sternotomy, and surgical procedures other
than CABG.
According to the practice of the Department of Pulmonary
Diseases, two different treatment protocols were used before and
after 2010. Before 2010, no treatment was applied to patients
with moderate COPD before the CABG procedure. After 2010, a
pre-treatment protocol was initiated (inhaled bronchodilator and
steroid treatment for 10 days before the day of surgery). Patients
who had undergone surgery between 2008 and 2010 comprised
group 1 (no pre-treatment) and patients who had undergone
surgery between 2010 and 2012 made up group 2 (pre-treatment
group). These two groups were compared according to the post-
operative morbidity and mortality rates retrospectively, from
medical reports.
According to the GOLD COPD 2011 guideline, COPD
was defined as a common, preventable and treatable disease,
characterised by persistent airflow limitations, which are
usually progressive and associated with an enhanced chronic
inflammatory response in the airways and the lung to noxious
particles and gases. Clinical diagnosis of COPD should be
considered in a patient who has dyspnoea, chronic cough, or
sputum production and/or a history of exposure to risk factors
for the disease.
Spirometry is required to make the diagnosis in this clinical
context; the presence of a post-bronchodilator and FEV
1
/
FVC
<
0.70 (forced expiratory volume/forced vital capacity)
confirms persistent airflow limitations and therefore COPD.
According to the GOLD COPD 2012 guideline, the severity of
airflow limitations in COPD is classified into four levels. In this
classification, moderate COPD patients are defined as 50%
≤
FEV
1
<
80%, predicted in patients with FEV
1
/FVC
<
0.70.
A pulmonary function test (spirometry) was performed
according to the previously described guidelines. FEV
1
, FVC
and FEV
1
/FVC were expressed according to the reference
values published by the European Respiratory Society in 1993.
All surgical records were reviewed to determine the surgical
procedure performed, cardioplegic technique, cross-clamp time,
cardiopulmonary bypass times, number of grafts, left internal
thoracic artery (LITA) usage, and number of blood products
used.
An isolated CABG procedure was performed in all patients.
Standard anaesthesia and surgical technique, extracorporeal
circulation and myocardial protection methods were used. A
median sternotomy approach was done in all patients. CPB was
installed through the ascending aorta and right atrial cannulation
and it was performed with roller pumps and membrane
oxygenation. Myocardial protection was intermittent cold blood
cardioplegia. All patients received antegrade cardioplegia and
‘hot-shot’ (reperfusion with warm cardioplegia). The lowest
core temperature was between 28 and 32°C, depending on the
surgeon’s preference.
The patients were transferred to the ICU just after the
operation and they received ventilator assistance and monitoring.
Extubation was undertaken when the patient’s criteria were
stable, and time to extubation was also recorded.
The primary outcome was post-operative mortality in hospital
and at 30 days. Secondary outcomes included the length
of hospital stay, length of stay in ICU, time to extubation,
re-intubations, pulmonary infections, pneumothorax, pleural
effusions, atrial fibrillation, other arrhythmias, 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 usage 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.
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 Levene’s test, Fischer’s exact test, the Mann-
Whitney
U
-test and chi-square test.
Results
The mean ages of the patients in both groups were 62.1
±
7.6
and 64.5
±
6.4 years, respectively. Thirty-nine of the patients
in group 1 and 38 in group 2 were male. Mean FEV
1
values of
the patients in both groups were 46.1
±
2.3% and 48.2
±
2.1%,
respectively. Mean ejection fractions of the patients were 53.3
±
11.5% and 50.2
±
10.8%, respectively. Mean EuroSCOREs of
the patients were 5.5
±
2.3 and 5.9
±
2.5, respectively in both
groups. There were similar risk factors in both groups, such
as diabetes, hypertension, renal disease (two patients in each
group), previous stroke and myocardial infarction. Demographic
details of the patients are summarised in Table 1.
With regard to the primary outcome, there were three
mortalities in group 1, and one in group 2. The causes of death
included cardiogenic shock (
n
=
2), sepsis and multi-organ
failure (
n
=
1), and cerebrovascular accident (
n
=
1).
There was no statistically significant difference between the
groups with regard to CPB time, cross-clamp time and average
graft numbers. However, when we looked at the mean extubation
