Materials and Methods
This prospectively planned study was conducted by including 80 patients
with microalbuminuria who underwent coronary artery bypass surgery in
our clinic between February 2019 and December 2020. For this study,
ethical approval was given by the local Ethics Committee and all
research was conducted in accordance with the Helsinki Declaration and
its later amendments or comparable ethical standards. The aim of the
study was clearly explained to all participants and their written
informed consent was obtained.
In this study, the exclusion criteria were as follows: Preoperative
chronic renal failure, preoperative dialysis, serum creatinine levels
above 1.2mg/dl for males and 1.1mg/dl for females, underwent emergency
surgery, active endocarditis, use of preoperative extracorporeal
membrane oxygenator. Patients who had insulin medication more than one
year were included in the group of having insulin medication while those
who had been receiving insulin for less than one year, were not
included.
Patients having insulin medication were using short-acting (regular
insulin) and/or long-acting (NPH) or mixed insulin. Those taking oral
antidiabetics were receiving metformin and/or stagliptin. The mean of
HbA1c was 7.1% in the group using insulin, and 6.8% in the group
receiving oral medication.
The records of the following risk factors were taken preoperatively:
Age, gender, body mass index (BMI), hypertension, chronic obstructive
pulmonary disease (COPD), smoking, whether they had an infarction in the
last 28 days, presence of peripheral artery disease (PAD), ejection
fractions, serum creatine and microalbuminuria levels in spot urine.
Albumin levels of 20-200 mg/L in spot urine were accepted as
microalbuminuria(14). The patients were divided into two groups, namely
as having insulin medication and taking oral antidiabetics. 42 patients
were in the insulin medication group and 38 patients were in the oral
antidiabetics medication group.
All operations were performed by the same surgical team, on-pump.
Stockert S5 Roller Pump (Sorin Group) and Terumo FX oxygenators were
used. Arterial cannula and single venous cannulation were applied from
the aorta after median sternotomy. Body temperature was reduced to 32
degrees. Cardiac arrest was achieved with the help of hyperpotassemic
isothermal blood cardioplegia. After the distal bypasses were made, the
cross clamp was lifted and the proximal anestomoses were side clamped.
pump outlet was inotrope, according to the need. In the diabetic patient
group, blood glucose regulation was achieved with continuous
crystallized insulin infusion.
Serum creatine levels on the postoperative 3rd day, duration of stay on
the ventilator after surgery, amount of drainage, length of stay in
intensive care unit (ICU), length of hospital stay, mediastinitis and
mortality rates of the patients were recorded. It was found in previous
publications that creatine levels increased 1-3 days after cardiac
surgery(15), and we thought that we would obtain the most reliable
results by recording creatine values on the 3rd day.