Association of time in blood glucose range with outcomes following cardiac surgery

Research article

Amr S Omar, Ahmed Salama, Mahmoud Allam, Yasser Elgohary, Shaban Mohammed, Alejandro Kohn Tuli and Rajvir Singh

BMC Anesthesiology 2015, 15:14 
doi:10.1186/1471-2253-15-14

Published: 26 January 2015

Abstract (provisional)

Background

The importance of optimal postoperative glycemic control in cardiac patients remains
unclear. Various glycemic targets have been prescribed to reduce wound infection and
overall mortality rates.

Aim of the work: To assess glucose control, as determined by time in range (TIR),
in patients with glycemic targets of 6.0 to 8.1 mmol/L, and to determine factors related
to poor control.

Methods

This prospective descriptive study evaluated 227 consecutive patients, 100 with and
127 without diabetes, after cardiac surgery. Patients received insulin to target glucose
concentrations of 6.0 to 8.1 mmol/L. Data analyzed included patient age, gender, race,
Euro score, cardiopulmonary bypass time (CPB), aortic cross clamp time (ACC), length
of ventilation, stay in the intensive care unit (ICU) and stay in the hospital. Patients
were divided into two groups, those who maintained 80% and 80% TIR. Outcome variables
were compared in diabetics and non-diabetics.

Results

Patients with 80% and 80% TIR were matched in age, sex, gender, and Euro score.
Failure to maintain target glycemia was significantly more frequent in diabetics (p
= 0.001), in patients with glycated hemoglobin (HbA1c) 8% (p = 0.0001), and in patients
taking dopamine (p = 0.04) and adrenaline (p = 0.05). Times of CPB and ACC, length
of stay in the ICU and ventilation were significantly higher in patients with TIR
80% than 80%. Rates of hypoglycemia, acute kidney injury, and in-hospital mortality
were similar in the two groups, although the incidence of wound infection was higher
in patients with TIR 80%. Both diabetics and non-diabetics with low TIR had poorer
outcomes, as shown by length of stay and POAF. No significant differences were found
between the two ethnic groups (Arabs and Asians).

Conclusion

Patients with 80% TIR, whether or not diabetics, had better outcomes than those with
80% TIR, as determined by wound infection, lengths of ventilation and ICU stay. Additionally,
they were not subject to frequent hypoglycemic events. Preoperatively high HbA1C is
likely a good predictor of poor glycemic control.