Heart surgery

Glycemic control in diabetics undergoing open heart surgery

Summary and introduction


Background: Intraoperative glycemic variability is associated with increased risks of mortality and morbidity and an increased incidence of hyperglycemia after cardiac surgery. As a result, clinicians tend to use tight blood glucose control to maintain perioperative blood glucose levels and therefore the need to develop a less laborious automated blood glucose monitoring system is great, especially in diabetic patients. at higher risk of developing complications.

Methods : Patients, aged 40 to 75 years, undergoing open-heart surgery were randomized to either an automated protocol (experimental) or our institution’s conventional technique (control).

Results: We showed that the percentage of patients remained between 7.8 and 10 mmol.l−1 was not statistically different between the two groups, however, through additional analysis, we showed that the proportion of patients whose blood glucose remained between a safe level of 6.7 to 10 mmol.l−1 was significantly higher in the experimental group compared to the control group, 14 (26.7%) versus 5 (17.2%) P = 0.025. In addition, the percentage of patients who had at least one intraoperative hyperglycaemic event was significantly higher in the control group compared to the experimental group, 17 (58.6%) vs 5 (16.7%). P

Conclusion: We concluded that the automated blood glucose control pump in diabetic patients undergoing open-heart surgeries kept most patients within a predefined blood glucose range with a very low incidence of hyperglycemic events and no incidence of hypoglycemic events.

Registration for the trial: Registered with clinicaltrials.gov (NCT #NCT03314272, Principal Investigator Roland Kaddoum, registration date: 10/19/2017).


Decades ago, glycemic control became an important treatment goal in hospitalized patients.[1] The notion of tight blood sugar control became more important in 2001 when a landmark study by Van Den Berghe demonstrated a significant decrease in mortality when maintaining blood sugar between 4.4 and 5.6 mmol.l−1 in patients in the intensive care unit.[1]

It has been found that the incidence of hyperglycemia after heart surgery is very high (stress-induced hyperglycemia) and occurs almost universally after heart surgery, whether a person has diabetes or not.[2] The mechanisms by which hyperglycemia affects outcome may be related to suppressive effects on immune function and increased risk of infection, endothelial damage, mitochondrial damage to hepatocytes, and potentiation of tissue ischemia due to acidosis or inflammation.[3–5]

Knowing that hyperglycemia, hypoglycemia, and increased glycemic variability have been associated with an increased risk of mortality and morbidity, many centers have established protocols for glycemic monitoring.[6] However, normoglycemia is not easy to establish, and barriers to widespread adoption of tight glycemic control were numerous, including an increased risk of severe hypoglycemia, difficulty achieving normoglycemia, as well as increased resources and workload of medical staff.[6,7] Because of these issues and uncertainty about the balance between risk and benefit, tight blood sugar control is rarely used by clinicians.[8,9]

The development of a closed-loop blood glucose monitoring system that automatically infuses insulin based on an automated algorithm that incorporates a continuous glucose signal, could help overcome these obstacles and enable tight blood glucose control without increase the workload of medical staff. This is the first study to examine the effectiveness of a closed-loop blood glucose monitoring system on intra- and post-operative glucose levels in patients undergoing open heart surgeries. Our hypothesis is that the automated protocol will allow a higher percentage of diabetic patients undergoing open-heart surgery to stay within the 7.8-10 mmol.l glycemic corridor.−1 compared to the conventional technique while avoiding hypoglycemic and hyperglycemic episodes.