[Perioperative monitoring and control of hyperglycemia during deep hypothermic circulatory arrest].

Objective: To observe the trend of change in perioperative blood glucose level in patients undergoing deep hypothermic circulatory arrest (DHCA), in order to evaluate the influencing factors of inciting hyperglycemia and the clinical effects of insulin control.

Methods: In the Department of Cardiothoracic Surgery of Changhai Hospital, 176 patients underwent aortic operation under DHCA from January 2000 to January 2010. Blood glucose, arterial blood gas and lactate levels were determined at four time points, including pre-cardiopulmonary bypass (CPB), pre-DHCA, post-DHCA, and at admission to intensive care unit (ICU). Hyperglycemia after surgery was controlled at the level of 6-8 mmol/L by intermittent subcutaneous injection or intravenous micropump injection of insulin. At the same time, the cumulative amount of insulin within 24 hours after surgery was recorded.

Results: The blood glucose (mmol/L) level at pre-DHCA time point was significantly higher than that of pre-CPB (9.62 ± 1.79 vs. 5.04 ± 1.401,P<0.05), and the blood glucose level was further elevated at the time point of post-DHCA (14.91 ± 2.36,P<0.01) and in-ICU (15.32 ± 2.47) compared with that of pre-CPB (P<0.01). The level of blood glucose elevation was positively correlated with blood lactate level. One hundred and thirty-four patients (76.1%) insulin was given with intravenous micropump due to poor effect of intermittent subcutaneous injection of insulin in controlling blood glucose. Among whom 30 patients (17.0%) developed the phenomenon of insulin resistance. Perioperative hyperglycemia during DHCA was associated with old age (≥ 50 years old), primary hypertension, serious aortic valve disease, diabetes or coronary heart disease, emergency operation, CPB time ≥ 3 hours and DHCA time ≥ 45 minutes. The cumulative amount of insulin within 24 hours after surgery was increased significantly. The results of blood glucose (mmol/L) in-ICU were as follows : age ≥ 50 years old or < 50 years old (18.66 ± 2.52 vs. 12.90 ± 2.27); hypertension with and without (18.98 ± 2.55 vs. 12.31 ± 2.34); serious aortic valve disease with and without (19.59 ± 2.95 vs. 12.13 ± 2.23); diabetes with and without (20.62 ± 1.76 vs. 11.75 ± 1.11); coronary heart disease with and without (19.77 ± 2.98 vs. 12.01 ± 2.02); emergency operation with and without (19.78 ± 1.97 vs. 12.23 ± 1.38); CPB time ≥ 3 hours or < 3 hours (19.86 ± 1.89 vs. 11.70 ± 1.15); DHCA time ≥ 45 minutes or < 45 minutes (19.92 ± 1.88 vs. 11.64 ± 1.12), and all of them should statistical difference (all P < 0.05). The cumulative amount of insulin (U) within 24 hours after surgery was as follows: age ≥ 50 years old or < 50 years old (169.5 ± 56.6 vs. 110.2 ± 38.5); hypertension with and without (171.6 ± 64.0 vs. 104.8 ± 34.3); aortic valve disease with and without (171.4 ± 36.8 vs. 109.4 ± 27.6); diabetes with and without (202.5 ± 46.7 vs. 100.4 ± 31.5); coronary heart disease with and without (178.5 ± 38.6 vs. 104.6 ± 26.4 ); emergency operation with and without (178.3 ± 35.7 vs. 102.7 ± 26.8); CPB time ≥ 3 hours or < 3 hours (168.6 ± 37.2 vs. 107.3 ± 27.5); DHCA time ≥ 45 minutes or < 45 minutes (172.5 ± 36.1 vs. 105.4 ± 28.7), and all of them showed significant statistical difference (all P < 0.05). and all of them showed significant statistical difference (all P < 0.05).

Conclusion: DHCA may cause significant increase in perioperative blood glucose and lactate, and even may lead to insulin resistance. Patients often require continuous intravenous administration of large doses of insulin. Perioperative hyperglycemia during DHCA is related to many factors, which should be considered in control of blood glucose.