Effect of glycaemic control on complications following cardiac surgery: literature review

Lymphocyte Levels and Morbidity and Mortality in Cardiovascular Surgery With Cardiopulmonary Bypass

INTRODUCTION

A year ago, in a sample of 113 patients, our research group found that a high number of lymphocytes in the immediate postoperative period was correlated to a poor prognosis in cardiovascular surgeries. This study is an expansion of the initial study in order to confirm this finding.

METHODS

We analyzed the data of 338 consecutive patients submitted to cardiovascular surgeries with cardiopulmonary bypass performed at Hospital Universitário Ciências Médicas (Belo Horizonte/Brazil) from 2015 to 2017. We analyzed 39 variables with the outcomes death, hospital stay, and intensive care unit stay.

RESULTS

The value of lymphocytes in the immediate postoperative period > 2175.0/mm³ was an indicator of poor prognosis in this sample (P<0.001). The variables female sex, age, high level of European System for Cardiac Operative Risk Evaluation II, increased stay in the intensive care unit and in the ward, elevation of creatinine in the preoperative period and at intensive care unit discharge, elevation of the percentage of immediate postoperative period segmented neutrophils, high immediate postoperative period neutrophil/lymphocyte ratio, fasting hyperglycemia, preoperative critical condition, reintubation, mild or transient acute renal failure, surgical infection, cardiopulmonary bypass, and aortic cross-clamping and mechanical ventilation durations also had an impact on the mortality outcome.

CONCLUSION

The value of lymphocytes in the immediate postoperative period > 2175.0/mm3 was an indicator of poor prognosis in cardiovascular surgery with cardiopulmonary bypass.

Continuous Glucose Monitoring System After Coronary Artery Bypass Graft Surgery: A Feasibility Study

BACKGROUND

Blood glucose level variability has been associated with increased risk of complication in the postoperative setting of cardiovascular surgery. Although interesting for optimization of blood glucose management in this context, continuous blood glucose (CBG) devices can have a limited reliability in this context, in particular because of the use of paracetamol. The aim of this study was to evaluate the reliability of Dexcom G6®, a recently developed continuous glucose monitoring device.

METHODS

We performed a prospective, observational, non-randomized, single-centre study comparing Dexcom G6® CBG level monitoring with the standard methods routinely used in this context. The standard blood glucose values were paired to the time corresponding values measured with Dexcom G6®. Agreement between the two methods and potential correlation in case of paracetamol use were calculated.

RESULTS

From May 2020 to August 2021, 36 out of 206 patients operated for isolated coronary artery bypass grafting were enrolled; 673 paired blood glucose level were analyzed. Global agreement (ρc) was 0.85 (95% C.I.: 0.84-0.86), intensive care unit agreement was 0.78 (95%C.I.: 0.74-0.82) and ward agreement was 0.91 (95%C.I.: 0.89-0.93). In the diabetic population, it was 0.87 (95%C.I.: 0.85-0.90). When paracetamol was used, the difference was 0.02 mmol/l (95%C.I.: 0.29-0.33).

CONCLUSIONS

Dexcom G6® provides good blood glucose level accuracy in the postoperative context of cardiac surgery compared to the standard methods of measurements. The results are particularly reliable in the ward where the need for repeated capillary glucose measurements implies patient discomfort and time-consuming manipulations for the nursing staff.

Perioperative Glycemic Management in Cardiac Surgery: A Narrative Review

Diabetes and hyperglycemic events in cardiac surgical patients are associated with postoperative morbidity and mortality. The causes of dysglycemia, the abnormal fluctuations in blood glucose concentrations, in the perioperative period include surgical stress, surgical techniques, medications administered perioperatively, and patient factors. Both hyperglycemia and hypoglycemia lead to poor outcomes after cardiac surgery. While trying to control blood glucose concentration tightly for better postoperative outcomes, hypoglycemia is the main adverse event. Currently, there is no definite consensus on the optimum perioperative blood glucose concentration to be maintained in cardiac surgical patients. This review provides an overview of perioperative glucose homeostasis, the pathophysiology of dysglycemia, factors that affect glycemic control in cardiac surgery, and current practices for glycemic control in cardiac surgery.

The Use of Sodium-Glucose Cotransporter-2 Inhibitors in Coronary Revascularization: Where Are We Now? A Systematic Review

INTRODUCTION

Diabetes and coronary artery disease are two common conditions that often co-exist. In recent years, sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been demonstrated to provide significant cardioprotective benefits, especially among patients with heart failure.

OBJECTIVE

In this systematic review, we look to identify the outcomes SGLT2i use in patients undergoing coronary revascularization.

METHODS

Pubmed and Embase were systematically searched for articles describing the outcomes of patients taking SGLT2i and undergoing coronary revascularization. 834 titles and abstracts were screened, 42 full texts were reviewed, and 18 studies were found to meet the inclusion criteria and were included in this review.

RESULTS

For patients undergoing coronary artery bypass grafting and percutaneous coronary intervention, the use of SGLT2i resulted in reductions in mortality, hospitalization for heart failure, and improved blood glucose; however, these benefits were not consistently reported in the literature. Reduced inflammatory markers and positive cardiac remodeling were identified among patients taking SGLT2i.

CONCLUSIONS

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been demonstrated to provide benefits for patients with heart failure along with a host of positive modulatory effects on the cardiovascular system, including reductions in inflammatory properties, hypertension, and left ventricular volume load. Given the clear benefit provided by SGLT2i to patients with cardiovascular disease and a host of positive properties that are expected to be protective for patients with ischemic heart disease, future investigation into the relationship between SGLT2i and outcomes for patients undergoing revascularization is imperative.

Intensive Care Unit Hyperglycemia After Cardiac Surgery: Risk Factors and Clinical Outcomes

OBJECTIVES

Patients with hyperglycemia after cardiac surgery face increased morbidity and mortality due to postoperative complications. The main purpose of this study was to evaluate the incidence of postoperative hyperglycemia, the hyperglycemia risk factors, and its association with clinical outcomes in patients admitted to the cardiac surgery intensive care unit after cardiac surgery.

DESIGN

Prospective, observational study.

SETTING

Single-center hospital.

PARTICIPANTS

Two hundred ten consecutive postoperative cardiac surgery patients admitted to the cardiac surgery intensive care unit.

INTERVENTIONS

Patients' blood glucose levels were evaluated immediately after cardiac surgery and every 3 hours daily for 7 days or earlier upon discharge. Intravenous insulin was administered as per the institution's protocol. Perioperative predisposing risk factors for hyperglycemia and clinical outcomes were assessed.

MEASUREMENTS AND MAIN RESULTS

Postoperative hyperglycemia, defined as glucose level ≥180 mg/dL, occurred in 30% of cardiac surgery patients. Diabetes mellitus (odds ratio [OR] 6.73; 95% CI [3.2-14.3]; p < 0.001), white blood cell count (OR 1.28; 95% CI [1.1-1.4]; p < 0.001), and EuroSCORE II (OR 1.20; 95% CI [1.1-1.4]; p = 0.004) emerged as independent prognostic factors for hyperglycemia. Moreover, patients with glucose ≥180 mg/dL had higher rates of acute kidney injury (34.9% v 18.9%, p = 0.013), longer duration of mechanical ventilation (959 v 720 min, p = 0.019), and sedation (711 v 574 min, p = 0.034), and higher levels of intensive care unit (ICU)-acquired weakness (14% v 5.5%, p = 0.027) and rate of multiorgan failure (6.3% v 0.7%, p = 0.02) compared with patients with glucose levels <180 mg/dL.

CONCLUSIONS

In the intensive care unit, hyperglycemia occurs frequently in patients immediately after cardiac surgery. Diabetes, high EuroSCORE II, and preoperative leukocytosis are independent risk factors for postoperative hyperglycemia. Hyperglycemia is associated with worse clinical outcomes, including a higher rate of acute kidney injury and ICU-acquired weakness, greater duration of mechanical ventilation, and a higher rate of multiorgan failure.

Effects of a telehealth program for wound healing promotion on the wound healing level in patients with diabetes undergoing coronary artery bypass graft surgery: A randomized controlled trial

Background

Patients with diabetes undergoing coronary artery bypass graft (CABG) are at risk of delayed wound healing. The telehealth program for wound healing promotion (TPWHP) was developed to improve wound healing in patients with diabetes undergoing CABG in a university hospital.

Objective

This study aimed to examine the effects of the TPWHP on the healing of the sternal wound and saphenous vein graft (SVG) donor site in patients with diabetes undergoing CABG.

Methods

In this randomized controlled trial, the participants were randomly assigned to the intervention (n = 30) and control (n = 30) groups. The control group received routine nursing care, whereas the intervention group received routine nursing care along with the TPWHP, which provides education and wound monitoring using multimedia and a surgical wound care booklet and monitors the wound through the LINE application on a smartphone after hospital discharge. Data were collected from June to November 2020 at two university hospitals in Bangkok, Thailand, using the demographic and health-related data form and the Thai wound assessment inventory (WAI). Data were analyzed using the Chi-squared, Fisher's exact, and Mann-Whitney U tests.

Results

The intervention group had significantly lower mean scores-indicating favorable wound healing-for SVG donor site wound healing level than the control group on days 14-21 after surgery (p = 0.012, mean = 0.58 ± 0.54 and 1.08 ± 0.82, respectively). No significant intergroup difference was observed in terms of the sternal wound healing level (p = 0.126); however, the intervention group showed lower mean scores-indicating good wound healing-than the control group.

Conclusion

The TPWHP promotes effective wound healing of the SVG donor site; however, its efficacy on sternal wound healing was uncertain. Therefore, nurses should implement the TPWHP in collaboration with a multidisciplinary team to improve wound healing after hospital discharge.

Trial registration

Thai Clinical Trials Registry (TCTR20211112002).

Effects of glargine on hyperglycemia in patients with diabetes mellitus type II undergoing off-pump coronary artery bypass graft: A randomized, controlled, double-blind clinical trial

Introduction: In this trial, effects of glargine on hyperglycemia in patients with diabetes mellitus type II who were undergoing off-pump coronary artery bypass graft (CAGB), were examined. Methods: Seventy diabetic patients who were candidate for off-pump CABG were randomly divided into the following two groups (1) Control group who were treated with normal saline+regular insulin and (2) Glargine group who received glargine+regular insulin. Normal saline and glargine were administered subcutaneously 2 hours before surgery, and regular insulin was injected before, during and after the surgery in the intensive care unit (ICU) in both groups. Finally, levels of blood sugar before, 2 hours after starting the surgery and at the end of the surgery, were recorded. Blood sugar levels during ICU stay were also measured every 4 hours for 36 hours. Results: There were no significant differences in blood sugar levels between the groups at the three time points (i.e. before, 2 hours after starting the surgery and at the end of the surgery). In addition, during 36 hours of ICU stay, blood sugar levels did not show significant variations between the groups; however, 20 hours after ICU admission, blood sugar level was significantly higher in the glargine group (P=0.04). Conclusion: The results indicated that both glargine and regular insulin effectively control the blood glucose in diabetic patients undergoing CABG. However, the blood sugar fluctuation was less in the glargine group than control group.

Multicenter Randomized Trial of Intermittently Scanned Continuous Glucose Monitoring Versus Self-Monitoring of Blood Glucose in Individuals With Type 2 Diabetes and Recent-Onset Acute Myocardial Infarction: Results of the LIBERATES Trial

OBJECTIVE

To analyze the impact of modern glucose-monitoring strategies on glycemic and patient-related outcomes in individuals with type 2 diabetes (T2D) and recent myocardial infarction (MI) and assess cost effectiveness.

RESEARCH DESIGN AND METHODS

LIBERATES was a multicenter two-arm randomized trial comparing self-monitoring of blood glucose (SMBG) with intermittently scanned continuous glucose monitoring (isCGM), also known as flash CGM, in individuals with T2D and recent MI, treated with insulin and/or a sulphonylurea before hospital admission. The primary outcome measure was time in range (TIR) (glucose 3.9-10 mmol/L/day) on days 76-90 post-randomization. Secondary and exploratory outcomes included time in hypoglycemia, hemoglobin A1c (HbA1c), clinical outcome, quality of life (QOL), and cost effectiveness.

RESULTS

Of 141 participants randomly assigned (median age 63 years; interquartile range 53, 70), 73% of whom were men, isCGM was associated with increased TIR by 17 min/day (95% credible interval -105 to +153 min/day), with 59% probability of benefit. Users of isCGM showed lower hypoglycemic exposure (<3.9 mmol/L) at days 76-90 (-80 min/day; 95% CI -118, -43), also evident at days 16-30 (-28 min/day; 95% CI -92, 2). Compared with baseline, HbA1c showed similar reductions of 7 mmol/mol at 3 months in both study arms. Combined glycemic emergencies and mortality occurred in four isCGM and seven SMBG study participants. QOL measures marginally favored isCGM, and the intervention proved to be cost effective.

CONCLUSIONS

Compared with SMBG, isCGM in T2D individuals with MI marginally increases TIR and significantly reduces hypoglycemic exposure while equally improving HbA1c, explaining its cost effectiveness. Studies are required to understand whether these glycemic differences translate into longer-term clinical benefit.

Comparison of glucose control by added liraglutide to only insulin infusion in diabetic patient undergoing cardiac surgery: A preliminary randomized-controlled trial

Background

Liraglutide, glucagon-like peptide-1 (GLP-1) receptor agonist, has been investigated for safety and effectiveness for blood glucose (BG) control in a surgical setting. However, there are only a few studies specific to cardiac surgery patients.

Aims

To primarily compare perioperative 1) BG and 2) glycemic variability (GV) between added liraglutide and only insulin infusion in diabetes mellitus (DM) patients undergoing cardiac surgery.

Setting and Design

A randomized control trial was conducted in DM patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Inclusion criteria were age 20-80 years and DM Type 2.

Material and Methods

: The recruited patients were randomly assigned to Group 1 (added liraglutide with insulin infusion) and Group 2 (insulin infusion). Insulin infusion was based on institutional protocol. Point of care testing (POCT) glucose was used for the adjustment of insulin and BG analysis. Continuous glucose monitor (CGM) was for GV analysis (using Standard deviation: SD).

Statistics

: t-test, Chi-square or Fisher-exact test, or Mann-Whitney U test.

Results

: Finally, 60 patients were in our study (Group 1 = 32 vs Group 2 = 28). Perioperative mean BG levels of Group 1 were significantly lower than Group 2 with a mean difference of 15.9 mg/dL. Nine patients (18.7% vs 10.7%, P = 0.384) had BG of 60-70 with mean BGs (109.1 vs 147.9, P = 0.001) in the morning. Thirteen patients (9.4% vs 35.7%, P = 0.025) had BG >180 mg/dL at the 1^st operative hour. SDs were increasing, but lower SD of Group 1 were observed at the postoperative period. Mean of SDs at postoperative day 2 were 23.65 vs 32.79 mg/dL, P = 0.018.

Conclusions

: Liraglutide added with insulin infusion can attenuate perioperative BG and is beneficial in the aspect of lowering GV together with BG at the postoperative period in DM patients. Liraglutide can be applied in cardiac surgery but a rearrangement of time and dosage should be further investigated.

Enhanced Recovery After Cardiac Surgery

The aims of "Fast track" cardiac anesthesia including shortening time to tracheal extubation and to hospital discharge in selected patients. The evidence is weak and recommendations are mostly based on observational, nonrandomized data and expert opinion. The majority of outcomes studied include: time to tracheal extubation, hospital/ICU length of stay, procedure-related financial costs, and the type/amount of opioids used in the peri-operative period. There should be a shift in focus to generating higher quality evidence supporting the use of enhanced recovery protocols in cardiac surgical patients and finding ways to tailor enhanced recovery principles to all cardiac surgical patients. Research should focus on the quality of care for individual patients and the delivery of health care to the public.

The value of prophylactic antibiotics in coronary artery bypass graft surgery: A review of literature

Infections have a significant impact on increasing both the morbidity and mortality rate of patients who have undergone coronary artery bypass graft (CABG) surgery. Infection after CABG imposes a clinical and economic burden on patients and health care organizations; therefore, prevention should be on the agenda. This review will focus on the value of using prophylactic antibiotics in coronary artery bypass graft surgery (CABG). Prophylactic antibiotics like cephalosporin and vancomycin are more commonly used antibiotics and are strongly associated with reduced infection risk in patients. The results showed that using antibiotics during the perioperative period and after CABG is an effective strategy for reducing post-infection problems without compromising the patients' clinical outcomes. Diabetic patients are prone to postoperative infection after CABG, however, prophylactic antibiotics should not be the only strategy used to reduce the risk of postoperative infection in diabetic patients. Perioperative glycaemic control is essential for diabetic patients undergoing CABG. Appropriate antibiotic prophylaxis has a great impact on preventing infection after CABG but duration and selecting appropriate antibiotic is important. Standardizing the use of antibiotic prophylaxis reduces the rate of infection and unwanted bacterial resistance, which could subsequently reduce economic costs to patients and public health.

Association between intraoperative hyperglycemia and postoperative end-organ dysfunctions after cardiac surgery: a retrospective observational study

PURPOSE

Hyperglycemia has been associated with postoperative morbidity in patients who undergo cardiac surgery. However, it remains unclear whether the duration of hyperglycemia is as important as its magnitude in the development of postoperative end-organ dysfunction (PEOD). This retrospective study investigated the hypothesis that the intraoperative blood glucose (BG) exposure index (GE index), calculated by the product of the magnitude and duration of BG concentration ≥ 180 mg/dL, which is an integration of the severity and duration of hyperglycemia, is associated with the incidence of PEOD in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

The primary outcome in this study was PEOD within 72 h of surgery, which was defined as a composite of postoperative acute kidney injury, delirium, myocardial injury, and prolonged mechanical ventilation. The GE index (the magnitude of BG concentration deviation ≥ 180 mg/dL [Formula: see text] duration of BG concentration ≥ 180 mg/dL) of each patient was calculated based on the intraoperative BG concentration. The relationship between the GE index and the primary outcome was examined via logistic regression model with adjustment for potential confounders.

RESULTS

Within 72 h of surgery, 301 patients (54.5%) developed PEOD. PEOD was more common in patients with greater GE index quartiles (first versus third quartile; adjusted odds ratio, 5.65, 95% confidence interval (95% CI), 2.94-10.90; P < 0.001; first versus forth quartile, adjusted odds ratio, 20.80; 95% CI, 8.01-54.00; P < 0.001).

CONCLUSION

In patients undergoing cardiac surgery with cardiopulmonary bypass, the GE index was an independent predictor of PEOD.

Investigating the effect of an education program on diabetes and lipid lowering medication usage following coronary artery bypass graft surgery

BACKGROUND

Guidelines advocate multifactorial cardiovascular risk management in patients with diabetes and atherosclerotic cardiovascular disease. In hospitalised patients with diabetes following coronary artery bypass graft (CABG) we evaluated the impacts of decision-support algorithms for optimising glycaemia and lipid-lowering. We also assessed the safety of initiating sodium-glucose cotransporter 2 (SGLT2) inhibitors near time of hospital discharge.

METHODS

This was a single-site, pre- and post-intervention analysis of glucose and lipid management in consecutive hospitalised patients with diabetes undergoing CABG surgery. The intervention involved education and decision-support algorithms designed by a multidisciplinary committee to guide cardiac surgery unit clinicians.

RESULTS

A total of 200 patients were included in the study. The pre- and post-intervention groups had similar baseline characteristics (HbA1c 7.9 ± 1.9% versus 8.1 ± 1.8%). Of 4092 blood glucose measurements the incidence of levels between 5 to 10 mmol/L was not different post-intervention (55.5% versus 57.0%, p = 0.441). Fewer endocrinology consultations occurred (59.0% versus 45.0%, p = 0.048) and rates of hypoglycaemia remained low. High-intensity statin was prescribed in >90% pre- and post-intervention although non-statin lipid-lowering agents remained <10% despite patients not achieving LDL-C targets. No 30-day readmissions for diabetic ketoacidosis occurred in patients prescribed SGLT2 inhibitors.

CONCLUSION

The intervention did not improve inpatient glycaemia or increase non-statin lipid-lowering prescriptions in patients with diabetes following CABG surgery but did reduce reliance on specialty input. Initiation of SGLT2 inhibitor therapy near time of hospital discharge was not associated with safety concerns. Alternative interventions or strategies are required to optimise glycaemia and non-statin lipid-lowering therapy prescribing in this setting. This article is protected by copyright. All rights reserved.

Diabetes management during cardiac surgery in the UK: A survey

AIM

To determine current practice regarding the diabetes management of people undergoing cardiac surgery in the UK.

METHODS

We conducted an online survey of UK cardiothoracic surgeons. All cardiothoracic surgeons listed in the Society of Cardiothoracic Surgery membership directory were invited to participate. The survey, compiled using SurveyMonkey software, comprised 15 closed and open-ended questions about the management of people with diabetes pre- and peri-operatively.

RESULTS

Sixty-two cardiothoracic surgeons from all 33 UK cardiac centres completed the survey. Of these, 44% responded that they routinely measure HbA_1c preoperatively for all patients, 19% had an HbA_1c threshold above which they would not operate and 21% currently undertake a point-of-care HbA_1c measurement during the cardiothoracic outpatient visit. A total of 74% of respondents reported that it was 'easy' or 'very easy' to obtain a diabetes team review; diabetes nurse specialists were the members of the diabetes team working most closely with cardiac surgeons. Up to a third of the surgeons did not provide physical activity recommendations prior to admission and over 80% did not have a different preoperative or surgical diabetes protocol. Inconsistency in the responses within centres suggests that differences in practice may depend on individual surgeons rather than local policy.

CONCLUSIONS

The study demonstrates there is only limited peri-operative management of diabetes in people undergoing cardiac surgery in the UK. There is an opportunity for greater involvement of the diabetes specialist team both before and during admission for surgery to improve outcomes. (Trial registration: ISRCTN10170306).

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

Hemoglobin A1c and Cardiovascular Outcomes Following Percutaneous Coronary Intervention: Insights From a Large Single-Center Registry

OBJECTIVES

The aim of this study was to evaluate post-percutaneous coronary intervention (PCI) outcomes in relation to pre-procedural glycated hemoglobin (HbA1c) levels from a large, contemporary cohort.

BACKGROUND

There are limited data evaluating associations between HbA1c, a marker of glycemic control, and ischemic risk following PCI.

METHODS

All patients with known HbA1c levels undergoing PCI at a single institution between 2009 and 2017 were included. Patients were divided into 5 groups on the basis of HbA1c level: ≤5.5%, 5.6% to 6.0%, 6.1% to 7.0%, 7.1% to 8.0%, and >8.0%. The primary endpoint was major adverse cardiac events (MACE), a composite of all-cause death or myocardial infarction (MI), at 1-year follow-up.

RESULTS

A total of 13,543 patients were included (HbA1c ≤5.5%, n = 1,214; HbA1c 5.6% to 6.0%, n = 2,202; HbA1c 6.1% to 7.0%, n = 4,130; HbA1c 7.1% to 8.0%, n = 2,609; HbA1c >8.0%, n = 3,388). Patients with both low (HbA1c ≤5.5%) and high (HbA1c >8.0%) levels displayed an increased risk for MACE compared with those with values between 6.1% and 7.0%. Excess risk was driven primarily by higher rates of all-cause death among those with low HbA1c levels, while higher values were strongly associated with greater MI risk. Patterns of risk were unchanged among patients with serial HbA1c levels and persisted after multivariate adjustment.

CONCLUSIONS

Among patients undergoing PCI, pre-procedural HbA1c levels display a U-shaped association with 1-year MACE risk, a pattern that reflects greater risk for death in the presence of low HbA1c (≤5.5%) and higher risk for MI with higher values (>8.0%).

Effectiveness of blood glucose control protocol for open heart surgery patients

AIMS

To evaluate the effectiveness of a tailored blood glucose control protocol for postoperative cardiac surgery patients treated in intensive care.

DESIGN

Retrospective study.

METHODS

Data for the control group (non-tailored protocol) were collected from medical records at a tertiary hospital in Seoul, Korea between April-July 2015. Data for the experimental group (tailored protocol) were obtained from medical records between April-July 2016. After adjusting the target blood glucose range, eliminating single-dose insulin administration and extending the blood glucose measurement time interval, data for blood glucose measurements, time for reaching and maintaining target blood glucose, mean number of daily blood glucose measurements and insulin dose adjustments for the experimental group were collected.

RESULTS

In the experimental group (where the target blood glucose rate was increased) the hypoglycaemia rate and the variation in blood glucose decreased significantly compared with the control group. In particular, the experimental group maintained relatively stable blood glucose levels by retaining a small variation range in glucose, regardless of the presence of diabetes. Time required for maintaining target blood glucose, mean number of daily blood glucose measurements and insulin dose adjustments per patient decreased.

CONCLUSION

The tailored protocol contributes to the safe and effective control of blood glucose in critical care patients after cardiac surgery and to the efficiency of nurses administering it.

IMPACT

This study has two significant impacts. The application of the tailored protocol has a positive impact on patients' blood glucose management, a critical component of treatment for postoperative cardiac patients in intensive care units. It also has a positive impact on the efficiency of nurses applying it. The results of this study are thus expected to facilitate successful implementation of clinical protocols for critical care after heart surgery.

Artificial endocrine pancreas with a closed-loop system effectively suppresses the accelerated hyperglycemic status after reperfusion during aortic surgery

OBJECTIVES

To control intraoperative hyperglycemia in patients who underwent aortic surgery using STG-55^® artificial endocrine pancreas and clarify the effectiveness of this device.

METHODS

Blood glucose control using the STG-55^® was performed in 18 patients (15 men and 3 women; age, 66 ± 10 years) who required hypothermic circulatory arrest (STG-55^® group). Seventeen patients (10 men and 7 women; age, 71 ± 8 years) whose blood glucose was controlled using the conventional method were included in the control group. Glucose concentration was controlled with the aim of maintaining it at 150 mg/dl.

RESULTS

In both groups, the blood glucose concentrations did not significantly change during the interruption of systemic perfusion; however, a sharp increase was noted immediately after reperfusion. Although the hyperglycemic status persisted after reperfusion in the control group, it was effectively suppressed in the STG-55^® group (STG^® vs. control group at 50 min after reperfusion: 180 ± 35 vs. 212 ± 47 mg/dl, p = 0.026) and blood glucose concentration reached the target value of 150 mg/dl at 100 min after reperfusion (STG^® vs. control group: 153 ± 29 vs. 215 ± 43 mg/dl, p = 0.0008). The total administered insulin dose was 175 ± 81 U and 5 ± 3 U in the STG^® and control groups, respectively (p < 0.0001).

CONCLUSIONS

To treat the accelerated hyperglycemic status in aortic surgery requiring circulatory arrest, strict glycemic control using an artificial endocrine pancreas might be beneficial.

Short-term outcomes following coronary artery bypass graft surgery in insulin treated and non-insulin treated diabetes: A tertiary hospital experience in Australia

BACKGROUND AND AIMS

Outcomes after coronary artery bypass graft (CABG) surgery have improved due to advances in surgical technique and post-operative care. We aimed to describe contemporary clinical characteristics and short-term post-operative outcomes in diabetic patients undergoing CABG surgery.

METHODS

A retrospective analysis of patients who underwent CABG surgery over a 4.5-year period in a Western Australian tertiary hospital was performed in September 2019. The cohort was stratified according to pre-operative diabetes status.

RESULTS

A total of 1327 patients underwent CABG surgery, of which 572 (43.1%) had diabetes. Diabetic patients were more likely to be female (24.7% vs. 13.9%, p < 0.001) and have dyslipidaemia (83.0% vs. 68.1%, p < 0.001), hypertension (82.0% vs. 68.7%, p < 0.001), raised body mass index (29.8 ± 5.6 vs. 28.7 ± 5.1 kg/m², p < 0.001), prior myocardial infarction (62.8% vs. 54.8%, p = 0.004), prior stroke (8.6% vs. 5.0%, p = 0.010), congestive cardiac failure (20.2% vs. 15.1%, p = 0.014), reduced estimated glomerular filtration rate (86.7 ± 36.1 vs. 90.8 ± 32.1 ml/min/1.73 m², p = 0.036) and three-vessel coronary artery disease (74.8% vs. 67.3%, p = 0.003). Post-operative wound infections (3.1% vs. 1.5%, p = 0.022), new dialysis requirement (2.9% vs. 1.0%, p = 0.009) and 30-day hospital admission (13.1% vs. 8.5%, p = 0.007) was more likely in diabetic patients, but not myocardial infarction (3.0% vs. 2.0%, p = 0.247), stroke (1.4% vs. 0.8%, p = 0.286) or 30-day mortality (2.4% vs. 1.7%, p = 0.354). No significant differences were detected in short-term outcomes between patients with non-insulin (n = 398) versus insulin treated (n = 174) diabetes.

CONCLUSIONS

Diabetic patients continue to represent a higher-risk cohort, highlighting the need for further strategies to reduce short-term adverse outcomes following CABG surgery.

IMPACT OF STRUCTURED INSULIN ORDER SETS ON INPATIENT HYPOGLYCEMIA AND GLYCEMIC CONTROL

Objective: In hospitalized patients, glycemic excursions outside recommended glycemic targets have been associated with increased morbidity and mortality. Despite recommendations to avoid use of correctional insulin alone for managing hyperglycemia, this approach remains common. We performed a quality improvement project aimed at both reducing hypoglycemic events and promoting increased use of basal insulin by updating our insulin order sets to reflect clinical practice guideline recommendations. Methods: Brooke Army Medical Center correctional insulin order sets were modified to reflect higher treatment thresholds and targets, and a basal insulin order was added with a recommended weight-based starting dose. Pre- and postintervention analyses were performed. Patients were included if they were prescribed subcutaneous insulin during their hospital stay. The following outcomes were measured: (1) glucose levels, and (2) prescriptions for basal insulin. Results: A significant reduction in hypoglycemia events was noted following the intervention (glucose <70 mg/dL: 9.2% pre-intervention vs. 8.8% postintervention; glucose <55 mg/dL: 4.2% pre-intervention vs. 2.2% postintervention). When excluding patients that were ordered correctional insulin alone but did not receive a dose, an increase in basal insulin use was seen (50% pre-intervention vs. 61% postintervention). Rates and severity of hyperglycemia (glucose >180 mg/dL) remained unchanged. Conclusion: The alteration in insulin order set parameters resulted in a significant reduction in hypoglycemia without significant increases in hyperglycemia. Although basal insulin use increased, optimal dosing recommendations were not often utilized. Further interventions are necessary to reduce hyperglycemia. Abbreviations: CPOE = computerized provider order entry; EMR = electronic medical record; HbA1c = hemoglobin A1c; LOS = length of stay; QI = quality improvement; SSI = sliding scale insulin.

Mitochondrial Dysfunction in Cardiac Surgery

Mitochondria are key to the cellular response to energetic demand, but are also vital to reactive oxygen species signaling, calcium hemostasis, and regulation of cell death. Cardiac surgical patients with diabetes, heart failure, advanced age, or cardiomyopathies may have underlying mitochondrial dysfunction or be more sensitive to perioperative mitochondrial injury. Mitochondrial dysfunction, due to ischemia/reperfusion injury and an increased systemic inflammatory response due to exposure to cardiopulmonary bypass and surgical tissue trauma, impacts myocardial contractility and predisposes to arrhythmias. Strategies for perioperative mitochondrial protection and recovery include both well-established cardioprotective protocols and targeted therapies that remain under investigation.

Diabetes, dysglycemia, and vascular surgery

BACKGROUND

Abnormalities in glucose metabolism are common in patients with arterial disease. Chronic hyperglycemia and insulin resistance contribute to the complexity of vascular disorders. They also overlap with the effects of perioperative hyperglycemia on adverse perioperative outcomes. We provide an overview of the pathophysiologic consequences of dysglycemia and the evidence behind glycemic control in patients undergoing vascular surgery.

METHODS

We searched the literature for major studies evaluating the pathophysiology of hyperglycemia in microvascular and macrovascular beds, randomized trials in perioperative populations, and meta-analyses. The literature was summarized to guide therapy in the population of vascular patients and for the perioperative period.

RESULTS

National standards for glycemic control after vascular interventions were not identified. Mounting evidence exists for the long-term consequences of poor glycemic control on the progression of vascular disease. Similarly, there is a large body of evidence supporting tight control of hyperglycemia after general and cardiac surgery during the critical perioperative period. The absolute glucose target remains controversial. Randomized controlled studies are lacking in vascular surgery patients, but the current evidence can be extrapolated to guide management after vascular interventions. Glycated hemoglobin is a biomarker for increased mortality and vascular morbidity after vascular surgery.

CONCLUSIONS

Hyperglycemia contributes to poor outcome in the vascular patient. Further vascular focused studies are required to determine the proper perioperative serum glucose target and the long-term glycated hemoglobin range.

Mid-term Outcome and Prognosis of Prediabetic Patients After Coronary Artery Bypass Graft Surgery, Regardless of the First Month After Surgery

OBJECTIVE

Current knowledge of the effects of prediabetes on the postsurgical outcomes of mortality and major adverse cardiovascular events (MACE) after coronary artery bypass graft surgery (CABG) is limited. The aim of this study is to evaluate the MACE and overall 1-year survival of patients with prediabetes who underwent elective isolated CABG.

MATERIAL AND METHODS

After a thorough analysis of CABG database since January 2016, 3741 patients were included. Patients were categorized as follows: diabetes mellitus type 2 (n = 2695), prediabetics (fasting blood sugar = 100-125 mg/dL and hemoglobin A1c (HbA1c) = 5.7%-6.4%) (n = 471), and nondiabetics (fasting blood sugar < 100 mg/dL and HbA1c < 5.7%) (n = 575). Primary end point (MACE) was the composite death, acute coronary syndrome, coronary revascularization, and cerebrovascular events after 1 month of surgery. Event-free survival was assessed and compared between groups over a median follow-up of 1 year.

RESULTS

In this retrospective cohort design, 3741 patients who underwent elective isolated CABG were evaluated. One-year overall survival percent was 100% for nondiabetic and prediabetic patients and 99.9% for diabetic patients (P value = 0.56). One-year event-free survival was 97.4% for nondiabetics, 98.1% for prediabetics, and 96.8% for diabetic patients (P value = 0.08).

CONCLUSIONS

One-year overall survival and also the event-free survival of prediabetic patients were similar to those without diabetes mellitus. Over the median follow-up of 1 year, descending trends shows the higher probability of adverse events in diabetic patients with longer follow-ups.

Current and emerging pharmacotherapy for the treatment of infections following open-heart surgery

INTRODUCTION

Patients undergoing open-heart surgery may suffer from postoperative complications, including severe infections. Antimicrobials to treat infectious complications in this population should be selected thoughtfully, taking into account three different and fundamental issues: (i) the site of infection; (ii) the suspected or proven causative agent and its susceptibility pattern; and (iii) the risk of suboptimal pharmacokinetic characteristics and potential toxicity of the chosen drug/s.

AREAS COVERED

The present narrative review summarizes the current and future antimicrobial options for the treatment of infections developing after open-heart surgery.

EXPERT OPINION

The pharmacological treatment of infections developing in cardiac surgery patients poses peculiar challenges, including the need for an active empirical therapy for severe events such as bloodstream infections, deep sternal wound infections, or early-onset postoperative prosthetic endocarditis. In addition, the risk for multidrug-resistant pathogens should also be taken into account in endemic areas. A multidisciplinary evaluation on a patient-by-patient basis, deeply involving infectious diseases specialists and cardiothoracic surgeons, remains essential for appropriately balancing both short-term and long-term risks and benefits of any possible surgical reintervention in combination with adequate pharmacotherapy.