Wider perioperative glycemic fluctuations increase risk of postoperative atrial fibrillation and ICU length of stay

The impact of glucagon-like peptide-1 receptor agonists in the patients undergoing anesthesia or sedation: systematic review and meta-analysis

BACKGROUND

Glucagon-like peptide-1 agonist receptors (GLP-1RAs), medications used for glycemic control and weight loss, are increasing worldwide. In the perioperative period, the major concern related to GLP-1RA is gastric emptying delay and risk of aspiration. This meta-analysis and systematic review compared the risks and benefits of using GLP-1 agonist receptors and control in surgical and nonsurgical procedures under anesthesia or sedation.

METHODS

We systematically searched MEDLINE, Embase, and Cochrane for randomized controlled trials and observational studies involving patients > 18 years undergoing elective surgeries or procedures. Outcomes of interest were pre-procedural gastrointestinal (GI) symptoms, residual gastric content assessed by endoscopy, pulmonary aspiration during anesthesia/sedation, perioperative glycemic control, postoperative inotropic support, nausea/vomiting (PONV), atrial fibrillation, and 30-day mortality rate. We used a random effects model, with odds ratio and mean difference computed for binary and continuous outcomes, respectively.

RESULTS

Fourteen randomized and observational studies with 2143 adult patients undergoing elective surgeries and procedures were included. GLP-1RA resulted in increased pre-procedural GI symptoms (OR 7.66; 95% CI 3.42, 17.17; p < 0.00001; I2 = 0%) and elevated residual gastric content (OR 6.08; 95% CI 2.86, 12.94; p < 0.00001; I2 = 0%). GLP-1RA resulted in lower glycemic levels (MD - 0.73; 95% CI - 1.13, - 0.33; p = 0.0003; I2 = 90%) and lower rate of rescue insulin administration (OR 0.39; 95% CI 0.23, 0.68 p = 0.0009; I2 = 35%). There was no significant difference in rate of perioperative hypoglycemia (OR 0.60; 95% CI 0.29, 1.24; p = 0.17; I2 = 0%), hyperglycemia (OR 0.89; 95% CI 0.59, 1.34; p = 0.58; I2 = 38%), need for postoperative inotropic support (OR 0.57; 95% CI 0.33, 1.01; p = 0.05; I2 = 0%), atrial fibrillation (OR 1.02; 95% CI 0.52, 2.01; p = 0.95; I2 = 16%), rate of PONV (OR 1.35; 95% CI 0.82, 2.21; p = 0.24; I2 = 0%), and 30-day mortality rate (OR 0.54; 95% CI 0.14, 2.05; p = 0.25; I2 = 0%).

CONCLUSION

Compared to control, pre-procedural GLP-1RA increased the rate of GI symptoms and the risk of elevated residual gastric content despite adherence to fasting guidelines. GLP-1RA improved glycemic control and decreased the rate of rescue insulin administration. There was no significant difference in the rates of perioperative hypo or hyperglycemia, postoperative inotropic support, PONV, atrial fibrillation, and 30-day mortality.

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.

Dysglycemia and arrhythmias

Disorders in glucose metabolism can be divided into three separate but interrelated domains, namely hyperglycemia, hypoglycemia, and glycemic variability. Intensive glycemic control in patients with diabetes might increase the risk of hypoglycemic incidents and glucose fluctuations. These three dysglycemic states occur not only amongst patients with diabetes, but are frequently present in other clinical settings, such as during critically ill. A growing body of evidence has focused on the relationships between these dysglycemic domains with cardiac arrhythmias, including supraventricular arrhythmias (primarily atrial fibrillation), ventricular arrhythmias (malignant ventricular arrhythmias and QT interval prolongation), and bradyarrhythmias (bradycardia and heart block). Different mechanisms by which these dysglycemic states might provoke cardiac arr-hythmias have been identified in experimental studies. A customized glycemic control strategy to minimize the risk of hyperglycemia, hypoglycemia and glucose variability is of the utmost importance in order to mitigate the risk of cardiac arrhythmias.

Glycemic variability and the risk of atrial fibrillation: a meta-analysis

Background

Glycemic variability (GV) has been associated with vascular complications in patients with diabetes. However, the relationship between GV and risk of atrial fibrillation (AF) remains not fully determined. We therefore conducted a systematic review and meta-analysis to evaluate the above association.

Methods

Medline, Embase, Web of Science, Wanfang, and China National Knowledge Infrastructure were searched for longitudinal follow-up studies comparing the incidence of AF between patients with higher versus lower GV. A random-effects model incorporating the potential heterogeneity was used to pool the results.

Results

Nine cohort studies with 6,877,661 participants were included, and 36,784 (0.53%) participants developed AF during follow-up. Pooled results showed that a high GV was associated with an increased risk of AF (risk ratio [RR]: 1.20, 95% confidence interval [CI]: 1.11 to 1.30, p < 0.001, I² = 20%). Subgroup analyses suggested consistent association between GV and AF in prospective (RR: 1.29, 95% CI: 1.05 to 1.59, p = 0.01) and retrospective studies (RR: 1.18, 95% CI: 1.08 to 1.29, p = 0.002), in diabetic (RR: 1.24, 95% CI: 1.03 to 1.50, p = 0.03) and non-diabetic subjects (RR: 1.13, 95% CI: 1.00 to 1.28, p = 0.05), in studies with short-term (RR: 1.25, 95% CI: 1.11 to 1.40, p < 0.001) and long-term GV (RR: 1.18, 95% CI: 1.05 to 1.34, p = 0.006), and in studies with different quality scores (p for subgroup difference all > 0.05).

Conclusion

A high GV may predict an increased risk of AF in adult population.

Prevalence of glucose metabolism disorders and its association with left atrial remodelling before and after catheter ablation in patients with atrial fibrillation

AIMS

To investigate the exact prevalence of glucose metabolism disorders, and their impact on left atrial (LA) remodelling and reversibility in patients with atrial fibrillation (AF).

METHODS AND RESULTS

We examined 204 consecutive patients with AF who underwent their first catheter ablation (CA). Oral glucose tolerance test was used to evaluate glucose metabolism disorders in 157 patients without known diabetes mellitus (DM). Echocardiography was performed before and 6 months after CA. Oral glucose tolerance test identified abnormal glucose metabolism in 86 patients [11 with newly diagnosed DM, 74 with impaired glucose tolerance (IGT) and 1 with impaired fasting glucose (IFG)]. Ultimately, 65.2% of patients had abnormal glucose metabolism. Diabetes mellitus group had the worst LA reservoir strain and LA stiffness (both P < 0.05), while there was no significant difference in baseline LA parameters between normal glucose tolerance (NGT) group and IGT/IFG group. The prevalence of LA reverse remodelling (≥15% decrease in the LA volume index at 6 months after CA) was significantly higher in NGT group compared with IGT/IFG and DM group (64.1 vs. 38.6 vs. 41.5%, P = 0.006). Both DM and IFG/IGT carry a significant risk of lack of LA reverse remodelling independent of baseline LA size and AF recurrence.

CONCLUSION

Approximately 65% of patients with AF who underwent their first CA had abnormal glucose metabolism. Patients with DM had significantly impaired LA function compared with non-DM patients. Impaired glucose tolerance/IFG as well as DM carries significant risk of unfavourable LA reverse remodelling. Our observations may provide valuable information regarding the mechanisms and therapeutic strategies of glucose metabolism-related AF.

Optimising risk factors for atrial fibrillation post-cardiac surgery

Postoperative atrial fibrillation (POAF) is an ongoing complication following cardiac surgery, with an incidence of 15%-60%. It is associated with substantial mortality and morbidity, as well increased hospital stays and healthcare costs. The pathogenesis is not fully understood, but the literature suggests that POAF occurs when transient, postoperative triggers act on vulnerable atrial tissue produced by preoperative, procedure-induced and postoperative processes such as inflammation, oxidative stress, autonomic dysfunction and electrophysiological remodelling of the atrial tissues. This sets the stage for arrhythmogenic mechanisms, such as ectopic firing secondary to triggered activity and re-entry mechanisms generating POAF. Preoperative factors include advanced age, sex, ethnicity, cardiovascular risk factors, preoperative drugs, electrocardiogram and echocardiogram abnormalities. Procedural factors include: the use of cardiopulmonary bypass and aortic cross clamp, type of cardiac surgery, use of hypothermia, left ventricular venting, bicaval cannulation and exclusion of the left atrial appendage. Postoperative factors include postoperative drugs, electrolyte and fluid balance and infection. This review explores the pathogenesis of POAF and the contribution of these perioperative factors in the development of POAF. Patients can be risk stratified for targeted treatment and prophylaxis, and how these factors can be attenuated to improve POAF outcomes following cardiac surgery.

The effect of dexmedetomidine on intraoperative blood glucose homeostasis: secondary analysis of a randomized controlled trial

Purpose

To investigate the effect of dexmedetomidine on intraoperative blood glucose hemostasis in elderly patients undergoing non-cardiac major surgery.

Methods

This was secondary analysis of a randomized controlled trial. Patients in dexmedetomidine group received a loading dose dexmedetomidine (0.6 μg/kg in 10 min before anaesthesia induction) followed by a continuous infusion (0.5 μg/kg/hr) till 1 h before the end of surgery. Patients in control group received volume-matched normal saline at the same time interval. Primary outcome was the incidence of intraoperative hyperglycemia (blood glucose higher than 10 mmol/L).

Results

303 patients in dexmedetomidine group and 306 patients in control group were analysed. The incidence of intraoperative hyperglycemia showed no statistical significance between dexmedetomidine group and control group (27.4% vs. 22.5%, RR = 1.22, 95%CI 0.92–1.60, P = 0.167). Median value of glycemic variation in dexmedetomidine group (2.5, IQR 1.4–3.7, mmol) was slightly lower than that in control group (2.6, IQR 1.5–4.0, mmol), P = 0.034. In multivariable logistic analysis, history of diabetes (OR 3.007, 95%CI 1.826–4.950, P < 0.001), higher baseline blood glucose (OR 1.353, 95%CI 1.174–1.560, P < 0.001) and prolonged surgery time (OR 1.197, 95%CI 1.083–1.324, P < 0.001) were independent risk factors of hyperglycaemia.

Conclusions

Dexmedetomidine presented no effect on intraoperative hyperglycemia in elderly patients undergoing major non-cardiac surgery.

Trial registration

Present study was registered at Chinese Clinical Trial Registry on December 1, 2015 (www.chictr.org.cn, registration number ChiCTR-IPR-15007654).

Atrial fibrillation risk in patients suffering from type I diabetes mellitus. A review of clinical and experimental evidence

Atrial fibrillation (AF) and diabetes mellitus (DM) are commonly encountered in clinical practice. Although, the long term macrovascular and microvascular sequela of DM are well validated, the association between the less prevalent type 1 DM (T1DM) and atrial arrhythmogenesis is poorly understood. In the present review we highlight the current experimental and clinical data addressing this complex interaction. Animal studies support that T1DM, characterized by insulin deficiency and glycemic variability, impairs phosphatidylinositol 3‑kinase (PI3K)/protein kinase B signaling pathway. This pathway holds a central role in atrial electrical and structural remodeling responsible for arrhythmia initiation and maintenance. The molecular ''footprint'' of T1DM in atrial myocytes seems to involve a state of increased oxidative stress, impaired glucose transportation, ionic channel dysregulation and eventually fibrosis. On the contrary only a few clinical studies have examined the role of T1DM as an independent risk factor for AF development, and are discussed here. Further research is needed to solidify the real magnitude of this association and to investigate the clinical implications of PI3K molecular signaling pathway in atrial fibrillation management.

[Atrial Fibrillation After Coronary Artery Bypass Surgery: Risk Factors, Prevention and Treatment]

This review focuses on the issue of atrial fibrillation (AF) following coronary bypass surgery in patients with ischemic heart disease. Risk factors of this complication are discussed in detail. The authors addressed the effect of diabetes mellitus on development of postoperative AF. Data on current methods for prevention and treatment of AF are provided.

Potential Risk of Hypoglycemia in Patients with Heart Failure

The properties of glucose changes in patients with chronic heart failure remain elusive. In the present study, we investigated the sequential changes of interstitial glucose concentrations in patients with chronic heart failure and heart disease who were not undergoing antidiabetic therapy.A glucose monitoring device (FreeStyle Libre Pro) was attached to the backside of an upper arm and the interstitial glucose concentration was monitored every 15 minutes for 1 week. Eleven patients with chronic heart failure (Heart failure (+) ) and 7 patients with chronic heart diseases but not with heart failure (Heart failure (-) ) were enrolled. The average level and peak value of interstitial glucose concentrations, and the duration of hyperglycemia (≥ 140 mg/dL) were not significantly different between Heart failure (+) and Heart failure (-). The duration of hypoglycemia (< 80 mg/dL) was significantly longer and the trough value was significantly lower in Heart failure (+) compared with Heart failure (-). Most of the patients in Heart failure (+) were exposed to a long duration of hypoglycemia from midnight to morning. Importantly, none of the patients who showed hypoglycemia complained of any subjective symptoms during hypoglycemia. Malabsorption may be one of the mechanisms of hypoglycemia.In summary, patients with chronic heart failure are at risk of developing hypoglycemia even if they do not undergo any antidiabetic therapy.

Determinants of left intra-atrial electromechanical delay as evaluated by tissue Doppler imaging in candidates for coronary artery bypass graft surgery

OBJECTIVES

Inhomogeneity in the atrial conduction time is a predisposing factor for atrial fibrillation. The aim of our study was to determine the independent determinants of the left intra-atrial electromechanical delay (LIAEMD) as a marker of left atrial (LA) dyssynchrony in candidates for coronary artery bypass graft surgery (CABGS).

METHODS

This prospective cross-sectional study recruited 516 consecutive candidates for CABGS. Via the pulsed-wave tissue Doppler imaging modality in echocardiography, the times between the P wave and the peak of the a' wave at the septal and lateral mitral annuli were measured and the difference between these times was considered to be LIAEMD. Additionally, clinical and laboratory data on each patient were gathered. The odds ratio for an increased LIAEMD was calculated in patients with and without diabetes in univariate and multivariate analyses.

RESULTS

The multivariable analysis revealed that in the patients without diabetes, obesity, calcium-channel blocker usage, an increased maximal LA volume, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio were independently correlated with an increased likelihood of LIAEMD occurrence (P < .05).

CONCLUSIONS

In our study on CABGS candidates, in the patients without diabetes, obesity, an increased maximal LA volume, calcium-channel blocker usage, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio independently determined increased LIAEMD. The prevention or treatment of factors that are detrimental to the LA electromechanical function may be helpful for the preservation of the LA electromechanical integrity.

Increased glucose variability is associated with atrial fibrillation after coronary artery bypass

BACKGROUND

Elevated preoperative hemoglobin A1c (HbA1c) is a predictor of poor outcomes following coronary artery bypass grafting (CABG), but the role of increased postoperative glucose variability (GV) is unknown. We hypothesized that short-term postoperative GV is associated with an increased risk of postoperative atrial fibrillation following isolated CABG.

METHODS

Multicenter retrospective study of 2073 patients who underwent isolated CABG from January 2012 to March 2018. Postoperative GV in the first 24 hours was measured by standard deviation, coefficient of variation, and mean amplitude of glycemic excursions. Multivariate logistic regression assessed the independent association of GV with postoperative atrial fibrillation.

RESULTS

A total of 2073 patients met the study criteria, and 446 patients (21.5%) developed postoperative atrial fibrillation. Using multivariate logistic regression to adjust for covariates, postoperative atrial fibrillation was associated with increased 24-hour GV (odds ratio [OR] = 1.16, 95% confidence interval [CI], 1.05-1.27, P < 0.01) and increased 24-hour mean glucose (OR = 1.14, 95% CI, 1.08-1.21, P < 0.01). Thus, for every 10% increase in 24-hour GV or 10 mg/dL increase in mean glucose, there was a 16% or 14% increased risk of postoperative atrial fibrillation respectively.

CONCLUSIONS

Increased 24-hour GV and mean glucose are predictors of atrial fibrillation after CABG. Preoperative HbA1c is not a risk factor for postoperative atrial fibrillation after adjusting for postoperative mean glucose and GV. Further investigation is needed to determine the relationship between adherence to strict glucose control and adverse events following CABG.

Atrial fibrillation and type 2 diabetes: Prevalence, etiology, pathophysiology and effect of anti-diabetic therapies

New-onset atrial fibrillation (NAF) is increased in the type 2 diabetic patient because of the presence of the metaboli syndrome and increased sympathetic activity. This results in inflammation, endothelial dysfunction and myocardial steatosis which, in turn, lead to atrial fibrosis and dilatation. The end result is the development of structural and electrical atrial remodeling. Drugs that lower insulin resistance, particularly pioglitazone, decrease the incidence of NAF while drugs that, through hypoglycaemia, stimulate the sympathetic nervous system, insulin and secretagogues, increase the incidence of NAF. Currently there is no evidence that GLP-1 agonists, SGLT2 inhibitors and DPP-4 inhibitors either accelerate or decelerate the development of NAF.

Practice Guidelines for Enteral Nutrition Management in Dysglycemic Critically Ill Patients: A Relook for Indian Scenario

Background and aim

Intensive-care practices and settings differ for India in comparison to other countries. While guidelines are available to direct the use of enteral nutrition (EN), there are no recommendations specific to nutritional management of EN in dysglycemic patients, specific to patients in Indian critical care settings. Advisory board meetings were arranged to develop the practice guidelines specific to the Indian context, for the use of EN in dysglycemic critically ill patients and to overcome challenges in this field.

Materials and methods

Two advisory board meetings were organized to review various existing guidelines, meta-analyses, randomized controlled trials (RCTs), controlled trials and review articles, for their contextual relevance and strength. Three rounds of Delphi voting were done to arrive at consensus on certain recommendations. A systematic grading of practice guidelines by the advisory board was done based on strength of the consensus voting and reviewed supporting evidences.

Results

Based on the literature review, the recommendations for developing the practice guidelines were made as per the grading criteria agreed upon by the advisory board. The recommendations were to address challenges regarding prediction and assessment of dysglycemia (DG), acceptable glycemic targets in such settings, general nutritional aspects pertaining to DG nutrition, and nutrition in various superspecialty cases in critical care settings, where DG is commonly encountered.

Conclusion

This paper summarizes the optimum EN practices for managing DG in critically ill patients. The practical solutions to overcome the challenges in this field are presented as practice guidelines at the end of each section. These guidelines are expected to provide guidance for EN management in dysglycemic critically ill patients. These guidelines also outline the model glycemic control task force and its roles in nutrition care as well as an intensive care unit DG nutrition protocol.

How to cite this article

Mehta Y, Mithal A, Kulkarni A, Reddy BR, Sharma J, Dixit S, et al. Practice Guidelines for Enteral Nutrition Management in Dysglycemic Critically Ill Patients: A Relook for Indian Scenario. Indian J Crit Care Med 2019;23(12):594–603.