Evidence-based Guidelines for Perioperative Management of Diabetes in Cardiac and Vascular Surgery

The frail patient undergoing cardiac surgery: lessons learned and future perspectives

Frailty is a geriatric condition characterized by the reduction of the individual's homeostatic reserves. It determines an increased vulnerability to endogenous and exogenous stressors and can lead to poor outcomes. It is an emerging concept in perioperative medicine, since an increasing number of patients undergoing surgical interventions are older and the traditional models of care seem to be inadequate to satisfy these patients' emerging clinical needs. Nowadays, the progressive technical and clinical improvements allow to offer cardiac operations to an older, sicker and frail population. For these reasons, a multidisciplinary team involving cardiac surgeons, clinical cardiologists, anesthesiologists, and geriatricians, is often needed to assess, select and provide tailored care to these high-risk frail patients to optimize clinical outcomes. There is unanimous agreement that frailty assessment may capture the individual's biological decline and the heterogeneity in risk profile for poor health-related outcomes among people of the same age. However, since commonly used preoperative scores for cardiac surgery fail to capture frailty, a specific preoperative assessment with dedicated tools is warranted to correctly recognize, measure and quantify frailty in these patients. On the contrary, pre-operative and post-operative interventions can reduce the risk of complications and support patient recovery promoting surgical resilience. Minimally invasive cardiac procedures aim to reduce surgical trauma and may be associated with better clinical outcome in this specific sub-group of high-risk patients. Among postoperative adverse events, the occurrence of delirium represents a risk factor for several unfavorable outcomes including mortality and subsequent cognitive decline. Its presence should be carefully recognized, triggering an adequate, evidence based, treatment. There is evidence, from several cross-section and longitudinal studies, that frailty and delirium may frequently overlap, with frailty serving both as a predisposing factor and as an outcome of delirium and delirium being a marker of a latent condition of frailty. In conclusion, frail patients are at increased risk to experience poor outcome after cardiac surgery. A multidisciplinary approach aimed to recognize more vulnerable individuals, optimize pre-operative conditions, reduce surgical invasivity and improve post-operative recovery is required to obtain optimal long-term outcome.

Chinese clinical practice guidelines for perioperative blood glucose management

With the increased incidence of diabetes, the number of diabetic patients who require surgical treatment is also increasing. Unfortunately, practices in this area lack standardisation. The purpose of this multidisciplinary, evidence-based guidelines for perioperative blood glucose management is to provide a comprehensive set of recommendations for clinicians treating diabetes with different types of surgery. The intended audience comprises Chinese endocrinologists, surgeons, anaesthetists, clinical pharmacists, nurses and professionals involved in perioperative blood glucose management. The guidelines were formulated as follows. First, a multidisciplinary expert group was established to identify and formulate key research questions on topics of priority according to the Population, Intervention, Comparator and Outcomes (PICO) process. We conducted a meta-analysis of available studies using Review Manager version 5.3, as appropriate. We pooled crude estimates as odds ratios with 95% confidence intervals using a random-effects model, and used the Grading of Recommendations Assessment, Development, and Evaluation methods to assess the quality of the retrieved evidence. Finally, 32 recommendations were gathered that covered 11 fields-management and coordination, endocrinologists' consultation, diabetes diagnosis, surgery timing and anaesthesia method, blood glucose target values and monitoring frequency, hypoglycaemia treatment, oral administration of blood glucose lowering drugs, use of insulin, enteral and parenteral nutritional, postoperative treatment and medication and education and training. Twenty-five systematic reviews and meta-analyses were conducted for these guidelines to address the PICO questions. These guidelines are intended to improve perioperative blood glucose management and help doctors in specifying medical diagnosis and treatment, and will be implemented / disseminated extensively in China.

The Effect of Preoperative Carbohydrate Loading on Clinical and Biochemical Outcomes after Cardiac Surgery: A Systematic Review and Meta-Analysis of Randomized Trials

Background and aim: Preoperative fasting leads to metabolic stress and causes insulin resistance in patients undergoing cardiac surgery. The aim of this study was to assess the effect of preoperative oral carbohydrate loading (OCH) on outcome in patients undergoing planned cardiac surgery by systematically reviewing the literature and synthesizing evidence from randomized controlled trials (RCTs). Methods: Systematic search of PubMed/MEDLINE/Embase/Cinahl/Web of Science/ClinicalTrials databases was performed to identify relevant RCTs from databased inception until 05/03/2020. We included studies that compared outcome measures between OCH with control (placebo or standard starvation). We conducted a random-effect meta-analysis of clinical and biochemical parameters. Results: Nine studies (N = 9) were included with a total of 507 patients. OCH significantly decreased aortic clamping duration (n = 151, standardized mean difference (SMD) = −0.28, 95% confidence interval (CI) = −0.521 to −0.038, p = 0.023 and differences in means (DM) = −6.388, 95%CI = −11.246 to −1.529, p = 0.010). Patients from treatment groups had shorter intensive care unit (ICU) stay (n = 202, SMD = −0.542, 95%CI = −0.789 to −0.295, p < 0.001 and DM = −25.925, 95%CI = −44.568 to −7.283, p = 0.006) and required fewer units of insulin postoperatively (n = 85, SMD = −0.349, 95%CI = −0.653 to −0.044, p = 0.025 and DM = −4.523, 95%CI = −8.417 to −0.630, p = 0.023). The necessity to use inotropic drugs was significantly lower in the OCH group (risk ratio (RR) = 0.795, 95%CI = 0.689 to 0.919, p = 0.002). All other primary outcomes did not reveal a significant effect. Conclusions: Preoperative OCH in patients undergoing cardiac surgery demonstrated a 20% reduction in the use of inotropic drugs, a 50% reduction of the length of ICU stay, a 28% decrease in aortic clamping duration and a 35% decrease of postoperative insulin requirement.

Surgical Site Infections in Cardiac Surgery

Surgical site infection (SSI) can be a significant complication of cardiac surgery, delaying recovery and acting as a barrier to enhanced recovery after cardiac surgery. Several risk factors predisposing patients to SSI including smoking, excessive alcohol intake, hyperglycemia, hypoalbuminemia, hypo- or hyperthermia, and Staphylococcus aureus colonization are discussed. Various measures can be taken to abolish these factors and minimize the risk of SSI. Glycemic control should be optimized preoperatively, and hyperglycemia should be avoided perioperatively with the use of intravenous insulin infusions. All patients should receive topical intranasal Staphylococcus aureus decolonization and intravenous cephalosporin if not penicillin allergic.

[Perioperative management of long-term medication]

Anesthesiologists and surgeons are increasingly faced with patients who are under long-term medication. Some of these drugs can interact with anaesthetics or anaesthesia and/or surgical interventions. As a result, patients may experience complications such as bleeding, ischemia, infection or severe circulatory reactions. On the other hand, perioperative discontinuation of medication is often more dangerous. The proportion of outpatient operations has increased dramatically in recent years and will probably continue to increase. Since the implementation of DRGs (pending in Switzerland, introduced in Germany for some time), the patient enters the hospital the day before operation. This means that the referring physician as well as anesthesiologists and surgeons at an early stage must deal with issues of perioperative pharmacotherapy. This review article is about the management of the major drug classes during the perioperative period. In addition to cardiac and centrally acting drugs and drugs that act on hemostasis and the endocrine system, special cases such as immunosuppressants and herbal remedies are mentioned.