Insulin resistance after abdominal surgery

Study protocol of the PRINCESS trial-PReoperative INtermittent fasting versus CarbohydratE loading to reduce inSulin resiStance versus standard of care in orthopaedic patients: a randomised controlled trial

INTRODUCTION

Surgical trauma induces a metabolic stress response, resulting in reduced insulin sensitivity and hyperglycaemia. Postoperative insulin resistance (IR) is associated with postoperative complications, and extended preoperative fasting may further aggravate the postoperative metabolic stress response. Nutritional strategies, such as carbohydrate loading (CHL), have been successfully used to attenuate postoperative IR. Recent evidence suggests that time-restricted feeding (TRF), a form of intermittent fasting, improves IR in the general population, even after a short period of TRF. We hypothesise that TRF, as well as CHL, improve postoperative IR.

METHODS AND ANALYSIS

This open-label, single-centre, randomised controlled trial will compare the effect of short-term preoperative TRF, CHL and standard preoperative fasting on perioperative IR. A total of 75 orthopaedic patients presenting for elective intermediate to major surgery at a Dutch academic hospital will be randomly assigned to a control group (standard preoperative fasting), a TRF group or a CHL group. The primary outcome is postoperative IR, based on the updated homeostasis model assessment of IR, on the first day after surgery. Statistical analyses are performed using Student's t-tests or Mann-Whitney U tests.

ETHICS AND DISSEMINATION

The local medical ethics committee of the Amsterdam UMC, the Netherlands, approved the trial protocol in January 2023 (NL81556.018.22). No publication restrictions apply, and the results of the study will be disseminated through a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05760339.

Can caloric restriction improve outcomes of elective surgeries?

Energy restriction (ER) is a nutrition method to reduce the amount of energy intake while maintaining adequate nutrition. In clinical medicine, applications of ER have been implicated in longevity, mortality, metabolic, immune, and psychological health. However, there are limited studies showing the clinical benefit of ER within the immediate surgical setting. A specific, clinically oriented summary of the potential applications of ER is needed to optimize surgery outcomes for patients. The purpose of this article is to examine how ER can be used for perioperative optimization to improve outcomes for the patient and surgeon. It will also explore how these outcomes can feasibly fit in with enhanced recovery after surgery protocols and can be used as a method for nutrition optimization in surgery. Despite evidence of caloric restriction improving outcomes in critically ill surgical patients, there is not enough evidence to conclude that ER, perioperatively across noncritically ill cohorts, improves postoperative morbidity and mortality in elective surgeries. Nevertheless, a contemporary account of how ER techniques may have a significant role in reducing risk factors of adverse surgical outcomes in this cohort, for example, by encouraging preoperative weight loss contributing to decreased operating times, is reviewed.

Preoperative carbohydrate load to reduce perioperative glycemic variability and improve surgical outcomes: A scoping review

The detrimental effects of both diabetes mellitus (DM) and hyperglycemia in the perioperative period are well established and have driven extensive efforts to control blood glucose concentration (BGC) in a variety of clinical settings. It is now appreciated that acute BGC spikes, hypoglycemia, and high glycemic variability (GV) lead to more endothelial dysfunction and oxidative stress than uncomplicated, chronically elevated BGC. In the perioperative setting, fasting is the primary approach to reducing the risk for pulmonary aspiration; however, prolonged fasting drives the body into a catabolic state and therefore may increase GV. Elevated GV in the perioperative period is associated with an increased risk for postoperative complications, including morbidity and mortality. These challenges pose a conundrum for the management of patients typically instructed to fast for at least 8 h before surgery. Preliminary evidence suggests that the administration of an oral preoperative carbohydrate load (PCL) to stimulate endogenous insulin production and reduce GV in the perioperative period may attenuate BGC spikes and ultimately decrease postoperative morbidity, without significantly increasing the risk of pulmonary aspiration. The aim of this scoping review is to summarize the available evidence on the impact of PCL on perioperative GV and surgical outcomes, with an emphasis on evidence pertaining to patients with DM. The clinical relevance of GV will be summarized, the relationship between GV and postoperative course will be explored, and the impact of PCL on GV and surgical outcomes will be presented. A total of 13 articles, presented in three sections, were chosen for inclusion. This scoping review concludes that the benefits of a PCL outweigh the risks in most patients, even in those with well controlled type 2 DM. The administration of a PCL might effectively minimize metabolic derangements such as GV and ultimately result in reduced postoperative morbidity and mortality, but this remains to be proven. Future efforts to standardize the content and timing of a PCL are needed. Ultimately, a rigorous data-driven consensus opinion regarding PCL administration that identifies optimal carbohydrate content, volume, and timing of ingestion should be established.

Hyperglycemia in the Perioperative Period

Perioperative hyperglycemia is a risk factor in surgical patients. Complications, including infection and mortality, are associated with hyperglycemia in both diabetic and nondiabetic patients. Stress hyperglycemia results in a state of insulin resistance. Insulin administration has been shown to reduce the complications associated with hyperglycemia. Glycemic targets provide goals for individualized treatment of hyperglycemia in surgical patients in the preoperative, intraoperative, and postoperative periods.

An analysis of enhanced recovery pathways for bariatric surgery-preoperative fasting, carbohydrate loading, and aspiration risk: a position statement from the International Society for the Perioperative Care of Patients with Obesity

Enhanced recovery pathways (ERPs) and recommendations have become widely accepted for metabolic and bariatric surgery, including recommendations for preoperative carbohydrate loading and duration of fasting status. There is still a lack of consensus regarding such protocols and the underlying issues of gastric emptying time, resting gastric volume and pH, and risk of aspiration in patients with severe obesity and in patients undergoing bariatric surgery. The goal of this position statement by the International Society for the Perioperative Care of Patients with Obesity (ISPCOP) is to provide an analysis of available data on preoperative fasting and loading with oral complex clear carbohydrate drinks as well its potential effects on perioperative risk of aspiration in the context of Enhanced Recovery Pathways for Metabolic and Bariatric Surgery (ERAMBS).

Association of dysglycemia with post-operative outcomes in pediatric surgery

BACKGROUND

Perioperative dysglycemia is associated with adverse surgical outcomes in adults. We sought to determine the association between perioperative dysglycemia and 30-day adverse surgical events in pediatric patients undergoing non-cardiac surgery.

METHODS

We analyzed records from the American College of Surgeons National Surgical Quality Improvement Program Pediatric (ACS-NSQIP-P) database from 2016 to 2021 at two academic tertiary care hospitals. The primary outcomes were individual 30-day adverse events, composite serious adverse events, composite hospital acquired infections and composite morbidity.

RESULTS

A total of 5410 records were analyzed: the cohort was 52.6% male and 52.6% non-Hispanic White, and 1472 (27.2%) had dysglycemia. Children undergoing procedures in general surgery (48.4%), neurosurgery (25.4%), and orthopedic surgery (16.0%) had higher rates of dysglycemia compared to other surgical specialties. Patients with dysglycemia were more likely to have surgical site infection (4.3% dysglycemic vs. 3.1% normoglycemic, p = 0.028), cardiac arrest (2.6% vs. 0.1%, p < 0.001), and sepsis (3.7% vs. 1.3%, p < 0.001); more likely to undergo reoperation (11.3% vs. 5.8%, p < 0.001); and more likely to remain hospitalized after 30 days (33.0% vs. 6.1%, p < 0.001). After controlling for patient and case demographics, perioperative dysglycemia was associated with more composite serious adverse events (OR 1.85, 95% CI 1.49-2.29, p = 0.000), composite hospital acquired infections (OR 1.42, 95% CI 1.04-1.93, p = 0.026), and composite morbidity (OR 2.52, 95% CI 2.13-2.97, p = 0.000).

CONCLUSIONS

Perioperative dysglycemia in children undergoing non-cardiac surgery is associated with increased risk of adverse events and outcomes. Interventions that screen and normalize blood glucose in the perioperative period may mitigate risk and improve quality of care.

Perioperative Identification and Management of Hyperglycemia in Orthopaedic Surgery

➤

The consequences of undermanaged perioperative hyperglycemia are notable and can have a serious impact on adverse postoperative outcomes, especially surgical site infections and periprosthetic joint infections (PJIs).

➤

Preoperative screening of hemoglobin A1c with a goal threshold of <7.45% is ideal.

➤

There are a variety of risk factors that contribute to hyperglycemia that should be considered in the perioperative period, including glucocorticoid use, nutritional factors, patient-specific factors, anesthesia, and surgery.

➤

There are expected trends in the rise, peak, and fall of postoperative blood glucose levels, and identifying and treating hyperglycemia as swiftly as possible are the fundamental aims of treatment and improved glucose control. Performing frequent postoperative blood glucose monitoring (in the post-anesthesia care unit, on the day of surgery at 1700 and 2100 hours, and in the morning of postoperative day 1) should be considered to allow for the early detection of alterations in glucose metabolism. In addition, instituting a postoperative dietary restriction of carbohydrates should be considered.

➤

The use of insulin as a hypoglycemic agent in orthopaedic patients is relatively safe and is an effective means of controlling fluctuating blood glucose levels. Insulin therapy should be administered to treat hyperglycemia at ≥140 mg/dL when fasting and ≥180 mg/dL postprandially. Insulin therapy should be ceased at blood glucose levels of <110 mg/dL; however, monitoring for glycemic dysregulation should be continued. In all cases of complex diabetes, consultation with diabetes specialty services should be considered.

➤

The emerging use of technology, including continuous subcutaneous insulin pump therapy and continuous glucose monitoring, is an exciting area of further research and development as such technology can more immediately detect and correct aberrations in blood glucose levels.

Preoperative administration of branched-chain amino acids reduces postoperative insulin resistance in rats by reducing liver gluconeogenesis

BACKGROUND

Postoperative insulin resistance (PIR) represents an important characteristic of metabolic response following surgical injury. Clinical outcomes are negatively correlated to postoperative insulin resistance and hyperglycemia, indicating a novel treatment for reducing postoperative insulin resistance is urgently needed. The current work aimed to assess the protective effects of branched-chain amino acids (BCAA) on glucose metabolism disorders induced surgically in a rat model, and to explore the underpinning mechanism.

METHODS AND RESULTS

Rats were randomly assigned to 2 groups, including the control and BCAA groups. Rats were given a compulsory oral 3 mL load by gavage two hours before surgery. The results showed that BCAA remarkably reduced glycemia by suppressing liver gluconeogenesis via reduction of cAMP-response element-binding protein-regulated transcription coactivator 2 (CRTC2) and glucose-6-phosphatase (G6PC) gene and protein expression levels (all Ps < 0.05).

CONCLUSIONS

This study revealed that BCAA lower blood glucose levels by reducing liver gluconeogenesis without significant elevation of plasma insulin levels. We anticipate that preoperative BCAA supplementation may be a means for preventing postoperative insulin resistance.

Perioperative Fully Closed-Loop Insulin Delivery in Patients Undergoing Elective Surgery: An Open-Label, Randomized Controlled Trial

OBJECTIVE

Perioperative management of glucose levels remains challenging. We aimed to assess whether fully closed-loop subcutaneous insulin delivery would improve glycemic control compared with standard insulin therapy in insulin-requiring patients undergoing elective surgery.

RESEARCH DESIGN AND METHODS

We performed a single-center, open-label, randomized controlled trial. Patients with diabetes (other than type 1) undergoing elective surgery were recruited from various surgical units and randomly assigned using a minimization schedule (stratified by HbA1c and daily insulin dose) to fully closed-loop insulin delivery with fast-acting insulin aspart (closed-loop group) or standard insulin therapy according to local clinical practice (control group). Study treatment was administered from hospital admission to discharge (for a maximum of 20 days). The primary end point was the proportion of time with sensor glucose in the target range (5.6-10.0 mmol/L).

RESULTS

Forty-five patients were enrolled and assigned to the closed-loop (n = 23) or the control (n = 22) group. One patient (closed-loop group) withdrew from the study before surgery and was not analyzed. Participants underwent abdominal (57%), vascular (23%), orthopedic (9%), neuro (9%), or thoracic (2%) surgery. The mean proportion of time that sensor glucose was in the target range was 76.7 ± 10.1% in the closed-loop and 54.7 ± 20.8% in the control group (mean difference 22.0 percentage points [95% CI 11.9; 32.0%]; P < 0.001). No episodes of severe hypoglycemia (<3.0 mmol/L) or hyperglycemia with ketonemia or any study-related adverse events occurred in either group.

CONCLUSIONS

In the context of mixed elective surgery, the use of fully closed-loop subcutaneous insulin delivery improves glucose control without a higher risk of hypoglycemia.

Optimal time period for blood glucose level evaluation after total knee arthroplasty in patients without diabetes: a prospective, observational study

Background

Postoperative hyperglycemia has been reported to be a risk factor for postoperative infection even in patients without diabetes mellitus (DM). However, there is no standard for how long blood glucose level (BGL) monitoring should be performed after total knee arthroplasty (TKA). The purpose of this study was to determine the optimal time period for BGL evaluation after TKA in patients without DM.

Methods

This prospective study included 132 knees of 110 patients who underwent TKA between March 2018 and July 2021 in our hospital. Fasting BGLs were measured preoperatively, at 9:00 PM on the day of surgery (DOS), and at 7:00 AM on postoperative days (PODs) 1, 2, and 3. Patients were divided into two groups with a preoperative hemoglobin A1c (HbA1c) cut-off value of 5.9%, and the BGLs on POD 1 were compared between the two groups.

Results

The BGLs were significantly higher on the DOS, POD 1, and POD 2 than preoperative levels. The BGL was significantly higher on POD 1 than at any other time point. Patients with an HbA1c ≥ 5.9% had significantly higher BGLs than those with an HbA1c < 5.9% on POD 1.

Conclusions

The optimal time period for BGL evaluation after TKA in patients without DM was considered to be from postoperative to POD 2. Patients with an HbA1c ≥ 5.9% may require careful perioperative glycemic control.

Dynamic changes in insulin requirements with post-operative time using bedside artificial pancreas to maintain normoglycemia without hypoglycemia after cardiac surgery

It is difficult to manage postoperative blood glucose levels without hyperglycemia and hypoglycemia in cardiac surgery patients even if continuous intravenous insulin infusion is used. Therefore, the insulin requirements for maintaining normoglycemia may be difficult to evaluate and need to be elucidated. In this single-center retrospective study, 30 adult patients (age 71.5 ± 9.0 years old, men 67%, BMI 22.0 ± 3.1 kg/m², diabetes 33%) who underwent cardiac surgery and used bedside artificial pancreas (STG-55) as a perioperative glycemic control were included. We investigated the insulin and glucose requirements to maintain normoglycemia until the day after surgery. The bedside artificial pancreas achieved intensive glycemic control without hypoglycemia under fasting conditions for 15 h after surgery (mean blood glucose level was 103.3 ± 3.1 mg/dL and percentage of time in range (70-140 mg/dL) was 99.4 ± 2.0%). The total insulin requirement for maintaining normoglycemia differed among surgical procedures, including the use of cardiopulmonary bypass during surgery, while it was not affected by age, body mass index, or the capacity of insulin secretion. Moreover, the mean insulin requirement and the standard deviation of the insulin requirements were variable and high, especially during the first several hours after surgery. Treatment using the bedside artificial pancreas enabled intensive postoperative glycemic control without hypoglycemia. Furthermore, the insulin requirements for maintaining normoglycemia after cardiac surgery vary based on surgical strategies and change dynamically with postoperative time, even in the short term.

The effect of glucose control in liver surgery on glucose kinetics and insulin resistance

BACKGROUND & AIMS

Clinical outcome is negatively correlated to postoperative insulin resistance and hyperglycemia. The magnitude of insulin resistance can be modulated by glucose control, preoperative nutrition, adequate pain management and minimal invasive surgery. Effects of glucose control on perioperative glucose kinetics in liver surgery is less studied.

METHODS

18 patients scheduled for open hepatectomy were studied per protocol in this prospective, randomized study. In the treatment group (n = 9), insulin was administered intravenously to keep arterial blood glucose between 6 and 8 mmol/l during surgery. The control group (n = 9) received insulin if blood glucose >11.5 mmol/l. Insulin sensitivity was measured by an insulin clamp on the day before surgery and immediately postoperatively. Glucose kinetics were assessed during the clamp and surgery.

RESULTS

Mean intraoperative glucose was 7.0 mM (SD 0.7) vs 9.1 mM (SD 1.9) in the insulin and control group respectively (p < 0.001; ANOVA). Insulin sensitivity decreased in both groups but significantly (p = 0.03, ANOVA) more in the control group (M value: 4.6 (4.4-6.8) to 2.1 (1.2-2.6) and 4.6 (4.1-5.0) to 0.6 (0.1-1.8) mg/kg/min in the treatment and control group respectively). Endogenous glucose production (EGP) increased and glucose disposal (WGD) decreased significantly between the pre- and post-operative clamps in both groups, with no significant difference between the groups. Intraoperative kinetics demonstrated that glucose control decreased EGP (p = 0.02) while WGD remained unchanged (p = 0.67).

CONCLUSION

Glucose control reduces postoperative insulin resistance in liver surgery. EGP increases and WGD is diminished immediately postoperatively. Insulin seems to modulate both reactions, but mostly the WGD is affected. Intraoperative EGP decreased while WGD remained unaltered.

REGISTRATION NUMBER OF CLINICAL TRIAL

ANZCTR 12614000278639.

Loss of FOXO transcription factors in the liver mitigates stress-induced hyperglycemia

Objective

Stress-induced hyperglycemia is associated with poor outcomes in nearly all critical illnesses. This acute elevation in glucose after injury or illness is associated with increased morbidity and mortality, including multiple organ failure. Stress-induced hyperglycemia is often attributed to insulin resistance as controlling glucose levels via exogenous insulin improves outcomes, but the mechanisms are unclear. Forkhead box O (FOXO) transcription factors are direct targets of insulin signaling in the liver that regulate glucose homeostasis via direct and indirect pathways. Loss of hepatic FOXO transcription factors reduces hyperglycemia in chronic insulin resistance; however, the role of FOXOs in stress-induced hyperglycemia is unknown.

Methods

We subjected mice lacking FOXO transcription factors in the liver to a model of injury known to cause stress-induced hyperglycemia. Glucose, insulin, glycerol, fatty acids, cytokines, and adipokines were assessed before and after injury. Liver and adipose tissue were analyzed for changes in glycogen, FOXO target gene expression, and insulin signaling.

Results

Stress-induced hyperglycemia was associated with reduced hepatic insulin signaling and increased hepatic FOXO target gene expression while loss of FOXO1, 3, and 4 in the liver attenuated hyperglycemia and prevented hyperinsulinemia. Mechanistically, the loss of FOXO transcription factors mitigated the stress-induced hyperglycemia response by directly altering gene expression and glycogenolysis in the liver and indirectly suppressing lipolysis in adipose tissue. Reductions were associated with decreased IL-6, TNF-α, and follistatin and increased FGF21, suggesting that cytokines and FOXO-regulated hepatokines contribute to the stress-induced hyperglycemia response.

Conclusions

This study implicates FOXO transcription factors as a predominant driver of stress-induced hyperglycemia through means that include cross-talk between the liver and adipose, highlighting a novel mechanism underlying acute hyperglycemia and insulin resistance in stress.

•

Liver forkhead box O (FOXO) target gene expression is increased in critical illness.

•

Loss of FOXO1, 3, and 4 in the liver mitigates stress-induced hyperglycemia (SIH).

•

Hepatic FOXO drives SIH via direct and indirect means in the liver and adipose.

Fasting habits over a 10-year period: An observational study on adherence to preoperative fasting and postoperative restoration of oral intake in 2 Dutch hospitals

BACKGROUND

Since 1999, international guidelines recommend fasting from solid foods up to 6 hours and clear liquids up to 2 hours before surgery. Early recovery after surgery programs recommend restoration of oral intake as soon as possible. This study determines adherence to these guidelines up to 20 years after its introduction.

METHODS

A 2-center observational study with a 10-year interval was performed in the Netherlands. In period 1 (2009), preoperative fasting time was observed as primary outcome. In period 2 (2019), preoperative fasting and postoperative restoration of oral intake were observed. Fasting times were collected using an interview-assisted questionnaire.

RESULTS

During both periods, 311 patients were included from vascular, trauma, orthopedic, urological, oncological, gastrointestinal, and ear-nose-throat and maxillary surgical units. Duration of preoperative fasting was prolonged in 290 (90.3%) patients for solid foods and in 208 (67.8%) patients for clear liquids. Median duration of preoperative fasting from solid foods and clear liquids was respectively 2.5 and 3 times the recommended 6 and 2 hours, with no improvements from one period to another. Postoperative food intake was resumed within 4 hours in 30.7% of the patients. Median duration of perioperative fasting was 23:46 hours (interquartile range 20:00-30:30 hours) for solid foods and 11:00 hours (interquartile range 7:53-16:00 hours) for clear liquids.

CONCLUSION

Old habits die hard. Despite 20 years of fasting guidelines, surgical patients are still exposed erroneously to prolonged fasting in 2 hospitals. Patients should be encouraged to eat and drink until 6 and 2 hours, respectively, before surgery and to restart eating after surgery.

Effects of preoperative oral single-dose and double-dose carbohydrates on insulin resistance in patients undergoing gastrectomy:a prospective randomized controlled trial

BACKGROUND & AIMS

Preoperative oral carbohydrates are strongly recommended for routine use before various elective procedures. The regimen mainly includes preoperative oral single-dose carbohydrate (2-3 h before surgery) and preoperative oral double-dose carbohydrates (10 h before surgery and 2-3 h before surgery). The choice between the two options is still controversial.

METHODS

A total of 139 patients with gastric cancer who underwent radical gastrectomy were recruited from a hospital in Sichuan Province, China. The patients were randomly assigned to a single-dose group (n = 70) or a double-dose group (n = 69). Insulin resistance indicators, subjective comfort indicators, inflammatory mediators, immunological indicators, postoperative recovery indexes, and complications were compared between the two groups.

RESULTS

There were no differences in insulin resistance indicators (fasting plasma glucose, fasting insulin, and homeostasis model assessment indexes), inflammatory mediators (C-reactive protein, interleukin-6, and tumor necrosis factor-α), immunological indicators (CD3+, CD4+, CD8+, and CD4+/CD8+) between the single-dose group and double-dose group (all P > 0.05) at preoperative day 1, preoperative 3 h, and postoperative day 1. There were no differences in subjective comfort indicators (thirst, hunger, anxiety, nausea, fatigue, and weakness) between the two groups (all P > 0.05) at preoperative day 1, preoperative 3 h, preoperative 1 h, and postoperative day 1. The postoperative recovery indexes and complications (exhaust time, liquid intake time, postoperative hospital stay, complication incidence, unplanned readmission rate, and unplanned reoperation rate 30 days after operation) did not significantly differ between the two groups (all P > 0.05). The number of preoperative nighttime urinations in the double-dose group was higher than that in the single-dose group (88.3% VS 48.5%, P < 0.001), and the number of hours of preoperative sleep in the double-dose group was lower than that in the single-dose group (4.56 ± 0.68 VS 5.71 ± 0.57, P < 0.001).

CONCLUSION

Oral carbohydrates administered the night before surgery did not enhance the effects of oral carbohydrates administered 2-3 h before surgery on insulin resistance, subjective comfort, inflammation, and immunity and might affect the patients' night rest. In making a decision between oral carbohydrate regimes, evening carbohydrates could be omitted.

TRIAL REGISTRATION

ChiCTR, ChiCTR1900020608. Registered January 10, 2019, http://www.chictr.org.cn: ChiCTR1900020608.

The Safety of Preoperative Amino Acid (Elental) Loading in Colon Cancer Surgery: Prospective Cohort Study

The aim of this prospective study was to evaluate the safety of preoperative amino acid plus carbohydrate drink (Elental) loading in colon cancer surgery. Prolonged preoperative fasting increases insulin resistance, and current evidence recommends carbohydrate drinks 2 hours before surgery. We prospectively enrolled consecutive patients with a preoperative diagnosis of colon cancer who underwent surgery. The patients received 600 mL of Elental the night before surgery and 300 mL of Elental 3 hours prior to induction of anesthesia. Primary end point was the safety of preoperative amino acid (Elental) loading in colon cancer surgery. Safety measurement was anastomotic leakage and aspiration pneumonia. Secondary end points were incidence rate of incisional surgical site infection, recovery of bowel movement, length of hospital stay, postoperative nutritional status, and insulin resistance. A total of 80 consecutive patients were enrolled in this study from February 2013 to January 2014. The incidence of anastomotic leakage was 3 patients (3.8%), and there was no aspiration pneumonia. The incidence of incisional surgical site infection was 2 patients (2.5%). The median times of first flatus, defecation after surgery, and postoperative hospital stay were 1 day, 2 days, and 6 days, respectively. The insulin resistance recovered to a preoperative level after 3 days after surgery. The preoperative amino acid plus carbohydrate drink (Elental) loading 3 hours prior to induction of anesthesia in colon cancer surgery is safe, and incisional surgical site infection rate and recovery of bowel movement and insulin resistance are feasible.

Prolonged preoperative fasting induces postoperative insulin resistance by ER-stress mediated Glut4 down-regulation in skeletal muscles

Preoperative fasting aims to prevent pulmonary aspiration and improve bowel preparation, but it may induce profound systemic catabolic responses that lead to protein breakdown and insulin-resistant hyperglycemia after operation. However, the molecular mechanisms of catabolic reaction induced by prolonged preoperative fasting and surgical stress are undetermined. In this study, anesthetized rats were randomly assigned to receive a sham operation or laparotomy cecectomy. Fasting groups were restricted from food and water for 12 h before operation, while the feeding group had free access to food throughout the study period. Twenty-four hours after operation, the animals were sacrificed to collect blood samples and soleus muscles for analysis. Postoperative blood glucose level was significantly increased in the fasting group with elevated serum insulin and C-peptide. Continuous feeding reduced serum myoglobin and lactate dehydrogenase concentrations. Preoperative fasting activated inositol-requiring transmembrane kinase/endoribonuclease (IRE)-1α and c-Jun N-terminal kinase (JNK) mediated endoplasmic reticulum (ER)-stress, and reduced glucose transporter type 4 (Glut4) expression in the soleus muscle. Phospholamban phosphorylation was reduced and intracellular calcium levels were increased in the isolated skeletal muscle cells. Similar results were found in ER stress-induced C1C12 myoblasts. The expression of Glut4 was suppressed in the stressed C1C12, but was potentiated following inhibition of ER stress and chelation of intracellular free calcium. This study provides evidence demonstrating that prolonged preoperative fasting induces ER stress and generates insulin resistance in the skeletal muscle through suppression of Glut4 and inactivation of Ca²⁺-ATPase, leading to intracellular calcium homeostasis disruption and peripheral insulin resistance.

Delirium

Delirium, a syndrome characterized by an acute change in attention, awareness and cognition, is caused by a medical condition that cannot be better explained by a pre-existing neurocognitive disorder. Multiple predisposing factors (for example, pre-existing cognitive impairment) and precipitating factors (for example, urinary tract infection) for delirium have been described, with most patients having both types. Because multiple factors are implicated in the aetiology of delirium, there are likely several neurobiological processes that contribute to delirium pathogenesis, including neuroinflammation, brain vascular dysfunction, altered brain metabolism, neurotransmitter imbalance and impaired neuronal network connectivity. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) is the most commonly used diagnostic system upon which a reference standard diagnosis is made, although many other delirium screening tools have been developed given the impracticality of using the DSM-5 in many settings. Pharmacological treatments for delirium (such as antipsychotic drugs) are not effective, reflecting substantial gaps in our understanding of its pathophysiology. Currently, the best management strategies are multidomain interventions that focus on treating precipitating conditions, medication review, managing distress, mitigating complications and maintaining engagement to environmental issues. The effective implementation of delirium detection, treatment and prevention strategies remains a major challenge for health-care organizations globally.

Randomized Trial to Compare Plasma Glucose Trends in Patients Undergoing Surgery for Supratentorial Gliomas under Maintenance of Sevoflurane, Desflurane, and Propofol

Background

Anesthetic agents influence the glycemic response by affecting the neuroendocrine surgical response or directly modifying pancreatic insulin release. Due to chances of neuronal damage, intraoperative hyperglycemia and hypoglycemia both are detrimental for patients undergoing neurosurgeries. Inhalational (sevoflurane and desflurane) and intravenous (propofol) agents have been found to raise intraoperative glucose levels in nonneurological surgeries.

Aim

We aimed to compare the intraoperative glucose levels in supratentorial glioma surgeries under the maintenance of three anesthetic agents such as sevoflurane, desflurane, and propofol.

Materials and Methods

This randomized trial was conducted with 90 nondiabetic adults with supratentorial glioma. Thirty patients were allocated randomly to the three groups receiving sevoflurane, desflurane, and propofol. Baseline and hourly plasma glucose levels were recorded. Postoperatively, the time required to achieve an Aldrete score of 9 and complications were assessed.

Results

Baseline plasma glucose levels were 111.23 ± 11.67, 109.47 ± 19.75, and 111.7 ± 13.88 mg/dL (P = 0.84) in sevoflurance, desflurane, and propofol group, respectively. All of them showed an elevation of plasma glucose in relation to the time of surgery with variable trends. In the 4^th and 5^th h, the elevations in the inhalational groups (sevoflurane and desflurane) were significantly higher than the propofol group (P = 0.003 and 0.002, respectively). The time for achieving Aldrete's score of 9 was higher in the propofol group (P < 0.0001). No differences were observed in the duration of hospital stay or complications.

Conclusions

Maintenance of anesthesia in nondiabetic patients showed clinically modest rise of plasma glucose which is higher in patients under sevoflurane and desflurane than under propofol. However, the immediate recovery was faster with inhalational agents compared to propofol-based anesthesia.

Pre-operative aerobic exercise on metabolic health and surgical outcomes in patients receiving bariatric surgery: A pilot trial

Objective

Examine if adding aerobic exercise to standard medical care (EX+SC) prior to bariatric surgery improves metabolic health in relation to surgical outcomes.

Methods

Fourteen bariatric patients (age: 42.3±2.5y, BMI: 45.1±2.5 kg/m²) met inclusion criteria and were match-paired to pre-operative SC (n = 7) or EX+SC (n = 7; walking 30min/d, 5d/wk, 65–85% HR_peak) for 30d. A 120min mixed meal tolerance test was performed pre- and post-intervention (~2d prior to surgery) to assess insulin sensitivity (Matsuda Index) and metabolic flexibility (indirect calorimetry). Aerobic fitness (VO₂peak), body composition (BodPod), and adipokines (adiponectin, leptin) were also measured. Omental adipose tissue was collected during surgery to quantify gene expression of adiponectin and leptin, and operating time and length of hospital stay were recorded. ANOVA and Cohen’s d effect size (ES) was used to test group differences.

Results

SC tended to increase percent body fat (P = 0.06) after the intervention compared to EX+SC. Although SC and EX+SC tended to raise insulin sensitivity (P = 0.11), EX+SC enhanced metabolic flexibility (P = 0.01, ES = 1.55), reduced total adiponectin (P = 0.01, ES = 1.54) with no change in HMW adiponectin and decreased the length of hospital stay (P = 0.05) compared to SC. Albeit not statistically significant, EX+SC increased VO₂peak 2.9% compared to a 5.9% decrease with SC (P = 0.24, ES = 0.91). This increased fitness correlated to shorter operating time (r = -0.57, P = 0.03) and length of stay (r = -0.58, P = 0.03). Less omental total adiponectin (r = 0.52, P = 0.09) and leptin (r = 0.58, P = 0.05) expression correlated with shorter operating time, and low leptin expression was linked to shorter length of stay (r = 0.70, P = 0.01), and low leptin expression was linked to shorter length of stay (r = 0.70, P = 0.01).

Conclusion

Adding pre-operative aerobic exercise to standard care may improve surgical outcomes through a fitness and adipose tissue derived mechanism.

Acute Inflammation Alters Brain Energy Metabolism in Mice and Humans: Role in Suppressed Spontaneous Activity, Impaired Cognition, and Delirium

Systemic infection triggers a spectrum of metabolic and behavioral changes, collectively termed sickness behavior, which while adaptive, can affect mood and cognition. In vulnerable individuals, acute illness can also produce profound, maladaptive, cognitive dysfunction including delirium, but our understanding of delirium pathophysiology remains limited. Here, we used bacterial lipopolysaccharide (LPS) in female C57BL/6J mice and acute hip fracture in humans to address whether disrupted energy metabolism contributes to inflammation-induced behavioral and cognitive changes. LPS (250 µg/kg) induced hypoglycemia, which was mimicked by interleukin (IL)-1β (25 µg/kg) but not prevented in IL-1RI^−/− mice, nor by IL-1 receptor antagonist (IL-1RA; 10 mg/kg). LPS suppression of locomotor activity correlated with blood glucose concentrations, was mitigated by exogenous glucose (2 g/kg), and was exacerbated by 2-deoxyglucose (2-DG) glycolytic inhibition, despite preventing IL-1β synthesis. Using the ME7 model of chronic neurodegeneration in female mice, to examine vulnerability of the diseased brain to acute stressors, we showed that LPS (100 µg/kg) produced acute cognitive dysfunction, selectively in those animals. These acute cognitive impairments were mimicked by insulin (11.5 IU/kg) and mitigated by glucose, demonstrating that acutely reduced glucose metabolism impairs cognition selectively in the vulnerable brain. To test whether these acute changes might predict altered carbohydrate metabolism during delirium, we assessed glycolytic metabolite levels in CSF in humans during inflammatory trauma-induced delirium. Hip fracture patients showed elevated CSF lactate and pyruvate during delirium, consistent with acutely altered brain energy metabolism. Collectively, the data suggest that disruption of energy metabolism drives behavioral and cognitive consequences of acute systemic inflammation.

SIGNIFICANCE STATEMENT Acute systemic inflammation alters behavior and produces disproportionate effects, such as delirium, in vulnerable individuals. Delirium has serious short and long-term sequelae but mechanisms remain unclear. Here, we show that both LPS and interleukin (IL)-1β trigger hypoglycemia, reduce CSF glucose, and suppress spontaneous activity. Exogenous glucose mitigates these outcomes. Equivalent hypoglycemia, induced by lipopolysaccharide (LPS) or insulin, was sufficient to trigger cognitive impairment selectively in animals with existing neurodegeneration and glucose also mitigated those impairments. Patient CSF from inflammatory trauma-induced delirium also shows altered brain carbohydrate metabolism. The data suggest that the degenerating brain is exquisitely sensitive to acute behavioral and cognitive consequences of disrupted energy metabolism. Thus “bioenergetic stress” drives systemic inflammation-induced dysfunction. Elucidating this may offer routes to mitigating delirium.

LC-QTOF-MS and 1H NMR Metabolomics Verifies Potential Use of Greater Omentum for Klebsiella pneumoniae Biofilm Eradication in Rats

Bacterial wound infections are a common problem associated with surgical interventions. In particular, biofilm-forming bacteria are hard to eradicate, and alternative methods of treatment based on covering wounds with vascularized flaps of tissue are being developed. The greater omentum is a complex organ covering the intestines in the abdomen, which support wound recovery following surgical procedures and exhibit natural antimicrobial activity that could improve biofilm eradication. We investigated changes in rats’ metabolome following Klebsiella pneumoniae infections, as well as the greater omentum’s ability for Klebsiella pneumoniae biofilm eradication. Rats received either sterile implants or implants covered with Klebsiella pneumoniae biofilm (placed in the peritoneum or greater omentum). Metabolic profiles were monitored at days 0, 2, and 5 after surgery using combined proton nuclear magnetic resonance (¹H NMR) and high performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC–QTOF-MS) measurements of urine samples followed by chemometric analysis. Obtained results indicated that grafting of the sterile implant to the greater omentum did not cause major disturbances in rats’ metabolism, whereas the sterile implant located in the peritoneum triggered metabolic perturbations related to tricarboxylic acid (TCA) cycle, as well as choline, tryptophan, and hippurate metabolism. Presence of implants colonized with Klebsiella pneumoniae biofilm resulted in similar levels of metabolic perturbations in both locations. Our findings confirmed that surgical procedures utilizing the greater omentum may have a practical use in wound healing and tissue regeneration in the future.

Effect of pre-operative oral carbohydrate loading on recovery after day-case cholecystectomy: A randomised controlled trial

BACKGROUND

Pre-operative carbohydrate loading has been shown to reduce pre-operative discomfort and postoperative nausea and vomiting in general surgical patients. Few studies have considered day-case surgery.

OBJECTIVE

The aim of this prospective randomised study was to determine whether pre-operative carbohydrate loading enhanced recovery after day-case cholecystectomy.

DESIGN

A randomised controlled trial.

SETTING

Secondary care in a district general and a university hospital in Finland between 2013 and 2016.

PATIENTS

A total of 113 patients American Society of Anesthesiologists physical status I or II aged 18 to 70 undergoing day-case cholecystectomy were included in the study. Exclusion criteria were bleeding or coagulation disorders, BMI more than 40 kg m, dementia, insulin-treated diabetes, migraine, Meniere's disease or a history of alcohol or drug abuse.

INTERVENTION

The carbohydrate-rich drink group received oral carbohydrate (200 ml) 2 to 3 h before surgery, and the control (fasting) group fasted from midnight according to standard protocol.

MAIN OUTCOME MEASURES

Visual analogue scales (VAS) were used to score six forms of discomfort: the need for analgesia and antiemetics, the time to drinking, eating and first mobilisation after surgery and the time to discharge. Any hospital re-admission was also recorded.

RESULTS

The highest VAS scores were seen for mouth dryness and tiredness 2 h after surgery in the fasting group. There were no significant differences in any VAS scores between the study groups. No differences in time to mobilisation, need for pain or antiemetic medication or time to discharge were seen between the groups.

CONCLUSION

Compared with overnight fasting, pre-operative carbohydrate loading did not significantly enhance peri-operative well being or recovery in patients undergoing day-case cholecystectomy.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03757208.

Guidelines for Perioperative Care in Elective Colorectal Surgery: Enhanced Recovery After Surgery (ERAS®) Society Recommendations: 2018

BACKGROUND

This is the fourth updated Enhanced Recovery After Surgery (ERAS®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS® protocol.

METHODS

A wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

All recommendations on ERAS® protocol items are based on best available evidence; good-quality trials; meta-analyses of good-quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly.

CONCLUSIONS

The evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS® Society in this comprehensive consensus review.

Nutritional prehabilitation: physiological basis and clinical evidence

In this narrative review, we describe the physiological basis for nutritional prehabilitation and evaluate the clinical evidence for its current roles in the perioperative period. Surgical stress and fasting induce insulin resistance as a result of altered mitochondrial function. Insulin resistance in the perioperative period leads to increased morbidity in a dose-dependent fashion, while preoperative carbohydrate loading attenuates insulin resistance, minimises protein loss and improves postoperative muscle function. Carbohydrate loading is an established practice in many countries and a key component of enhanced recovery after surgery (ERAS) programs, yet its independent effects on clinical outcomes remain unclear. Amino acid supplements may confer additional positive effects on a number of markers of clinical outcomes in the perioperative period, but their current role is also poorly defined. Clinical studies evaluating nutritional interventions have been marred by conflicting data, which may be due to small sample sizes, as well as heterogeneity of patients and surgical procedures. At present, it is known that carbohydrate loading is safe and improves patients' wellbeing, but does not appear to influence length of hospital stay or rate of postoperative complications. This should be appreciated before its routine inclusion in ERAS programs.

Perioperative insulin therapy

Surgical patients commonly develop hyperglycemia secondary to the neuroendocrine stress response. Insulin treatment of hyperglycemia is required to overcome the perioperative catabolic state and acute insulin resistance. Besides its metabolic actions on glucose metabolism, insulin also displays nonmetabolic physiological effects. Preoperative glycemic assessment, maintenance of normoglycemia, and avoidance of glucose variability are paramount to optimize surgical outcomes. This review discusses the basic physiology and effects of insulin as well as practical issues pertaining to its management during the perioperative period.

Influence of IL-6, TNF-α and Hs-CRP on Insulin Sensitivity in Patients after Laparoscopic Cholecystectomy or Open Hernia Repair

BACKGROUND

The aim of this study was to investigate the influence of IL-6, TNF-α and hs-CRP on insulin sensitivity during postoperative follow-up in patients with laparoscopic cholecystectomy (LC) or open hernia repair (OHR).

METHODS

65 patients were studied: after laparoscopic cholecystectomy (LC; n=40) or open hernia repair (OHR; n=25). Glucose, insulin, hs-CRP, IL-6 and TNF-a were determined at day 0 (before the operation) and at days 1, 3 and 7 (after the operation).

RESULTS

There were no difference between LC and OHR groups concerning age, BMI, glucose, insulin, hs-CRP, IL-6 and TNF-α at day 0. hs-CRP increased at day 1, 3 and 7 vs. day 0 (p<0.0005), without difference between groups (p=0.561). IL-6 increased at day 1 and day 3 vs. day 0 (p<0.005). IL-6 was higher at day 1 in OHR group in comparison with LC group (p=0.044). There were no differences in TNF-a levels between LC and OHR groups (p=0.056). There was increase of HOMA-IR at day 1, 3 and 7 vs. day 0 (p<0.0005) in both groups. Significantly higher increase of HOMA-IR was in OHR group compared with LC group at day 1 (p=0.045). There was a positive correlation between hs-CRP and HOMA-IR (r=0.46; p=0.025) and between IL-6 and HOMA-IR at day 1 in OHR group (r=0.44; p=0.030).

CONCLUSIONS

Significantly higher HOMA-IR was found in OHR group compared with LC. Positive correlation between hs-CRP and IL-6 with HOMA-IR in OHR group at day 1, indicate possible influence of this mediators on impairment of insulin sensitivity.

Comparison of sevoflurane and propofol anesthesia on the incidence of hyperglycemia in patients with type 2 diabetes undergoing lung surgery

Background

The type and regimen of anesthesia may affect perioperative hyperglycemia following major surgical stress. This study compared the effects of sevoflurane and propofol on the incidence of hyperglycemia and clinical outcomes in diabetic patients undergoing lung surgery.

Methods

This retrospective study included 176 patients with type 2 diabetes mellitus who had undergone lung surgery. Blood glucose levels and clinical outcomes from the preoperative period to the first 2 post-operative days (PODs) were retrospectively examined in patients who received sevoflurane (group S, n= 87) and propofol (group P, n=89) for maintenance of general anesthesia. The primary endpoint was the incidence of persistent hyperglycemia (2 consecutive blood glucose levels >180 mg/dL [10.0 mmol/L]) during the perioperative period. The secondary composite endpoint was the incidence of major postoperative complications and 30-day mortality rate after surgery.

Results

Blood glucose levels similarly increased from the preoperative period to the second POD in both groups (p=0.857). Although blood glucose levels at 2 hours after surgery were significantly lower in group P than in group S (p=0.022; 95% confidence interval for mean difference, -27.154 to -2.090), there was no difference in the incidence of persistent hyperglycemia during the perioperative period (group S, 70%; group P, 69%; p=0.816). The composite of major postoperative complications and all-cause in-hospital and 30-day mortality rates were also comparable between the two groups.

Conclusion

Sevoflurane and propofol were associated with a comparable incidence of perioperative hyperglycemia and clinical outcomes in diabetic patients undergoing lung surgery.

Recent advances in perioperative glucose monitoring

PURPOSE OF REVIEW

There is ongoing controversy surrounding the use of glucose monitoring in the perioperative setting. It is an important aspect of patient care, but the best way to go about monitoring this parameter is still up for debate. This article will review previously established data and new developments in this field.

RECENT FINDINGS

Several different methods exist to measure blood glucose levels in the perioperative setting, including central laboratory devices, blood gas analyzers, and point-of-care devices. However, it has been recommended that point-of-care devices not be used on 'critically ill' patients, which throws into question the common use of these devices perioperatively. Recently, the Centers for Medicare and Medicaid placed a moratorium on this recommendation, and these devices continue to be a staple in the perioperative setting, but there are other methods of glucose monitoring that can be employed.

SUMMARY

The monitoring of blood glucose levels in the perioperative patient remains an important part of patient care; however, debate still exist on how best to reliably measure blood glucose levels in the most effective manner.

Percutaneous muscle biopsy-induced tissue injury causes local endoplasmic reticulum stress

Endoplasmic reticulum (ER) stress is likely involved in the pathogenesis of metabolic dysfunction in people with obesity and diabetes. Although tissue biopsy is often used to evaluate the presence and severity of ER stress, it is not known whether acute tissue injury‐induced by percutaneous muscle biopsy causes ER stress and its potential downstream effects on markers of inflammation and metabolic function. In this study, we tested the hypothesis that percutaneous biopsy‐induced tissue injury causes ER stress and alters inflammatory and metabolic pathways in skeletal muscle. Vastus lateralis muscle tissue was obtained by percutaneous biopsy at 0600 h and 12 h later from either the contralateral leg (Group 1, n = 6) or at the same site as the initial biopsy (Group 2, n = 6) in women who were overweight. Muscle gene expression of selected markers of ER stress, inflammation, and regulators of glucose and lipid metabolism were determined. Compared with Group 1, muscle gene expression in the second biopsy sample obtained in Group 2 demonstrated marked increases in markers of ER stress (GRP78, XBP1, ATF6) and inflammation (IL6, TNF), and alterations in metabolic regulators (decreased expression of GLUT4 and PPARGC1A and increased expression of FASN). Our results suggest that acute tissue injury induced by percutaneous muscle biopsy causes an integrated local response that involves an induction of ER stress and alterations in markers of inflammation and regulators of glucose and lipid metabolism.

Enhanced recovery after surgery-Preoperative fasting and glucose loading-A review

In this review, we explore the rationale and history behind the practice of preoperative fasting in elective surgery including the gradual move toward longer fasting and the more recent change in direction of practice. Gastric emptying physiology and the metabolic effects of prolonged fasting and carbohydrate loading are examined. Most recent guidelines related to these topics are discussed and practical recommendations for implementing these guidelines are suggested.

Variability in Perioperative Fasting Practices Negatively Impacts Nutritional Support of Critically Ill Intubated Patients

The aim of the study was to quantify nutritional losses related to pre- and postoperative fasts in critically ill intubated patients and to explore whether shorter fasts are safe and appropriate in this population. A retrospective review of mechanically ventilated adults undergoing surgery more than 24 hours after admission to a Level I trauma center over 15 months was done, which yielded 132 procedures and 81 unique patients. Ninety per cent of preoperative periods and 43 per cent of postoperative periods were affected by nonmedical barriers to feeding. Eighty-two per cent of gastrically fed nonemergent cases were fasted for longer than the 6-hour American Society of Anesthesiologists guideline, whereas 91 per cent of emergent cases had shorter fasts. There were no anesthetic complications, placing an upper limit of 6 per cent on the rate of aspiration for fasts shorter than six hours (95% confidence). Forty-three per cent of cases did not resume tube feeds within 90 minutes postoperatively, and only 37 per cent had a documented justification for delay. Intubated patients were frequently fasted preoperatively for longer than recommended and postoperatively for longer than medically indicated. No complications were observed with shorter-than-guideline fasts. This strengthens the evidence that “standard” preoperative fasting is unnecessary and deleterious in many critically ill intubated patients. New protocols and national guidelines are needed to ensure adequate nutrition.

High dose amino acid administration achieves an anabolic response in type 2 diabetic patients that is independent of glycaemic control: A randomized clinical trial

BACKGROUND & AIMS

Surgical stress provokes protein catabolism and hyperglycaemia that is enhanced in patients with type 2 diabetes (T2DM), and increases perioperative morbidity. This study hypothesized that perioperative administration of high dose intravenous (IV) amino acids (AA) will augment protein balance in T2DM patients receiving tight plasma glucose control via continuous IV insulin compared to standard plasma glucose control via subcutaneous (SC) insulin sliding scale.

METHODS

Eighteen patients with well-controlled T2DM (HbA1C% < 7.1) undergoing colorectal surgery were assigned randomly to receive standard glucose control (6-10 mmol/l, SC insulin, n = 9) or tight glucose control (4-6 mmol/l, IV insulin, n = 9). Both groups received general anaesthesia and epidural analgesia. AA (1 ml/kg h Aminoven™ 10%, ∼2.4 g/kg d) were infused via a peripheral vein for two 3-h periods: at the beginning of surgery and in the post-operative care unit. Whole-body protein and glucose kinetics were assessed by stable isotope tracers, L-[1-¹³C]leucine and [6,6-²H₂]glucose.

RESULTS

Whole-body protein balance was positive after surgery in all patients. Since protein synthesis, breakdown and leucine oxidation were comparable in both groups, whole body protein balance was not different (p = 0.605). Tight glucose control suppressed endogenous glucose production (EGP, p < 0.001) and increased glucose clearance (p < 0.001) compared to standard glucose control during both study periods. No episode of hypoglycaemia occurred in either group.

CONCLUSION

High-dose perioperative AA administration under optimal anti-catabolic care with epidural analgesia was effective in achieving a positive protein balance in T2DM patients undergoing surgery that was independent of glycaemic control strategy. Continuous IV insulin maintained normoglycaemia by inhibiting EGP and increasing glucose clearance. Improved glucose control, without a pronounced increase in protein balance with the intravenous insulin regimen, suggests perioperative protein metabolism may be less sensitive to insulin than is glucose.

Perioperative Hyperglycemia Management: An Update

An association between perioperative hyperglycemia and adverse outcomes has been established in surgical patients, 1 -3 with morbidity being reduced in those treated with insulin.5 -6 A practical treatment algorithm and literature summary is provided for surgical patients with diabetes and hyperglycemia.

A Carbohydrate-Rich Beverage Prior to Surgery Prevents Surgery-Induced Immunodepression: A Randomized, Controlled, Clinical Trial

BACKGROUND

Fasting before surgery is still common care in a lot of western hospitals. Overnight fasting can induce postoperative insulin resistance. Insulin resistance has been shown to be related to infectious morbidity. It was shown that postoperative insulin resistance can be attenuated by preoperative intake of a clear carbohydrate-rich beverage. The aim of this study was to investigate whether preoperative intake of carbohydrate-rich beverages could postoperatively influence the immune system.

METHODS

In this randomized, controlled study, we investigated the effect of surgery on the postoperative immune response in 10 preoperatively fasted patients (control) and 2 groups of 10 patients receiving 2 different carbohydrate-rich beverages preoperatively, by measuring human leukocyte antigen (HLA)-DR expression on monocytes on the day before and on the day after surgery. Furthermore, we studied perioperative fluid homeostasis and preoperative well-being of the patients.

RESULTS

HLA-DR expression decreased significantly after surgery in the control group. Patients receiving any of the 2 carbohydrate-rich beverages did not show this postoperative decrease. Fluid homeostasis was not affected in any of the groups, and well-being tended to be better in patients receiving carbohydrate-rich beverages compared with controls.

CONCLUSION

This study suggests that preoperative intake of a carbohydrate-rich beverage can prevent surgery-induced immunodepression and thus might reduce the risk of infectious complications.

Enhanced recovery after surgery for gastric cancer and an assessment of preoperative carbohydrate loading

BACKGROUND

We previously reported on the feasibility of enhanced recovery after surgery (ERAS) protocol for gastric cancer with a prospective phase II study, but the superiority of this approach over non-ERAS perioperative management remains unclear. Preoperative carbohydrate loading, an important element of the ERAS protocol, has been shown to reduce insulin resistance, but its effects on clinical endpoints in gastric cancer surgery remain controversial. The aim of this study was to clarify the efficacy of the ERAS protocol for gastric cancer surgery, with particular focus on preoperative carbohydrate loading.

METHODS

In this ERAS case-control study, we enrolled 121 patients as a case group and 259 patients undergoing gastrectomy for gastric cancer with our conventional perioperative management as a control group. Matched-pair analysis was performed to balance the patients' characteristics for comparison analysis.

RESULTS

After matching, 108 patients were included in each group. Postoperative hospital stay was significantly shorter in the ERAS group than in the control group (8 days vs. 9 days, p < 0.001), while the incidence of Clavien-Dindo classification grade II or more postoperative complication was similar between the groups (11.1% vs. 15.7%, p = 0.325). No significant differences were found in serum albumin level, body weight, or grip strength between the groups before surgery and at 1 week and 1 month after surgery.

CONCLUSION

Use of the ERAS protocol for gastric cancer shortened the length of postoperative hospital stay without increasing complications. Preoperative carbohydrate loading didn't improve the postoperative nutritional status or maintain the muscle strength postoperatively.

Immediate Metabolic Response Following Sleeve Gastrectomy in Obese Diabetics

BACKGROUND

Although laparoscopic sleeve gastrectomy (LSG) has been shown to have a long-term antidiabetic effect, little is known regarding the immediate response to surgery. This study's objective was to evaluate the glycemic and lipid metabolic response in the first postoperative week.

METHODS

The study included 21 obese diabetic participants. Glycemic markers, lipids, and hepatic function tests were measured just prior to surgery and at 1 week and 3 months postoperatively. Two participants were dropped prior to all measurements due to technical reasons, and two more were lost to follow-up.

RESULTS

At 1 week after surgery, compared to preoperative baseline, we found reduced hemoglobin A1c (7.63 to 7.31, P < 0.001), insulin (24.96 to 10.92, P < 0.05), and borderline significant homeostatic model assessment insulin resistance (HOMA-IR, 9.48 to 3.91, P > 0.05). Low-density lipoprotein (LDL) cholesterol increased and high-density lipoprotein (HDL) cholesterol decreased. Three months after surgery, hemoglobin A1c, insulin, and HOMA-IR continued to decrease (6.05, 7.11, and 1.92, respectively, P < 0.05), with hemoglobin A1c correlated to weight loss (P < 0.05). Triglycerides, triglyceride to HDL ratio, and total cholesterol to HDL ratio also decreased, but there was no significant change in LDL cholesterol or HDL versus presurgery levels. Reduced triglyceride levels were correlated with reduced alanine transaminase (ALT) and gamma-glutamyl transpeptidase (GGT) (P < 0.05).

CONCLUSIONS

LSG is associated with marked antidiabetic effects as early as 1 week after surgery, unrelated to weight loss. The antidiabetic effect improves at 3 months. Triglyceride reduction was associated with improved hepatic functions, but cholesterol did not show a meaningful reduction.

Enhanced recovery program is safe and improves postoperative insulin resistance in gastrectomy

AIM: To assess the safety of enhanced recovery after surgery (ERAS) program in gastrectomy and influences on nutrition state and insulin-resistance.

METHODS: Our ERAS program involved shortening the fasting periods and preoperative carbohydrate loading. Eighty gastrectomy patients were randomly assigned to either the conventional group (CG) or ERAS group (EG). We assessed the clinical characteristics and postoperative outcomes prospectively. The primary endpoint was noninferiority in timely discharge from the hospital within 12 d. Secondary endpoints were the incidence of aspiration at anesthesia induction, incidence of postoperative complications, health related quality of life (HRQOL) using the SF8 Health Survey questionnaire, nutrition state [e.g., albumin, transthyretin (TTR), retinal-binding protein (RBP), and transferrin (Tf)], the homeostasis model assessment-insulin resistance (HOMA-R) index, postoperative urine volume, postoperative weight change, and postoperative oral intake.

RESULTS: The ERAS program was noninferior to the conventional program in achieving discharge from the hospital within 12 d (95.0% vs 92.5% respectively; 95%CI: -10.0%-16.0%). There was no significant difference in postoperative morbidity between the two groups. Adverse events such as vomiting and aspiration associated with the induction of general anesthesia were not observed. There were no significant differences with respect to postoperative urine volume, weight change, and oral intake between the two groups. EG patients with preoperative HOMA-R scores above 2.5 experienced significant attenuation of their HOMA-R scores on postoperative day 1 compared to CG patients (P = 0.014). There were no significant differences with respect to rapid turnover proteins (TTR, RBP and Tf) or HRQOL scores using the SF8 method.

CONCLUSION: Applying the ERAS program to patients who undergo gastrectomy is safe, and improves insulin resistance with no deterioration in QOL.

Stress Hyperglycemia During Surgery and Anesthesia: Pathogenesis and Clinical Implications

Numerous studies have demonstrated an association between hyperglycemia in the perioperative period and adverse clinical outcomes. Many patients who experience hyperglycemia while hospitalized do not have a known history of diabetes and experience a transient phenomenon often described as "stress hyperglycemia" (SH). We discuss the epidemiology and pathogenesis of SH as well as evidence to date regarding predisposing factors and outcomes. Further research is needed to identify the long-term sequelae of SH as well as perioperative measures that may modulate glucose elevations and optimal treatment strategies.

Simulation and qualitative analysis of glucose variability, mean glucose, and hypoglycemia after subcutaneous insulin therapy for stress hyperglycemia

Background

The critically ill can have persistent dysglycemia during the “subacute” recovery phase of their illness because of altered gene expression; it is also not uncommon for these patients to receive continuous enteral nutrition during this time. The optimal short-acting subcutaneous insulin therapy that should be used in this clinical scenario, however, is unknown. Our aim was to conduct a qualitative numerical study of the glucose-insulin dynamics within this patient population to answer the above question. This analysis may help clinicians design a relevant clinical trial.

Methods

Eight virtual patients with stress hyperglycemia were simulated by means of a mathematical model. Each virtual patient had a different combination of insulin resistance and insulin deficiency that defined their unique stress hyperglycemia state; the rate of gluconeogenesis was also doubled. The patients received 25 injections of subcutaneous regular or Lispro insulin (0-6 U) with 3 rates of continuous nutrition. The main outcome measurements were the change in mean glucose concentration, the change in glucose variability, and hypoglycemic episodes. These end points were interpreted by how the ultradian oscillations of glucose concentration were affected by each insulin preparation.

Results

Subcutaneous regular insulin lowered both mean glucose concentrations and glucose variability in a linear fashion. No hypoglycemic episodes were noted. Although subcutaneous Lispro insulin lowered mean glucose concentrations, glucose variability increased in a nonlinear fashion. In patients with high insulin resistance and nutrition at goal, “rebound hyperglycemia” was noted after the insulin analog was rapidly metabolized. When the nutritional source was removed, hypoglycemia tended to occur at higher Lispro insulin doses. Finally, patients with severe insulin resistance seemed the most sensitive to insulin concentration changes.

Conclusions

Subcutaneous regular insulin consistently lowered mean glucose concentrations and glucose variability; its linear dose-response curve rendered the preparation better suited for a sliding-scale protocol. The longer duration of action of subcutaneous regular insulin resulted in better glycemic-control metrics for patients who were continuously postprandial. Clinical trials are needed to examine whether these numerical results represent the glucose-insulin dynamics that occur in intensive care units; if present, their clinical effects should be evaluated.

Obesity-related insulin resistance: implications for the surgical patient

In healthy surgical patients, preoperative fasting and major surgery induce development of insulin resistance (IR). IR can be present in up to 41% of obese patients without diabetes and this can rise in the postoperative period, leading to an increased risk of postoperative complications. Inflammation is implicated in the aetiology of IR. This review examines obesity-associated IR and its implications for the surgical patient. Searches of the Medline and Science Citation Index databases were performed using various key words in combinations with the Boolean operators AND, OR and NOT. Key journals, nutrition and metabolism textbooks and the reference lists of key articles were also hand searched. Adipose tissue has been identified as an active endocrine organ and the chemokines secreted as a result of macrophage infiltration have a role in the pathogenesis of IR. Visceral adipose tissue appears to be the most metabolically active, although results across studies are not consistent. Results from animal and human studies often provide conflicting results, which has rendered the pursuit of a common mechanistic pathway challenging. Obesity-associated IR appears, in part, to be related to inflammatory changes associated with increased adiposity. Postoperatively, the surgical patient is in a proinflammatory state, so this finding has important implications for the obese surgical patient.