Oral Carbohydrate Loading Research Articles

Randomized Clinical Trial To Compare The Effects Of Preoperative Oral Carbohydrate Loading Versus Placebo On Insulin Resistance And Cortisol Level After Laparoscopic Cholecystectomy.

Postoperative insulin resistance, used as a marker of stress response, is clearly an adverse event. It may induce postoperative hyperglycemia, which according to some authors can increase the risk of postoperative complications. One of the elements of modern perioperative care is preoperative administration of oral carbohydrate loading (CHO-loading), which shortens preoperative fasting and reduces insulin resistance. The aim of the study is to establish the influence of CHO-loading on the level of insulin resistance and cortisol in patients undergoing elective laparoscopic cholecystectomy. Patients were randomly allocated to one of 2 groups. The intervention group included 20 patients who received CHO-loading (400 ml Nutricia pre-op®) 2 hours prior surgery. The control group received a placebo (clear water). In every patient blood samples were taken 2 hours prior to surgery, immediately after surgery, and on the 1st postoperative day. Levels and changes in glucose, cortisol and insulin resistance were analyzed in both groups. Although there were differences in the levels of cortisol, insulin, and insulin resistance, no statistically significant differences were observed between groups in every measurement. The length of stay and postoperative complications were comparable in both groups. We believe that CHO-loading is not clinically justified in case of laparoscopic cholecystectomy. No effect on the levels of glucose, insulin resistance and cortisol was observed. Even though such procedure is safe, in our opinion there is no clinical benefit from CHO-loading prior to laparoscopic cholecystectomy.

Does perioperative nutrition and oral carbohydrate load sustainably preserve muscle mass after bariatric surgery? A randomized control trial

BackgroundPerioperative nutrition and preoperative oral carbohydrate loading (CHL) have a beneficial impact on the outcomes of gastrointestinal oncological surgery. However no data exists on their effect on morbidly obese patients. ObjectivesOur aim was to establish the short-term and long-term impact of these modalities, notably on metabolically active lean body mass (LBM) — an important factor in maintaining long-term weight loss. MethodsPatients undergoing laparoscopic Roux-en-Y gastric bypass were randomized to standard management or intervention: CHL drinks consumed 12 and 2 hours presurgery, and immediate postoperative peripheral parenteral nutrition. The primary outcome measured was LBM, measured by Bioelectrical Impedance Analysis (BIA), one and 12 months postsurgery. Secondary outcomes included excess weight loss (EBWL), 30-day complication rate, and length of stay. ResultsOf the 203 randomized patients, 198 were included in the analysis. All 101 patients in the control group completed the one-year follow up and 76 completed the BIA. In the intervention group, 93 of 97 patients completed the one-year follow-up and 71 completed the BIA. At one and 12 months follow-up, body composition, LBM, or EBWL were comparable. There was no difference in operative outcomes, complications rates, or length of stay. There was no adverse effect in the intervention group. ConclusionsIn a highly homogeneous group of morbidly obese patients with one-year follow-up, CHL and short-term parenteral nutrition did not lead to significant or sustained LBM preservation or modification in EBWL. There was no significant decrease in complications or length of stay. Our study confirms the safety of these interventions, even in previously unstudied Type 2 diabetic patients.

Pre-Operative Oral Carbohydrate Loading Is Safe and Improves Patient Satisfaction with Elective Ambulatory Surgery and Anesthesia

INTRODUCTION: Most plastic surgeries are performed on an ambulatory basis. While patient safety is a priority for plastic surgeons, many are unaware of the current ASA preoperative fasting guidelines. Decades of research attest to the safety and health benefits of consuming carbohydrate-rich clear liquids 2 hours before elective surgery. This best evidence is rarely put into practice. The objective of this study was to assess the effects of such a beverage (Clearfast®) on patients’ discomforts from preoperative fasting and their safety and compliance. METHODS: A two-part multicenter, prospective clinical trial involved ASA Risk I-II adult patients having elective plastic, orthopedic or general surgical procedures at 5 hospitals. Part I was a descriptive observational pilot (n=263: Controls =108; Intervention =155). Part II was an IRB approved randomized trial (n=34: Controls =21; Intervention =13). All sites had previously adopted the ASA guidelines that determined patient eligibility. Exclusion criteria were pregnancy, obesity and GERD. Control groups observed the traditional midnight fast; Intervention groups consumed a carbohydrate-rich drink (Clearfast®) about 2 hours pre-op. Patient demographics, length of fasting, occurrence of regurgitation and/or aspiration and patient preoperative questionnaires assessing thirst, hunger, headache, nausea, anxiety about fasting and surgery plus discomfort were analyzed by a biostatistician. RESULTS: Regurgitation, aspiration, or other perioperative complications did not occur in Part I or II. Binary logistic regression model of Part I showed that if patients (1) did not have Clearfast®, (2) had surgical anxiety or (3) had fasting anxiety, or (4) had all three, they were (1) 5.7, (2) 4.1, (3) 2.7 or (4) 63 times more likely to be uncomfortable with their preoperative experience. Mann Whitney mean rank scores from the pooled data (n=297) indicated that, if patients did not consume Clearfast®, they were more likely to be thirsty (P=0.00), hungry (P<0.05), nauseous (P<0.05), anxious about both fasting and surgery (P<0.05) and uncomfortable (P=0.00). Control vs. Intervention fasting times were markedly different: 5-20 vs. 2-5 hours (P=0.00). CONCLUSION: In appropriately selected patients, following the ASA guidelines and using a preoperative carbohydrate-rich beverage 2 hours prior to elective ambulatory surgery resulted in significantly shorter fasting times, reduced thirst, hunger, anxiety and nausea and improved comfort. Plastic surgeons should be aware of and comply with these guidelines to improve patient safety and satisfaction.

The Relationship between Anagliptin Concentration Showing Over 80% Inhibition of Plasma Dipeptidyl Peptidase-4 Activity and its Protective Effect against Glucagon-like Peptide-1 Degradation

In dipeptidyl peptidase-4 (DPP-4) inhibitors, the inhibition of plasma DPP-4 activity by 80% is considered sufficient to have an effect on glycemic control improvement through the elevation of intact glucagon-like peptide-1 (GLP-1). To clarify whether or not the 80% inhibition is sufficient to protect against GLP-1 degradation, we investigated rats with a continuous infusion of exogenous GLP-1. When GLP-1 was infused into the femoral or portal vein, the steady state active GLP-1 levels in plasma significantly increased (P<0.05) at the 80% inhibitory concentration (IC80) of anagliptin (a highly selective DPP-4 inhibitor) against plasma DPP-4 activity, compared with control. In addition, the peptide levels increased in a concentration-dependent manner at drug concentrations from IC80 to 10-fold IC80, and the levels at the 10-fold IC80 were significantly higher (P<0.05) than those at IC80. The concentration dependency on GLP-1 increment was also confirmed based on the experiment in which the endogenous active GLP-1 levels were measured after an oral carbohydrate load. These findings suggest that an almost complete inhibition (80%) of plasma DPP-4 activity was insufficient to protect GLP-1 degradation, and much higher drug concentrations such as 10-fold IC80 are necessary to potently protect GLP-1 from degradation by DPP-4 commonly present in blood and tissues.

Randomized clinical trial on enhanced recovery versus standard care following open liver resection

Enhanced recovery programmes (ERPs) have been shown to reduce length of hospital stay (LOS) and complications in colorectal surgery. Whether ERPs have the same benefits in open liver resection surgery is unclear, and randomized clinical trials are lacking. Consecutive patients scheduled for open liver resection were randomized to an ERP group or standard care. Primary endpoints were time until medically fit for discharge (MFD) and LOS. Secondary endpoints were postoperative morbidity, pain scores, readmission rate, mortality, quality of life (QoL) and patient satisfaction. ERP elements included greater preoperative education, preoperative oral carbohydrate loading, postoperative goal-directed fluid therapy, early mobilization and physiotherapy. Both groups received standardized anaesthesia with epidural analgesia. The analysis included 46 patients in the ERP group and 45 in the standard care group. Median MFD time was reduced in the ERP group (3 days versus 6 days with standard care; P < 0·001), as was LOS (4 days versus 7 days; P < 0·001). The ERP significantly reduced the rate of medical complications (7 versus 27 per cent; P = 0·020), but not surgical complications (15 versus 11 per cent; P = 0·612), readmissions (4 versus 0 per cent; P = 0·153) or mortality (both 2 per cent; P = 0·987). QoL over 28 days was significantly better in the ERP group (P = 0·002). There was no difference in patient satisfaction. ERPs for open liver resection surgery are safe and effective. Patients treated in the ERP recovered faster, were discharged sooner, and had fewer medical-related complications and improved QoL. ISRCTN03274575 (http://www.controlled-trials.com).

Oral carbohydrate loading with 18% carbohydrate beverage alleviates insulin resistance.

Preoperative 12.6% oral carbohydrate loading is an element of the Enhanced Recovery After Surgery (ERAS) protocol aimed at alleviating postoperative insulin resistance; however, in Japan, beverages with 18% carbohydrate content are generally used for preoperative carbohydrate loading. We investigated the effect of 18% carbohydrate loading on alleviating insulin resistance. Six healthy volunteers participated in this crossover-randomized study and were segregated into 2 groups: volunteers in the carbohydrate-loading group (group A) who fasted from after 9 pm and ingested 375 mL of a beverage containing 18% carbohydrate (ArginaidWaterTM; Nestle, Tokyo, Japan) between 9 pm and 12 pm, and 250 mL of the same liquid at 6:30 am. Volunteers in control group (group B) drank only water. At 8:30 am, a hyperinsulinemic normoglycemic clamp was initiated. Glucose infusion rate (GIR) and levels of ketone bodies and cytokines (IL-1β, IL-6, and TNF-α) before clamping were evaluated. p<0.05 was considered statistically significant. Levels of blood glucose, insulin, and cytokines at the start of the clamp were similar in both the groups. The GIR in group A was significantly higher than that in group B (11.5±2.4 vs 6.2±2.2 mg/kg/min, p=0.005), while blood ketone body levels were significantly lower in group A (22±4 vs 124±119 μmol/L, p=0.04). Preoperative 18% carbohydrate loading could prevent the decrease in insulin sensitivity and suppress catabolism in healthy volunteers. Thus, carbohydrate loading with a beverage with 18% carbohydrate content might contribute to improvements in perioperative management.

絶食見直し・術前炭水化物負荷食導入時に直面する課題

絶食見直し・術前炭水化物負荷食導入時に直面する課題

The Society of Academic and Research Surgery

Abstract The Annual Meeting of the Society of Academic and Research Surgery was held at the University of Nottingham Medical School, Nottingham, on Wednesday 4th and Thursday 5th January 2012 under the Presidency of Professor J Andrew Bradley. The Patey Prize was awarded to Miss M Mallik from the University Department of Surgery, Addenbrooke's Hospital, Cambridge Biomedical Research Centre, Cambridge, for her presentation entitled REGULATORY B CELLS INDUCE LONG-TERM ALLOGRAFT SURVIVAL IN A MOUSE MODEL OF CHRONIC REJECTION. The Norman Williams Prize for the best clinical paper was awarded to Miss S A Hosgood from University of Leicester, Department of 31s, Transplant Group for her presentation entitled PLACEBO CONTROLLED DOUBLE BLIND RANDOMISED CLINICAL TRIAL OF TRANSVERSUS ABDOMINIS PLANE BLOCK IN LIVE DONOR NEPHRECTOMY. The Kevin Burnand Prize for the best experimental/basic science paper was awarded to Mr S Buczacki from Cancer Research UK, Cambridge Research Institute, Cambridge, for his presentation entitled CHARACTERISATION OF QUIESCENT INTESTINAL STEM AND CANCER STEM CELLS. The President's Poster Prize was awarded to Mr S Awad from Division of Gastrointestinal Surgery, Nottingham University Hospitals, Queen's Medical Centre, Nottingham for his poster presentation entitled PREOPERATIVE ORAL CARBOHYDRATE LOADING IN ELECTIVE SURGERY: A META-ANALYSIS.

Baroreflex sensitivity in acute hypoxia and carbohydrate loading

Hypoxia decreases baroreflex sensitivity (BRS) and can be a sufficient cause for syncope in healthy individuals. Carbohydrate loading enhances efferent sympathetic activity, which affects cardiac contractility, heart rate and vascular resistance, the main determinants of blood pressure. Thus, in both normoxia and hypoxia, carbohydrate loading may be more than simply metabolically beneficial, as it may affect blood pressure regulation. We hypothesised that carbohydrate loading will, in both normoxia and hypoxia, alter the regulation of blood pressure, as reflected in a change in baroreflex sensitivity. Fourteen subjects participated in two experiments, composed of a 15-min normoxic period, after which the subjects ingested water or an equal amount of water with carbohydrates. A 30-min rest period was then followed by a 10-min second normoxic and a 30-min hypoxic period. Blood pressure and heart rate were monitored continuously during the experiment to determine BRS. Despite an increased sympathetic activation, reflected in increased heart rate (P<0.001) BRS was lower (P<0.01) after carbohydrate loading, as compared to the water experiment, in both normoxic [23.7 (12.4) versus 28.8 (13.8) ms/mmHg] and hypoxic [16.8 (11.0) versus 24.3 (12.3) ms/mmHg] phases of the present study. As BRS was decreased in acute hypoxic exposure, the results confirm that hypoxia interferes with blood pressure regulation. However, although oral carbohydrate loading induced sympathoexcitation, it did not improve blood pressure regulation in hypoxia, as evident from the BRS data. Baroreflex effects of other forms of carbohydrate loading, not causing postprandial blood shifts to digestive system, should therefore be investigated.

Majör ve Minör Cerrahi Geçiren Hastalarda Preoperatif Oral Karbonhidrat Yüklemesinin Stres Cevaba Etkisi

Majör ve Minör Cerrahi Geçiren Hastalarda Preoperatif Oral Karbonhidrat Yüklemesinin Stres Cevaba Etkisi

Preoperative carbohydrate loading in patients undergoing coronary artery bypass or spinal surgery

Surgery induces a state of insulin resistance (IR) which may be aggravated by current fasting practices. Oral preoperative carbohydrate (CHO) loading may reduce postoperative IR and subsequently complications. The current study was designed to determine whether CHO loading would blunt the development of postoperative IR, reduce preoperative discomfort and improve clinical outcomes in elective coronary artery bypass or spinal surgical patients. Thirty‐eight patients were randomized to receive a CHO supplement the evening before (100g CHO) and two hours prior to surgery (50g CHO) or fast for 12 hours preoperatively. Insulin sensitivity was measured using the short insulin tolerance test and homeostasis model assessment (HOMA). Patient discomfort was measured immediately before surgery using visual analog scales. Insulin sensitivity was not significantly different between groups. However, the treated group experienced a significantly smaller rise in glucose levels following surgery (p=0.03) and had higher postoperative HOMA‐β scores (p=0.02). Supplemented patients were also significantly less thirsty (p=0.01), hungry (p=0.04) and anxious (p=0.01) before surgery and experienced a significantly shorter hospital stay (p=0.008). CHO loading improved outcomes, warranting re‐evaluation of fasting practices in this population. This research was supported by a CIHR student fellowship.

Compliance with enhanced recovery programmes in elective colorectal surgery

Enhanced recovery after surgery (ERAS) protocols are often criticized for being difficult to implement outside clinical trials. This audit evaluated compliance with an ERAS protocol and compared it with that during a trial. Compliance was audited by case-note review of 100 consecutive patients undergoing colorectal surgery. This was compared with the compliance in a group of 95 patients who participated in a clinical trial. Fewer patients in the audit group than in the study group received preoperative oral carbohydrate loading (61.0 versus 96 per cent; P < 0.001), a transverse incision (25.0 versus 39 per cent; P = 0.037), early fluid and diet reintroduction (73.0 versus 99 per cent; P < 0.001), and non-opiate postoperative oral analgesia (70.0 versus 99 per cent; P < 0.001). Lower non-opiate oral analgesia use in the audit group was not associated with a commensurate increase in opiate use (P = 0.061). There was no difference between groups in length of hospital stay (median (interquartile range) 7 (5-8) versus 6 (5-7) days respectively), septic morbidity or 30-day mortality rates. Observance to some aspects of the ERAS protocol was lower outside the clinical trial. However, this made little difference to patient outcome.

Vinegar lacks antiglycemic action on enteral carbohydrate absorption in human subjects

The antiglycemic effects of vinegar have been known for more than a century and have been demonstrated in animal as well as human studies. Although the exact mechanism of vinegar action is not known, several possibilities have been proposed including suppression of disaccharidase activity, delayed gastric emptying, enhanced glucose uptake in the periphery and conversion to glycogen, and increased satiety. We hypothesized that by suppressing endogenous insulin secretion, we could estimate the glucose absorption rate from an oral carbohydrate load and determine the effects of vinegar ingestion on this rate. To do so, 5 subjects had 4 studies at 1-week intervals, randomly receiving placebo twice (60 mL water) and vinegar twice (20 mL apple cider vinegar, 40 mL water), followed 2 minutes later by a meal of mashed potatoes (0.75 g carbohydrate per kilogram body weight) that was consumed over 20 minutes. At the beginning of the meal, an oral octreotide/insulin suppression test (25-microg bolus octreotide; 180 minute infusion 5 mU/m(2) body surface area per minute regular human insulin, and 0.5 microg/min octreotide) was begun. Blood samples for insulin and glucose were drawn at 20-minute intervals. The oral octreotide/insulin suppression test suppressed endogenous insulin secretion for the first 100 minutes of the study. During this time, the rate of rise of glucose was modestly but significantly (P = .01) greater after vinegar ingestion compared to placebo, suggesting that vinegar does not act to decrease glycemia by interference with enteral carbohydrate absorption.

Preoperative conditioning with oral carbohydrate loading and oral nutritional supplements can be combined with mechanical bowel preparation prior to elective colorectal resection

Preoperative conditioning with oral fluid and carbohydrate (CHO) loading allows the patient to undergo surgery in the fed state and is associated with reduced postoperative insulin resistance. Further benefit may accrue from oral nutritional supplements (ONS) to counteract the fasting associated with mechanical bowel preparation (MBP). In this study we assess the ability to prescribe, dispense and have patients comply with a protocol combining preoperative ONS and CHO/fluid loading during MBP. One hundred and forty-seven patients undergoing elective left colonic or rectal resection were recruited to an Enhanced Recovery after Surgery (ERAS) programme. All patients were prescribed MBP (2 sachets Picolax). On the daytime prior to surgery, eligible patients were prescribed 2 x 200 ml of ONS (Fortijuice, Nutricia) and in the evening 800 ml oral CHO/fluid loading (Preop(R), Nutricia,). Patients were prescribed a further 400 ml of oral/CHO/fluid on the morning of surgery 2 h prior to induction of anaesthesia. Protocol compliance was audited prospectively. One hundred and forty-seven patients received MBP. Twenty-three patients were ineligible for oral CHO/fluid loading [diabetes (n = 22), allergy to lemon flavoured drinks (n = 1)]. Fourteen patients did not receive the preoperative CHO drinks due to failure to prescribe (n = 8) or dispense (n = 6). One hundred and ten patients were dispensed the combined ONS and CHO/fluid loading regimen, compliance rates were 83% with ONS, 80% with CHO/fluid loading and 74% with both. Approximately 74% of patients undergoing MBP can comply with preoperative conditioning with ONS and CHO/fluid loading. Prescription and dispensing requires close attention to detail.

Preoperative administration of oral carbohydrate-rich solutions: Comparison of glucometabolic responses and tolerability between patients with and without insulin resistance

Objective Preoperative carbohydrate loading with clear fluids is thought to reduce surgery-related insulin resistance (IR). However, IR per se is already present in some patients scheduled for elective surgery. Data on the safety of preoperative oral carbohydrate loading in patients with IR undergoing surgery is lacking. We aimed to evaluate the effects of preoperative carbohydrate loading on the glucometabolic state and gastric content of patients with and without IR. Methods Thirty-four non-diabetics received 800 mL of a special carbohydrate-containing drink on the evening before the operation and then 400 mL 2 h before surgery. Blood samples for glucose, insulin, and cortisol levels were taken immediately before the second dose, at 40 and 90 min after intake of the drink, and at the onset of surgery. Patients with a homeostasis model assessment IR score >2.5 were considered to have IR. The differences between patients with and without IR were then evaluated. Results Eight of the 34 patients had IR and the remaining 26 did not. Glucose levels in the IR group were higher than those in the non-IR group, but the differences did not reach significance. The initially elevated insulin concentrations then tended to decrease to the corresponding levels detected in the non-IR group. The cortisol concentrations were similar in both groups. Conclusion Patients with IR receiving a carbohydrate-rich drink before surgery appear not to be affected adversely by the beverage. Furthermore, they also obtain the probable beneficial effects related to these drinks and, like patients without IR, can undergo surgery safely.

Pre‐operative carbohydrate loading may be used in type 2 diabetes patients

Post-operative insulin resistance and hyperglycaemia are associated with an impaired outcome after surgery. Pre-operative oral carbohydrate loading (CHO) reduces post-operative insulin resistance with a reduced risk of hyperglycaemia during post-operative nutrition. Insulin-resistant diabetic patients have not been given CHO because the effects on pre-operative glycaemia and gastric emptying are unknown. Twenty-five patients (45-73 years) with type 2 diabetes [glycated haemoglobin (HbA1c) 6.2 +/- 0.2%, mean +/- SEM] and 10 healthy control subjects (45-72 years) were studied. A carbohydrate-rich drink (400 ml, 12.5%) was given with paracetamol 1.5 g for determination of gastric emptying. Peak glucose was higher in diabetic patients than in healthy subjects (13.4 +/- 0.5 vs. 7.6 +/- 0.5 mM; P<0.01) and occurred later after intake (60 vs. 30 min; P<0.01). Glucose concentrations were back to baseline at 180 vs. 120 min in diabetic patients and healthy subjects, respectively (P<0.01). At 120 min, 10.9 +/- 0.7% and 13.3 +/- 1.2% of paracetamol remained in the stomach in diabetic patients and healthy, subjects respectively. Gastric half-emptying time (T50) occurred at 49.8 +/- 2.2 min in diabetics and at 58.6 +/- 3.7 min in healthy subjects (P<0.05). Neither peak glucose, glucose at 180 min, gastric T50, nor retention at 120 min differed between insulin (HbA1c 6.8 +/- 0.7%)- and non-insulin-treated (HbA1c 5.6 +/- 0.4%) patients. Type 2 diabetic patients showed no signs of delayed gastric emptying, suggesting that a carbohydrate-rich drink may be safely administrated 180 min before anaesthesia without risk of hyperglycaemia or aspiration pre-operatively.

Insulin resistance after cardiopulmonary bypass in the elderly patient

Objectives. Preoperative carbohydrate administration attenuates insulin resistance. We studied effects of preoperative oral carbohydrate loading in elderly patients undergoing coronary artery bypass grafting. Design. Eighteen patients were assigned either to get a carbohydrate drink or to be controls. Perioperatively, glucose was administered. A gastric emptying test was performed. Glucose and insulin concentrations were measured. Levels of glucose, insulin and stress hormones were studied pre-, per- and postoperatively. Results and discussion. Preoperative carbohydrate loading did not affect stress hormones. Gastric residual after the carbohydrate drink was 11±3% (mean±SEM). Glucose concentration was lower before anaesthesia induction in the carbohydrate group, possibly due to increased insulin release. Insulin levels differed at baseline, induction and day six. All patients returned to baseline on day six. Conclusions. The study group was insulin resistant on postoperative day one and two. The effects were explainable by the traumatic stress response. No adverse effect was noted from the carbohydrate drink. If glucose is administered intravenously during surgery, there is no obvious advantage of preoperative carbohydrate loading on insulin resistance or stress hormone response.

Pre‐operative oral carbohydrate loading in colorectal surgery: a randomized controlled trial

Surgery induces a catabolic response with stress hormone release and insulin resistance. The aim of this study was to assess the effect of pre-operative carbohydrate administration on grip strength, gastrointestinal function and hospital stay following elective colorectal surgery. Thirty-six patients undergoing elective colonic resection were randomized into one of three groups. Group 1 were fasted; Group 2 were given pre-operative oral water, Group 3 received equivalent volumes of a Maltodextrin drink. Time to first flatus, first bowel movement and hospital stay were recorded. Muscle strength was measured pre-operatively, and on alternate days thereafter until discharge using a grip strength dynamometer. Patients in the carbohydrate group had a median postoperative hospital stay of 7.5 days compared with 13 days in the water group (P > 0.01) and 10 days in the fasted group (P = 0.06). The median time postsurgery to first flatus was 3 days for both the fasted and water groups compared with 1.5 days in the carbohydrate group (P = 0.13). First bowel movement occurred on day 3 in the carbohydrate group, day 4 in the fasting group and day 5 in the water group. The fasted group showed a significant reduction in postoperative grip strength (P < 0.05) with a median drop of 10% at discharge. Neither the water nor the carbohydrate groups showed significant reductions in muscle strength. We found that pre-operative administration of oral carbohydrate leads to a significantly reduced postoperative hospital stay, and a trend towards earlier return of gut function when compared with fasting or supplementary water.

Preoperative oral carbohydrate nutrition: an update.

Insulin resistance is a central feature of the metabolic response after elective surgery as well as other trauma, and has been shown to be a predictor of the length of stay after surgery. Carbohydrate treatment instead of overnight fasting before surgery has been shown to reduce postoperative insulin resistance and to reduce hospital stay approximately 20% after elective surgery. For potential use as a clinical routine before surgery, a carbohydrate-rich drink was developed. Gastric emptying of a 50 g oral carbohydrate load using this drink is complete within 90 min after intake. Oral carbohydrate loading before surgery has confirmed previous data, using glucose and insulin infusions, that postoperative insulin resistance is reduced compared with overnight fasted patients before surgery, and this is associated with improved well-being before and after surgery.

Euglycemic hyperinsulinemic clamp to assess posthepatic glucose appearance after carbohydrate loading. 1. Validation in pigs

Precise knowledge of the rate of glucose absorption after meal feeding requires invasive methods in humans. This study aimed to validate in an animal model a technique combining the euglycemic hyperinsulinemic clamp and oral carbohydrate loading (OC-Clamp) as a noninvasive procedure to quantify the posthepatic appearance of glucose after oral carbohydrate loading. Twenty-one pigs were fitted with arterial, jugular, portal, and duodenal catheters and a portal blood flow probe. At glucose clamp steady state, duodenal glucose (0.9 g/kg; DG-Clamp) and oral carbohydrate (140 g corn or mung bean starch as part of a mixed meal; OC-Clamp) were administered while the glucose infusion was progressively reduced to compensate for the incremental posthepatic appearance of glucose. [3-3H]glucose was used to assess the glucose turnover rate. Hepatic glucose production was totally suppressed by insulin infusion, and the whole-body glucose turnover rate remained stable during glucose absorption. The incremental portal appearance of glucose after the DG load was not altered by hyperinsulinemia, and the cumulative posthepatic appearance of glucose was 63 +/- 3% (x +/- SEM) of the DG load. The net hepatic portal appearance of glucose remained constant during absorption (34 +/- 3% of the load). After the OC load, the respective portal appearance rates of glucose were significantly different between carbohydrate sources; however, the rates paralleled those of the posthepatic appearance of glucose. Again, net hepatic glucose uptake expressed as portal appearance was similar for both carbohydrates. The results validate the OC-Clamp method to monitor the posthepatic appearance of glucose after carbohydrate ingestion and to discriminate between different carbohydrate sources. The results suggest that the technique be used in humans.