Preoperative Carbohydrate Loading Research Articles

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.

The effects of fasting and refeeding with a ‘metabolic preconditioning’ drink on substrate reserves and mononuclear cell mitochondrial function

Preoperative fasting induces metabolic stress and leads to reduced postoperative insulin sensitivity, changes attenuated by preoperative carbohydrate loading. However, the mechanisms underlying these effects remain unknown. We investigated the dynamic changes in substrate metabolism and mononuclear cell mitochondrial function after fasting followed by refeeding with a drink [ONS (Fresenius Kabi, Germany)] designed to improve metabolic function preoperatively. Twelve healthy volunteers took part in this study. They were fed a standardized meal and studied 4h later (baseline 'fed' state), after 12 and 24h of fasting, and 2, 4 and 6h after ingestion of ONS (contained 100g carbohydrate, 30g glutamine, and antioxidants). Changes in liver and muscle glycogen and lipids were studied using (13)C and (1)H magnetic resonance spectroscopy. The activities of mitochondrial electron transport chain complexes I, II and IV in blood mononuclear cells were measured spectrophotometrically. Compared to the baseline fed state, 12 and 24h fasts led to 29% and 57% decreases (P<0.001) in liver glycogen content, respectively. Fasting for 24h decreased mitochondrial membrane complexes I (-72%, P<0.05), II (-49%, P<0.01) and IV (-41%, P<0.05) activities compared to those following a 12h fast. A 23% increase (P<0.05) in calf intramyocellular lipid (IMCL) content occurred after a 24h fast. Liver glycogen reserves increased by 47% (P<0.05) by 2h following ingestion of ONS. Short-term fasting (up to 24h) affected mononuclear cell mitochondrial function adversely and increased IMCL content. Refeeding with ONS partially reversed the changes in liver glycogen.

Preoperative carbohydrate loading in contrast to fasting

Preoperative carbohydrate loading in contrast to fasting

Preoperative carbohydrate loading: a review of the current evidence

Background: Surgery induces a stress response associated with injury resulting in insulin resistance (Thorell et al., 1999). Fasting is a common procedure presurgery and leads to reduced insulin sensitivity as a result of disturbances in glucose, protein and fat metabolism. Reduced insulin sensitivity has been associated with increased surgical outcome and enhanced patient recovery (van den Berghe et al., 2001). The purpose of this study was to review the current evidence relating to preoperative carbohydrate loading, particularly focusing on outcomes including post‐operative complications, patient well‐being and length of hospital stay.Methods: A structured review was carried out in a systematic manner of randomised clinical trials published between 1998 and 2008 using four medical databases (Medline, CSA Illumni, Pubmed and ISI Web of Knowledge). The available literature published within the last 10 years that measured an objective clinical load was considered for inclusion. Initially, literature searches were commenced using the broad terms ‘preoperative’ and ‘carbohydrate’ (both terms present). This approach was then refined to improve specificity using the following terms in a variety of different combinations: preoperative carbohydrate load; oral carbohydrate; post‐operative period; hospital stay; preoperative nutrition; and treatment outcomes. Exclusion criteria included duplicate records, those not written in English language, animal studies, observational studies with and without controls, protocols, proposals, discussion papers and conference abstracts. The bibliographies of relevant literature were searched for further studies not found by the database searches.Results: A total of 16 randomised control trials were identified from initial searches. Of the 16 that were assessed in full form, three were excluded. The remaining thirteen randomised trials all measured clinical outcomes after a preoperative carbohydrate load 2–3 h prior to elective surgery. The study intervention was similar in each study. The number of patients included in each study varied greatly, from 12 to 252, with seven studies having unequal sample sizes between comparison groups. Nine of the 13 studies had a placebo group, and six studies had a control group. The post‐operative regimen was similar in all thirteen studies and was standardised in studied groups. The clinical, metabolic and nutritional outcomes were reported in all of the studies. Results showed that a preoperative carbohydrate load could reduce post‐operative insulin resistance. Statistical significance was not reached for length of hospital stay, improved well‐being and reduced loss of lean tissue, although trends were seen. None of the trials noted any adverse affects as a result of preoperative carbohydrate load.Discussion: The body of evidence surrounding reduced insulin resistance was of good quality and was consistent with a study by Nygren et al. (1995) where insulin resistance was shown to be reduced by 50% in the same population group. Statistically, individual studies did not provide significant evidence with regard to reduced length of stay, reduced loss of lean muscle mass and patient well‐being. Further research is warranted in all of the reported outcomes because a small sample size has resulted in trends, rather than conclusive evidence. A meta‐analysis may produce more conclusive results.Conclusions: A preoperative oral carbohydrate was associated with several positive outcomes; however, statistical significance was not reached as a result of the small nature of the studies. No adverse affects were associated with a preoperative oral carbohydrate 2–3 h prior to surgery; therefore, overnight fasting guidelines in elective surgery should be questioned.References Nygren, J., Thorell, A., Jacobsson, H., Larsson, S., Schnell, P., Hylen, L. &amp; Ljundqvist, O. (1995) Preoperative gastric emptying: effects of anxiety and oral carbohydrate administration. Ann. Surg.222, 728–734.Thorell, A. Nygren, J. &amp; Ljundqvist, O. (1995) Insulin resistance – a marker of surgical stress. Curr. Opin. Clin. Nutr. Metab Care2, 69–79.Van den Berghe, G., Wouters, P. &amp; Weekers, F. (2001) Intensive insulin therapy in critically ill patients. N. Engl. J. Med.345, 1359–1367.

Nutritional aspects of colorectal cancer surgery care in a district general hospital

Background: Nutritional screening and support as well as early re‐introduction of enteral feeding can enhance recovery in colorectal surgical patients (Fearon &amp; Luff, 2003; Fearon et al., 2005). Recent advances in multi‐modal surgical care have highlighted many changes that are required in practice compared to traditional approaches. The aim of this study was to compare the current nutritional practice for colorectal cancer patients undergoing elective surgery at Queen Mary's Hospital Sidcup against current evidence‐based recommendations (Fearon et al., 2005; Arends et al., 2006).Methods: Surgical and nursing notes of patients that underwent elective procedures for colorectal malignancy in 2006 were examined. Data collected included information regarding preoperative nutritional screening and anthropometrics, the use of preoperative fasting and carbohydrate loading, use of nasogastric tubes and the time to re‐introduction of oral diet and fluids.Results: Thirty‐three patients underwent elective surgery for colorectal cancer in 2006. Less than half of patients (37.2%) did not receive any form of preoperative nutritional assessment. No patients received carbohydrate loading; 93.9% were fasted for &gt;6 h prior to surgery for liquids and solids. Post‐operatively (PO); clear fluids were commenced at a mean (SD) of 1.6 (1.1) days, free fluids at 2.7 (1.4) days PO, and diet at 3.9 (1.8) days PO. 90.9% of patients received nasogastric tube intubation; mean (SD) removal time was 4.0 (4.0) days PO. Audit standard Aim (%) Results (%) Patients should receive nutritional screening prior to surgery 100 37.2 Patients should be fasted for solids for 6 h and clear liquids for 2 h prior to surgery 100 0.0 Patients should receive preoperative carbohydrate loading 100 0.0 Nasogastric tubes should not be used post‐operatively 100 3.0 Oral diet should be restarted immediately after surgery 100 0.0 Discussion: Current practice varies between surgical teams within the same hospital. The majority of patients are not being screened for malnutrition prior to surgery using either anthropometrics or a validated method. Patients are not receiving carbohydrate loading prior to surgery and there is often a delay in the re‐removal of nasogastric tubes and the re‐introduction of oral fluids and nutrition post‐operatively.Conclusions: In summary, current practice is not in line with current evidence‐based recommendations (Fearon et al., 2005; Arends et al., 2006).Acknowledgment: This research was sponsored by Macmillan Cancer Support.References Arends, J., Bodoky, G., Bozzetti, F., Fearon, K., Muscaritoli, M., Selga, G., van Bokhorst de van der Schueren, M.A.E., von Meyenfeldt, M., Zurcher, G., Fietkau, R., Aulbert, E., Frick, B., Holm, M., Kneb, M., Mestrom, H.J. &amp; Zander, A. (2006) ESPEN Guidelines on Enteral Nutrition: Non‐surgical oncology. Clin. Nutr.25, 245–259.Fearon, K.C.H. &amp; Luff, R. (2003) The nutritional management of surgical patients:enhanced recover after surgery. Proc. Nutr. Soc.62, 807–811.Fearon, K.C.H., Ljungqvist, O., Von Meyenfeldt, M., Revhaug, A., Dejong, C.H.C., Lassen, K., Nygren, J., Hausel, J., Soop, M., Anderson, J. &amp; Kehlet, H. (2005) Enhanced recovery after surgery: a consensus review of clinical care for patients undergoing colonic resection. Clin. Nutr.24, 466–477.

Perioperative Ernährung – Metabolische Konditionierung

Surgery elicits a series of metabolic stress reactions. Stress hormones and inflammatory mediators (i. e. cytokines) cause catabolism of glycogen, lipids and proteins. Glucose, free fatty acids, and amino acids are released for the tasks of healing and immune response. Thus, substrates are diverted from normal purposes such as physical activity. However, the patient requires anabolic metabolism to reach optimal recovery. Many stress-reducing measures have proven to minimize catabolism and support anabolism, and have led to faster and better rehabilitation, even after major surgical trauma. The so-called „Enhanced Recovery After Surgery” (ERAS) concepts focus on better preoperative preparation, anaesthesia, analgesia, and early mobilisation as well as improved supplies of nutritional substrates. This includes generally reduced preoperative fasting, preoperative carbohydrate loading, no interruption of oral nutritional intake after surgery, if possible, and a perioperative consumption of oral nutritional supplements. Studies have shown that such nutritional practices contribute to perioperative stabilisation of the organism by reducing postoperative insulin resistance, minimising protein catabolism, decreasing oxidative stress, and improving various organ functions. Further consequences are improved perioperative condition, attenuated depletion of muscle mass, reduction of postoperative complications, and reduced intensive care unit and hospital stays.

Effect of preoperative intravenous carbohydrate loading on preoperative discomfort in elective surgery patients

We studied the effect of three different fasting protocols on preoperative discomfort and glucose and insulin levels. Two hundred and ten ASA I-III patients undergoing general or gastrointestinal surgery were randomly assigned to three groups: overnight intravenous 5% glucose infusion (1000 ml), carbohydrate-rich drink (400 ml) at 6-7 a.m., or overnight fasting. The subjective feelings of thirst, hunger, mouth dryness, weakness, tiredness, anxiety, headache and pain of each patient were questioned preoperatively using a visual analogue scale. Serum glucose and insulin levels were measured at predetermined time points preoperatively. During the waiting period before surgery, the carbohydrate-rich drink group was less hungry than the fasting group (P = 0.011). No other differences were seen in visual analogue scale scores among the study groups. Trend analysis showed increasing thirst, mouth dryness and anxiety in the intravenous glucose group (P < 0.05). The carbohydrate-rich drink group experienced decreasing thirst but increasing hunger and mouth dryness (P < 0.05). In the fasting group, thirst, hunger, mouth dryness, weakness, tiredness and anxiety increased (P < 0.05). Both intravenous and oral carbohydrate caused a significant increase in glucose and insulin levels. Intravenous glucose infusion does not decrease the sense of thirst and hunger as effectively as a carbohydrate-rich drink but does alleviate the feelings of weakness and tiredness compared with fasting.

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.

Effects of preoperative carbohydrate loading on the changes in serum tumor necrosis factor receptors 1 and 2 and insulin resistance in patients of colon carcinoma

To investigate the effects of preoperative carbohydrate loading and new fasting protocol treatment on the postoperative changes in serum tumor necrosis factor receptor1 (sTNFR1), sTNFR2, and insulin resistance (IR) in patients of colon carcinoma. 51 patients of colon carcinoma were randomly divided into 2 groups: carbohydrate-rich beverage group (n = 24), undergoing fasting 6 h before operation and water deprivation 2 h before operation, receiving carbohydrate-rich beverage 3 h before operation and fluid therapy with glucose post-operatively, and placebo group (n = 27) undergoing routine fasting and water deprivation pre-operatively. Peripheral blood samples were collected before, during, and 1, 4, and 7 d after operation. ELISA was used to detect the sTNFR1 and sTNFR2 of preoperative, 1, 4, 7day Insulin sensitivity index (S1) was calculated. The S(1) levels at different post-operational time points of the treatment group were not significantly different from those preoperatively (all P > 0.05), while the S(1) levels of the control group decreased significantly compared to those before operation (all P < 0.05). The sTNFR1 level of the treatment group increased postoperatively and did not return to the pre-operative level 7 d after operation(all P < 0.05). The sTNFR1 levels at different post-operative time points of the treatment group were all significantly higher than those of the control group (all P < 0.05). The sTNFR2 level of the treatment group decreased postoperatively and did not return to the pre-operative level 7d after operation (all P < 0.05). The sTNFR2 levels at different post-operative time points of the treatment group were all significantly lower than those of the control group (all P < 0.05). There was not significant differences in the sTNFR1 level in the control group before and after operation (all P > 0.05). The time to first flatus and days staying in hospital of the treatment group were (77 +/- 15) hours and (11 +/- 1.2) gays respectively, both significantly shorter than those of the control group [(86 +/- 13) hours and (15.1 +/- 3.8) days respectively, both P < 0.05]. Preoperative carbohydrate loading and new fasting protocol reduce the degree and course of IR, increase the sTNFR1 level, and decrease the sTNFR2 level and days of staying in hospital.

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.

Pre-operative carbohydrate loading in patients undergoing major abdominal surgery: Results of a double-blind randomised controlled trial

Pre-operative carbohydrate loading in patients undergoing major abdominal surgery: Results of a double-blind randomised controlled trial

Effects of preoperative carbohydrate loading on glucose metabolism and gastric contents in patients undergoing moderate surgery: A randomized, controlled trial

Objective Despite contrary evidence, the practice of overnight fasting before elective surgery maintains its place in tradition. However, prolonged starvation, by its catabolic action, may increase the detrimental effects of surgery. In this study, we evaluated the effects of preoperative carbohydrate loading on the gastric contents of patients and perioperative metabolism. Methods Seventy patients scheduled for cholecystectomy or thyroidectomy randomly were assigned to the treatment or control group. Patients in the treatment group ( n = 34) received 800 mL of a carbohydrate-rich fluid on the evening before surgery and 400 mL of the same fluid 2 h preoperatively. Conversely, control patients ( n = 36) underwent overnight fasting. Plasma glucose and serum insulin levels were obtained across the perioperative period and during anesthesia induction. The volume and pH of preoperative residual gastric contents also were measured. Results Preoperative plasma glucose levels were found to remain significantly higher in patients who had received the carbohydrate-rich fluid. Serum insulin levels that were elevated initially in the study group returned to control levels by the time of anesthesia induction. There was no statistical difference between the two groups with respect to gastric residue contents or gastric fluid pH. Conclusion The preoperative intake of carbohydrate-rich fluids does not appear to alter the amount or pH of gastric contents, suggesting that this is a safe procedure, in terms of aspiration risk. Furthermore, the intake of such fluid might prevent energy malnutrition.

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.

Management of perioperative nutrition support

Perioperative nutrition has been extensively studied, but numerous questions remain unanswered. This review focuses on new developments in nutrient delivery in the immediate perioperative period. Issues specifically addressed include which patients are most likely to benefit from perioperative nutritional supplementation, and the optimal route, timing, and quantity of nutrient delivery. Visceral proteins, particularly albumin, play an important role in nutritional and perioperative risk assessment. Although the recommendation to use the enteral route for delivery of nutrition whenever possible is clear, the cautious introduction of enteral feeds in the labile group of patients with circulatory failure is essential. Preoperative use of immune-modulating enteral formulas, preoperative carbohydrate loading, and the concept of early enteral feeding are important developments. Supplementary arginine, glutamine, and omega-3 fats play a potential role in nutritional management, as does 'permissive' hypocaloric feeding. The particulars of nutritional support for perioperative and critically ill patients remain controversial. Recent studies addressing specific issues in this diverse discipline perhaps raise more questions than are answered. However, each new contribution to the literature brings us closer to an understanding of optimal nutritional management in the metabolically stressed patient.

Modulation of post-operative insulin resistance by pre-operative carbohydrate loading.

Insulin resistance develops as a response to virtually all types of surgical stress. There is an increasing body of evidence that suggests that insulin resistance in surgical stress is not beneficial for outcome. A recent large study in intensive-care patients showed that aggressive treatment of insulin resistance using intravenous insulin reduced mortality and morbidity substantially. Similarly, in burn patients, intensive insulin and glucose treatment has been shown to improve N economy and enhance skin-graft healing. In surgical patients insulin resistance has been characterized in some detail, and has been shown to have many similarities with metabolic changes seen in patients with type 2 diabetes. This finding may be important since insulin resistance has been shown to be one independent factor that influences length of stay. When patients about to undergo elective surgery have been treated with glucose intravenously or a carbohydrate-rich drink instead of overnight fasting, insulin resistance was reduced by about half. A small meta-analysis showed that when post-operative insulin resistance was reduced by pre-operative carbohydrates, length of hospital stay was shortened. Overnight intravenous glucose at high doses improved post-operative N economy. This type of treatment has also been shown repeatedly to reduce cardiac complications after open-heart surgery. Furthermore, if the carbohydrates are given as a drink pre-operatively, pre-operative thirst, hunger and anxiety are markedly reduced. In summary, preventing or treating insulin resistance in surgical stress influences outcome. Fasting overnight is not an optimal way to prepare patients for elective surgery. Instead, pre-operative carbohydrates have clinical benefits.

Preoperative nutrition therapy - novel developments

Elective surgery has until recently been performed in the overnight fasted state in order to reduce the risk of aspiration of gastric content during the induction of anaesthesia. However, in order to increase the preoperative well-being of surgical patients, most western countries have changed their routines during the last 10-15 years, allowing intake of clear fluids up to 2 hours before anaesthesia in most patients. Animal studies have demonstrated that undergoing different situations of stress in the fed state is superior to stress in the short-term fasted state. To evaluate whether this also applies to surgical patients, a series of clinical studies have been performed, in which the metabolic, subjective, and clinical outcome has been compared in patients randomised to preoperative carbohydrate loading or not. These studies include the development of a carbohydrate-rich drink, which has been tested and shown to be safe in the perioperative situation. The results from these studies, reviewed in this article, suggest that fasting is not the optimal way to prepare for surgical stress, and that preoperative carbohydrate loading could have metabolic as well as clinical benefits. Keywords: carbohydrates, insulin resistance, preoperative fasting, surgery, well-being

The effect of preoperative carbohydrate loading on hormonal changes, hepatic glycogen, and glucoregulatory enzymes during abdominal surgery

The effect of preoperative glucose infusion on preoperative alterations in hepatic glycogen content, the activity of key hepatic glucoregulatory enzymes (fructose 1,6-diphosphatase [FDPase]), pyruvate kinase (PK), hormonal developments, and plasma levels of free fatty acids (FFA) were investigated in 16 patients undergoing open cholecystectomy. Patients were randomized to receive (group G) or not receive (group C) overnight glucose infusion (5 mg·kg −1·d −1) preoperatively. Infusion of glucose overnight resulted in preoperative elevations of insulin and c-peptide ( P < 0.05) and lower plasma levels of FFA, while the same glucose levels were found in both groups, 4.6 mmol/L. During and after surgery, only minor changes in the plasma levels of insulin, c-peptide, catecholamines, glucagon, cortisol, growth hormone, and FFA were found, with minimal differences between groups. The hepatic glycogen content was 65% higher in group G and a significant reduction was confirmed only in this group of patients during surgery. The higher glycogen content was associated with a higher FDPase activity ratio ( P < 0.05), which remained unchanged during surgery. In contrast, a significant ( P < 0.05) increase in the activity of this enzyme was found in group C. The PK activity ratio did not differ between groups and remained unchanged during surgery. The finding of enhanced FDPase activity suggests that the indirect route (via gluconeogenesis) represents an important contributor to the increased glycogen formation during glucose infusion. Additionally, surgery in the overnight fasted patient induces enzymatic changes favoring gluconeogenesis. Lastly, preoperative high-dose glucose infusion has only minor effects on the endocrine response, plasma levels of FFA, and glycogen depletion during elective open cholecystectomy.