The metabolic effects of fasting and surgery

Effectiveness and safety of perioperative enteral feeding in patients with burn injuries: a systematic review protocol

OBJECTIVE

The objective of this review is to determine whether perioperative enteral feeding improves outcomes in patients with burns.

INTRODUCTION

Literature has identified many positive benefits of nutrition support for patients with burn injuries, including preservation of lean body mass, improved wound healing, reduced gastrointestinal permeability and enhanced immunity. Fasting for surgery can undermine the nutritional care of these patients by causing nutrient deficits. It may also negatively affect patient well-being and insulin resistance. Perioperative fasting is intended to protect patients from regurgitation and pulmonary aspiration. This research aims to investigate whether perioperative feeding impacts outcomes in patients with burn injuries.

INCLUSION CRITERIA

This systematic review will consider studies whose participants have a burn injury. The intervention is perioperative enteral feeding (either intragastric or post-pyloric). Patients who received perioperative feeding will be compared with patients who had enteral nutrition withheld during the perioperative period. A number of outcome measures will be investigated, including mortality, length of stay, wound infection, wound healing rate and aspiration pneumonia.

METHODS

The key databases searched will be PubMed, CINAHL, Embase, Web of Science and Cochrane Central Register of Controlled Trials and Scopus. Only studies published in English will be considered. There will be no date limits. Full texts of selected studies will be retrieved and assessed against inclusion criteria. Studies that do not meet the inclusion criteria will be excluded, with reasons provided. Data synthesis will be pooled in a statistical meta-analysis. Subgroup analysis will be conducted where possible. Where statistical pooling is not possible, the findings will be presented in narrative form.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42018119034.

Enhanced Perioperative Care for Major Spine Surgery

STUDY DESIGN

The enhanced perioperative care (EPOC) program is an institutional quality improvement initiative. We used a historically controlled study design to evaluate patients who underwent major spine surgery before and after the implementation of the EPOC program.

OBJECTIVE

To determine whether multidisciplinary EPOC program was associated with an improvement in clinical and financial outcomes for elective adult major spine surgery patients.

SUMMARY OF BACKGROUND DATA

The enhanced recovery after surgery (ERAS) programs successfully implemented in hip and knee replacement surgeries, and improved clinical outcomes and patient satisfaction.

METHODS

We compared 183 subjects in traditional care (TRDC) group to 267 intervention period (EPOC) in a single academic quaternary spine surgery referral center. One hundred eight subjects in no pathway (NOPW) care group was also examined to exclude if the observed changes between the EPOC and TRDC groups might be due to concurrent changes in practice or population over the same time period. Our primary outcome variables were hospital and intensive care unit lengths of stay and the secondary outcomes were postoperative complications, 30-day hospital readmission and cost.

RESULTS

In this highly complex patient population, we observed a reduction in mean hospital length of stay (HLOS) between TRDC versus EPOC groups (8.2 vs. 6.1 d, standard deviation [SD] = 6.3 vs. 3.6, P < 0.001) and intensive care unit length of stay (ILOS) (3.1 vs. 1.9 d, SD = 4.7 vs. 1.4, P = 0.01). The number (rate) of postoperative intensive care unit (ICU) admissions was higher for the TRDC n = 109 (60%) than the EPOC n = 129 (48%) (P = 0.02). There was no difference in postoperative complications and 30-day hospital readmissions. The EPOC spine program was associated with significant average cost reduction-$62,429 to $53,355 (P < 0.00).

CONCLUSION

The EPOC program has made a clinically relevant contribution to institutional efforts to improve patient outcomes and value. We observed a reduction in HLOS, ILOS, costs, and variability.

LEVEL OF EVIDENCE

3.

The effects of vitamin-rich carbohydrate pretreatment on the surgical stress response and S-100β after splenectomy in elderly rats

Background

Preoperative oral carbohydrates has been suggested to attenuate insulin resistance and decrease postoperative complications. In this study, a vitamin-rich carbohydrate beverage was administered before surgery in an animal model to investigate its effects on the surgical stress response and S-100β levels.

Methods

Thirty aged male Sprague-Dawley rats were randomly assigned to three groups: control group (n = 6), fasting group (n = 12), and carbohydrate-treated group (CHO group, n = 12). Rats in the control group were not given any treatment. Rats in the fasting group received splenectomy after 12 h of fasting. In the CHO group, rats were given 5 ml of vitamin-rich carbohydrate by gavage 2 h before surgery. Fasting plasma glucose, insulin, insulin resistance (HOMA-IR index, IRI), the S-100β protein level, and the inflammatory mediators IL-1β, IL-6 and TNF-α were assessed after surgery (postoperative day (POD) 1 and 3).

Results

Postoperative insulin resistance was significantly greater in the fasting group than in the control and CHO group. The median plasma S-100β level was significantly higher in the fasting group than in the control and CHO groups on POD 1. The median plasma IL-1β level was significantly lower in the CHO group than in the fasting group on POD 1; however, no other differences in the concentrations of immunological biomarkers of stress were found between the fasting group and the CHO group.

Conclusions

Vitamin-rich carbohydrate pretreatment attenuated the metabolic aspect of the surgical stress response and decreased the level of plasma S-100β, which may decrease the risk of postoperative complications in elderly rats.

Preoperative Oral Carbohydrate Load Versus Placebo in Major Elective Abdominal Surgery (PROCY): A Randomized, Placebo-controlled, Multicenter, Phase III Trial

OBJECTIVE

To explore whether preoperative oral carbohydrate (CHO) loading could achieve a reduction in the occurrence of postoperative infections.

BACKGROUND

Hyperglycemia may increase the risk of infection. Preoperative CHO loading can achieve postoperative glycemic control.

METHODS

This was a randomized, controlled, multicenter, open-label trial. Nondiabetic adult patients who were candidates for elective major abdominal operation were randomized (1:1) to a CHO (preoperative oral intake of 800 mL of water containing 100 g of CHO) or placebo group (intake of 800 mL of water). The blood glucose level was measured every 4 hours for 4 days. Insulin was administered when the blood glucose level was >180 mg/dL. The primary endpoint was the occurrence of postoperative infection. The secondary endpoint was the number of patients needing insulin.

RESULTS

From January 2011 through December 2015, 880 patients were randomly allocated to the CHO (n = 438) or placebo (n = 442) group. From each group, 331 patients were available for the analysis. Postoperative infection occurred in 16.3% (54/331) of CHO group patients and 16.0% (53/331) of placebo group patients (relative risk 1.019, 95% confidence interval 0.720-1.442, P = 1.00). Insulin was needed in 8 (2.4%) CHO group patients and 53 (16.0%) placebo group patients (relative risk 0.15, 95% confidence interval 0.07-0.31, P < 0.001).

CONCLUSIONS

Oral preoperative CHO load is effective for avoiding a blood glucose level >180 mg/dL, but without affecting the risk of postoperative infectious complication.

Comparative ultrasound study of gastric emptying between an isotonic solution and a nutritional supplement

Background and objectives

Preoperative fasting may lead to undesirable effects in the surgical patient in whom there is a stimulus to ingesting clear liquids until 2 hours before anesthesia. The aim of this study was to evaluate the gastric emptying of two different solutions using ultrasound.

Methods

In a prospective, randomized, blind study, 34 healthy volunteers ingested 200 mL of two solutions without residues in two steps: an isotonic solution with carbohydrates, electrolytes, osmolarity of 292 mOsm.L⁻¹, and 36 kcal; and other nutritional supplementation with carbohydrates, proteins, electrolytes, osmolarity of 680 mO.L⁻¹, and 300 kcal. After 2 hours, a gastric ultrasound was performed to assess the antrum area and gastric volume, and the relation of gastric volume to weight (vol.w⁻¹), whose value above 1.5 mL.kg⁻¹ was considered a risk for bronchoaspiration. A p-value <0.05 was considered statistically significant.

Results

There was a significant difference between all parameters evaluated 2 hours after the ingestion of nutritional supplementation compared to fasting. The same occurred when the parameters between isotonic solution and nutritional supplementation were compared 2 hours after ingestion. Only one patient had vol.w⁻¹ <1.5 mL.kg⁻¹ 2 hours after ingestion of nutritional supplementation; and only one had vol.w⁻¹ >1.5 mL.kg⁻¹ after ingestion of isotonic solution.

Conclusion

This study demonstrated that gastric emptying of equal volumes of different solutions depends on their constitution. Those with high caloric and high osmolarity, and with proteins present, 2 hours after ingestion, increased the gastric volumes, which is compatible with the risk of gastric aspiration.

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.

Effects of overnight fasting on handgrip strength in inpatients

Objective:

To investigate the effects of overnight fasting on handgrip strength of adult inpatients.

Methods:

A prospective clinical study enrolling 221 adult patients. The endpoints were handgrip strength obtained by dynamometry in three time points (morning after an overnight fasting, after breakfast and after lunch) and the cumulative handgrip strength (mean of handgrip strength after breakfast and lunch) in the same day. The mean of three handgrip strength measures was considered to represent each time point. A cut-off for the mean overnight fasting handgrip strength at the 50^th percentile (35.5kg for males and 27.7kg for females) was used for comparisons. We registered the age, sex, current and usual weight (kg), weight loss (kg), diagnosis of cancer, nutritional status, elderly frequency, digestive tract symptoms, type of oral diet, and the amount of dinner ingested the night before handgrip strength (zero intake, until 50%, <100% and 100%).

Results:

Handgrip strength evaluated after an overnight fasting (31.2±8.7kg) was lesser when compared with handgrip strength after breakfast (31.6±8.8kg; p=0.01), and with cumulative handgrip strength (31.7±8.8kg; p<0.001). Handgrip strength was greater in patients who ingested 100% (33.2±9.1kg versus 30.4±8.4kg; p=0.03) and above 50% of dinner (32.1±8.4kg versus 28.6±8.8kg; p=0.006). Multivariate analysis showed that ingesting below 50% of dinner, severe malnutrition, and elderly were independent factors for handgrip strength reduction after overnight fasting.

Conclusion:

The muscular function was impaired after an overnight fasting of adult patients hospitalized for medical treatment, especially for those with low ingestion, malnourished and elderly.

Daytime variation of perioperative myocardial injury in non-cardiac surgery and effect on outcome

Objective

Recently, daytime variation in perioperative myocardial injury (PMI) has been observed in patients undergoing cardiac surgery. We aim at investigating whether daytime variation also occurs in patients undergoing non-cardiac surgery.

Methods

In a prospective diagnostic study, we evaluated the presence of daytime variation in PMI in patients at increased cardiovascular risk undergoing non-cardiac surgery, as well as its possible impact on the incidence of acute myocardial infarction (AMI), and death during 1-year follow-up in a propensity score–matched cohort. PMI was defined as an absolute increase in high-sensitivity cardiac troponin T (hs-cTnT) concentration of ≥14 ng/L from preoperative to postoperative measurements.

Results

Of 1641 patients, propensity score matching defined 630 with similar baseline characteristics, half undergoing non-cardiac surgery in the morning (starting from 8:00 to 11:00) and half in the afternoon (starting from 14:00 to 17:00). There was no difference in PMI incidence between both groups (morning: 50, 15.8% (95% CI 12.3 to 20.3); afternoon: 52, 16.4% (95% CI 12.7 to 20.9), p=0.94), nor if analysing hs-cTnT release as a quantitative variable (median morning group: 3 ng/L (95% CI 1 to 7 ng/L); median afternoon group: 2 ng/L (95% CI 0 to 7 ng/L; p=0.16). During 1-year follow-up, the incidence of AMI was 1.2% (95% CI 0.4% to 3.2%) among morning surgeries versus 4.1% (95% CI 2.3% to 6.9%) among the afternoon surgeries (corrected HR for afternoon surgery 3.44, bootstrapped 95% CI 1.33 to 10.49, p log-rank=0.03), whereas no difference in mortality emerged (p=0.70).

Conclusions

Although there is no daytime variation in PMI in patients undergoing non-cardiac surgery, the incidence of AMI during follow-up is increased in afternoon surgeries and requires further study.

Clinical trial registration

NCT02573532;Results.

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.

Preoperative fasting in the department of plastic surgery

Preoperative fasting is necessary to reduce the risk of regurgitation of gastric contents and pulmonary aspiration in patients undergoing general anaesthetic and procedural sedation. Excessive fasting is associated with metabolic, cardiovascular and gastrointestinal complications and patient discomfort. We aimed to reduce the fasting time for patients on the plastic surgery trauma list. Adult inpatients awaiting surgery were asked to complete a preoperative assessment sheet. Questions included the length of preoperative fasting, clarity of instructions and wellness scores. Three cycles of data collection were performed over a 12-month period, patients who declined to participate or were unable to consent were excluded. The first cycle revealed the need for significant improvement. Interventions included staff education, patient information sheets, preoperative drinks, greater availability of ward snacks and improved communication between the ward staff and surgical team through our electronic trauma database. The initial audit of 15 patients revealed a mean fasting time of 16.3 hours for fluid (range 10–22) and a mean of 19.3 hours for solid food (range 10–24). The mean wellness score was 6/10 (10 being very well), 67% of patients felt they were given clear information. The final cycle demonstrated clear improvement in all domains. The mean fasting time declined to 5.1 hours for fluid (range 3–10 hours) and 13 hours for solid food (range 7.5–17 hours). The mean wellness score (10=very well) increased from 6 to 8, the mean thirst score declined from 6.1 to 5.1 and 100% patients felt they had been given clear information. Removal of the traditional ‘NBM from midnight’, patient education, a clear fasting routine with preoperative drinks and improved communication between the full multidisciplinary team has led to a reduction in the fasting times on our trauma list.

[Comparative ultrasound study of gastric emptying between an isotonic solution and a nutritional supplement]

BACKGROUND AND OBJECTIVES

Preoperative fasting may lead to undesirable effects in the surgical patient in whom there is a stimulus to ingesting clear liquids until 2hours before anesthesia. The aim of this study was to evaluate the gastric emptying of two different solutions using ultrasound.

METHODS

In a prospective, randomized, blind study, 34 healthy volunteers ingested 200mL of two solutions without residues in two steps: an isotonic solution with carbohydrates, electrolytes, osmolarity of 292 mOsm.L^-1, and 36 kcal; and other nutritional supplementation with carbohydrates, proteins, electrolytes, osmolarity of 680 mO.L^-1, and 300 kcal. After 2hours, a gastric ultrasound was performed to assess the antrum area and gastric volume, and the relation of gastric volume to weight (vol.w^-1), whose value above 1.5mL.kg^-1 was considered a risk for bronchoaspiration. A p-value <0.05 was considered statistically significant.

RESULTS

There was a significant difference between all parameters evaluated 2hours after the ingestion of nutritional supplementation compared to fasting. The same occurred when the parameters between isotonic solution and nutritional supplementation were compared 2hours after ingestion. Only one patient had vol.w^-1 <1.5mL.kg^-1 2hours after ingestion of nutritional supplementation; and only one had vol.w^-1> 1.5mL.kg^-1 after ingestion of isotonic solution.

CONCLUSION

This study demonstrated that gastric emptying of equal volumes of different solutions depends on their constitution. Those with high caloric and high osmolarity, and with proteins present, 2hours after ingestion, increased the gastric volumes, which is compatible with the risk of gastric aspiration.

Evaluation of preoperative oral carbohydrate administration on insulin resistance in off-pump coronary artery bypass patients: A randomised trial

BACKGROUND

In fasting cardiac surgery patients, preoperative carbohydrate (CHO) drink intake attenuated insulin resistance and improved cardiac metabolism, although its beneficial effects were not evident after cardiac surgery possibly due to cardiopulmonary bypass-related extreme systemic inflammation.

OBJECTIVE

We aimed to evaluate whether preoperative CHO intake affected insulin resistance and free-fatty acid (FFA) concentrations in off-pump coronary revascularisation.

DESIGN

A randomised controlled trial.

SETTING

Primary care in a university hospital in Korea from January 2015 to July 2016.

PATIENTS

Sixty patients who underwent elective multi-vessel off-pump coronary revascularisation were randomised into two groups. Three patients were excluded from analysis and 57 patients completed study.

INTERVENTION

The CHO group received oral CHO (400 ml) the prior evening and 2 to 3 h before surgery, and the control group was fasted from food and water according to standard protocol.

MAIN OUTCOME MEASURES

Insulin resistance was assessed twice, after anaesthetic induction and after surgery via short insulin tolerance test. FFA, C-reactive protein and creatine kinase-myocardial band concentrations were determined serially for 48 h after surgery.

RESULTS

Insulin sensitivity was greater (P = 0.002) and plasma FFA concentrations were lower (P = 0.001) after anaesthetic induction in the CHO group compared with the Control group, although there were no intergroup differences after surgery. The postoperative peak creatine kinase-myocardial band concentration was significantly lower in the CHO group compared with the Control group [8.8 (5.4 to 18.2) vs. 6.4 (3.5 to 9.7) ng ml, P = 0.031].

CONCLUSION

A preoperative CHO supplement significantly reduced insulin resistance and FFA concentrations compared with fasting at the beginning of the surgery, but these benefits were lost after off-pump coronary revascularisation. Despite their transient nature, these beneficial effects resulted in less myocardial injury, mandating further studies focused on the impact of preoperative CHO on myocardial ischaemia and cardiac function after coronary revascularisation.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT 02330263.

Determinants, time trends and dynamic consequences of postoperative hyperglycemia in nondiabetic patients undergoing major elective abdominal surgery: A prospective, longitudinal, observational evaluation

BACKGROUND & AIMS

In retrospective studies an indisputable causal relationship between hyperglycemia and postoperative infections cannot be entirely disclaimed. We aimed investigate whether the time trends of blood glucose levels in the perioperative period could be a determinant of surgery-related infections.

METHODS

Adult patients without diabetes who were candidates for elective major abdominal operation were prospectively enrolled in a longitudinal, observational multicenter study. The blood glucose level was measured every 6 h for 3 days. We calculated the association between blood glucose (BG) levels and the risk of occurrence of surgery-related infections using a joint regression modeling for longitudinal and time-to-event outcomes which accounts for the effect of other risk factors.

RESULTS

Between January 2016 and November 2017, we obtained 6078 BG measures distributed on different time-points in 452 patients. There was a nearly 3-fold increased risk of having hyperglycemia, defined as BG ≥ 125 mg/dL, if the BG level at admission was >100 mg/dL (OR = 2.986, P < 0.001).The hazard of infection for each 10 mg/dL increase of BG levels over time was marginal (HR = 1.065, P = 0.045). The calculated risk of having an infection was 9.6% for BG going from 110 mg/dL during surgery to 84 mg/dL at the end of day 3, 10.5% for BG decreasing from 140 to 114, 11.8% for BG decreasing from 180 to 154 and 24.5% for BG increasing from 80 to 145, 24.7% for BG increasing from 110 to 175, and 25.4% for BG increasing from 140 to 205.

CONCLUSIONS

The time trends of BG - as opposed to the absolute concentration -are major determinants of the risk of postoperative infections.

The effect of preparative solid food status on the occurrence of nausea, vomiting and aspiration symptoms in enhanced CT examination: prospective observational study

OBJECTIVE:

To evaluate the correlation between preparative solid food status and the incidence of nausea, vomiting and aspiration symptoms in contrast-enhanced CT examination, and to provide direction for standardizing the preparative dietary policies.

METHODS:

Patients who underwent routine enhanced CT examination at our hospital between June 2015 and June 2017 (110,836 cases) were enrolled and allocated into solid food fasting group (51,807 cases) and solid food non-fasting group (59,029 cases). Fluids ingestion was not restricted for any case. The differences in the incidence of nausea, vomiting and aspiration symptoms between the two groups of patients with various basic data were compared. The risk factors for the occurrence of nausea, vomiting and aspiration symptoms were analyzed.

RESULTS:

The total incidence of nausea and vomiting was extremely low (0.071%), and no aspiration developed. There was no significant difference in the incidence of nausea and vomiting between the two groups in all respects (p > 0.05). The incidence of nausea and vomiting in patients with an iodine adverse drug reaction (ADR) history was higher than those with other ADR history (p = 0.008) and those without ADR history (p = 0.001).

CONCLUSION:

The occurrence of nausea and vomiting has no correlation with the preparative solid food status. Unless compulsory in clinical needs and constraints and gastrointestinal examination, solid food fasting is not a must in other examinations. Particular attention should be paid to the patients with an iodine ADR history in an effort to prevent possible ADRs.

ADVANCES IN KNOWLEDGE:

The correlation between preparative solid food status and the incidence of nausea, vomiting and aspiration symptoms in contrast-enhanced CT examination were comprehensively analyzed in a large-scale population.

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.

Effects of preoperative oral carbohydrate administration on patient well-being and satisfaction in thyroid surgery

Background

Although the positive effects of preoperative oral carbohydrate administration on clinical outcomes followingmajor surgery have been reported continuously, there are few investigations of them in minor surgical patients. Thepresent study was designed to examine the effects of preoperative oral carbohydrate administration on patient well-beingand satisfaction in patients undergoing thyroidectomy.

Methods

Fifty adults aged 20–65 years and scheduled for elective thyroidectomy in first schedule in the morning wereallocated to one of two groups. The Control group (n = 25) was requested to obey traditional preoperative fasting aftermidnight prior to the day of surgery. The Carbohydrate group (n = 25) also fasted overnight but drank 400 ml of carbohydrate-richdrink 2 hours before induction of anesthesia. Patient well-being (thirst, hunger, mouth dryness, nauseaand vomiting, fatigue, anxiety and sleep quality) and satisfaction were assessed just before the operating room admission(preoperative) and 6 hours following surgery (postoperative). Other secondary outcomes including oral Schirmer’s testand plasma glucose concentrations were also evaluated.

Results

The two groups were homogenous in patient characteristics. Seven parameters representing patient well-beingevaluated on NRS (0–10) and patient satisfaction scored on a 5-point scale were not statistically different between thetwo groups preoperatively and postoperatively. There were no statistically significant differences in secondary outcomes.

Conclusions

Preoperative oral carbohydrate administration does not appear to improve patient well-being and satisfactioncompared with midnight fasting in patients undergoing thyroidectomy in first schedule in the morning.

Introducing the 6-4-0 fasting regimen and the incidence of prolonged preoperative fasting in children

BACKGROUND

Children often starve for longer than recommended by current preoperative fasting guidelines.

AIMS

We studied the effects of implementing a more lenient fasting regimen on the duration of clear fluid fasting, as well as the incidence of extended fasting in children.

METHODS

Preoperative duration of clear fluid fasting was recorded for patients scheduled for procedures in a unit applying the standard 6-4-2 fasting regimen. This group was compared with a cohort in the same unit 1 year after transitioning to a 6-4-0 fasting regimen. The latter includes no limitations on clear fluid intake until the child is called to theater. A third cohort from a unit in which the 6-4-0 fasting regimen has been implemented for over a decade was also studied for comparison.

RESULTS

Patients fasting according to the 6-4-2 fasting regimen (n = 66) had a median fasting time for clear fluids of 4.0 h and a 33.3% incidence of fasting more than 6 h. After transitioning to the 6-4-0 fasting regimen (n = 64), median duration of fasting for clear fluids decreased to 1.0 h, and the incidence of fasting more than 6 h decreased to 6.3%. In the second unit (n = 73), median fasting time was 2.2 h and the proportion of patients fasting more than 6 h was 21.9%.

CONCLUSION

The introduction and implementation of the 6-4-0 fasting regimen reduces median fluid fasting duration and the number of children subjected to extended fasting.

Best practice in major elective rectal/pelvic surgery: enhanced recovery after surgery (ERAS)

Within traditional clinical care, the postoperative recovery after pelvic/rectal surgery has been slow with high morbidity and long hospital stay. The enhanced recovery after surgery program is a multimodal approach to perioperative care designed to accelerate recovery and safely reduce hospital stay. This review will briefly summarize optimal perioperative care, before, during and after surgery in this group of patients and issues related to implementation and audit.

Multimodal Nutritional Management in Primary Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

This study aims at evaluating the effectiveness of a new multimodal nutritional management (MNM) on albumin (ALB) transfusion, the incidence of electrolyte disorders, blood loss, perioperative levels of ALB and electrolyte, length of hospital stay (LOH), and complications in patients following total knee arthroplasty without tourniquet.

METHODS

A total of 162 patients were randomized to receive either the MNM protocol (n = 81, experimental group) or traditional protocol (n = 81, control group). The primary outcomes were the rate and amount of ALB infusion, LOH, total blood loss, maximum hemoglobin drop, allogeneic transfusion rate, and the incidence of electrolyte disorders. The secondary outcomes were levels of ALB and electrolyte at different time points and the incidence of complications.

RESULTS

The rate and amount of ALB transfusion required in MNM group were significantly lower than those in control group (P = .006, P = .021, respectively). LOH was shorter in MNM group (P < .001). Total blood loss and maximum hemoglobin drop were similar. The incidence of kaliopenia and hypocalcemia was lower in MNM group on the first postoperative day (P = .019, P = .028, respectively). Patients in MNM group had higher levels of ALB, sodium, potassium, and calcium than those in control group on the first postoperative day.

CONCLUSION

The MNM protocol can effectively low down the amount of ALB transfusion, the number of patients requiring ALB transfusion, the incidence of electrolyte disorders, and LOH following primary total knee arthroplasty without tourniquet. Patients can obtain a smaller decline in ALB, sodium, potassium, and calcium.

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.

Residual gastric volume evaluation with ultrasonography after ingestion of carbohydrate- or carbohydrate plus glutamine-enriched beverages: a randomized, crossover clinical trial with healthy volunteers

BACKGROUND

- Abbreviation of preoperative fasting to 2 hours with maltodextrin (CHO)-enriched beverage is a safe procedure and may enhance postoperative recovery. Addition of glutamine (GLN) to CHO beverages may include potential benefits to the metabolism. However, by adding a nitrogenous source to CHO beverages, gastric emptying may be delayed and increase the risk of bronchoaspiration during anesthesia.

OBJECTIVE

- In this study of safety, we aimed at investigating the residual gastric volume (RGV) 2 hours after the intake of either CHO beverage alone or CHO beverage combined with GLN.

METHODS

- We performed a randomized, crossover clinical trial. We assessed RGV by means of abdominal ultrasonography (US) in 20 healthy volunteers (10 males and 10 females) after an overnight fast of 8 hours. Then, they were randomized to receive 600 mL (400 mL immediately after US followed by another 200 mL 2 hours afterwards) of either CHO (12.5% maltodextrin) or CHO-GLN (12.5% maltodextrin plus 15 g GLN). Two sequential US evaluations were done at 120 and 180 minutes after ingestion of the second dose. The interval of time between ingestion of the two types of beverages was 2 weeks.

RESULTS

- The mean (SD) RGV observed after 8 hours fasting (13.56±13.25 mL) did not statistically differ (P>0.05) from the RGV observed after ingesting CHO beverage at both 120 (16.32±11.78 mL) and 180 minutes (14.60±10.39 mL). The RGV obtained at 120 (15.63±18.83 mL) and 180 (13.65±10.27 mL) minutes after CHO-GLN beverage also was not significantly different from the fasting condition.

CONCLUSION

- The RGV at 120 and 180 minutes after ingestion of CHO beverage combined with GLN is similar to that observed after an overnight fast.

Effect of Hypoglycemia on the Incidence of Revision in Total Knee Arthroplasty

BACKGROUND

It is well established that diabetic patients undergoing total knee arthroplasty (TKA) are more susceptible to infection, problematic wound healing, and overall higher complication rates. However, a paucity in current literature exists. The purpose of this study was to determine the effect of hypoglycemia on TKA revision (rTKA) incidence by analyzing a national private payer database for procedures performed between 2007 and 2015 Q1 Q2.

METHODS

A retrospective review of a national private payer database within the PearlDiver Supercomputer application for patients undergoing TKA with blood glucose levels from 20 to 219 mg/mL, in 10-mg/mL increments, was conducted. Patients who underwent TKA were identified by Current Procedural Terminology (CPT) and International Classification of Disease (ICD) codes. Glucose ranges were identified by filtering for Logical Observation Identifiers Names and Codes within the PearlDiver database. Patients with diagnosed diabetes mellitus type I or II were excluded by using ICD-9 codes 250.00-250.03, 250.10-250.13, and 250.20-250.21. rTKA causes including mechanical loosening, failure/break, periprosthetic fracture, osteolysis, infection, pain, arthrofibrosis, instability, and trauma were identified with CPT and ICD-9 codes. Statistical analysis was primarily descriptive.

RESULTS

Our query returned 264,824 TKAs, of which 12,852 (4.9%) were revised. Most TKAs were performed with a glucose of 70-99 mg/mL (26.1%), followed by 100-109 mg/mL (18.5%). Patients with TKAs performed with glucose 20-29 mg/mL had the highest rate of revision (17.2%; P < .001). Infection was the most common cause of revision among all glucose ranges (P < .001).

CONCLUSION

Infection remains one of the most common causes of rTKA irrespective of glucose level. Our results suggest that hypoglycemia may increase revision rates among TKA patients. Tight glycemic control before and during surgery may be warranted.

Network meta-analysis of the effect of preoperative carbohydrate loading on recovery after elective surgery

BACKGROUND

Three meta-analyses have summarized the effects of preoperative carbohydrate administration on postoperative outcomes in adult patients undergoing elective surgery. However, these studies could not account for the different doses of carbohydrate administered and the different controls used. Multiple-treatments meta-analysis allows robust synthesis of all available evidence in these situations.

METHODS

Article databases were searched systematically for RCTs comparing preoperative carbohydrate administration with water, a placebo drink, or fasting. A four-treatment multiple-treatments meta-analysis was performed comparing two carbohydrate dose groups (low, 10-44 g; high, 45 g or more) with two control groups (fasting; water or placebo). Primary outcomes were length of hospital stay and postoperative complication rate. Secondary outcomes included postoperative insulin resistance, vomiting and fatigue.

RESULTS

Some 43 trials involving 3110 participants were included. Compared with fasting, preoperative low-dose and high-dose carbohydrate administration decreased postoperative length of stay by 0·4 (95 per cent c.i. 0·03 to 0·7) and 0·2 (0·04 to 0·4) days respectively. There was no significant decrease in length of stay compared with water or placebo. There was no statistically significant difference in the postoperative complication rate, or in most of the secondary outcomes, between carbohydrate and control groups.

CONCLUSION

Carbohydrate loading before elective surgery conferred a small reduction in length of postoperative hospital stay compared with fasting, and no benefit in comparison with water or placebo.

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.

The Influence of Oral Carbohydrate Solution Intake on Stress Response before Total Hip Replacement Surgery during Epidural and General Anaesthesia

OBJECTIVE

The effects of oral carbohydrate solutions, ingested 2 h prior to operation, on stress response were studied in patients undergoing general or epidural anaesthesia.

METHODS

The study was performed on 80 ASA I-II adult patients undergoing elective total hip replacement, which were randomized to four groups (n=20). Group G patients undergoing general anaesthesia fasted for 8 h preoperatively; Group GN patients undergoing general anaesthesia drank oral carbohydrate solutions preoperatively; Group E patients undergoing epidural anaesthesia fasted for 8 h and Group EN patients undergoing epidural anaesthesia drank oral carbohydrate solutions preoperatively. Groups GN and EN drank 800 mL of 12.5% oral carbohydrate solution at 24:00 preoperatively and 400 mL 2 h before the operation. Blood samples were taken for measurements of glucose, insulin, cortisol and IL-6 levels.

RESULTS

The effect of preoperative oral carbohydrate ingestion on blood glucose levels was not significant. Insulin levels 24 h prior to surgery were similar; however, insulin levels measured just before surgery were 2-3 times higher in groups GN and EN than in groups G and E. Insulin levels at the 24(th) postoperative hour in epidural groups were increased compared to those at basal levels, although general anaesthesia groups showed a decrease. From these measurements, only the change in Group EN was statistically significant (p<0.05). Plasma cortisol levels at the 2(nd) peroperative hour were higher in epidural groups than in general anaesthesia groups. Both anaesthesia techniques did not have an effect on IL-6 levels.

CONCLUSION

We concluded that epidural anaesthesia suppressed stress response, although preoperative oral carbohydrate nutrition did not reveal a significant effect on surgical stress response.

Multimodal perioperative care plus immunonutrition versus traditional care in total hip arthroplasty: a randomized pilot study

Background

Multimodal protocols of perioperative care may enhance postoperative recovery. However, limited information is available on preoperative immune and carbohydrate (CHO)-enriched drinks in patients undergoing hip arthroplasty. We aimed to investigate the effect of a multimodal protocol (ACERTO protocol) plus preoperative immune nutrition on the length of stay (LOS) and the postoperative acute phase response of patients undergoing total hip arthroplasty.

Methods

Thirty-two patients (mean age, 58 years; range, 26–85 years; 16 males) were randomized to receive either the ACERTO protocol (n = 15, ACERTO Group), which consisted of 6 h preoperative fasting for solids, an oral drink (200 mL of 12.5 % maltodextrin) up to 2 h before induction of anesthesia, restricted intravenous fluids (only 1000 mL of crystalloid fluid after surgery) and preoperative immune nutrition (600 mL/day of Impact - Nestlé, Brazil) for five days prior to surgery, or traditional care (n = 17; control group), which consisted of 6–8 h preoperative fasting, intravenous hydration until the 1^st postoperative day and no preoperative immune supplementation. The main endpoint was LOS. C-reactive protein (CRP) was the secondary endpoint and was assessed during induction of anesthesia and on postoperative day 2.

Results

Neither deaths nor postoperative complications occurred. The median LOS was 3 (2–5) days in the ACERTO group and 6 (3–8) days in controls (P <0.01). Postoperative CRP was higher in the control group (P <0.01).

Conclusion

The ACERTO multimodal protocol of perioperative care plus preoperative immune nutrition may decrease LOS and postoperative CRP levels in total hip arthroplasty.

Trial registration

Clinical Trials: NCT02580214

Enhanced muscle strength with carbohydrate supplement two hours before open cholecystectomy: a randomized, double-blind study

Objective: to investigate the effects of preoperative fasting abbreviation with oral supplementation with carbohydrate in the evolution of grip strength in patients undergoing cholecystectomy by laparotomy. Methods : we conducted a clinical, randomizeddouble blind study with adult female patients, aged 18-60 years. Patients were divided into two groups: Control Group, with fasting prescription 6-8h until the time of operation; and Intervention Group, which received prescription of fasting for solids 6-8h before surgery, but ingested an oral supplement containing 12.5% carbohydrate, six (400ml) and two (200ml) hours before theprocedure. The handgrip strength was measured in both hands in both groups, at patient's admission (6h before surgery), the immediate pre-operative time (1h before surgery) and 12-18h postoperatively. Results : we analyzed 27 patients, 14 in the intervention group and 13 in the control group. There was no mortality. The handgrip strength (mean [standard deviation]) was significantly higher in the intervention group in the three periods studied, in at least one hand: preoperatively in the dominant hand (27.8 [2.6] vs 24.1 [3.7] kg; p=0.04), in the immediate preoperative in both hands, and postoperatively in the non-dominant hand (28.5 [3.0] vs 21.3 [5.9] kg; p=0.01). Conclusion : the abbreviation of preoperative fasting to two hours with drink containing carbohydrate improves muscle function in the perioperative period.

Improving the outcome of kidney transplantation by ameliorating renal ischemia reperfusion injury: lost in translation?

Kidney transplantation is the treatment of choice in patients with end stage renal disease. During kidney transplantation ischemia reperfusion injury (IRI) occurs, which is a risk factor for acute kidney injury, delayed graft function and acute and chronic rejection. Kidneys from living donors show a superior short- and long-term graft survival compared with deceased donors. However, the shortage of donor kidneys has resulted in expansion of the donor pool by using not only living- and brain death donors but also kidneys from donation after circulatory death and from extended criteria donors. These grafts are associated with an increased sensitivity to IRI and decreased graft outcome due to prolonged ischemia and donor comorbidity. Therefore, preventing or ameliorating IRI may improve graft survival. Animal experiments focus on understanding the mechanism behind IRI and try to find methods to minimize IRI either before, during or after ischemia. This review evaluates the different experimental strategies that have been investigated to prevent or ameliorate renal IRI. In addition, we review the current state of translation to the clinical setting. Experimental research has contributed to the development of strategies to prevent or ameliorate IRI, but promising results in animal studies have not yet been successfully translated to clinical use.

Effects of a New Metabolic Conditioning Supplement on Perioperative Metabolic Stress and Clinical Outcomes: A Randomized, Placebo-Controlled Trial

BACKGROUND

Insulin resistance is a measure of metabolic stress in the perioperative period. Before now, no clinical trial has determined the summative effects of glutamine, L-carnitine, and antioxidants as metabolic conditioning supplements in the perioperative period.

OBJECTIVES

The purpose of this study was to determine the effects of a new conditioning supplement on perioperative metabolic stress and clinical outcomes in non-diabetic patients.

PATIENTS AND METHODS

In this randomized controlled trial, 89 non-diabetic patients scheduled for coronary artery bypass grafting, with ejection fractions above 30%, were selected. Using the balanced block randomization method, the patients were allocated to one of four study arms: 1) SP (supplement/placebo): supplement seven days before and placebo 30 days after the surgery; 2) PS: placebo before and supplement after the surgery; 3) SS: supplement before and after the surgery; and 4) PP: placebo before and after the surgery. The supplement was composed of glutamine, L-carnitine, vitamin C, vitamin E, and selenium, which was manufactured for the first time by this research team. Five blood samples were drawn: seven days preoperatively, at the entrance to the operating room, while leaving the operating room, seven days postoperatively, and 30 days postoperatively. Levels of glucose, insulin, and HbA1c were measured in blood samples. Insulin resistance and sensitivity were calculated using a formula. Surgical complications were assessed 30 days postoperatively. Data analysis was done using one-way ANOVA, the Chi-square test, and a general linear model repeated-measures analysis with Bonferroni adjustment.

RESULTS

Blood glucose levels were increased postoperatively in the four groups (< 0.001), but a significantly higher increase occurred in the PP group compared to the SP (0.027), PS (0.026), and SS (0.004) groups. The superficial wound infection rate was significantly different between the four groups (0.021): 26.08% in PP, 9.09% in SP, 4.54% in PS, and 0% in SS.

CONCLUSIONS

Our new metabolic conditioning supplement, whether given pre- or postoperatively, led to better perioperative glycemic control and decreased postsurgical wound infections in non-diabetic patients.

Intraoperative infusion of branched-chain amino acids in patients undergoing gastrointestinal tumor surgery

Background

The purpose of this study is to investigate the effects of intraoperative infusion of branched-chain amino acids (BCAA) in patients undergoing gastrointestinal tumor surgery.

Methods

Sixty-one patients with gastrointestinal tumors undergoing gastrointestinal surgery were enrolled and randomly assigned to receive an intraoperative infusion of 3-compound BCAA solution (N = 20), amino acids (AA) solution (N = 21), or normal saline (NS) (N = 20). Nasopharyngeal temperature, blood glucose (BG), plasma insulin, and blood free fatty acids (FFA) concentrations were measured at 30 min before and 10 min after induction (T₀,T₁), 30 min and 2 h after skin incision (T₂,T₃), and 1 h after tracheal extubation (T₄). Intensity of shivering and pain was accessed at 1 h after extubation.

Results

The temperature in the BCAA and AA group was significantly higher than that in the NS group at T₄ (P = 0.014 and 0.033). The incidence of shivering in the BCAA and AA group was significantly lower than in the NS group (P = 0.027 and 0.012). BG increased in AA group at T₃ and T₄ (P = 0.001 and 0.045). The plasma insulin concentration increased in the BCAA and AA group from T₁ to T₃. The plasma FFA concentrations in the BCAA group were lower than in the AA and NS group from T₂ to T₄.

Conclusions

Intraoperative BCAA and AA infusion alleviated postoperative hypothermia and shivering. BCAA infusion also inhibited fat mobilization, without adversely affecting blood glucose.

Trial registration

ChiCTR-TRC-14004668

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-015-0751-y) contains supplementary material, which is available to authorized users.

Demonstrating Value: A Case Study of Enhanced Recovery

An enhanced recovery after surgery strategy will be increasingly adopted in the era of value-based care. The various elements in each enhanced recovery after surgery protocol are likely to add value to the overall patient surgical journey. Although the evidence varies considerably based on type of surgery and patient group, the team-based approach of care should be universally applied to patient care. This article provides an overview of up-to-date techniques and methodology for enhanced recovery, including an overview of value-based care, delivery, and the evidence base supporting enhanced recovery after surgery.

Effects of preoperative and intraoperative glucose administration on glucose use and fat catabolism during laparotomy under sevoflurane anesthesia in fasted rats

Preoperative fasting as well as surgical stress significantly modifies metabolisms. Recent studies reported the possible advantageous effects of glucose administration on perioperative metabolisms; however, the underlying mechanisms have not been fully elucidated. Rats were allocated to three groups. During the fasting period, groups A and B were administered water, but group C was administered glucose. During laparotomy and the insulin tolerance test (ITT) under sevoflurane anesthesia, group A was administered saline, but groups B and C were administered glucose. During laparotomy, group C showed higher glucose levels and lower β-hydroxybutyrate (β-OHB) levels than group A, and group B showed more decreases in β-OHB levels than group A without differences in changes in glucose levels. Insulin levels and insulin sensitivity during laparotomy were similar among the three groups. No significant difference in insulin sensitivity was also confirmed in ITT. In conclusion, perioperative glucose administration suppresses lipolysis without affecting insulin secretion and sensitivity.

[Major surgery in two days of hospitalization]

A reduction to 2 days the length of stay after a major surgery is possible by enhancing patient empowerment and decreasing morbidity. A rapid patient's empowerment is obtained by the use of means that reduce the impact of the surgical stress and facilitate the recovery. The decrease in postoperative morbidity is obtained by improving the perioperative quality of care. All of these means are gathered in enhanced recovery programs that are clinical pathways designed by a multidisciplinary and multiprofessional team. Regular audits are mandatory for the sustainability of these programs. Organization of a network between hospital and out-of-hospital caregivers is important in order to secure the patient's return home.

Gastric residual volume by magnetic ressonance after intake of maltodextrin and glutamine: a randomized double-blind, crossover study

CONTEXT

The addition of glutamine in preoperative drinks may enhance the benefits of carbohydrate alone.

OBJECTIVES

To evaluate the gastric residual volume after the intake of a beverage containing carbohydrate plus glutamine.

METHODS

Eleven healthy volunteers (24-30 years-old) were randomized in a crossover fashion to intake 400 mL (4h before) and 200 mL (2h before) of a beverage containing either 12.5% maltodextrin (carbohydrate group) or 12.5% maltodextrin plus 15 g of glutamine (glutamine group) in two different moments 7 days apart. Magnetic ressonance was performed to measure the gastric residual volume (mL) 120 and 180 minutes after the last ingestion.

RESULTS

Gastric residual volume similar to basal condition was found after 2h and 3h of the intake of beverages. There was no difference in the mean ±SD GRV (mL) found at 120 minutes (carbohydrate group: 22.9±16.6 and glutamine group: 19.7±10.7) and at 180 minutes (carbohydrate group: 21.5±24.1 and glutamine group: 15.1±10.1) between the two drinks.

CONCLUSIONS

Gastric emptying is efficient, and occurs in up to two hours after the intake of a beverage containing either carbohydrate alone or carbohydrate associated with glutamine. The addition of glutamine to carbohydrate-enriched drink seems to be safe for the use up to 2h before an operation.

Preoperative carbohydrate treatment for enhancing recovery after elective surgery

BACKGROUND

Preoperative carbohydrate treatments have been widely adopted as part of enhanced recovery after surgery (ERAS) or fast-track surgery protocols. Although fast-track surgery protocols have been widely investigated and have been shown to be associated with improved postoperative outcomes, some individual constituents of these protocols, including preoperative carbohydrate treatment, have not been subject to such robust analysis.

OBJECTIVES

To assess the effects of preoperative carbohydrate treatment, compared with placebo or preoperative fasting, on postoperative recovery and insulin resistance in adult patients undergoing elective surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 3), MEDLINE (January 1946 to March 2014), EMBASE (January 1947 to March 2014), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1980 to March 2014) and Web of Science (January 1900 to March 2014) databases. We did not apply language restrictions in the literature search. We searched reference lists of relevant articles and contacted known authors in the field to identify unpublished data.

SELECTION CRITERIA

We included all randomized controlled trials of preoperative carbohydrate treatment compared with placebo or traditional preoperative fasting in adult study participants undergoing elective surgery. Treatment groups needed to receive at least 45 g of carbohydrates within four hours before surgery or anaesthesia start time.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by at least two review authors, with discrepancies resolved by consensus. Data were abstracted and documented pro forma and were entered into RevMan 5.2 for analysis. Quality assessment was performed independently by two review authors according to the standard methodological procedures expected by The Cochrane Collaboration. When available data were insufficient for quality assessment or data analysis, trial authors were contacted to request needed information. We collected trial data on complication rates and aspiration pneumonitis.

MAIN RESULTS

We included 27 trials involving 1976 participants Trials were conducted in Europe, China, Brazil, Canada and New Zealand and involved patients undergoing elective abdominal surgery (18), orthopaedic surgery (4), cardiac surgery (4) and thyroidectomy (1). Twelve studies were limited to participants with an American Society of Anaesthesiologists grade of I-II or I-III.A total of 17 trials contained at least one domain judged to be at high risk of bias, and only two studies were judged to be at low risk of bias across all domains. Of greatest concern was the risk of bias associated with inadequate blinding, as most of the outcomes assessed by this review were subjective. Only six trials were judged to be at low risk of bias because of blinding.In 19 trials including 1351 participants, preoperative carbohydrate treatment was associated with shortened length of hospital stay compared with placebo or fasting (by 0.30 days; 95% confidence interval (CI) 0.56 to 0.04; very low-quality evidence). No significant effect on length of stay was noted when preoperative carbohydrate treatment was compared with placebo (14 trials including 867 participants; mean difference -0.13 days; 95% CI -0.38 to 0.12). Based on two trials including 86 participants, preoperative carbohydrate treatment was also associated with shortened time to passage of flatus when compared with placebo or fasting (by 0.39 days; 95% CI 0.70 to 0.07), as well as increased postoperative peripheral insulin sensitivity (three trials including 41 participants; mean increase in glucose infusion rate measured by hyperinsulinaemic euglycaemic clamp of 0.76 mg/kg/min; 95% CI 0.24 to 1.29; high-quality evidence).As reported by 14 trials involving 913 participants, preoperative carbohydrate treatment was not associated with an increase or a decrease in the risk of postoperative complications compared with placebo or fasting (risk ratio of complications 0.98, 95% CI 0.86 to 1.11; low-quality evidence). Aspiration pneumonitis was not reported in any patients, regardless of treatment group allocation.

AUTHORS' CONCLUSIONS

Preoperative carbohydrate treatment was associated with a small reduction in length of hospital stay when compared with placebo or fasting in adult patients undergoing elective surgery. It was found that preoperative carbohydrate treatment did not increase or decrease postoperative complication rates when compared with placebo or fasting. Lack of adequate blinding in many studies may have contributed to observed treatment effects for these subjective outcomes, which are subject to possible biases.