New preoperative fasting guidelines in Norway

Enhanced recovery pathways for head and neck surgery with free tissue transfer reconstruction

The enhanced recovery after surgery (ERAS) pathway is designed to facilitate recovery after surgery by packaging evidence-based protocols specific to each aspect of the perioperative period, including the preoperative, intraoperative, postoperative, and post-discharge periods. The ERAS pathway, which was originally developed for use with colonic resection, is now being expanded to include a variety of surgical procedures, and the ERAS Society has published a consensus review of the ERAS pathway for head and neck surgery with free tissue transfer reconstruction (HNS-FTTR). The ERAS pathway for HNS-FTTR consists of various important protocols, including early postoperative mobilization, early postoperative enteral nutrition, abolition of preoperative fasting, preoperative enteral fluid loading, multimodal pain management, and prevention of postoperative nausea and vomiting. In recent years, meta-analyses investigating the utility of the ERAS pathway in head and neck cancer surgery have also been presented, and all reports showed that the length of the postoperative hospital stay was reduced by the implementation of the ERAS pathway. The ERAS pathway is now gaining traction in the field of head and neck surgery; however, the details of its efficacy remain uncertain. We believe the future direction will require research focused on improving the quality of postoperative patient recovery and patient satisfaction. It will be important to use patient-reported outcomes to determine whether the ERAS pathway is actually beneficial.

Even chained acylcarnitines predict long-term cardiovascular prognosis in patients with chest pain and non-obstructive coronary artery disease

Background

Acylcarnitines are essential for mitochondrial fatty acid oxidation. Earlier studies suggest that impaired energy metabolism may be implicated in the pathogenesis of microvascular angina. We explored metabolites from the carnitine pathway as predictors of cardiovascular disease (CVD) - and all-cause mortality among patients with non-obstructive coronary artery disease (NOCAD).

Methods

A total of 1046 patients with suspected stable coronary syndrome underwent coronary angiography during 2000–2004, with findings of NOCAD. Serum levels of 8 selected carnitine metabolites were analyzed through liquid chromatography tandem mass spectrometry. Associations with CVD- and all-cause mortality were assessed by multivariable Cox regression models.

Results

Median age at inclusion was 57 years. 51.5% were men. During median (25th- 75th percentiles), 14.1 (13.2–15.4) years of follow-up, 5.7% of the participants died from CVD and the incidence of all-cause mortality was 17.3%. Serum acetyl, octanoyl- and palmitoylcarnitine predicted CVD mortality with multivariable HR and 95% CI (per SD increment log transformed) of 1.36 (1.01–1.83), 1.49 (1.15–1.93) and 2.07 (1.49–2.85), p ≤ 0.04, respectively. Higher serum acetyl- and palmitoylcarnitines were also associated with increased risk of all-cause mortality (HR (95% CI): 1.27 (1.01–1.50), and 1.51 (1.26–1.81), p ≤ 0.007. Baseline levels of the precursors trimethyllysine and ƴ-butyrobetaine, carnitine or the odd chained propionylcarnitine and (iso)valerylcarnitine were not associated with adverse outcomes.

Conclusion

Elevated serum even-chained acylcarnitines predicted adverse long-term prognosis in NOCAD. The strongest risk estimates were observed for palmitoylcarnitine, which predicted both CVD- and all-cause mortality after extensive multivariable adjustments. Underlying pathomechanisms should be further elucidated.

ESPEN practical guideline: Clinical nutrition in surgery

Early oral feeding is the preferred mode of nutrition for surgical patients. Avoidance of any nutritional therapy bears the risk of underfeeding during the postoperative course after major surgery. Considering that malnutrition and underfeeding are risk factors for postoperative complications, early enteral feeding is especially relevant for any surgical patient at nutritional risk, especially for those undergoing upper gastrointestinal surgery. The focus of this guideline is to cover both nutritional aspects of the Enhanced Recovery After Surgery (ERAS) concept and the special nutritional needs of patients undergoing major surgery, e.g. for cancer, and of those developing severe complications despite best perioperative care. From a metabolic and nutritional point of view, the key aspects of perioperative care include the integration of nutrition into the overall management of the patient, avoidance of long periods of preoperative fasting, re-establishment of oral feeding as early as possible after surgery, the start of nutritional therapy immediately if a nutritional risk becomes apparent, metabolic control e.g. of blood glucose, reduction of factors which exacerbate stress-related catabolism or impaired gastrointestinal function, minimized time on paralytic agents for ventilator management in the postoperative period, and early mobilization to facilitate protein synthesis and muscle function.

Enhanced Recovery After Surgery (ERAS®) in thoracic surgical oncology

Enhanced recovery after surgery (ERAS®) is a strategy that seeks to reduce patients’ perioperative stress response, thereby reducing potential complications, decreasing hospital length of stay and enabling patients to return more quickly to their baseline functional status. The concept was introduced in the late 1990s and was first adopted for use with patients undergoing open colorectal surgery. Since that time, the concept of ERAS has spread to multiple surgical specialties. This article explores the key elements for patient care using an ERAS protocol applied to minimally invasive thoracic surgery.

Serum Carnitine Metabolites and Incident Type 2 Diabetes Mellitus in Patients With Suspected Stable Angina Pectoris

CONTEXT

Carnitine and its metabolites are centrally involved in fatty acid metabolism. Although elevated circulating concentrations have been observed in obesity and insulin resistance, prospective studies examining whether these metabolites are associated with incident type 2 diabetes mellitus (T2D) are sparse.

OBJECTIVE

We performed a comprehensive evaluation of metabolites along the carnitine pathway relative to incident T2D.

DESIGN

A total of 2519 patients (73.1% men) with coronary artery disease, but without T2D, were followed for median 7.7 years until the end of 2009, during which 173 (6.9%) new cases of T2D were identified. Serum levels of free carnitine, its precursors trimethyllysine (TML) and γ-butyrobetaine, and the esters acetyl-, propionyl-, (iso)valeryl-, octanoyl-, and palmitoylcarnitine were measured by liquid chromatography/tandem mass spectrometry. Risk associations were explored by logistic regression and reported per (log-transformed) standard deviation increment.

RESULTS

Median age at inclusion was 62 years and median body mass index (BMI) 26.0 kg/m2. In models adjusted for age, sex, fasting status, BMI, estimated glomerular filtration rate, glycated hemoglobin A1c, triglyceride and high-density lipoprotein cholesterol levels, and study center, serum levels of TML and palmitoylcarnitine associated positively [odds ratio (95% confidence interval), 1.22 (1.04 to 1.43) and 1.24 (1.04 to 1.49), respectively], whereas γ-butyrobetaine associated negatively [odds ratio (95% confidence interval) 0.81 (0.66 to 0.98)] with T2D risk.

CONCLUSION

Serum levels of TML, γ-butyrobetaine, and the long-chained palmitoylcarnitine predict long-term risk of T2D independently of traditional risk factors, possibly reflecting dysfunctional fatty acid metabolism in patients susceptible to T2D development.

Serum Acylcarnitines and Risk of Cardiovascular Death and Acute Myocardial Infarction in Patients With Stable Angina Pectoris

Background

Excess levels of serum acylcarnitines, which are intermediate products in metabolism, have been observed in metabolic diseases such as type 2 diabetes mellitus. However, it is not known whether acylcarnitines may prospectively predict risk of cardiovascular death or acute myocardial infarction in patients with stable angina pectoris.

Methods and Results

This study included 4164 patients (median age, 62 years; 72% men). Baseline serum acetyl‐, octanoyl‐, palmitoyl‐, propionyl‐, and (iso)valerylcarnitine were measured using liquid chromatography/tandem mass spectrometry. Hazard ratios (HRs) and 95% CIs for quartile 4 versus quartile 1 are reported. The multivariable model included age, sex, body mass index, fasting status, current smoking, diabetes mellitus, apolipoprotein A1, apolipoprotein B, creatinine, left ventricular ejection fraction, extent of coronary artery disease, study center, and intervention with folic acid or vitamin B6. During median 10.2 years of follow‐up, 10.0% of the patients died of cardiovascular disease and 12.8% suffered a fatal or nonfatal acute myocardial infarction. Higher levels of the even‐chained acetyl‐, octanoyl‐, and palmitoyl‐carnitines were significantly associated with elevated risk of cardiovascular death, also after multivariable adjustments (HR [95% CI]: 1.52 [1.12, 2.06]; P=0.007; 1.73 [1.23, 2.44]; P=0.002; and 1.61 [1.18, 2.21]; P=0.003, respectively), whereas their associations with acute myocardial infarction were less consistent.

Conclusions

Among patients with suspected stable angina pectoris, elevated serum even‐chained acylcarnitines were associated with increased risk of cardiovascular death and, to a lesser degree with acute myocardial infarction, independent of traditional risk factors.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00354081.

Perioperative care with fast-track management in patients undergoing pancreaticoduodenectomy

BACKGROUND

It has been considered that allowing patients to return to daily life earlier after surgery helps recovery of physiological function and reduces postoperative complications and hospital stay. We investigated the usefulness of fast-track management in perioperative care of patients undergoing pancreaticoduodenectomy (PD).

METHODS

Patients (n = 90) who received conventional perioperative management from 2005 to 2009 were included as the 'conventional group' (historical control group), and patients who received perioperative care with fast-track management (n = 100) from 2010 to March 2013 were included as the 'fast-track group'. To evaluate the efficacy of perioperative care with fast-track management, the incidence of postoperative complications and the length of hospital stay were compared between the two groups (comparative study). For statistical analysis, univariate analysis was performed using the χ (2) test or Fisher's exact test.

RESULTS

There was no significant difference between the two groups in sex, mean age, presence/absence of diabetes mellitus, preoperative drainage for jaundice, previous disease, operative procedure, mean duration of operation, or blood loss (p < 0.01). The incidence of surgical site infection in the conventional group and fast-track group was 28.9 and 14.0 %, respectively, with a significant difference between the two groups (p = 0.019). In addition, the incidence of pancreatic fistula (grade B, C) significantly differed between the two groups (27.8 % in the conventional group, 9.0 % in the fast-track group; p = 0.001). The mean postoperative hospital stay was 36.3 days in the conventional group and 21.9 days in the fast-track group (p < 0.001).

CONCLUSIONS

Perioperative care with fast-track management may reduce postoperative complications and decrease the length of hospital stay in patients undergoing PD.

[Preoperative fasting guidelines: an update]

Anesthesiology societies have issued various guidelines on preoperative fasting since 1990, not only to decrease the incidence of lung aspiration and anesthetic morbidity, but also to increase patient comfort prior to anesthesia. Some of these societies have been updating their guidelines, as such that, since 2010, we now have 2 evidence-based preoperative fasting guidelines available. In this article, an attempt is made to review these updated guidelines, as well as the current instructions for more controversial patients such as infants, the obese, and a particular type of ophthalmic surgery.

Preparation of patients submitted to thyroidectomy with oral glucose solutions

The AIM OF THE STUDY was to determine postoperative insulin-resistance in patients subject to total thyroidectomy, the prevalence of subjective feelings of hunger immediately before surgery, and the incidence of nausea/vomiting after surgery in patients prepared for elective operations by means of oral glucose solutions.

MATERIAL AND METHODS

The study group comprised 115 patients, including 71 patients prepared for surgery by means of oral glucose solutions (12.5% glucose) administered 12 and 3 hours before the procedure, at a dose of 800 and 400 ml. The control group comprised 44 patients prepared for surgery by means of the traditional manner- the last meal was served before 2pm the day before the surgical procedure, while fluids before 10pm. Considering both groups, we evaluated glucose and insulin levels three times, as well as determined the insulin-resistance ratio (HOMA-IR) 24 before, and 12 hours and 7 days after surgery. The incidence of nausea and vomiting after surgery, and the subjective feeling of hunger before surgery were also evaluated.

RESULTS

Statistically significant differences considering insulin level and HOMA-IR values were observed during the II and III measurements. The glucose and insulin values, and the HOMA-IR insulin-resistance ratio, showed no statistically significant differences during measurement I. No statistically significant glucose level differences were observed during measurements II and III. A significantly greater subjective feeling of hunger before surgery and nausea/vomiting afterwards were observed in the control group.

CONCLUSIONS

The preparation of patients with oral glucose solutions decreases the incidence of postoperative (thyroidectomy) insulin-resistance, and occurrence of nausea/vomiting during the postoperative period.

Reducing preoperative fasting in elective adult surgical patients: a case-control study

BACKGROUND

The practice of fasting from midnight prior to surgery is an outdated one.

AIMS

The aim of this study was to assess the impact of an evidence-based protocol for reduced preoperative fasting on fasting times, patient safety, and comfort.

METHODS

A non-randomised case-control study of preoperative fasting times among adult surgical patients undergoing elective procedures was conducted. Consecutive patients were allocated to a reduced preoperative fasting protocol allowing fluids and solids up to 2 and 6 h prior to anaesthesia, respectively (n = 21). These were compared to control patients identified from an historic study of preoperative fasting times who followed the traditional fast from midnight (n = 29). Fasting times and details of patients' subjective comfort were collected using an interview-assisted questionnaire. Incidence of intraoperative aspirations was obtained from anaesthetic records.

RESULTS

Significant reductions in fasting times for fluids (p = 0.000) and solids (p = 0.000) were achieved following implementation of the fasting protocol. Less preoperative thirst (0.000), headache (0.012) and nausea (0.015) were reported by those who had a shorter fast. Intraoperative aspiration did not occur in either group.

CONCLUSION

Implementation of this protocol for reduced preoperative fasting achieved an appreciable reduction in fasting times and enhanced patient comfort. Patient safety was not compromised. Further modifications of our protocols are necessary to meet the international best practice. We recommend its implementation across all surgical groups in our institution.

The impact and safety of preoperative oral or intravenous carbohydrate administration versus fasting in colorectal surgery--a randomized controlled trial

BACKGROUND AND AIMS

Increasing evidence suggests that preoperative fasting, as was the clinical practice for many decades, might be associated with untoward consequences and that a standardized preoperative intake of nutrients might be advantageous; this is a component of the enhanced recovery after surgery (ERAS) concept. Thus, in a randomized controlled trial we compared preoperative fasting with preoperative preparation with either oral or intravenous intake of carbohydrates, minerals and water. Biochemical, psychosomatic, echocardiographic and muscle-power parameters were assessed in surgical patients with colorectal diseases during the short-term perioperative period. We also assessed the safety of peroral intake shortly before surgery.

METHODS

A total of 221 elective colorectal surgery patients in this bicentric, randomized, prospective and blinded clinical trial were divided into three groups: A - patients fasting from midnight (control group); B - patients supported preoperatively by glucose, magnesium and potassium administered intravenously; C - patients supported preoperatively by oral consumption of a specifically composed solution (potion).

RESULTS

The general perioperative clinical status of patients in groups C and B was significantly better than those in group A. Psychosomatic conditions postoperatively were found to be best in group C (P < 0.029). The rise in the index of insulin resistance (QUICKI) from the preoperative to the postoperative state was significant in group A (P < 0.05). The systolic and diastolic function of the left ventricle improved postoperatively in group C vs. group A (P < 0.04), and the ejection fraction was also significantly higher postoperatively in group C vs. group A (P < 0.03). The gastric residual volume was 5 ml and the pH of stomach juice was 3.5-5 in all groups without statistically significant difference. No difference was found in the length of hospital stay or the rate of complications.

CONCLUSIONS

Preoperative fasting does not confer any benefit or advantage for surgical patients. In contrast, consumption of an appropriate potion composed of water, minerals and carbohydrates offers some protection against surgical trauma in terms of metabolic status, cardiac function and psychosomatic status. Peroral intake shortly before surgery did not increase gastric residual volume and was not associated with any risk.

Short-term starvation and mitochondrial dysfunction - a possible mechanism leading to postoperative insulin resistance

BACKGROUND

Preoperative starvation results in the development of insulin resistance. Measures to attenuate the development of insulin resistance, such as preoperative carbohydrate loading, lead to clinical benefits. However, the mechanisms that underlie the development of insulin resistance during starvation and its attenuation by preoperative carbohydrate loading remain to be defined. Insulin resistance associated with type 2 diabetes and ageing has been linked to mitochondrial dysfunction. The metabolic consequences of preoperative starvation and carbohydrate loading and mechanisms linking insulin resistance to impaired mitochondrial function are discussed.

METHODS

Searches of the Medline and Science Citation Index databases were performed using various key words in combinations with the Boolean operators AND, OR and NOT. Key journals, nutrition and metabolism textbooks and the reference lists of key articles were also hand searched.

RESULTS

Animal studies have shown that short-term energy deprivation decreases mitochondrial ATP synthesis capacity and complex activity, and increases oxidative injury. Furthermore, evidence from human studies suggests that the development of insulin resistance during starvation may be linked to impaired mitochondrial function.

CONCLUSIONS

There is evidence from animal studies that short-term starvation causes mitochondrial dysfunction. Future studies should investigate whether mitochondrial dysfunction underlies the development of insulin resistance in patients undergoing elective surgery.

Effect of the preliminary hydration on gastric emptying time for water in healthy volunteers

BACKGROUND

International guidelines allow healthy patients to drink clear liquid up to 2 h before general anesthesia. Recently, MRI measurements have been used for tracking gastric volume in humans. Hence, we used MRI to examine the gastric emptying rate of water in healthy volunteers with or without prior water loading.

METHODS

Fifteen healthy volunteers were enrolled. The participants had MRI examinations on separate days under two different protocols: The preliminary hydration protocol (group H) and the water restriction protocol (group R). After the intake of water, MR imaging was performed every 10 min for 60 min. The gastric content was outlined as area of interest (AOI), and the AOI area of each slice was summated to calculate the volume of gastric contents.

RESULTS

The 50% reduction time of gastric volume in group R and group H was 18+/-9 and 16+/-8 min (mean+/-SD), respectively. There were no significant changes between the two groups.

CONCLUSION

The gastric emptying time for water evaluated with MRI was not affected by preliminary hydration, which shows the safety of repeated oral hydrations in the pre-operative period.

The resistance to changing guidelines – what are the challenges and how to meet them

Bridging the gap between scientific evidence and its practical application is of the utmost importance in improving the quality of care and increasing patient safety. Guidelines based on evidenced-based medicine (EBM) have led to improved performances and better outcomes. However, even though scientific data are available, resistance to adopting evidence-based guidelines is still enormous. Significant barriers hinder the introduction of best medical practice into the daily clinical routine. The barriers to implementing change are complex, multifunctional, and influenced on many levels by various interests both inside and outside the health-care system. Political, organizational, financial, cultural and scientific interests are regarded as being as important as the perception of patients and health workers. Strategies need to be planned which take account of the multidimensional character of quality of care and incorporate it at the various levels. The conclusion, therefore, is that we need to combine methods and tools to tailor our interventions to the patient's needs.

Fasting from midnight – the history behind the dogma

The purpose of this chapter is to review historical fasting guidelines and how the dogma of fasting from midnight arose and came to be challenged by randomized clinical trials of preoperative clear liquids versus overnight fast. Medical and anaesthesia textbooks and journals from the 19th and 20th centuries were consulted, and the results of clinical trials and the reaction to them are reviewed. The dogma appeared to result from extrapolation of pulmonary aspiration risk in 'full-stomach' emergency cases to healthy elective cases. This was reinforced when 25 mL in the stomach, present in half of all healthy fasting patients, was used as a surrogate marker for high risk of aspiration. Subsequent large-scale studies showed the risk to be minimal. Meta-analysis of randomized clinical trials demonstrated the safety of clear oral liquids until 2 hr preoperatively in healthy patients undergoing elective surgery. Reaction was cautious but led to eventual acceptance of evidence-based fasting guidelines.

ESPEN Guidelines on Enteral Nutrition: Surgery including organ transplantation

Enhanced recovery of patients after surgery ("ERAS") has become an important focus of perioperative management. From a metabolic and nutritional point of view, the key aspects of perioperative care include: Enteral nutrition (EN) by means of oral nutritional supplements (ONS) and if necessary tube feeding (TF) offers the possibility of increasing or ensuring nutrient intake in cases where food intake is inadequate. These guidelines are intended to give evidence-based recommendations for the use of ONS and TF in surgical patients. They were developed by an interdisciplinary expert group in accordance with officially accepted standards and are based on all relevant publications since 1980. The guideline was discussed and accepted in a consensus conference. EN is indicated even in patients without obvious undernutrition, if it is anticipated that the patient will be unable to eat for more than 7 days perioperatively. It is also indicated in patients who cannot maintain oral intake above 60% of recommended intake for more than 10 days. In these situations nutritional support should be initiated without delay. Delay of surgery for preoperative EN is recommended for patients at severe nutritional risk, defined by the presence of at least one of the following criteria: weight loss >10-15% within 6 months, BMI<18.5 kg/m(2), Subjective Global Assessment Grade C, serum albumin <30 g/l (with no evidence of hepatic or renal dysfunction). Altogether, it is strongly recommended not to wait until severe undernutrition has developed, but to start EN therapy early, as soon as a nutritional risk becomes apparent.

Preoperative fasting: an outdated concept?

Recent studies have shown that fasting during the preoperative period for elective surgery induces a metabolic state that seems unfavorable for patients. Results from animal studies indicate that rapid depletion of liver glycogen before surgery leads to mobilization of muscle glycogen after surgery, in turn leading to reduced muscle strength. Depletion of liver glycogen also influences the function of the mononuclear phagocytic system (MPS), which is located predominantly in the liver. The MPS is essential in restricting endotoxin, which may translocate from the gut. In addition, surgery per se puts a substantial physical strain on the patient, and fasting may adversely affect the metabolic response to surgery. This paper presents experimental and clinical data that, when combined together, prove that fasting before surgery has adverse consequences for the patient.

Pre-operative fasting guidelines: an update

Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children <6 months, most recommendations now allow breast- or formula milk feeding up to 4 h before anaesthesia. Recently, the concept of pre-operative oral nutrition using a special carbohydrate-rich beverage has also gained support and been shown not to increase gastric fluid volume or acidity. Based on the available literature, our Task Force has produced new consensus-based Scandinavian guidelines for pre-operative fasting. What is still not clear is to what extent the new liberal fasting routines should apply to patients with functional dyspepsia or systematic diseases such as diabetes mellitus. Other still controversial areas include the need for and effect of fasting in emergency patients, women in labour and in association with procedures done under 'deep sedation'. We think more research on the effect of various fasting regimes in subpopulations of patients is needed before we can move one step further towards completely evidence-based pre-operative fasting guidelines.

Enhanced recovery after surgery: a consensus review of clinical care for patients undergoing colonic resection

BACKGROUND & AIMS

Clinical care of patients undergoing colonic surgery differs between hospitals and countries. In addition, there is considerable variation in rates of recovery and length of hospital stay following major abdominal surgery. There is a need to develop a consensus on key elements of perioperative care for inclusion in enhanced recovery programmes so that these can be widely adopted and refined further in future clinical trials.

METHODS

Medline database was searched for all clinical studies/trials relating to enhanced recovery after colorectal resection. Relevant papers from the reference lists of these articles and from the authors' personal collections were also reviewed. A combination of evidence-based and consensus methodology was used to develop the resulting enhanced recovery after surgery (ERAS) clinical care protocol.

RESULTS AND CONCLUSIONS

Within traditional perioperative practice there is considerable evidence supporting a range of manoeuvres which, in isolation, may improve individual aspects of recovery after colonic surgery. The present manuscript reviews these issues in detail. There is also growing evidence that an integrated multimodal approach to perioperative care can result in an overall enhancement of recovery. However, effects on major morbidity and mortality remain to be determined. A protocol is presented which is in current use by the ERAS Group and may provide a standard of care against which either current or future novel elements of an enhanced recovery approach can be tested for their effect on outcome.

Preoperative fasting

BACKGROUND AND METHODS

To avoid pulmonary aspiration, fasting after midnight has become standard in elective surgery, but recent studies have found no scientific support for this practice. Several anaesthesia societies now recommend a 2-h preoperative fast for clear fluids and a 6-h fast for solids in most elective patients. The literature supporting such fasting recommendations was reviewed.

RESULTS

The recommendations are safe and improve well-being before operation, mainly by reducing thirst. A carbohydrate-rich beverage given before anaesthesia and surgery alters metabolism from the overnight fasted to the fed state. This reduces the catabolic response (insulin resistance) after operation, which may have implications for postoperative recovery.

CONCLUSION

Most patients having elective operations can be allowed a free intake of clear fluids up to 2 h before anaesthesia. Preoperative carbohydrates reduce postoperative insulin resistance.