Fasting from midnight – the history behind the dogma

Intermittent fasting and the liver: Focus on the Ramadan model

Intermittent fasting (IF) is an intervention that involves not only dietary modifications but also behavioral changes with the main core being a period of fasting alternating with a period of controlled feeding. The duration of fasting differs from one regimen to another. Ramadan fasting (RF) is a religious fasting for Muslims, it lasts for only one month every one lunar year. In this model of fasting, observers abstain from food and water for a period that extends from dawn to sunset. The period of daily fasting is variable (12-18 hours) as Ramadan rotates in all seasons of the year. Consequently, longer duration of daily fasting is observed during the summer. In fact, RF is a peculiar type of IF. It is a dry IF as no water is allowed during the fasting hours, also there are no calorie restrictions during feeding hours, and the mealtime is exclusively nighttime. These three variables of the RF model are believed to have a variable impact on different liver diseases. RF was evaluated by different observational and interventional studies among patients with non-alcoholic fatty liver disease and it was associated with improvements in anthropometric measures, metabolic profile, and liver biochemistry regardless of the calorie restriction among lean and obese patients. The situation is rather different for patients with liver cirrhosis. RF was associated with adverse events among patients with liver cirrhosis irrespective of the underlying etiology of cirrhosis. Cirrhotic patients developed new ascites, ascites were increased, had higher serum bilirubin levels after Ramadan, and frequently developed hepatic encephalopathy and acute upper gastrointestinal bleeding. These complications were higher among patients with Child class B and C cirrhosis, and some fatalities occurred due to fasting. Liver transplant recipients as a special group of patients, are vulnerable to dehydration, fluctuation in blood immunosuppressive levels, likelihood of deterioration and hence observing RF without special precautions could represent a real danger for them. Patients with Gilbert syndrome can safely observe RF despite the minor elevations in serum bilirubin reported during the early days of fasting.

Preoperative fasting and the risk of pulmonary aspiration-a narrative review of historical concepts, physiological effects, and new perspectives

In the early days of anaesthesia, the fasting period for liquids was kept short. By the mid-20th century 'nil by mouth after midnight' had become routine as the principles of the management of 'full stomach' emergencies were extended to include elective healthy patients. Back then, no distinction was made between the withholding of liquids and solids. Towards the end of the last century, recommendations of professional anaesthesiology bodies began to reduce the fasting time of clear liquids to 2 h. This reduction in fasting time was based on the understanding that gastric emptying of clear liquids is rapid, exponential, and proportional to the current filling state of the stomach. Furthermore, there was no evidence of a link between drinking clear liquids and the risk of aspiration. Indeed, most instances of aspiration are caused by failure to identify aspiration risk factors and adjust the anaesthetic technique accordingly. In contrast, long periods of liquid withdrawal cause discomfort and may also lead to serious postoperative complications. Despite this, more than two decades after the introduction of the 2 h limit, patients still fast for a median of up to 12 h before anaesthesia, mainly because of organisational issues. Therefore, some hospitals have decided to allow patients to drink clear liquids within 2 h of induction of anaesthesia. Well-designed clinical trials should investigate whether these concepts are safe in patients scheduled for anaesthesia or procedural sedation, focusing on both aspiration risk and complications of prolonged fasting.

Liberal Preoperative Fasting in Adults Undergoing Elective Surgery: A Scoping Review Protocol

Background

Prolonged fasting before surgery has negative effects on the physiology and psychology of patients. Preoperative liberal fasting proposes that patients can drink clear liquids before entering the operating theater, challenging the guideline strategy of a two-hour preoperative liquid fast for adults. In recent years, there have been an increasing number of studies on liberal preoperative fasting in adults. However, currently there is no consensus on the safe amount of fluid consumed, adverse effects, or benefits of this new policy.

Objective

This scoping review protocol will map the existing evidence of liberal preoperative fasting in adults undergoing elective surgery for clinical practice, to summarize more scientific evidence to healthcare professionals when providing perioperative care. Methods and Analysis. The methodology will follow the six steps of the Arksey and O'Malley methodological framework and be guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review. A comprehensive search of six databases will be performed from their inception to 31 May 2023 to identify suitable English studies. Two trained investigators will independently screen and extract the data, and any disagreements will be judged by a third investigator. The results of the study will be presented as graphs or tables. Ethics and Dissemination. This scoping review only examines literature in the database, without reference to human or animal studies, and therefore does not require ethical approval. The findings of this scoping review will be published in peer-reviewed journals or presented at conferences. The Registration Number. This scoping review has been registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/PMW7C).

RESIDUAL GASTRIC VOLUME IN MORBIDLY OBESE DIABETICS AFTER AN OVERNIGHT FASTING OR 3 HOURS OF A CARBOHYDRATE-ENRICHED SUPPLEMENT: A RANDOMIZED CROSSOVER PILOT STUDY

BACKGROUND

To reduce the risk of regurgitation during anesthesia for elective procedures, residual gastric volumes (RGV) have traditionally been minimized by overnight fasting. Prolonged preoperative fasting presents some adverse consequences and has been abandoned for most surgical procedures, except for obese and/or diabetic patients.

AIMS

The aim of this study was to assess the RGV in morbidly obese diabetic patients after traditional or abbreviated fasting.

METHODS

This study was approved by the Ethics Committee for Research with Human Beings from the Federal University of Mato Grosso, under number 179.017/2012. This is a prospective, randomized, and crossover design study in eight morbidly obese type II diabetic patients. RGV was measured endoscopically after either traditional overnight fasting of at least 8 hours, or after abbreviated fasting of 6 hours for solids and 3 hours for a drink containing water plus 25 g (12.5%) of maltodextrin. Data were expressed as mean and range and differences were compared with paired t-tests at p<0.05.

RESULTS

The study population had a mean age of 41.5 years (28-53), weight of 135 kg (113-196), body mass index of 48.2 kg/m2 (40-62.4), and type II diabetes for 4.5 years (1-10). The RGV after abbreviated fasting was 21.5 ml (5-40) vs 26.3 ml (7-65) after traditional fasting. This difference was not significant (p=0.82).

CONCLUSIONS

Gastric emptying in morbidly obese diabetic patients is similar after either traditional or abbreviated fasting with a carbohydrate drink.

Effects of caloric and nutrient content of oral fluids on gastric emptying in volunteers: a randomised crossover study

BACKGROUND

Previous studies demonstrated conflicting results regarding the determinants of gastric emptying for fluids. Our aim was to compare gastric emptying times of fluids with different caloric and nutrient content.

METHODS

Healthy adult volunteers underwent gastric ultrasound assessment for 4 h after consuming beverages with different caloric and nutrient content using a crossover design (oat drink with 3% fat [310 kcal], mango juice [310 kcal], oat drink with 0.5% fat [185 kcal], and blackcurrant juice [175 kcal]). Gastric emptying time, gastric content volume, and the area under the curve (AUC) of gastric content volume-time profiles were calculated.

RESULTS

Eight females and eight males completed the study protocol. The mean (sd) gastric emptying times were 89 (32) min for blackcurrant juice, 127 (54) min for oat drink with 0.5% fat, 135 (36) min for mango juice, and 152 (40) min for oat drink with 3% fat. Gastric emptying times were slower for oat drink with 3% fat (P=0.007) and mango juice (P=0.025) than for blackcurrant juice. At 1 h after ingestion, gastric content volume was greater for mango juice (P=0.021) and oat drink with 3% fat (P=0.003) than for blackcurrant juice. The AUC was greater for oat drink with 3% fat than mango juice (P=0.029), oat drink with 0.5% fat (P=0.004), and blackcurrant juice (P=0.002), and for mango juice than blackcurrant juice (P=0.019).

CONCLUSIONS

Caloric and nutrient content significantly affected gastric emptying times. A high-calorie fruit juice (mango) exhibited delayed emptying times compared with a low-calorie fruit juice (blackcurrant).

CLINICAL TRIAL REGISTRATION

ISRCTN17147574.

Validation of a novel patient satisfaction questionnaire for preoperative fasting in cataract surgery: a discrimination analysis

OBJECTIVE

Preoperative fasting is routinely performed to prevent anaesthesia-related pulmonary aspiration. To capture patients' experiences with preoperative fasting, a 13-item questionnaire was developed and validated using Rasch analysis and shortened to 6 items. This extension study aims to assess this questionnaire's ability to discriminate between participants with a short versus long duration of fasting and early versus late day surgery.

DESIGN

Single-centred cross-sectional study.

PARTICIPANTS

Subjects were recruited via consecutive sampling of cataract patients on surgery day at Kensington Eye Institute in Toronto from February to December 2019.

METHODS

A validated preoperative fasting questionnaire was administered. Discriminative ability was assessed by comparing responses in patients scheduled for surgery in the morning (8:00 am-12:00 pm) versus afternoon (12:00 pm-3:30 pm) and fasting for short (≤8 hours) versus long (>8 hours) duration. Diagnostic ability of the 6-item questionnaire relative to the 13-item questionnaire was assessed with receiver operating characteristics curve analysis.

RESULTS

A total of 164 patients (mean age 70.8 ± 10.0 years; 57% female) were included. Total scores of patients having surgery in the morning were greater (i.e., less fasting-related burden) than in the afternoon (p = 0.04). There was no significant difference in scores between patients fasting for a short versus long duration (p > 0.05). Receiver operating characteristics curve analysis showed excellent diagnostic ability of the 6-item questionnaire relative to the 13-item version (area under the curve = 0.964).

CONCLUSION

The 6-item questionnaire for fasting-related burden has excellent discriminative ability between early versus late surgery patients. The time fasting while awake may be a more relevant predictor of fasting-related burden relative to the total duration of fasting.

Effects of a Preoperative Carbohydrate Load on Postoperative Recovery in Children: A Randomised, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Nausea and vomiting are common causes for prolonged postoperative length of hospital stay (LOS) in children. A preoperative carbohydrate load may reduce postoperative nausea and vomiting by improving the perioperative metabolic state. The aim of this study was to determine if a preoperative carbohydrate-containing drink would lead to an improvement in the perioperative metabolic state and consequently reduce the incidence of postoperative nausea, vomiting and LOS in children undergoing day-case surgical procedures.

METHOD

Randomised, double-blind, placebo-controlled trial involving children aged 4 to 16-years undergoing day-case surgical procedures. Patients were randomised to receive a carbohydrate-containing drink or a placebo. During the induction of anaesthesia, a venous blood gas, and blood glucose and ketone levels were measured. Postoperatively, the incidence of nausea, vomiting, and LOS were documented.

RESULTS

120 patients were randomised with 119/120 (99.2%) undergoing analysis. Blood glucose level was higher in the carbohydrate group; 5.4 mmol/L [3.3-9.4] versus 4.9 mmol/L [3.6-6.5] (p = 0.01). Blood ketone level was lower in the carbohydrate group; 0.2 mmol/L versus 0.3 mmol/L (p = 0.003). The incidence of nausea and vomiting was not different (p > 0.9 and p = 0.8, respectively). LOS in the carbohydrate group was 26 min shorter than the placebo group (p = 0.02).

CONCLUSION

Although a preoperative carbohydrate load may provide a more stable metabolic state at the induction of anaesthesia, we did not find a reduction in postoperative nausea and vomiting. A preoperative carbohydrate load has also minimal effects on the postoperative LOS.

TYPE OF STUDY

Randomised clinical trial.

LEVEL OF EVIDENCE

I.

Preoperative carbohydrate drink in fast-track primary total knee arthroplasty: a randomized controlled trial of 168 patients

A key component in fast-track total knee arthroplasty (TKA) is early mobilization. Preoperative fasting might cause orthostatic hypotension and -intolerance which both can interfere with early mobilization. It was hypothesized that consuming a carbohydrate drink 2-3 hours prior to surgery is a viable option to reduce orthostatic hypotension, and as a result, improve rehabilitation. In this randomized controlled trial, all consecutive unilateral primary TKA patients were reviewed for eligibility. Exclusion criteria were American Society of Anesthesiologists (ASA) class above 3, older than 80 years of age, Diabetes Mellitus, and an insufficient comment of Dutch language. Patients were distributed in two groups. The control group was allowed to eat till 6 hours and drink clear fluids till 2 hours before surgery (standard treatment). The intervention group consumed, additionally to the standard treatment, a carbohydrate drink 2-3 hours before surgery. Blood pressure was measured both lying and standing as a measure for orthostatic hypotension during first time postoperative mobilization on day of surgery. A total of 168 patients were included. Prevalence of orthostatic hypotension in the control- and intervention group was 24 patients (34%) and 14 patients (19%) respectively, (p=0.05). Prevalence of orthostatic intolerance was 13 patients (19%) in the control group and 9 patients (13%) in the intervention group (p=0.32). No drink related adverse events occurred. In conclusion, taking a carbohydrate drink 2-3 hours before TKA significantly lowers the number of patients with orthostatic hypotension in early mobilization. However, the clinical relevance of the carbohydrate drink has to be studied further.

Preoperative Snack Prescription: A Single-Centre Experience in Optimising Preoperative Fasting Time and Enhancing Guideline Adherence

Objectives Preoperative fasting plays a pivotal role in adequately preparing patients for anaesthesia and surgical procedures. However, it is imperative to consider not only the medical aspects but also patients' overall comfort, as this can significantly contribute to improved surgical outcome. The primary objective of this quality improvement project (QIP) is to provide healthcare professionals, including anaesthetists, surgeons, nurses, and stakeholders with information regarding insights required to embrace the concept of preoperative snack prescription as a strategy for enhancing patient-centred care. Methods This QIP was conducted in the vascular surgery department of a district general hospital in Wales, United Kingdom. A prospective analysis was conducted in two cycles, i.e., the pre-intervention group (PrIG) and post-intervention group (PoIG), with preoperative snacks such as biscuits, chips, or cakes, being prescribed to the PoIG. A total of 40 patients who met the inclusion criteria were enrolled in this study, with 20 patients participating in each cycle. The timing of preoperative meals, i.e., the closest preoperative breakfast, lunch, or dinner, preoperative snacks (for the PoIG), anaesthesia commencement, and surgical commencement were collected. Data analysis was performed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, New York, United States), in conjunction with Microsoft Excel (Microsoft Corporation, Redmond, Washington, United States). Results In our QIP, the PrIG and PoIG comprised 40% (8 out of 20) and 35% (7 out of 20) female patients, respectively, with mean ages of 74 years (range, 61-86 years) and 61.3 years (range, 36-81 years). Within the PrIG, the mean duration from the preoperative meal to anaesthesia and surgery commencement was 17.8 hours (range, 14.6-22.5 hours) and 18.5 hours (range, 16.0-23.3 hours), respectively. In the PoIG, following the initiation of preoperative snack prescription, the mean time intervals between preoperative snack prescription and anaesthesia and surgery commencement were 10.9 hours (range, 6.5-16.0 hours) and 12.0 hours (range, 7.5-16.5 hours), respectively. Conclusions In summary, our QIP has successfully integrated preoperative snack prescription into the local hospital's preoperative care policy, prioritising the balance between patient safety and comfort. Based on our single-centre experience, we observed a significant reduction in the time interval between preoperative fasting and the initiation of anaesthesia, decreasing from 18.3 hours to 10.9 hours post-implementation of preoperative snacks. This QIP holds relevance for healthcare professionals as it underscores the benefits of shorter fasting periods, which contribute to heightened patient satisfaction and comfort.

Preoperative Oral Carbohydrate (CHO) Supplementation Is Beneficial for Clinical and Biochemical Outcomes in Patients Undergoing Elective Cesarean Delivery under Spinal Anaesthesia-A Randomized Controlled Trial

BACKGROUND

Preoperative fasting and surgery cause metabolic stress, insulin resistance with ketosis, and postoperative nausea and vomiting (PONV). Oral carbohydrate loading strategy (CHO) improves outcomes in labor and general surgery. We aimed to compare the effectiveness of CHO with standard fasting in patients undergoing elective cesarean delivery (CD) under spinal anesthesia.

METHODS

A single-center, parallel, prospective randomized controlled trial (RCT) was conducted in a tertiary university obstetrics department at Pomeranian Medical University in Szczecin, Poland. Patients were randomly assigned (1:1 ratio) to the CHO group (oral carbohydrate 2 h before elective CD, n = 75) or the SF group (control-standard fasting, n = 73). The main outcome measures were incidence and severity of PONV at 6 and 24 h after CD, time to the first peristalsis, time to first bowel movement, and biochemical parameters indicating ketosis in mothers and their children.

RESULTS

A total of 148 adult females with singleton pregnancies undergoing elective CD under spinal anesthesia (ASA I and II) were included in the final analysis. At 24 h after CD, 8.0% from the CHO group vs. 20.55% reported three or more episodes of vomiting or dry retching as compared to patients in the SF group (p = 0.041). Preoperative CHO supplementation decreased preoperative feelings of hunger (p < 0.001) and thirst (p < 0.001). Laboratory results in the CHO group showed higher plasma pH (p = 0.001) and glucose (p < 0.001), lower F2-isoprostane in plasma (p = 0.049) and urine (p = 0.018), lower urine F2-isoprostane/creatinine ratio (p = 0.045) than in the SF group. HOMA-IR (p < 0.001) and lactate (p < 0.001) were higher in the CHO group than in the control group.

CONCLUSIONS

There was no significant difference in the incidence or severity of early PONV at 6 h. The incidence of vomiting or dry retching at 24 h after cesarean delivery was lower in the CHO group as compared to standard starvation, but the combined results of PONV frequency and severity on the Wengritzky scale did not differ between the two study groups. Preoperative CHO supplementation decreased preoperative feelings of hunger and thirst, enhancing the comfort of pregnant women.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04069806.

Carbohydrate Loading and Aspiration Risk in Bariatric Patients: Safety in Preoperative Enhanced Recovery Protocols

BACKGROUND

Enhanced recovery protocols have been developed to improve perioperative outcomes; however, there is ongoing concern for aspiration with recent oral intake in patients with obesity, who may be predisposed to impaired gastrointestinal motility and greater gastric volumes. We aim to study the safety of a 300-mL preoperative carbohydrate-loading drink preceding bariatric surgery.

STUDY DESIGN

Data were collected prospectively from patients undergoing primary bariatric surgery. All bariatric patients at our institution are prescribed a proton pump inhibitor for 4 weeks before surgery and undergo a screening preoperative esophagogastroduodenoscopy (EGD) before surgery with a traditional 8-hour fast (NOCARB), followed by an intraoperative day-of-operation EGD with carbohydrate loading (CARB) 2 to 4 hours before incision. Gastric volumes and pH are measured after being endoscopically suctioned via direct visualization during both settings.

RESULTS

We identified 203 patients: 94 patients (46.3%) in the CARB group and 109 patients (53.7%) in the NOCARB group. The patients were 82.3% female with a mean age of 42.8 years and average BMI of 41.7 kg/m 2 . There was no difference in gastric volume between NOCARB and CARB (17.0 vs 16.1 mL, p = 0.59). The NOCARB group had lower pH values than the CARB group (2.8 vs 3.8, p = 0.001). Subset analysis of 23 patients who had measurements on both screening and intraoperative EGD revealed lower gastric volumes in CARB patients (13.3 vs 18.3, p < 0.0001).

CONCLUSIONS

When included in an enhanced recovery protocol, proton pump inhibitor use and preoperative carbohydrate loading 2 to 4 hours before bariatric surgery does not increase aspiration risk based on gastric volumes and pH and should be strongly considered in all eligible bariatric patients.

Key Strategies for Optimizing Pediatric Perioperative Nutrition-Insight from a Multidisciplinary Expert Panel

Adequate nutrition is an essential factor in healing and immune support in pediatric patients undergoing surgery, but its importance in this setting is not consistently recognized. Standardized institutional nutrition protocols are rarely available, and some clinicians may be unaware of the importance of assessing and optimizing nutritional status. Moreover, some clinicians may be unaware of updated recommendations that call for limited perioperative fasting. Enhanced recovery protocols have been used in adult patients undergoing surgery to ensure consistent attention to nutrition and other support strategies in adult patients before and after surgery, and these are now under evaluation for use in pediatric patients as well. To support better adoption of ideal nutrition delivery, a multidisciplinary panel of experts in the fields of pediatric anesthesiology, surgery, gastroenterology, cardiology, nutrition, and research have gathered and reviewed current evidence and best practices to support nutrition goals in this setting.

Prospective audit on fasting status of elective ambulatory surgery patients, correlated to gastric ultrasound

INTRODUCTION

Recent guidelines advocate a preoperative fasting interval of 6 h for solid food, 4 h for breast milk and 2 h for clear fluids. Long nil per mouth intervals give rise to complications and discomfort in the perioperative period. Gastric ultrasound is easily accessible and generates reliable information about gastric content.

PATIENTS AND METHODS

One hundred patients were offered a questionnaire regarding preoperative fasting. Important outcome measures were hour of last meal, last clear fluids intake, the source of preoperative information. Gastric ultrasound was performed in prone position and lateral decubitus.

RESULTS

The mean duration of fasting for solid food was 13h29 and 9h51 for clear fluids. 48% of patients were well aware of the correct fasting guidelines. The most frequent source of information was the preoperative phone call. Gastric ultrasound only found insignificant amounts of gastric content.

DISCUSSION

Too few patients are aware of the correct guidelines or fear complications and therefore adhere to the nil per mouth from midnight as most conservative measure. A phone call informing patients about the hour of surgery and allowing clear fluid intake until 2 h before surgery, is still not convincing enough. Some health care providers advise their patients the nil per mouth from midnight rule, due to risk of interfering with the operating room schedule.

CONCLUSION

It is still difficult to implement liberal intake of clear fluids according to current guidelines. Ambulatory surgery patients have long fasting intervals with decrease of subjective well-being and increased incidence of hunger and thirst.

Residual gastric volume after 3 h of the ingestion of an oral supplement containing carbohydrates alone or associated with whey protein: a randomized crossover pilot study

BACKGROUND

New formulas including a nitrogenous source to maltodextrin have been reported as preoperative beverages 2-3 h before anesthesia in the elective procedure. Whey protein is a potential candidate for the composition of this clear oral supplement. This study aimed to investigate the gastric residual volume (GRV) of healthy volunteers 3 h after the ingestion of an oral supplement containing carbohydrates (CHO) alone or combined with whey protein (WP).

METHODS

This crossover clinical trial design includes young, healthy male volunteers with normal body mass index. Magnetic resonance imaging (MRI) scan of the upper abdomen to measure the GRV was performed in the participants in three phases: (1) after a fasting period of 8 h; (2) immediately after the ingestion of 200 mL of a clear supplement containing: (2a) 10 g of WP and 54 g of CHO (74% glucose and 26% maltodextrin)-WP + CHO group or (2b) 12.5% maltodextrin (25 g)-CHO group; and (3) after 3 h of the ingestion of both types of supplements. A week interval was programmed between phases 2a and 2b.

RESULTS

There was no significant difference (p = 0.91; within-group comparison) of the mean ± SD of the GRV between phase 1 (WP + CHO: 23.45 ± 14.01; CHO: 25.03 ± 15.17 cm³; p = 0.78; between-groups comparison) and phase 3 (WP + CHO: 25.66 ± 9.31; CHO: 23.45 ± 13.58 cm³, p = 0.86; between-groups comparison). The GRV of phase 2 (WP + CHO: 206.43 ± 23; CHO: 203.99 ± 12.18 cm³; p = 0.82; between-groups comparison) was significantly greater (p < 0.01; within-group comparison) than both other two phases.

CONCLUSION

The GRV after 3 h of the ingestion of either WP + CHO or CHO oral supplement returns to basal fast condition implying that gastric emptying after this interval of time is significantly completed.

TRIAL REGISTRATION

Registered and posted on the ClinicalTrials.gov public website with Identifier: NCT05573854.

Using Kotter's 8 steps of change to tackle over-fasting of children attending day surgery

Over-fasting before surgery can lead to dehydration, irritability, lethargy, nausea, hypoglycemia, tricky intravenous cannulation, and decreased patient satisfaction (Newton et al., Pediatr Anesth, 2017, 27, 793). We used "Kotter's 8 steps for change" as an approach to tackling the problem of over-fasting in our day surgery unit (Kotter, Leading Change, Harvard Business School Press, 1996). Using a video of a patient's experience with overfasting, we created a sense of urgency and need for change (Step1: create urgency). We formed a multi-disciplinary fasting improvement team (FIT) (Step2: form a powerful coalition) and conducted a retrospective data analysis to establish a baseline. We then studied the system thoroughly using Ishikawa charts, process mapping, bench-marking, user surveys, and Pareto charts. Using these findings, we created a vision for our change (Step3: create a vision for change). Within 6 months, we aimed for 90% of patients to have a fluid fasting time of <2 h and for 90% of afternoon patients to have had breakfast. We communicated this vision to all staff involved in the day surgery (Step4: communicate the vision). Following this, we empowered them (Step5: empower action) by asking for their opinions for changes and let them take over various tasks without micromanagement. The Institute for Healthcare Improvement (IHI) Psychology of Change Framework described a focus on the human side of change, to increase the likelihood that improvement efforts will succeed by activating people's agency (Hilton & Anderson. IHI Psychology of Change Framework to Advance and Sustain Improvement, Institute for Healthcare Improvement, 2018). Our change ideas were divided into "short-term wins," "intermediate term goals," and "longer term goals." We focussed on creating short-term wins (Step6: create quick wins) and celebrated successes along the way to create initial momentum. We did this in parallel with working on longer term changes. We continued to work on cementing these new ideas (Step7: build on the changes), so that transformation in the day surgery would persist before using the same system to spread the change to the rest of the hospital (Step8: making it stick).

Postoperative fasting is associated with longer ICU stay in oncologic patients undergoing elective surgery

Background

Cancer patients present nutritional and complications risks during the postoperative period. Fasting contributes to surgical catabolic damage. This study evaluates the consequence of fasting time on the surgical outcomes of cancer patients undergoing elective surgeries.

Methods

Prospective cohort, evaluating two categories of patients according to postoperative fasting: less than or greater than 24 h. Outcomes: Hospitalization time, 28-day mortality, ICU stay and infection rates.

Discussion

We included 109 patients (57% men, 60 ± 15 years, BMI: 26 ± 5 kg/m², SAPS3 43 ± 12), hepatectomy was the most frequent surgery (13.8%), and colon and rectum were the most common neoplasia (18.3%). The ICU stay was longer in postoperative fasting > 24 h (5.5 [4–8.25] vs. 3 [2–5] days, p < 0.001). Fasting > 24 h persisted as a risk factor for longer length of stay (LOS) in the ICU after adjustments. There were no differences in the mortality analysis within 28 days and total hospitalization time between groups. A tendency to experience more infections was observed in patients who fasted > 24 h (34.8% vs. 16.3%, p = 0.057). Onset of diet after the first 24 h postoperatively was a risk factor for longer ICU stay in cancer patients who underwent major surgeries.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-022-00261-4.

Abbreviated perioperative fasting management for elective fresh fracture surgery: guideline adherence analysis

BACKGROUND

Long-term fasting for elective surgery has been proven unnecessary based on established guidelines. Instead, preoperative carbohydrate loading 2 h before surgery and recommencing oral nutrition intake as soon as possible after surgery is recommended. This study was performed to analyze the compliance with and effect of abbreviated perioperative fasting management in patients undergoing surgical repair of fresh fractures based on current guidelines.

METHODS

Patients with fresh fractures were retrospectively analyzed from the prospectively collected database about perioperative managements based on enhanced recovery of surgery (ERAS) from May 2019 to July 2019 at our hospital. A carbohydrate-enriched beverage was recommended up to 2 h before surgery for all surgical patients except those with contraindications. Postoperatively, oral clear liquids were allowed once the patients had regained full consciousness, and solid food was allowed 1 to 2 h later according to the patients' willingness. The perioperative fasting time was recorded and the patients' subjective comfort with respect to thirst and hunger was assessed using an interview-assisted questionnaire.

RESULTS

In total, 306 patients were enrolled in this study. The compliance rate of preoperative carbohydrate loading was 71.6%, and 93.5% of patients began ingestion of oral liquids within 2 h after surgery. The median (interquartile range) preoperative fasting time for liquids and solids was 8 (5.2-12.9) and 19 (15.7-22) hours, respectively. The median postoperative fasting time for liquids and solids was 1 (0.5-1.9) and 2.8 (2.2-3.5) hours, respectively. A total of 70.3% and 74.2% of patients reported no thirst and hunger during the perioperative period, respectively. Logistic regression analysis showed that the preoperative fasting time for liquids was an independent risk factor for perioperative hunger. No risk factor was identified for perioperative thirst. No adverse events such as aspiration pneumonia or gastroesophageal reflux were observed.

CONCLUSIONS

In this study of a real clinical practice setting, abbreviated perioperative fasting management was carried out with high compliance in patients with fresh fractures. The preoperative fasting time should be further shortened to further improve patients' subjective comfort.

A randomized trial of non-fasting vs. fasting for cardiac implantable electronic device procedures (Fast-CIED Study)

AIMS

Data on safety and efficacy of a non-fasting strategy in minimal invasive cardiac procedures are lacking. We assessed a non-fasting strategy compared with a fasting strategy regarding patient's well-being and safety in elective cardiac implantable electronic device (CIED) procedures.

METHODS AND RESULTS

In this randomized, single-blinded clinical trial, 201 patients (non-fasting = 100, fasting = 101) with a mean age of 72.0 ± 11.6 years (66.7% male) were assigned to a non-fasting strategy (solids/fluids allowed up to 1 h) or a fasting strategy (at least 6 h no solids and 2 h no fluids) before the procedure and analysed on an intention-to-treat basis. The co-primary outcomes were patients' well-being scores (based on numeric rating scale, 0-10) and incidence of intra-procedural food-related adverse events, including vomiting, perioperative pulmonary aspiration, and emergency intubation. Renal, haematological, and metabolic blood parameters and 30-day follow-up data were gathered. The summed pre-procedural patients' well-being score was significantly lower in the non-fasting group [non-fasting: 13.1 ± 9.6 vs. fasting: 16.5 ± 11.4, 95% confidence interval (CI) of mean difference (MD) -6.35 to -0.46, P = 0.029], which was mainly driven by significantly lower scores for hunger and tiredness in the non-fasting group (non-fasting vs. fasting; hunger: 0.9 ± 1.9 vs. 3.1 ± 3.2, 95% CI of MD -2.86 to -1.42, P < 0.001; tiredness: 1.6 ± 2.3 vs. 2.6 ± 2.7, 95% CI of MD -1.68 to -0.29, P = 0.023). No intra-procedural food-related adverse events were observed. Relevant blood parameters and 30-day follow-up did not show significant differences.

CONCLUSION

These results showed that a non-fasting strategy is beneficial to a fasting one regarding patient's well-being and comparable in terms of safety for CIED procedures (NCT04389697).

Enhanced recovery after surgery strategy to shorten perioperative fasting in children undergoing non-gastrointestinal surgery: A prospective study

BACKGROUND

Enhanced recovery after surgery strategies are increasingly implemented to improve the management of surgical patients.

AIM

To evaluate the effects of new perioperative fasting protocols in children ≥ 3 mo of age undergoing non-gastrointestinal surgery.

METHODS

This prospective pilot study included children ≥ 3 mo of age undergoing non-gastrointestinal surgery at the Children’s Hospital (Zhejiang University School of Medicine) from January 2020 to June 2020. The children were divided into either a conventional group or an ERAS group according to whether they had been enrolled before or after the implementation of the new perioperative fasting strategy. The children in the conventional group were fasted using conventional strategies, while those in the ERAS group were given individualized fasting protocols preoperatively (6-h fasting for infant formula/non-human milk/solids, 4-h fasting for breast milk, and clear fluids allowed within 2 h of surgery) and postoperatively (food permitted from 1 h after surgery). Pre-operative and postoperative fasting times, pre-operative blood glucose, the incidence of postoperative thirst and hunger, the incidence of perioperative vomiting and aspiration, and the degree of satisfaction were evaluated.

RESULTS

The study included 303 patients (151 in the conventional group and 152 in the ERAS group). Compared with the conventional group, the ERAS group had a shorter pre-operative food fasting time [11.92 (4.00, 19.33) vs 13.00 (6.00, 20.28) h, P < 0.001), shorter preoperative liquid fasting time [3.00 (2.00, 7.50) vs 12.00 (3.00, 20.28) h, P < 0.001], higher preoperative blood glucose level [5.6 (4.2, 8.2) vs 5.1 (4.0, 7.4) mmol/L, P < 0.001], lower incidence of thirst (74.5% vs 15.3%, P < 0.001), shorter time to postoperative feeding [1.17 (0.33, 6.83) vs 6.00 (5.40, 9.20), P < 0.001], and greater satisfaction [7 (0, 10) vs 8 (5, 10), P < 0.001]. No children experienced perioperative aspiration. The incidences of hunger, perioperative vomiting, and fever were not significantly different between the two groups.

CONCLUSION

Optimizing fasting and clear fluid drinking before non-gastrointestinal surgery in children ≥ 3 mo of age is possible. It is safe and feasible to start early eating after evaluating the recovery from anesthesia and the swallowing function.

Is NPO (Nil Per Os) order helping or hindering elective cardiac procedures?

The practice of fasting before elective cardiac procedures including cardiac catheterization and transesophageal echocardiography is commonly implemented but evidence for these requirements is lacking. Fasting periods often exceed the intended length of time, increasing the risk of irritability, dehydration, acute kidney injury, hypoglycemia, and length of hospitalization. The practice of perioperative fasting relies on the premise that aspiration during general anesthesia can be mitigated by minimizing the volume of gastric contents, and stomach acidity. But the evidence has shown that fasting does not guarantee an empty stomach, and there is no observed association between aspiration and compliance with common fasting guidelines. Elective cardiac procedures are performed using procedural sedation, where the risk of serious aspiration is small. In most patients, we argue, that strict fasting requirements should be reduced, and a more nuanced fasting protocol based on individual patient characteristics and risk factors should be utilized given the overall low risk of aspiration with elective procedures utilizing procedural sedation. In this review, we examine the historical origins and current evidence relating to the practice of fasting as it relates to cardiac catheterization and transesophageal echocardiography.

Anesthesia and Enhanced Recovery After Surgery in Bariatric Surgery

The Enhanced Recovery After Surgery Society published guidelines for bariatric surgery reviewing the evidence and providing specific care recommendations. These guidelines emphasize preoperative nutrition, multimodal analgesia, postoperative nausea and vomiting prophylaxis, anesthetic technique, nutrition, and mobilization. Several studies have since evaluated these pathways, showing them to be safe and effective at decreasing hospital length of stay and postoperative nausea and vomiting. This article emphasizes anesthetic management in the perioperative period and outlines future directions, including the application of Enhanced Recovery After Surgery principles in patients with extreme obesity, diabetes, and metabolic disease and standardization of the pathways to decrease heterogeneity.

Fluid and Hemodynamics

Several components of an Enhanced Recovery After Surgery (ERAS) pathway act to improve and simplify perioperative fluid and hemodynamic therapy. Modern perioperative fluid management has shifted away from the liberal fluid therapy and toward more individualized approaches. Clinical evidence has also emphasized the importance of maintaining adequate mean arterial pressure and avoiding intraoperative hypotension. Goal-directed hemodynamic therapy (GDHT), or the use of cardiac output monitoring to guide fluid and vasopressor use, has been shown to reduce complications, but its role within ERAS pathways is likely best-suited to high-risk patients or those undergoing high-risk procedures. This article reviews the mechanisms by which ERAS pathways aid the provider in hemodynamic management, reviews trends, and evidence regarding fluid and hemodynamic therapy approaches, and provides guidance on the practical implementation of these concepts within ERAS pathways.

Effect of Carbohydrate-Enriched Drink Compared to Fasting on Hemodynamics in Healthy Volunteers. A Randomized Trial

Fasting prior to surgery can cause dehydration and alter hemodynamics. This study aimed to determine the impact of a carbohydrate-enriched drink (NutriciaTM Pre-op®) on selected hemodynamical parameters, measured in a non-invasive manner. We enrolled 100 healthy volunteers and measured their weight, height, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), thoracic fluid content (TFC), thoracic fluid index (TFCI), stroke volume (SV), stroke volume variation (SVV), stroke index (SI), cardiac output (CO), cardiac index (CI), heather index (HI), systolic time ration (STR), systemic time ratio index (STRI), systemic vascular resistance (SVR), and systemic vascular resistance index (SVRI) by a Niccomo™ device, implementing the impedance cardiography (ICG) method. Measurements were performed at the beginning of the study, and after 10 h and 12 h. We randomly allocated participants to the control group and the pre-op group. The pre-op group received 400 mL of Nutricia™ preOp®, as suggested in the ERAS guidelines, within 10 h of the study. Student's t-test or the Mann-Whitney U test were used to compare the two groups, and p < 0.05 was considered significant. We did not observe any changes in hemodynamical parameters, blood pressure, and heart rate between the groups. We have proven that carbohydrate-enriched drink administration did not have a significant impact on the hemodynamical parameters of healthy volunteers.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations: A 2021 Update

Background

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

Methods

A principal literature search was performed utilizing the Pubmed, EMBASE, Cochrane databases and ClinicalTrials.gov through December 2020, with particular attention paid to meta-analyses, randomized controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. After critical appraisal of these studies, the group of authors reached consensus regarding recommendations.

Results

The quality of evidence for many ERAS interventions remains relatively low in a bariatric setting and evidence-based practices may need to be extrapolated from other surgeries.

Conclusion

A comprehensive, updated evidence-based consensus was reached and is presented in this review by the ERAS® Society.

The Effect of the Preoperative Fasting Regimen on the Incidence of Gastro-Oesophageal Reflux in 90 Dogs

Simple Summary

Gastro-oesophageal reflux (GOR), a potential risk during anaesthesia, happens when the stomach contents move up into the oesophagus. The refluxed contents can damage the lining of the oesophagus or the respiratory tract. For many years it was believed that an increase in the stomach contents’ volume increases the risk of GOR. However, more recent studies have demonstrated this to be incorrect. The objective of this study was to compare the effects of three different pre-anaesthetic fasting regimens on the frequency of GOR in dogs under anaesthesia. Ninety dogs undergoing non-abdominal and non-thoracic elective surgery were included in the study and equally allocated to three groups. The results of this study suggest that the administration of a meal 3 h before anaesthesia does not have any beneficial effect in the reduction of GOR incidence in dogs compared to the administration of a meal 12 h before anaesthesia.

Abstract

This study aimed to investigate the effect of three different preoperative fasting regimens on the incidence of gastro-oesophageal reflux (GOR) in dogs under general anaesthesia. Ninety dogs undergoing non-abdominal and non-thoracic elective surgery were included in the study and equally allocated to three groups. Dogs received canned food providing half the daily resting energy requirements (RER) 3 h prior to premedication (group 3H), a quarter of the daily RER 3 h before premedication (group 3Q), and half the daily RER 12 h before premedication (group 12H). The animals were premedicated with acepromazine and pethidine, anaesthesia was induced with propofol and maintained with isoflurane vaporised in oxygen. Oesophageal pH was monitored throughout anaesthesia. Demographic and surgery-related parameters were not different among groups. The incidence of GOR was 11/30 in group 3H (36.7%), 9/30 in group 3Q (30.0%) and 5/30 in group 12H (16.7%), which was not statistically different (p = 0.262). Reduction of the amount of the preoperative meal from half to a quarter of the daily RER did not reduce the incidence of GOR but resulted in a lower oesophageal pH (p = 0.003). The results of this study suggest that the administration of a meal 3 h before anaesthesia does not have any beneficial effect in the reduction of GOR incidence in dogs compared to the administration of a meal 12 h before anaesthesia.

How Does Fasting Affect Cognition? An Updated Systematic Review (2013-2020)

PURPOSE OF REVIEW

The goal of this review was to provide an update on the literature examining how voluntary, temporary abstention from eating impacts cognitive function.

RECENT FINDINGS

We evaluated peer-reviewed articles published between August 2013 and January 2021 that assessed adults, included a measure of cognitive functioning with neutral stimuli, and compared individuals in a fasted state to individuals in a fed state (either within- or between-subject designs). Nineteen articles (21 studies) met inclusion criteria. Sample sizes, fasting methods, and tasks varied across studies. Review of studies indicated that fasting was associated with deficits in cognitive functioning; few studies indicated a benefit in cognitive functioning following a single voluntary fast. The heterogeneity and rarity of available studies limits the conclusions that can be drawn. Several crucial psychosocial and sociodemographic moderators remain unexplored. Recommendations for future work are discussed.

Pro-Con Debate: 1- vs 2-Hour Fast for Clear Liquids Before Anesthesia in Children

Perioperative fasting guidelines are designed to minimize the risk of pulmonary aspiration of gastrointestinal contents. The current recommendations from the American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology and Intensive Care (ESAIC) are for a minimum 2-hour fast after ingestion of clear liquids before general anesthesia, regional anesthesia, or procedural sedation and analgesia. Nonetheless, in children, fasting guidelines also have consequences as regards to child and parent satisfaction, hemodynamic stability, the ability to achieve vascular access, and perioperative energy balance. Despite the fact that current guidelines recommend a relatively short fasting time for clear fluids of 2 hours, the actual duration of fasting time can be significantly longer. This may be the result of deficiencies in communication regarding the duration of the ongoing fasting interval as the schedule changes in a busy operating room as well as to poor parent and patient adherence to the 2-hour guidelines. Prolonged fasting can result in children arriving in the operating room for an elective procedure being thirsty, hungry, and generally in an uncomfortable state. Furthermore, prolonged fasting may adversely affect hemodynamic stability and can result in parental dissatisfaction with the perioperative experience. In this PRO and CON presentation, the authors debate the premise that reducing the nominal minimum fasting time from 2 hours to 1 hour can reduce the incidence of prolonged fasting and provide significant benefits to children, with no increased risks.

The effects of diabetes mellitus on gastric emptying: A prospective observational cohort study

STUDY OBJECTIVE

Our goal was to evaluate the effect of diabetic severity and duration on preoperative residual gastric volume. Secondarily we compared ultrasonic estimates of residual gastric volume with actual volume determined by aspiration during endoscopy.

DESIGN

This was a prospective, observational cohort study that included adults with a history of diabetes mellitus and/or opioid use scheduled for gastrointestinal endoscopic procedures.

SETTING

Endoscopy unit at Cleveland Clinic Main Campus from 2017 to 2019.

PARTICIPANT

Adults scheduled for upper endoscopy with or without colonoscopy.

INTERVENTION AND MEASUREMENTS

Residual gastric volumes were primarily determined by aspiration during endoscopy, and secondarily estimated with ultrasound. We evaluated the relationship between gastric residual volume and preoperative HBA1C concentration and duration of diabetes. Secondarily, we conducted an agreement analysis between the two gastric volume measurement techniques.

MAIN RESULTS

Among 145 enrolled patients, 131 were diabetic and 17 were chronic opioid users. Among 131 diabetic patients, the mean ± SD HbA1c was 7.2 ± 1.5% and the median (Q1, Q3) duration of diabetes was 8.5 (3, 15) years. Neither HbA1c nor duration of diabetes was associated with residual gastric volume. The adjusted mean ratio of residual gastric volume was 1.07 (98.3% CI: 0.89, 1.28; P = 0.38) for 1% increase in HbA1c concentration, and 0.84 (98.3% CI: 0.63, 1.14; P = 0.17) for each 10-year increase induration of diabetes. The median [Q1-Q3] absolute difference between gastric ultrasound measurement and endoscopic measurement was 25 [15, 65] ml.

CONCLUSIONS

In this prospective observational cohort study, neither the duration nor severity of diabetes influenced preoperative residual gastric volume. Gastric ultrasound can help identify patients who have excessive residual volumes despite overnight fasting.

The influence of preoperative carbohydrate loading on postoperative outcomes in bariatric surgery patients: a randomized, controlled trial

BACKGROUND

Preoperative carbohydrate loading is a component of Enhanced Recovery After Surgery (ERAS) protocols, but there is limited literature in bariatric surgery patients.

OBJECTIVES

The objective of this study was to characterize the impact of preoperative carbohydrate loading on postoperative bariatric surgery outcomes.

SETTING

University Hospital.

METHODS

Patients undergoing a primary minimally invasive Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2018 and 2020 were randomized to standard management or intervention. Standard management patients were nothing by mouth (NPO) after midnight prior to surgery. Intervention patients consumed 2 carbohydrate drinks: 1 the night before and another 3 hours prior to surgery. Primary outcomes analyzed included postoperative nausea and vomiting (PONV), length of stay, and overall complications.

RESULTS

In total, 134 patients were analyzed: 64 intervention (47.8%) and 70 (52.2%) standard. In the end, 7% and 15% of patients were lost to follow-up at 6-weeks and 3-months, respectively. There was no statistically significant difference in length of stay (2.0 ± 1.2 vs 2.1 ± .9 d; P = .65) or postoperative outcomes between the 2 groups. There were no episodes of aspiration among the intervention group. Among RYGB patients, intervention patients had a shorter duration of nausea compared with standard patients. There was no significant difference in glycemic control among patients with and without diabetes.

CONCLUSIONS

Preoperative carbohydrate drinks can be administered to bariatric surgery patients without significant risks. Carbohydrate loading preoperatively can decrease the duration of PONV in RYGB patients. Carbohydrate drinks can be safely included in bariatric ERAS protocols for patients with and without diabetes, although the benefits remain unknown.

Fasting and surgery timing (FaST) audit

BACKGROUND & AIMS

International guidance advocates the avoidance of prolonged preoperative fasting due to its negative impact on perioperative hydration. This study aimed to assess the adherence to these guidelines for fasting in patients undergoing elective and emergency surgery in the East Midlands region of the UK.

METHODS

This prospective audit was performed over a two-month period at five National Health Service (NHS) Trusts across the East Midlands region of the UK. Demographic data, admission and operative details, and length of preoperative fasting were collected on adult patients listed for emergency and elective surgery.

RESULTS

Of the 343 surgical patients included within the study, 50% (n = 172) were male, 78% (n = 266) had elective surgery and 22% (n = 77) underwent emergency surgery. Overall median fasting times (Q1, Q3) were 16.1 (13.0, 19.4) hours for food and 5.8 (3.5, 10.7) hours for clear fluids. Prolonged fasting >12 h was documented in 73% (n = 250) for food, and 21% (n = 71) for clear fluids. Median fasting times from clear fluids and food were longer in the those undergoing emergency surgery when compared with those undergoing elective surgery: 13.0 (6.4, 22.6) vs. 4.9 (3.3, 7.8) hours, and 22.0 (14.0, 37.4) vs. 15.6 (12.9, 17.8) hours respectively, p < 0.0001.

CONCLUSIONS

Despite international consensus on the duration of preoperative fasting, patients continue to fast from clear fluids and food for prolonged lengths of time. Patients admitted for emergency surgery were more likely to fast for longer than those having elective surgery.

Development and Validation of a Questionnaire Assessing Patient Distress from Preoperative Fasting in Cataract Surgery

Purpose: To develop and psychometrically validate a questionnaire to measure patient distress with preoperative fasting related to cataract surgery.Methods: In this single-centered cross-sectional study, consecutive sampling of cataract patients was undertaken immediately preoperatively from February to December 2019. A questionnaire evaluating patient distress with fasting was designed and administered. Questionnaire development occurred in an iterative process and was conducted with consultation from expert investigators and patients. Validation and psychometric evaluation of the questionnaire were performed with Rasch analysis.Results: A preliminary version of the questionnaire was developed by 10 study investigators. Across five iterations of development, the questionnaire was administered to 186 cataract patients. Psychometric evaluation of the 13-item questionnaire demonstrated ordered thresholds, acceptable item calibration and fit, adequate internal consistency, ability to discriminate between three levels of distress from preoperative fasting and no notable differential item functioning. However, issues with mistargeting, clustering of items on the person-item map and multidimensionality remained. Given these concerns, 13 separate re-analyses were conducted via removal of certain items. A 6-item subset was determined to be well targeted, unidimensional, did not display item clustering and was able to discriminate between patients with high and low distress from preoperative fasting.Conclusion: A 6-item questionnaire is a valid, psychometrically robust and reliable measure for the assessment of patient distress with preoperative fasting in cataract surgery. Items include hunger, thirst, hoarseness, weakness, anxiety and nausea. Future studies should seek to validate this questionnaire across a variety of sociodemographic contexts, languages and specialties.

Evidence-Based Perioperative Nutrition Recommendations: Optimizing Results and Minimizing Risks

Plastic surgery patients span the nutritional spectrum from generally healthy, nutritionally competent patients to inherently catabolic, nutritionally deficient, and chronic wound patients. Therefore, plastic and reconstructive surgery affords the opportunity to investigate the impact of nutrition across a heterogeneous patient population following a wide variety of procedures. Although patients may be nutritionally deficient in certain vitamins warranting perioperative repletion, other supplements have the potential to benefit all patients, regardless of nutritional status. Despite these putative benefits, there is a dearth of information regarding nutritional optimization, with the limited, available literature focusing mostly on herbal supplements and their potential side effects. A significant barrier to supplement use is the lack of education and available supporting information regarding the indications, contraindications, and physiology of these adjuncts. The goal of this article is to provide a comprehensive, evidence-based review of available nutritional supplements that can be considered for the plastic surgery patient in the perioperative period to optimize surgical outcomes while minimizing risk. Prospective, well-designed studies using validated, high-quality supplements will be critical in determining the significance that perioperative supplementation can have for surgical outcomes. Until well-done prospective studies are performed, the supplement, dose, and duration should be determined on an individual, patient-per-patient basis at the discretion of the operating surgeon.

Fast-track- recovery surgery with a whey-protein-infused carbohydrate-loading drink pre-operatively and early oral feeding post-operatively among surgical gynaecological cancer patients: study protocol of an open-labelled, randomised controlled trial

Introduction

There has been growing evidence on the favourable outcomes of fast-track-recovery (FTR) surgery; to expedite recovery, minimise complications, and reduce the length of hospital stay for surgical patients. However, there is lack of evidence on the effectiveness of FTR in surgical gynaecological cancer (GC) patients. Most of the previous studies did not focus on feeding composition in the FTR surgery protocol. This study aims to determine the effectiveness of FTR feeding with a whey-protein-infused carbohydrate-loading drink pre-operatively and early oral feeding post-operatively on post-operative outcomes among surgical GC patients.

Methods/design

This open-labelled, randomised controlled trial (RCT) will randomly allocate patients into intervention and control groups. Ambulated Malaysian aged over 18 years and scheduled for elective surgery for (suspected) GC, will be included in this study. The intervention group will be given whey-protein-infused carbohydrate-loading drinks on the evening before their operation and 3 h before their operation as well as started on early oral feeding 4 h post-operatively. The control group will be fasted overnight pre-operation and only allowed plain water, and return to a normal diet is allowed when bowel sounds return post-operatively. The primary outcomes of study are length of post-operative hospital stay, length of clear-fluid tolerance, solid-food tolerance and bowel function. Additional outcome measures are changes in nutritional status, biochemical profile and functional status. Data will be analysed on an intention-to-treat basis.

Trial registration

ClinicalTrials.gov, ID: NCT03667755. Retrospectively registered on 12 September 2018;

Protocol version: version 3 dated 27 September 2017.

An exploration of pre-operative fasting practices in adult patients having elective surgery

Background:

Patients fast routinely before elective surgery in order to reduce gastric volume and acidity. The standard fasting time is ‘nil by mouth’ from midnight before surgery. In recent years, new guidelines have recommended that patients remain nil by mouth from clear fluids for 2 hours and from solids for 6 hours. This literature review explored preoperative fasting practices in adult patients from an international perspective.

Methods:

A literature search was undertaken of databases, including CINAHL Plus, PubMed, Medline, the Cochrane Central Register of Controlled Trials, Science Direct, Sage Journals and Embase.

Results:

Anaesthetists were found to possess greater knowledge of reduced preoperative fasting than other health professionals including nurses.

Conclusion:

Actual fasting time was found to be relatively longer than prescribed fasting times.

Slated versus actual operating room entry time in a British Columbia health authority

PURPOSE

To determine how frequently the published operating room (OR) schedule of case start times correlated with the actual OR entry time for elective cases in the Fraser Health Authority (FHA) in British Columbia, Canada. Society guidelines recommend periods of fasting of two hours prior to the induction of general anesthesia, but patients frequently end up fasting much longer. This review aimed to determine when patients arrive in the OR-either earlier than their scheduled time or later. The premise of some is that patients often arrive earlier, and advising short fasting times on the basis of the OR slate time is unreliable. I wished to determine whether this fear is justified.

METHODS

The computerized OR management database was queried for slated time of entry and actual time of entry for elective surgical cases in 11 hospitals in the FHA. The difference in slated vs actual entry time of patients (in 30 min blocks) was reviewed to examine the proportion of patients entering the OR earlier than 90 min from their slated time. Additionally, anesthesiologists from the Royal Columbian/Eagle Ridge Hospitals were surveyed for their recall of case delays that were related to inappropriate consumption of fluids.

RESULTS

One hundred and twenty-three thousand eight hundred and sixty-five cases from 11 hospitals over a 32-month period were analyzed. A very small proportion of cases (753 of 123,865 cases, 0.6%) entered the OR earlier than 90 min from their slated time. Relatively few cases were actually cancelled because of inappropriate fluid consumption in the recall of anesthesiologists in two institutions.

CONCLUSION

In the FHA, the OR schedule is a reliable guide to providing instructions on timing of preoperative fluid consumption in appropriately selected elective surgical patients. Quality of care and patient satisfaction will safely be enhanced by limiting the period of fasting for elective surgical patients.

Preoperative Fasting Practices Across Three Anesthesia Societies: Survey of Practitioners

Background

Pulmonary aspiration of gastric contents is recognized as a complication of anesthesia. To minimize that risk, anesthesiologists advised fasting for solid foods and liquids for an often prolonged period of time. However, 30 years ago, evidence was promulgated that fasting for clear liquids was unnecessary to ensure an empty stomach. Despite a strong evidence base and the knowledge that fasting may be physiologically harmful and unpleasant for patients, the adoption of society guidelines recommending short fasting periods for clear fluids into clinical practice is uncertain.

Objective

This study aimed to determine the current practices of anesthetists with respect to fasting guidelines.

Methods

An electronic internet survey was distributed to anesthetists in Canada (CAN), Australia and New Zealand (ANZ), and Europe (EUR) during April 2014 to February 2015. The anesthetists were asked about fasting guidelines, their recommendations to patients for the consumption of clear fluids and solid foods, and the reasons and consequences if these guidelines were not followed.

Results

A total of 971 anesthetists completed the survey (CAN, n=679; ANZ, n=185; and EUR, n=107). Although 85.0% (818/962) of these participants claimed that their advice to patients followed current society guidelines, approximately 50.4% (476/945) enforced strict fasting and did not allow clear fluids after midnight. The primary reasons given were with regard to problems with a variable operating room schedule (255/476, 53.6%) and safety issues surrounding the implementation of clear fluid drinking guidelines (182/476, 38.2%).

Conclusions

Many anesthetists continue to follow outdated practices. The current interest in further liberalizing preoperative fluid intake will require more change in anesthesia culture.

Evidence according to Cochrane Systematic Reviews on Alterable Risk Factors for Anastomotic Leakage in Colorectal Surgery

Anastomotic leakage reflects a major problem in visceral surgery, leading to increased morbidity, mortality, and costs. This review is aimed at evaluating and summarizing risk factors for colorectal anastomotic leakage. A generalized discussion first introduces risk factors beginning with nonalterable factors. Focus is then brought to alterable impact factors on colorectal anastomoses, utilizing Cochrane systematic reviews assessed via systemic literature search of the Cochrane Central Register of Controlled Trials and Medline until May 2019. Seventeen meta-anaylses covering 20 factors were identified. Thereof, 7 factors were preoperative, 10 intraoperative, and 3 postoperative. Three factors significantly reduced the incidence of anastomotic leaks: high (versus low) surgeon's operative volume (RR = 0.68), stapled (versus handsewn) ileocolic anastomosis (RR = 0.41), and a diverting ostomy in anterior resection for rectal carcinoma (RR = 0.32). Discussion of all alterable factors is made in the setting of the pre-, intra-, and postoperative influencers, with the only significant preoperative risk modifier being a high colorectal volume surgeon and the only significant intraoperative factors being utilizing staples in ileocolic anastomoses and a diverting ostomy in rectal anastomoses. There were no measured postoperative alterable factors affecting anastomotic integrity.

Assessing the effect of sugar-free chewing gum use on the residual gastric volume of patients fasting for gastroscopy: A randomised controlled trial

There is no clear consensus in the current guidelines published by major international anaesthetic associations on what is the most appropriate time for a patient to stop chewing gum. This open-label balanced-group randomised controlled trial aimed to evaluate whether the chewing of sugar-free gum caused an increased volume or reduced pH of residual gastric fluid in fasting patients. For this study 212 patients undergoing elective gastroscopy were randomised into a control group who followed routine fasting instructions and an intervention group who were asked to chew gum while fasting. Residual gastric fluid was aspirated under direct vision via a gastroscope under anaesthesia. The primary outcome was the incidence of a gastric residual volume >50 ml in participants who chewed gum compared with a control group. Secondary outcomes were variability in the overall gastric volume distribution and gastric pH distribution between the two groups. Nine out of 110 (8.2%) in the chewing gum group and six out of 102 (5.9%) in the control group had a residual gastric fluid volume >50 ml: incidence rate ratio 1.39 (95% confidence intervals (CI) 0.51–3.77; P = 0.60). However, only one patient (in the control group) had a residual gastric volume >73 ml. There was no statistically significant difference in gastric volume distribution between groups, odds ratio 1.60 (95% CI 0.99–2.58; P = 0.054) or in the distribution of gastric pH measurement, odds ratio 0.90 (95% CI 0.57–1.44; P = 0.67). These results indicate that if there is an increase in the incidence of residual gastric volume >50 ml in patients who chew gum preoperatively, it is likely to be small. Moreover, the absence of any patients in our chewing gum group with a residual gastric volume >73 ml is reassuring.

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 Antenatal and Preoperative care in Cesarean Delivery: Enhanced Recovery After Surgery Society Recommendations (Part 1)

This Enhanced Recovery After Surgery (ERAS) Guideline for perioperative care in cesarean delivery will provide best practice, evidenced-based, recommendations for preoperative, intraoperative, and postoperative phases with, primarily, a maternal focus. The focused pathway process for scheduled and unscheduled cesarean delivery for this ERAS Cesarean Delivery Guideline will consider from the time from decision to operate (starting with the 30-60 minutes before skin incision) to hospital discharge. The literature search (1966-2017) used Embase and PubMed to search medical subject headings that included "Cesarean Section," "Cesarean Section," "Cesarean Section Delivery" and all pre- and intraoperative ERAS items. Study selection allowed titles and abstracts to be screened by individual reviewers to identify potentially relevant articles. Metaanalyses, systematic reviews, randomized controlled studies, nonrandomized controlled studies, reviews, and case series were considered for each individual topic. Quality assessment and data analyses that evaluated the quality of evidence and recommendations were evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation system, as used and described in previous ERAS Guidelines. The ERAS Cesarean Delivery Guideline/Pathway has created a maternal focused pathway (for scheduled and unscheduled surgery starting from 30-60 minutes before skin incision to maternal discharge) with ERAS cesarean delivery consensus recommendations preoperative elements (anesthetic medications, fasting, carbohydrate supplementation, prophylactic antibiotics/skin preparation, ), intraoperative elements (anesthetic management, maternal hypothermia prevention, surgical technique, hysterotomy creation and closure, management of peritoneum, subcutaneous space, and skin closure), perioperative fluid management, and postoperative elements (chewing gum, management of nausea and vomiting, analgesia, timing of food intake, glucose management, antithrombotic prophylaxis, timing of ambulation, urinary management, and timing of maternal and neonate discharge). Limited topics for optimized care and for antenatal education and counselling and the immediate neonatal needs at delivery are discussed. Strong recommendations for element use were given for preoperative (antenatal education and counselling, use of antacids and histamine, H2 receptor antagonists, 2-hour fasting and small meal within 6 hours surgery, antimicrobial prophylaxis and skin preparation/chlorhexidine-alcohol), intraoperative (regional anesthesia, prevention of maternal hypothermia [forced warm air, warmed intravenous fluids, room temperature]), perioperative (fluid management for euvolemia and neonatal immediate care needs that include delayed cord clamping), and postoperative (fluid management to prevent nausea and vomiting, antiemetic use, analgesia with nonsteroidal antiinflammatory drugs/paracetamol, regular diet within 2 hours, tight capillary glucose control, pneumatic compression stocking for venous thromboembolism prophylaxis, immediate removal of urinary catheter). Recommendations against the element use were made for preoperative (maternal sedation, bowel preparation), intraoperative (neonatal oral suctioning or increased inspired oxygen), and postoperative (heparin should not be used routinely venous thromboembolism prophylaxis). Because these ERAS cesarean delivery pathway recommendations (elements/processes) are studied, implemented, audited, evaluated, and optimized by the maternity care teams, this will create an opportunity for the focused and optimized areas of care research with further enhanced care and recommendation.