Preoperative fasting abbreviation (Enhanced Recovery After Surgery protocol) and effects on the metabolism of patients undergoing gynecological surgeries under spinal anesthesia: A randomized clinical trial

Ultrasound evaluation of gastric emptying time of standardized high-calorie liquid meals in healthy adults: A double-blind cross-over randomized study

BACKGROUND AND AIMS

Commercially available high-calorie drinks containing fat and protein can be used as dietary supplements in surgical patients. According to preoperative fasting guidelines, high-calorie drinks are non-clear fluids and should not be consumed 6 h before elective procedures. The aim of this study was to evaluate the gastric emptying time of commercially available high-calorie drink formulations in healthy adults using gastric ultrasound.

METHODS

25 healthy adult volunteers were included in this double-blind, cross-over prospective study. On three study sessions, fasted volunteers ingested one of the three study products: a solution of 75 g of glucose in 200 ml of water, a fat-free liquid meal, and a nutritionally complete liquid meal with equal volume and energy content. Gastric ultrasound examinations were performed to evaluate the gastric contents qualitatively and the volume of the gastric contents was calculated from the cross-sectional area of the gastric antrum measured in right lateral position by using a validated model. Repeated gastric ultrasounds were performed at baseline and half-hourly after ingesting the products in supine and right lateral position until the criteria for an empty stomach were met.

RESULTS

The glucose solution and the standard fat-free high-calorie drink with the same caloric content had a median gastric emptying time of 150 min. The nutritionally complete liquid meal had a median gastric emptying time of 180 min. Gastric emptying was complete in all participants before 6 h had elapsed since ingesting the study products.

CONCLUSIONS

High calorie liquid meals have a gastric emptying time longer than the recommended fasting time for clear fluids, but shorter than the recommended fasting time for solids in healthy adults.

2023 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting: Carbohydrate-containing Clear Liquids with or without Protein, Chewing Gum, and Pediatric Fasting Duration-A Modular Update of the 2017 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting

These practice guidelines are a modular update of the "Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: Application to healthy patients undergoing elective procedures." The guidance focuses on topics not addressed in the previous guideline: ingestion of carbohydrate-containing clear liquids with or without protein, chewing gum, and pediatric fasting duration.

Effects of preoperative carbohydrate loading on recovery after elective surgery: A systematic review and Bayesian network meta-analysis of randomized controlled trials

Background

Preoperative carbohydrate loading is an important element of the enhanced recovery after surgery (ERAS) paradigm in adult patients undergoing elective surgery. However, preoperative carbohydrate loading remains controversial in terms of improvement in postoperative outcomes and safety. We conducted a Bayesian network meta-analysis to evaluate the effects and safety of different doses of preoperative carbohydrates administrated in adult patients after elective surgery.

Methods

MEDLINE (PubMed), Web of Science, EMBASE, EBSCO, the Cochrane Central Register of Controlled Trials, and China National Knowledge Infrastructure (CNKI) were searched to identify eligible trials until 16 September 2022. Outcomes included postoperative insulin resistance, residual gastric volume (RGV) during the surgery, insulin sensitivity, fasting plasma glucose (FPG), fasting serum insulin (Fin) level, the serum levels of C-reactive protein (CRP), postoperative scores of pain, patients' satisfaction, thirst, hunger, anxiety, nausea and vomit, fatigue, and weakness within the first 24 h after surgery and the occurrences of postoperative infection. The effect sizes were estimated using posterior mean difference (continuous variables) or odds ratios (dichotomous variables) and 95 credible intervals (CrIs) with the change from baseline in a Bayesian network meta-analysis with random effect.

Results

Fifty-eight articles (N = 4936 patients) fulfilled the eligibility criteria and were included in the meta-analysis. Both preoperative oral low-dose carbohydrate loading (MD: -3.25, 95% CrI: -5.27 to -1.24) and oral high-dose carbohydrate loading (MD: -2.57, 95% CrI: -4.33 to -0.78) were associated with postoperative insulin resistance compared to placebo/water. When trials at high risk of bias were excluded, association with insulin resistance was found for oral low-dose carbohydrate loading compared with placebo/water (MD: -1.29, 95%CrI: -2.26 to -0.27) and overnight fasting (MD: -1.17, 95%CrI: -1.88 to -0.43). So, there was large uncertainty for all estimates vs. control groups. In terms of safety, oral low-dose carbohydrate administration was associated with the occurrences of postoperative infection compared with fasting by 0.42 (95%Crl: 0.20-0.81). In the other outcomes, there was no significant difference between the carbohydrate and control groups.

Conclusion

Although preoperative carbohydrate loading was associated with postoperative insulin resistance and the occurrences of postoperative infection, there is no evidence that preoperative carbohydrate administration alleviates patients' discomfort.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022312944].

Current practice of postoperative fasting: results from a multicentre survey in China

OBJECTIVE

A gap between clinical practice and evidence is common. The present multicentre study was designed to explore the actual postoperative fasting practice, including the instructed fasting time from the ward staff and the actual postoperative fasting time.

DESIGN

Multicentre survey.

SETTING

Four tertiary hospitals in Shenzhen City, China.

PARTICIPANTS

A total of 988 patients completed a survey on instructed and actual postoperative fasting.

OUTCOMES

All patients received postoperative instructed fasting time from the ward staff. The median instructed fasting time for fluids from ward staff was 6 hours (IQR, 4-6 hours), and the median instructed fasting time for solid food was also 6 hours (IQR 5-6 hours) after surgery. The actual postoperative fasting time, including fluid and solid food intake, was significantly longer than the time recommended by the ward staff (both p<0.001).

RESULTS

The median time to postoperative first flatus (FFL) was 16.5 hours (IQR 8-25.5 hours), and the median time to postoperative first faeces (FFE) was 41 hours (IQR 25-57 hours). The fasting time was significantly shorter than the time to FFL and the time to FFE, regardless of surgery type or anaesthesia type (all p<0.001). Postoperative nausea and vomiting (PONV) occurred in 23.6% of patients. After surgery, 58.70% of patients reported thirst, and 47.47% reported hunger. No ileus occurred.

CONCLUSION

Approximately half of the patients reported thirst and hunger postoperatively. Patients initiated oral intake earlier than the time to FFL or FFE without increasing serious complications. This study may support the rationale for interventions targeting postoperative oral intake time in future studies.

Framework, component, and implementation of enhanced recovery pathways

The introduction of enhanced recovery pathways (ERPs) has led to a considerable paradigm shift towards evidence-based, multidisciplinary perioperative care. Such pathways are now widely implemented in a variety of surgical specialties, with largely positive results. In this narrative review, we summarize the principles, components and implementation of ERPs, focusing on recent developments in the field. We also discuss ‘special cases’ in ERPs, including: surgery in frail patients; emergency procedures; and patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2/COVID-19).

Research Status and Progress of Nutritional Support Therapy for Ovarian Cancer

Ovarian cancer is one of the most fatal gynecological cancers. For most ovarian cancer patients, nutritional risk or malnutrition may accompany them for life. Regular nutritional risk screening, timely nutritional assessment and necessary nutritional treatment play an extremely important role in the process of comprehensive treatment of ovarian cancer. The nutritional status and influence of ovarian cancer patients, preoperative screening and assessment of nutritional risk, preoperative and postoperative nutritional treatment indicate that nutritional treatment of ovarian cancer is one of the key factors in the treatment of cancer. We have summarized the status and progress of nutritional support therapy for ovarian cancer. We are aimed to improve the understanding of the impact of nutritional support therapy for ovarian cancer and to guide the clinical work.