Effect of Preoperative Oral Carbohydrate Administration on Patients Undergoing Cesarean Section with Epidural Anesthesia: A Pilot Study

Gastric emptying in pregnancy and its clinical implications: a narrative review

Delayed gastric emptying increases the risk of pulmonary aspiration during anaesthesia for Caesarean delivery. Our aim in conducting this narrative review was to consider the effect of pregnancy on gastric emptying. The indices of gastric emptying after liquids, solids, or both and when fasted in the various trimesters of pregnancy, at the time of Caesarean delivery, in labour, and the postpartum period were assessed. We considered 32 observational studies, one nonrandomised controlled study, and 22 randomised controlled trials. The evidence indicates that, compared with the nonpregnant state, gastric emptying is decreased in the first but not the second and third trimesters. Before elective Caesarean delivery, carbohydrate drink or tea with milk leads to no difference in gastric cross-sectional area at 2 h relative to fasting or water. Following a standard fast for elective Caesarean delivery, patients may still have high-risk gastric contents. Compared with the nonpregnant state and third trimester, gastric emptying is delayed in labour, although the choice of analgesia has modifying effects. Systemic opioids delay gastric emptying. Epidural analgesia increases gastric emptying, but not back to baseline. Intrathecal analgesia delays gastric emptying relative to epidural analgesia. Women in labour who have eaten solids in the last 8 h still have high-risk gastric contents present in the stomach. The evidence with respect to the postpartum period is conflicting. In conclusion, inconsistencies in the literature reflect the unpredictability of gastric emptying in pregnancy and underline the potential value of gastric ultrasound in women who are pregnant.

Trends in preoperative carbohydrate load practice: A systematic review

BACKGROUND

The preoperative carbohydrate load (PCL) is intended to improve surgical outcomes by reducing the catabolic state induced by overnight fasting. However, there is disagreement on the optimal PCL prescription, leaving local institutions without a standardized PCL recommendation. Results from studies that do not prescribe PCL in identical ways cannot be pooled to draw larger conclusions on outcomes affected by the PCL. The aim of this systematic review is to catalog prescribed PCL characteristics, including timing of ingestion, percentage of carbohydrate contribution, and volume, to ultimately standardize PCL practice.

METHODS

A comprehensive search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials were included if they studied at least one group of patients who were prescribed a PCL and the PCL was described with respect to timing of ingestion, carbohydrate contribution, and total volume.

RESULTS

A total of 67 studies with 6551 patients were included in this systematic review. Of the studies, 49.3% were prescribed PCL on the night before surgery and morning of surgery, whereas 47.8% were prescribed PCL on the morning of surgery alone. The mean prescribed carbohydrate concentration was 13.5% (±3.4). The total volume prescribed was 648.2 ml (±377).

CONCLUSION

Variation in PCL practices prevent meaningful data pooling and outcome analysis, highlighting the need for standardized PCL prescription. Efforts dedicated to the establishment of a gold standard PCL prescription are necessary so that studies can be pooled and analyzed with respect to meaningful clinical end points that impact surgical outcomes and patient satisfaction.

Evidence-based cesarean delivery: preoperative management (part 7)

Preoperative preparation for cesarean delivery is a multistep approach for which protocols should exist at each hospital system. These protocols should be guided by the findings of this review. The interventions reviewed and recommendations made for this review have a common goal of decreasing maternal and neonatal morbidity and mortality related to cesarean delivery. The preoperative period starts before the patient's arrival to the hospital and ends immediately before skin incision. The Centers for Disease Control and Prevention recommends showering with either soap or an antiseptic solution at least the night before a procedure. Skin cleansing in addition to this has not been shown to further decrease rates of infection. Hair removal at the cesarean skin incision site is not necessary, but if preferred by the surgical team then clipping or depilatory creams should be used rather than shaving. Preoperative enema is not recommended. A clear liquid diet may be ingested up to 2 hours before and a light meal up to 6 hours before cesarean delivery. Consider giving a preoperative carbohydrate drink to nondiabetic patients up to 2 hours before planned cesarean delivery. Weight-based intravenous cefazolin is recommended 60 minutes before skin incision: 1-2 g intravenous for patients without obesity and 2 g for patients with obesity or weight ≥80 kg. Adjunctive azithromycin 500 mg intravenous is recommended for patients with labor or rupture of membranes. Preoperative gabapentin can be considered as a way to decrease pain scores with movement in the postoperative period. Tranexamic acid (1 g in 10-20 mL of saline or 10 mg/kg intravenous) is recommended prophylactically for patients at high risk of postpartum hemorrhage and can be considered in all patients. Routine use of mechanical venous thromboembolism prophylaxis is recommended preoperatively and is to be continued until the patient is ambulatory. Music and active warming of the patient, and adequate operating room temperature improves outcomes for the patient and neonate, respectively. Noise levels should allow clear communication between teams; however, a specific decibel level has not been defined in the data. Patient positioning with left lateral tilt decreases hypotensive episodes compared with right lateral tilt, which is not recommended. Manual displacers result in fewer hypotensive episodes than left lateral tilt. Both vaginal and skin preparation should be performed with either chlorhexidine (preferred) or povidone iodine. Placement of an indwelling urinary catheter is not necessary. Nonadhesive drapes are recommended. Cell salvage, although effective for high-risk patients, is not recommended for routine use. Maternal supplemental oxygen does not improve outcomes. A surgical safety checklist (including a timeout) is recommended for all cesarean deliveries.

The Effect of Oral Fluid Administration 1 Hour before Surgery on Preoperative Anxiety and Gastric Volume in Pediatric Patients

INTRODUCTION

Today, preoperative fasting guidelines have changed, allowing clear liquid intake up to 1 h before surgery. However, concerns remain regarding the risk of aspiration associated with clear liquid intake. This study aimed to investigate the impact of clear fluid given 1 h before surgery on child anxiety and gastric volumes.

METHODS

A prospective, randomized, controlled study included 90 patients aged 5-12 years. The patients were randomly allocated into three groups by a computer-generated randomization: group F (n = 30): standard fasting group, group W (n = 30): patients who received oral water at a dose of 5 mL/kg 1 h before surgery, group C (n = 30): patients who received oral carbohydrate fluid at a dose of 5 mL/kg 1 h before surgery. All patients were assessed using the modified Yale Preoperative Anxiety Scale (m-YPAS) before and 1 h after fluid administration. Antral cross-sectional area (CSA) was measured with ultrasonography after intubation, and gastric residual volume (GRV) was calculated. Hemodynamic data, blood sugar level, and parental satisfaction were also recorded.

RESULTS

The m-YPAS scores obtained after 1 h were significantly lower in group C than in the other groups (p < 0.001). Antral CSA and GRV values were lower in group C and group W than in the fasting group (p < 0.001). Parental satisfaction was highest in group C.

CONCLUSION

This study suggests that allowing a carbohydrate-rich clear liquid intake 1 h before surgery can significantly reduce preoperative anxiety in pediatric patients without increasing the risk of aspiration.

Effects of Preoperative Oral Carbohydrate on Perioperative Maternal Outcomes Undergoing Cesarean Section: A Systematic Review and Meta-Analysis

Purpose

Preoperative oral carbohydrate (CHO) is a rapid postoperative rehabilitation protocol that improves perioperative outcomes and is widely used in adult surgical patients. However, pregnant women are excluded because of the possibility of aspiration due to delayed gastric emptying. This meta-analysis was conducted to evaluate the efficacy of preoperative oral CHO in elective cesarean section.

Methods

PubMed, Embase, Web of Science, and the Cochrane Library were searched from inception to July 2023. Randomized controlled trials were included. The risk of bias was assessed using the Cochrane tool. Risk ratios and 95% confidence intervals were calculated. Meta-analysis was performed using random-effects models to estimate risk ratios and mean differences (MDs) with 95% confidence intervals (CIs). The outcomes included thirst and hunger scores, incidence of vomiting and nausea, time to flatus, and homeostatic model assessment of insulin resistance (HOMA-IR).

Results

A total of nine studies with 1211 patients were included in the analysis. The levels of thirst and hunger were evaluated using a 10-point visual analog scale, with 0 representing the best and 10 representing the worst. The severity of hunger (weighted mean difference (WMD: -2.34, 95% CI: -3.13 to -1.54), time to flatus (WMD: -3.51 hours, 95% CI: -6.85 to -0.17), and HOMA-IR (WMD: -1.04, 95% CI: -1.31 to -0.77) were significantly lower in the CHO group compared to the control group. However, there were no significant differences in the severity of thirst or the incidence of vomiting and nausea between the CHO and control groups.

Conclusion

Preoperative oral CHO during cesarean section alleviates thirst and hunger, shortens the time of postoperative flatus, and reduces HOMA-IR. However, the available evidence is insufficient to reach a clear consensus on the benefits or harms of preoperative oral CHO during cesarean section. Therefore, it is premature to make a definitive recommendation for or against its routine use.

Therapeutic potential of traditional Chinese medicine on heat stroke

As global warming progresses, heat waves are becoming increasingly frequent and intense, meanwhile the incidence of heat stroke (HS) has increased sharply during the past decades. HS is typically associated with significant morbidity and mortality, and there is an urgent need for further research to solve this difficult issue. There currently exists difficulties regarding on-site emergency treatment methods and limited in-hospital treatment approaches, and better treatments are required as soon as possible. Theories and therapies from various traditional Chinese medicine (TCM) academic groups have been widely reported. Therefore, an exploration of prevention and protection methods should consider TCM experiences as an alternative. This article primarily reviews TCM herbal therapies and external therapies that have been described in various clinical reports and demonstrated in relevant studies. Herbal therapies, including herbal formulas, Chinese patent medicines (CPMs), single Chinese herbs, and associated extracts or monomers, are summarized based on the shared perspectives of the underlying mechanisms from TCM. In addition, external therapies including acupuncture, bloodletting, cupping, Gua sha and Tui na that have rarely been rarely mentioned and considered in most cases, are introduced and discussed to offer a unique perspective in the search for novel interventions for HS. In summary, TCM may provide abundant potential clinical benefits and research directions in the fight against HS.

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.

Effect of preoperative oral rehydration before cesarean section on ultrasound assessment of gastric volume and intraoperative hemodynamic changes: a randomized controlled trial

BACKGROUND

Cesarean section often requires an urgent transfusion load due to decreased blood pressure after spinal anesthesia. This prospective randomized study aimed to investigate whether a preoperative oral rehydration solution (ORS) stabilized perioperative circulatory dynamics.

METHODS

Sixty-three parturients scheduled for cesarean section under combined spinal epidural anesthesia (CSEA) were randomly allocated to one of three groups: Group O received 500 mL ORS before bedtime and 500 mL 2 h before CSEA; Group M received mineral water instead of ORS; and Group C had no fluid intake (controls). After entering the operating room, stomach size was measured using ultrasound. Blood samples were obtained, and CSEA was induced. Vasopressors were administered when systolic blood pressure was < 90 mmHg or decreased by > 20%. As a vasopressor, phenylephrine (0.1 mg) was administered at ≥ 60 beats/min heart rate or ephedrine (5 mg) at < 60 beats/min heart rate. The primary outcome was the total number of vasopressor boluses administered. Secondary outcomes were the cross-sectional area of the stomach antrum, maternal plasma glucose levels, serum sodium levels, total intravenous fluid, bleeding volume, urine volume, operative time, and cord blood gas values after delivery.

RESULTS

The total number of vasopressor boluses was lower in Group O than in Group C (P < 0.05). Group O had lower total dose of phenylephrine than Group C (P < 0.05). There were no significant differences between Group M and other groups. No differences were detected regarding secondary outcomes.

CONCLUSIONS

In women scheduled for cesarean section, preoperative ORS stabilized perioperative circulatory dynamics. Neither ORS nor mineral water consumption increased the stomach content volume.

TRIAL REGISTRATION

This trial is registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000019825: Date of registration 17/11/2015).

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.

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].

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.