Incidence of adverse respiratory events after adjustment of clear fluid fasting recommendations to 1 h: a prospective, observational, multi-institutional cohort study

BACKGROUND

Preoperative fasting reduces the risk of pulmonary aspiration during anaesthesia, and 2-h fasting for clear fluids has commonly been recommended. Based on recent evidence of shorter fasting times being safe, the Swiss Society of Paediatric Anaesthesia began recommending 1-h fasting for clear fluids in 2018. This prospective, observational, multi-institutional cohort study aimed to investigate the incidence of adverse respiratory events after implementing the new national recommendation.

METHODS

Eleven Swiss anaesthesia institutions joined this cohort study and included patients aged 0-15 yr undergoing anaesthesia for elective procedures after implementation of the 1-h fasting instruction. The primary outcome was the perioperative (defined as the time from anaesthesia induction to emergence) incidence of pulmonary aspiration, gastric regurgitation, and vomiting. Data are presented as median (inter-quartile range; minimum-maximum) or count (percentage).

RESULTS

From June 2019 to July 2021, 22 766 anaesthetics were recorded with pulmonary aspiration occurring in 25 (0.11%), gastric regurgitation in 34 (0.15%), and vomiting in 85 (0.37%) cases. No major morbidity or mortality was associated with pulmonary aspiration. Subgroup analysis by effective fasting times (<2 h [n=7306] vs ≥2 h [n=14 660]) showed no significant difference for pulmonary aspiration between these two groups (9 [0.12%] vs 16 [0.11%], P=0.678). Median effective fasting time for clear fluids was 157 [104-314; 2-2385] min.

CONCLUSIONS

Implementing a national recommendation of 1-h clear fluid fasting was not associated with a higher incidence of pulmonary aspiration compared with previously reported data.

A convenient machine learning model to predict full stomach and evaluate the safety and comfort improvements of preoperative oral carbohydrate in patients undergoing elective painless gastrointestinal endoscopy

BACKGROUND AND AIMS

Assessment of the patient's gastric contents is the key to avoiding aspiration incidents, however, there is no effective method to determine whether elective painless gastrointestinal endoscopy (GIE) patients have a full stomach or an empty stomach. And previous studies have shown that preoperative oral carbohydrates (POCs) can improve the discomfort induced by fasting, but there are different perspectives on their safety. This study aimed to develop a convenient, accurate machine learning (ML) model to predict full stomach. And based on the model outcomes, evaluate the safety and comfort improvements of POCs in empty- and full stomach groups.

METHODS

We enrolled 1386 painless GIE patients between October 2022 and January 2023 in Nanjing First Hospital, and 1090 patients without POCs were used to construct five different ML models to identify full stomach. The metrics of discrimination and calibration validated the robustness of the models. For the best-performance model, we further interpreted it through SHapley Additive exPlanations (SHAP) and constructed a web calculator to facilitate clinical use. We evaluated the safety and comfort improvements of POCs by propensity score matching (PSM) in the two groups, respectively.

RESULTS

Random Forest (RF) model showed the greatest discrimination with the area under the receiver operating characteristic curve (AUROC) 0.837 [95% confidence interval (CI): 79.1-88.2], F1 71.5%, and best calibration with a Brier score of 15.2%. The web calculator can be visited at https://medication.shinyapps.io/RF_model/. PSM results demonstrated that POCs significantly reduced the full stomach incident in empty stomach group (p < 0.05), but no differences in full stomach group (p > 0.05). Comfort improved in both groups and was more significant in empty stomach group.

CONCLUSIONS

The developed convenient RF model predicted full stomach with high accuracy and interpretability. POCs were safe and comfortably improved in both groups, with more benefit in empty stomach group. These findings may guide the patients' gastrointestinal preparation.

Pediatric perioperative fluid management

The purpose of perioperative fluid management in children is to maintain adequate volume status, electrolyte level, and endocrine system homeostasis during the perioperative period. Although hypotonic solutions containing glucose have traditionally been used as pediatric maintenance fluids, recent studies have shown that isotonic balanced crystalloid solutions lower the risk of hyponatremia and metabolic acidosis perioperatively. Isotonic balanced solutions have been found to exhibit safer and more physiologically appropriate characteristics for perioperative fluid maintenance and replacement. Additionally, adding 1-2.5% glucose to the maintenance fluid can help prevent children from developing hypoglycemia as well as lipid mobilization, ketosis, and hyperglycemia. The fasting time should be as short as possible without compromising safety; recent guidelines have recommended that the duration of clear fluid fasting be reduced to 1 h. The ongoing loss of fluid and blood as well as the free water retention induced by antidiuretic hormone secretion are unique characteristics of postoperative fluid management that must be considered. Reducing the infusion rate of the isotonic balanced solution may be necessary to avoid dilutional hyponatremia during the postoperative period. In summary, perioperative fluid management in pediatric patients requires careful attention because of the limited reserve capacity in this population. Isotonic balanced solutions appear to be the safest and most beneficial choice for most pediatric patients, considering their physiology and safety concerns.

A review of pediatric fasting guidelines and strategies to help children manage preoperative fasting

Fasting for surgery is a routine step in the preoperative preparation for surgery. There have however been increasing concerns with regard to the high incidence of prolonged fasting in children, and the subsequent psycho-social distress and physiological consequences that this poses. Additionally, the past few years have yielded new research that has shown significant inter-individual variation in gastric emptying regardless of the length of the fast, with some patients still having residual gastric contents even after prolonged fasts. Additionally, multiple large-scale studies have shown no long-term sequalae from clear fluid aspiration, although two deaths from aspiration have been reported within the large Wake Up Safe cohort. This has led to a change in the recommended clear fluid fasting times in multiple international pediatric societies; similarly, many societies continue to recommend traditional fasting times. Multiple fasting strategies exist in the literature, though these have mostly been studied and implemented in the adult population. This review hopes to summarize the recent updates in fasting guidelines, discuss the issues surrounding prolonged fasting, and explore potential tolerance strategies for children.

[Preoperative fasting in children-Experiences with implementing a liberal fasting policy]

BACKGROUND

Traditional fasting rules for children prior to elective operations ("6‑4‑2 rule") often lead to prolonged fasting times with possible adverse events (discomfort, hypoglycemia, metabolic disorders, agitation/delirium). A new liberal fasting policy allowing children to drink clear fluids until being called to the operating room ("6‑4‑0") was established in our university hospital. This article describes our experiences and retrospectively examines the effects.

OBJECTIVE

Evaluation of real fasting times before and up to 6 months after the intervention (success and durability of changing fasting policy). Evaluation of impact on outcome parameters, such as patients' resp. parents' satisfaction as well as perioperative agitation, arterial hypotension after induction and postoperative nausea and vomiting (PONV).

MATERIAL AND METHODS

Retrospective evaluation of methods and interventions from 1 month before to 6 months after changing the fasting policy (June-December 2020). Statistical analysis using descriptive statistics, odds ratio and χ2-test.

RESULTS

Of 216 analyzed patients 44 were in the pre-change group and 172 in the post-change group. We could significantly reduce clear fluids fasting times over the 6 months after the intervention (median fasting time: from 6.1 h to 4.5 h; p = 0.034) and achieve our aim (fasting time for clear fluids less than or equal to 2h) in 47% of the patients. Fasting times became longer again reaching pre-change intervals in the 4th and 5th month, so reminder measures turned out to be necessary. By reminding the staff we could reduce fasting times again in the 6th month and restore patients' resp. parents' satisfaction. Satisfaction was improved by shorter fasting times (median school grade from 2.8 to 2.2; p = 0.004; odds ratio for better satisfaction 5.24, 2.1-13.2), and preoperative agitation was reduced (agitation modified PAED scale 1-2 in only 34.5% instead of 50%, p = 0.032). In the liberal fasting group, we observed a nonsignificant smaller incidence of hypotension after induction (7% vs. 14%, p = 0.26) while PONV was too rare in both groups for statistical purposes.

CONCLUSION

With multiple interventions we could significantly reduce fasting times for clear fluids and improve patients' resp. parents' satisfaction as well as preoperative agitation. These interventions included regular presence in all staff meetings, a handout for both parents and staff, as well as a remark on the anesthesia protocol. Children who were operated on later in the day, benefited most from the new liberal fasting policy as they were allowed to drink until being called to the operating room. Following our experience, we consider simple and safe fasting rules for the whole staff as most important for change management. Nevertheless, we could not reduce the fasting intervals in all cases and had to remind the staff after 5 months to preserve this success. For enduring success, we suggest regular staff updates during the change process instead of one single kick-off information event.

Preoperative ultrasound evaluation of gastric contents in children one hour after ingestion of clear liquid: An observational study

Background

Gastric ultrasound is an effective, non-invasive method to assess the nature and volume of gastric content in the pediatric population. Recently, the UK, European, and French Pediatric Anesthesia Societies recommend fast for clear fluids in children for 1 h. However, studies showing that 1 h of fasting is safe in the pediatric population are still scarce. This study aims to verify by ultrasound evaluation if 1 h of fasting for clear liquids is sufficient to have an empty stomach before anesthetic induction.

Methodology

Patients between 11 months and 16 years of age scheduled for elective outpatient surgery were included. A qualitative and quantitative ultrasound evaluation was performed by calculating the cross-sectional area (CSA) of the gastric antrum, 1 h after ingesting a volume of 3 mL/kg of a non-carbonated sports drink, before anesthetic induction.

Results

Fifty patients were included. The average CSA measured by ultrasound was 2.85 ± 1.64 cm2 with an average calculated total volume of 12.9 ± 11.06 mL. All patients had an empty stomach criterion (calculated volume ≤1.5 mL/kg) during the ultrasound evaluation, with an average of 0.40 ± 0.23 mL/kg. With the qualitative assessment of gastric volume, 19 patients (38%) were classified as grade 0, 31 patients (62%) as grade 1, and none as grade 2.

Conclusion

One hour of fasting after ingestion of 3 mL/kg of a non-carbonated sports drink is sufficient to meet ultrasound criteria for an empty stomach in a pediatric population undergoing elective outpatient surgery.

Ultrasound Assessment of Gastric Fluid Volume in Children Scheduled for Elective Surgery After Clear Fluid Fasting for 1 Versus 2 Hours: A Randomized Controlled Trial

BACKGROUND

This study aimed to compare the gastric fluid volume (GFV) in children who fasted 1 versus 2 hours using ultrasound, after ingestion of a defined volume of clear fluid.

METHODS

Children scheduled for elective surgery were enrolled in this randomized, double-blinded, controlled trial. After receiving 3 mL kg -1 clear fluid, participants were randomized to have a gastric ultrasound after fasting for either 1 hour (1-hour group, n = 116) or 2 hours (2-hour group, n = 111). Our primary outcome was the GFV. Other outcomes included the antral cross-sectional area, frequency of high risk and low risk of aspiration, and qualitative grading for the gastric antrum.

RESULTS

Two hundred and twenty-seven children were available for final analysis. The median (Q1-Q3) GFV was higher in the 1-hour group versus the 2-hour group (0.61 [0.41-0.9] mL kg -1 vs 0.32 [0.23-0.47] mL kg -1 ; P value = .001). None of the study groups had GFV ≥1.5 mL kg -1 . The frequency (%) of GFV ≥1.25 mL kg -1 was comparable between both groups (2 [1.7%] vs 0 [0%], P value = .165). However, the frequency of GFV ≥0.8 mL kg -1 was higher in 1-hour group than in 2-hour group (34.5% vs 4.5%), and grade 2 antral grading score was 56.9% in 1-hour group vs 0.9% in 2-hour group ( P value <.001).

CONCLUSIONS

In healthy children scheduled for elective surgery receiving 3 mL kg -1 clear fluid, the median GFV after 1-hour fasting was double the volume after conventional 2-hour fasting. These findings should be considered whether weighting the risk/benefit of a liberal approach to preoperative fasting versus the risk of pulmonary aspiration.

Preoperative clear fluid fasting and endoscopy-measured gastric fluid volume in children

BACKGROUND

In light of new recommendations to shorten clear fluid fasting time before anesthesia, our study aimed at exploring residual fluid volume in the stomach after different fasting times. We intended to perform direct endoscopic aspiration of stomach contents under vision, as part of routine gastroscopy assessment. Hereby we would be able to quantify true residual gastric fluid volume and acidity in children and measure their correlation with fasting times.

METHODS

The study was performed as a single-center, prospective study in pediatric perioperative day care at a university-affiliated tertiary care center. Aspiration of gastric fluid contents was performed in anesthetized children aged 1-18 years undergoing an elective gastroscopy. Recorded data included patient fast time, last meal content, last clear fluid content, and aspirated gastric volume and pH, as well as patient characteristics.

RESULTS

We included 253 gastroscopies, performed in 245 children. Mean fasting time for clear fluids was 6.9 h (range 1 h 40 min - 18 h 35 min) (SD 4.5). Mean age was 9.8 years (SD 5.1) and mean body weight was 33.2 kg (SD 18.7). Mean residual gastric volume was 12 mL (0-90) (SD 13.5) or 0.34 mL/kg (SD 0.37) and mean pH was 1.5 (SD 0.9). No significant correlation was observed between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight (r = -.103, p = .1), nor between clear fluid fasting time and the pH of the residual gastric fluid (r = -.07, p = .3). In more than half of the patients the residual gastric volume was less than 10 mL, unrelated to fasting time.

CONCLUSIONS

In children undergoing gastroscopy, we could not demonstrate any association between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight. Since we did not see a clinically relevant association between clear fluids fasting time and gastric residual volume, this study may support the recommendation to shorten clear fluids fasting time.

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.

Gastrointestinal Fluid Volumes in Pediatrics: A Retrospective MRI Study

The volume and distribution of fluids available in the gastrointestinal (GI) tract may substantially affect oral drug absorption. Magnetic resonance imaging (MRI) has been used in the past to quantify these fluid volumes in adults and its use is now being extended to the pediatric population. The present research pursued a retrospective, explorative analysis of existing clinical MRI data generated for pediatric patients. Images of 140 children from all pediatric subpopulations were analyzed for their resting GI fluid volumes in fasting conditions. In general, an increase in fluid volume as a function of age was observed for the stomach, duodenum, jejunum, and small intestine (SI) as a whole. No specific pattern was observed for the ileum and colon. Body mass index (BMI), body weight, body height, and SI length were evaluated as easy-to-measure clinical estimators of the gastric and SI fluid volumes. Although weight and height were identified as the best estimators, none performed ideally based on the coefficient of determination (R2). Data generated in this study can be used as physiologically relevant input for biorelevant in vitro tests and in silico models tailored to the pediatric population, thereby contributing to the efficient development of successful oral drug products for children.

A pragmatic approach to quality improvement in pediatric anesthesia

PURPOSE OF REVIEW

The concept of quality improvement (QI) is well implemented in pediatric anesthesia. Conductance, reporting and publishing of QI projects and -results is well described and promoted. However, the perception of quality might differ between stakeholders and beneficiaries. Based on measures of quality as perceived by healthcare professionals and pediatric patients, a pragmatic approach to choosing the relevant quality measure is suggested.

RECENT FINDINGS

Design of QI projects is often motivated by an incentive to avoid errors and adverse events, and with an overall aim to reduce morbidity and mortality. From a patient- and parent point of view, avoidance of perioperative stress and anxiety might be a priority measure of quality.

SUMMARY

In an attempt to embrace both perspectives of quality in pediatric anesthesia care, it is suggested to choose quality items for improvement based on patient safety, professional excellency and benignancy. By following this approach, QI is expected to remain relevant to both healthcare professionals and patients.

Ultrasound-Determined Residual Gastric Volume after Clear-Fluid Ingestion in the Paediatric Population: Still a Debatable Issue

Background: Current fasting guidelines are often exceeded in clinical practice, resulting in stressful events during anaesthesia in children. This prospective study compares residual gastric volume after 1 versus 2 h of clear fluid ingestion in fasted children. METHODS: A total of 106 patients were enrolled in the study. Ultrasonography (USG) of gastric antrum (GA) was performed in the supine and right lateral decubitus (RLD) positions. All children fasted from solid food for 6 h. Blackcurrant flavoured drink (3 mL/kg) was given following the measurement of baseline (T0) USG of GA, with follow-ups after 1 (T1) and 2 (T2) hours post-ingestion. Residual gastric volume (RGV) was calculated from the cross-sectional area of GA using a standard formula. Parental satisfaction with their children’s behaviour concerning fasting time was recorded. Results: RGV was significantly higher at T1 compared to T2 (p < 0.001). No significant difference was seen between T0 and T2 (p = 0.30). Parental satisfaction was similar at T1 and T2 (p = 0.158). Conclusions: The RGV in paediatric patients after 1 h of clear fluid ingestion was significantly higher than after 2 h of ingestion. There was no difference observed in parental satisfaction concerning the two intervals of fluid fasting. RLD and supine positions can be used reliably to measure the RGV in children.

Effect of pre-operative oral paracetamol on gastric residual volume and pH in young children in the context of a 1-hour clear fluid fast: a randomised controlled trial

High gastric residual volume and low pH are associated with increased mortality following pulmonary aspiration in animal studies. The use of pre-operative oral paracetamol has not been investigated in younger children and infants in the context of a prescriptive 1-h clear fluid fast aimed at reducing the risk of pulmonary aspiration while improving patient experience. Children aged 1 month up to a weight of 25 kg and scheduled for elective surgery were randomly allocated to receive a prescribed 3.6 ml.kg^-1 drink of water alone (water group) or 3 ml.kg^-1 water and oral Infant Calpol® syrup (24 mg.ml^-1 concentration, equivalent volume 0.6 ml.kg^-1 , paracetamol group) 1 h before the induction of anaesthesia. Following induction, a nasogastric tube was used to aspirate gastric contents and the volume and pH were recorded. Ninety-seven children, median (IQR [range]) age 24 (12-45 [1-96]) months and weight 12.4 (9.7-16.0 [2.9-27.0]) kg, were analysed. Median time from drink to induction was 54 (45-60 [21-113]) min. There was no significant difference in gastric residual volume (p = 1) or pH (p = 0.99) between the water and the paracetamol groups. Sub-group analysis revealed no significant difference in gastric residual volume or pH for 29 children who weighed < 10 kg compared with > 10 kg. Using a prescriptive fluid regime of 3 ml.kg^-1 of water, the addition of oral paracetamol syrup did not significantly alter gastric residual volume or pH in the context of a 1-h fast in infants and young children.

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

Pre-operative fasting in children: A guideline from the European Society of Anaesthesiology and Intensive Care

Current paediatric anaesthetic fasting guidelines have recommended conservative fasting regimes for many years and have not altered much in the last decades. Recent publications have employed more liberal fasting regimes with no evidence of increased aspiration or regurgitation rates. In this first solely paediatric European Society of Anaesthesiology and Intensive Care (ESAIC) pre-operative fasting guideline, we aim to present aggregated and evidence-based summary recommendations to assist clinicians, healthcare providers, patients and parents. We identified six main topics for the literature search: studies comparing liberal with conservative regimens; impact of food composition; impact of comorbidity; the use of gastric ultrasound as a clinical tool; validation of gastric ultrasound for gastric content and gastric emptying studies; and early postoperative feeding. The literature search was performed by a professional librarian in collaboration with the ESAIC task force. Recommendations for reducing clear fluid fasting to 1 h, reducing breast milk fasting to 3 h, and allowing early postoperative feeding were the main results, with GRADE 1C or 1B evidence. The available evidence suggests that gastric ultrasound may be useful for clinical decision-making, and that allowing a 'light breakfast' may be well tolerated if the intake is well controlled. More research is needed in these areas as well as evaluation of how specific patient or treatment-related factors influence gastric emptying.

The effect of acetate Ringer's solution versus lactate Ringer's solution on acid base physiology in infants with biliary atresia

BACKGROUND

The choice of the perioperative crystalloid is a key component of the fluid management and must take into account the liver function and the appearing metabolic disorders to avoid increase the liver extra metabolism. The aim of this study is to analyze the effect of acetate Ringer's solution or lactate Ringer's solution in biliary atresia patients.

METHODS

We included 68 infant patients aged between 21 ~ 65 d, ASA physical status II or III, who underwent elective Kasai hepatoportoenterostomy, received either AR and LR for intravenous fluid resuscitation according to their group allocation. Lactate concentration, serum electrolytes and pH were noteded before skin incision (T₁), end of surgery (T₂) and postoperative 12 h. We also recorded the time of operation, stay of hospital, loss of blood and urinary, total volume of infusion of crystalloid.

RESULTS

Lactate level was significantly higher in Group LR than in Group AR patients at T₂ (0.76 ± 0.13 versus 0.57 ± 0.22, P = 0.03). Compared with T₃, sodium and chlorine were significantly higher in two groups at T₂ (145.2 ± 3.1 versus 143.4 ± 3.4 and 104.6 ± 3.7 versus 105.2 ± 2.1). No significant differences were noted in potassium, HCO₃^- and calcium. There was no statistically significant difference in pH. No glycopenia was recorded in two groups. No significant difference was noted in administration of vasoactive drug (0.7% versus 1%).

CONCLUSIONS

Resuscitation with AR and LR was associated with similar clinical improvement in infants with biliary atresia. Use of AR reduced the level of lactate comparison with LR.

Gastric emptying time of two different quantities of clear fluids in children: A double-blinded randomized controlled study

BACKGROUND

Perioperative pulmonary aspiration risk increases with increased preoperative gastric volume; hence traditionally, healthy children are kept fasted overnight before surgery. Current guidelines recommend 2-h clear fluids fasting prior to anesthesia. However, emerging evidence favors allowing 3 ml/kg clear fluids up to 1-h before anesthesia. We compared the gastric volume and gastric emptying time after ingestion of 3 ml/kg and 5 ml/kg of clear fluids.

METHODS

The present study enrolled 44 children, aged between 6 and 14 years. On the day of surgery, baseline gastric volume was estimated using ultrasound and patients were randomly allocated into two groups of equal number, that is, Group 3 and Group 5 (patients received 3 ml/kg and 5 ml/kg 5% Dextrose respectively). Repeated gastric ultrasound was performed at every 5 min until the gastric volume reached baseline levels. The primary objective of the study was to compare gastric emptying time. Secondary objectives included comparison of antral cross-sectional area and gastric volume.

RESULTS

The demographic profile, preoperative fasting duration for clear fluids, and baseline gastric volume were comparable between groups. In both groups, compared to baseline the antral cross-sectional area and gastric volume increased significantly following fluid ingestion and then decreased exponentially to reach baseline within 1-h. The median (IQR) (range) gastric emptying time (minutes) [35.0 (28.8, 40.0) (20.0-45.0) in group 3 and 40.0 (28.8, 45.0) (20.0-50.0) in group 5] and emptying half-time (minutes) [17.0 (15.7, 21.5) (14.4-24.0) in group 3 and 18.6 (16.0, 22.0) (15.1-23.8) in group 5] were comparable [median difference -5 (95% CI -7.8 to 2.1) and -1.5 (95% CI -2.3 to 1.0), respectively] (p = .16 and p = .44, respectively).

CONCLUSION

As the gastric volume returned to baseline within 1-h even after ingesting 5 ml/kg clear fluids, the preoperative fasting time can be reduced to 1-h and healthy children undergoing elective procedure can be safely allowed to drink up to 5 ml/kg clear fluids.

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.

GASTRIC RESIDUAL VOLUME FACTORS AFTER BOWEL PREPARATION WITH MANNITOL EXPRESS

BACKGROUND

Bowel preparation with mannitol is a well-established method in Brazil. However, factors that interfere with the gastric emptying time period are yet to be known. Knowing these factors may favor the examination scheduling logistics and the individualized orientation for each patient.

OBJECTIVE

Know the factors that can contribute to the gastric emptying time after intestinal preparation with express mannitol.

METHODS

This is a prospective observational study to know factors that may contribute on the gastric emptying timing: predominant type of diet, comorbidities, medication usage, previous surgeries, number of evacuation per week, bearer of bowel obstipation, fecal type, diet type, number of evacuations after the home usage of bisacodyl before the ingestion of mannitol and number of evacuations after the ingestion of mannitol until reaching a proper bowel preparation. Before starting the colonoscopy exam, an upper digestive endoscopy exam was made to aspirate the gastric content.

RESULTS

Sample was composed of 103 patients, 55 (53.4%) women, medium age 61 (±12.1) years, medium weight 75.3 (±14.1) kg, medium height 1.7 (±10) m and medium BMI of 26.6 (±3.9) kg/m2. Average gastric residual volume was 120.9 (0-900) mL. Gastric residual volume (GRV) below 100 mL (GRV ≤100 mL) occurred in 45 (43.6%) patients, 24 (53.3%) women, medium age of 61.0 years and medium BMI of 26.7 kg/m2. Gastric residual volume above 100 mL (GRV >100 mL) occurred on 58 (56.3%) patients, 29 (50%) women, medium age of 61.0 years and medium BMI of 26.2 kg/m2. Comparing both groups, average fasting time period after the ingestion of mannitol was significantly higher on the group with GRV ≤100 mL than group with GRV >100 mL, 123.1 (60-246) vs 95.3 (55-195) minutes, respectively. There was also statistical significance concerning the usage of ezetimibe 6 (13.7%) in the group with GRV ≤100 mL and statistical significance in the group with GRV >100 mL concerning the usage of paroxetine 3 (6.7%) and tadalafil 3 (6.7%) and surgical history of prostatectomy 3 (6.7%) and bridle withdrawal 3 (6.7%).

CONCLUSION

We may conclude in this study that the usage of ezetimibe and fasting above 2 hours after the ingestion of mannitol decrease significantly the incidence of a GRV >100 mL. The usage of paroxetine, tadalafil and surgical history of prostatectomy or bridle withdrawal may contribute to increase de incidence of a GRV >100 mL.

Pre-operative fasting times for clear liquids at a tertiary children's hospital; what can be improved?

Background

The goal of preoperative fasting is to prevent pulmonary aspiration during general anesthesia. Fasting times are often prolonged leading to patient discomfort and risk for adverse events. This retrospective quality improvement survey evaluated effective nil-per-os (NPO) times and causes for prolonged NPO times with the aim to suggest improvement strategies by a newly founded fasting task force.

Methods

Data from all electronic anesthesia records from 2019 at our institution were reviewed for fasting times. Our NPO instructions follow American Society of Anesthesiology guidelines and are calculated based on the patient’s arrival time (90 min before operating room [OR] time). Primary outcome was the effective NPO time for clear liquids, secondary outcomes were incidence of delays and the parental compliance with the NPO instructions. Data are presented as median (interquartile range).

Results

In total 9,625 cases were included in the analysis. NPO time was documented in 72.1% with a median effective NPO time of 7:13 h (7:36). OR in room times were documented in 72.8%, 2,075 (29.5%; median time 0:10 h [0:21]) were earlier and 4,939 (70.5%; median time 0:29 h [0:54]) were later than scheduled. Parental NPO compliance showed a median deviation for clear liquid intake of 0:55 h (8:30).

Conclusions

This study revealed that effective NPO times were longer than current ASA guidelines. Contributing causes include case delays and parental non-compliance to NPO instructions. Thus, task force recommendations include change NPO instruction calculations to scheduled OR time versus arrival time, and encourage parents to give their child clear liquids at the instructed time.

Observance of preoperative clear fluid fasting in pediatric anesthesia: oral and written information versus text message information. A before-and-after study

INTRODUCTION

Prolonged fasting before surgery is common in pediatrics. In the literature, it is responsible for hypotension, irritability and postoperative nausea and vomiting. Despite clear instructions given during the preanesthetic consultation, fasting rules are respected in only 30%-40% of cases. We aimed to evaluate the benefit of sending a text message the day before surgery to improve the parents' observance of fasting rules.

METHODS

We conducted a before-and-after study at the University Hospital of Poitiers. From August to October 2018, 172 parents of children under 15 years of age scheduled for all types of surgery were enrolled into two groups according to the period: the control group with parents receiving information on preoperative fasting rules during the preanesthetic consultation several days before surgery, and the text message group, receiving the same information during consultation plus a text message the day before the surgery.

RESULTS

There was a difference in observance of clear fluid fasting instructions (between 2 and 3 h before the admission at hospital) in favor of the text message group 33% versus 92% OR 29.2 (10.9-95.2) p < 0.001, and in average fasting time for clear fluids 8.7 h ± 4.8 h vs. 4.3 h ± 2.4 h (p < 0.001).

CONCLUSION

Sending of a reminder text message to the parents the day before the surgery resulted in a significant increase in observance of fasting rules in children undergoing scheduled surgery.

Effects of a short message service (SMS) by cellular phone to improve compliance with fasting guidelines in patients undergoing elective surgery: a retrospective observational study

Background

Contemporary perioperative fasting guidelines aim to alleviate patient discomfort before surgery and enhance postoperative recovery whilst seeking to reduce the risk of pulmonary aspiration during anesthesia. The impact of a short message service (SMS) reminder on fasting guideline compliance is unknown. Therefore, we performed a retrospective observational study and quality improvement project aiming to quantify the extent of excessive and prolonged fasting, and then assessed the impact of a SMS reminder in reducing fasting times.

Methods

After ethics committee approval we performed a retrospective observational study investigating preoperative fasting times of adult patients undergoing elective surgery. First, we assessed whether the fasting guideline times were adhered to (Standard Care group). All patients received internationally recommended fasting guidelines in the form of a written hospital policy document. We then implemented an additional prompt via a mobile phone SMS 1 day prior to surgery containing a reminder of fasting guideline times (SMS group). The primary aims were to compare fasting times between the Standard Care group and the SMS group.

Results

The fasting times of 160 patients in the Standard Care group and 110 patients in the SMS group were evaluated. Adherence to the fasting guidelines for solids occurred in 14 patients (8.8%) in the Standard Care group vs. Twenty-two patients (13.6%) in the SMS group (p=0.01). Adherence to the fasting guidelines for fluids occurred in 4 patients (2.5%) in the Standard Care group vs. Ten patients (6.3%) in the SMS group (p=0.023). Patients in the Standard Care group had a longer median (inter-quartile range (IQR)) fasting time for fluids compared the SMS group [6.5 h (IQR 4.5:11) vs 3.5 h (IQR 3:8.5), p< 0.0001]. Median fasting times for solids were 11 h (IQR 7:14) in the Standard Care group and 11.5 h (IQR 7:13.5) in the SMS group (p=0.756).

Conclusion

Adherence to internationally recommended fasting guidelines for patients undergoing elective surgery is poor. The introduction of a fasting guideline reminder via a mobile phone SMS in addition to a written hospital policy improved adherence to fasting advice and reduced the fasting times for fluids but not for solids. The use of an SMS reminder of fasting guidelines is a simple, feasible, low-cost, and effective tool in minimising excessive fasting for fluids among elective surgical patients.

Trial registration

ACTRN12619001232123 (Australia New Zealand Clinical Trials Registry). Registered 6th September 2019 (retrospectively registered).

Characterisation of fasted state gastric and intestinal fluids collected from children

Fundamental knowledge about the composition of intestinal fluids in paediatric populations is currently unavailable. This study aimed to characterise gastric and intestinal fluid from paediatric populations. Gastric and intestinal fluid samples were obtained during routine clinical endoscopy from paediatric patients at a large teaching hospital. These fluids were characterised to measure the pH; buffer capacity; osmolality; bile acid concentration and composition. A total of 55 children were recruited to the study aged from 11 months to 15 years of age where 53 gastric fluid samples and 40 intestinal fluid samples were obtained. pH values recorded ranged from pH 0.57 to 11.05 (median: 2.50) in gastric fluids and from 0.89 to 8.97 (median: 3.27) in intestinal fluids. The buffer capacity did not change significantly between gastric and intestinal fluids with median values of 12 mM/L/ΔpH for both fluids. Gastric fluid osmolality values ranged from 1 to 615 mOsm/kg, while intestinal fluid values ranged from 35 to 631 mOsm/kg. Gastric fluid bile acid concentrations ranged from 0.002 to 2.3 mM with a median value of 0.017 mM whilst intestinal fluid bile acid concentrations ranged from 0.0008 to 3.3 mM with a median value of 0.178 mM. Glycocholate; taurocholic acid; glycochenodeoxycholate and taurochenodeoxycholate were the most commonly identified bile acids within paediatric intestinal fluids. All compositional components were associated with large inter-individual variability. Further work is required to develop simulated paediatric media and to explore the impact of these media on drug solubility and dissolution.

Interventions Aimed at Reducing Fasting Times in Acute Hospital Patients: A Systematic Literature Review

Despite current guidelines recommending fasting from solids for ≤6 hours and clear fluids for ≤2 hours prior to surgery, outdated practices endure; patients fast for unnecessarily prolonged periods because of beliefs regarding aspiration risk upon anaesthesia induction. This literature review aimed to identify and evaluate current interventions aiming to reduce preoperative fasting times for acutely ill hospital patients, summarizing effective interventional strategies and associated outcomes. EMBASE, MEDLINE, PreMEDLINE, and CINAHL were systematically searched. Quality of evidence was assessed using Cochrane risk-of-bias tools. Studies, of any type, reporting fasting times as a primary or secondary outcome were included. A total of 1918 potential studies were identified; of these, 16 studies were included. Seven studies investigated the effect of changing fasting protocol on gastric fluid volume/residual gastric volume (GFV/RGV) and gastric pH as surrogate measures for aspiration risk. No significant differences in GFV/RGV and gastric pH due to reduced preoperative fasting were reported, thus no change in aspiration risk. Eight studies documented improvements in patient-reported outcomes with shorter fasting times. However, this review identified a paucity of studies that trialled interventions to reduce fasting times as the primary aim. These interventions were multimodal and multidisciplinary in nature, incorporating principles of implementation science to successfully achieve significant reductions in fasting times. This review highlights that reducing the preoperative fasting period is safe while improving patient's physical and psychological well-being. Further high-quality studies that investigate multimodal interventions, and that utilize implementation science principles, are required in this area.

Effect of Oral Glucose Water Administration 1 Hour Preoperatively in Children with Cyanotic Congenital Heart Disease: A Randomized Controlled Trial

Background

Guidelines recommend a clear liquid fasting time of 2 h before surgery, which is often exceeded, leading to adverse reactions (ARs) such as discomfort, thirst, and dehydration. We assessed the gastric contents and ARs after oral glucose water administration 1 h prior to surgery in children with cyanotic congenital heart disease (CCHD).

Material/Methods

This was a non-inferiority randomized controlled trial of children with CCHD enrolled at the Fujian Medical University Union Hospital from 09/2014 to 05/2017 and randomized to receive oral glucose water (10 g of glucose in 100 ml of warm water, 5 ml/kg) 2 h (2-h group, n=174) or 1 h (1-h group, n=170) before surgery. The primary endpoint was gastric volume. Secondary endpoints included pH of gastric content, preoperative blood glucose, and risk factors for aspiration pneumonia. Pre- and intraoperative ARs were recorded.

Results

The 1-h group showed smaller gastric content volumes (0.34±0.35 (95% CI: 0.29–0.39) vs. 0.43±0.33 (95% CI: 0.38–0.48) ml/kg, t=2.55, P<0.05) and higher blood glucose (6.21±0.78 (95% CI: 6.09–6.33) vs. 5.59±1.11 (95% CI: 5.43–5.76) mmol/L, t=−5.91, P<0.001). The 95% confidence interval of the volume difference between the 2 groups was 0.017–0.163, the upper limit value was 0.163 <δ=0.2 (P<0.01). The non-inferiority hypothesis was correct. The 1-h group showed lower incidence of crying, thirst and hypoxia (all P<0.05 vs. 2-h group). There were no differences in ARs between the 2 groups.

Conclusions

A 1-h fast prior to surgery was not inferior to a 2-h fast in terms of gastric residuals and ARs in pediatric patients with CCHD.

Clinical trial registration: http://www.chictr.org.cn/showprojen.aspx?proj=9563

Registration number: ChiCTR-IPR-14005270

Metabolic and Inflammatory Benefits of Reducing Preoperative Fasting Time in Pediatric Surgery

OBJECTIVE

To investigate the metabolic/inflammatory impact of reducing the preoperative fasting time in preschool children.

METHODS

Forty children were randomly assigned to a fasting group (absolute fasting after 00:00) and a carbohydrate (CHO) group (allowed to ingest, two hours before surgery, a carbohydrate-rich beverage). Blood samples were collected right before and after surgery to quantify the levels of albumin, interleukin-6, glucose, insulin, C-reactive protein and to calculate insulin resistance by the HOMA-IR index.

RESULTS

Preoperative fasting time in the CHO group were shorter than in the fasting group (2.49h vs. 11.24h, p <0.001). Pre- and post-surgical CRP levels were significantly lower in the CHO group (p = 0.05 and p = 0.02, respectively). The preoperative CRP/albumin ratios in the CHO group were lower than in the fasting group (p = 0.03). Four patients (21%) in the fasting group but none in the CHO group were hyperglycemic before surgery (p = 0.04). The two groups had similar levels of albumin, interleukin-6, insulin and HOMA index. There were no adverse events.

CONCLUSION

Reducing the preoperative fasting time with carbohydrate-rich beverages improves the perioperative metabolic and inflammatory responses of preschool children undergoing inguinal hernia surgery.

Ultrasonographic evaluation of gastric emptying after ingesting carbohydrate-rich drink in young children: A randomized crossover study

BACKGROUND

A recent consensus statement in Europe has suggested that the fasting time for clear liquid in children can be shortened to 1 hour before a surgery. However, the study to show that 1-hour fasting time for clear fluids is safe in young children is still lacking. This study aimed to investigate the gastric emptying time for carbohydrate-rich drink and regular 5% glucose solution in children aged 3-7 years.

METHODS

After overnight fasting, individuals were randomly assigned to ingest 5 mL kg^-1 of either carbohydrate-rich drink or 5% glucose solution. One week later, the same subjects were asked to ingest the other one. Ultrasonography was performed to examine the gastric contents. Gastric antral cross-sectional area was measured, and the gastric fluid volume was calculated before and after fluid ingestion within 120 minutes. The primary outcome was the gastric emptying time for both the clear fluids calculated using the antral cross-sectional area and logarithms of gastric fluid volume. The degrees of thirst and hunger of two drinks were evaluated using a visual analogue scale as the secondary outcomes.

RESULTS

Data from 16 individuals were analyzed. In the glucose solution group, the antral cross-sectional area and logarithms of gastric fluid volume returned to baseline at 30 minutes after ingestion. However, in the carbohydrate-rich drink group, the median [interquartile range; range] antral cross-sectional area (3.69 [2.64-5.15; 1.83-8.93] cm² vs 2.41 [2.10-2.96; 1.81-4.37] cm² , P < .001) and mean (95% confidence interval) logarithms of gastric fluid volume (2.54 [2.30-2.79] mL vs 2.12 [1.94-2.30] mL, P = .048) were still higher than at 60 minutes and returned to the baseline values at 90 minutes after ingestion, respectively. The degree of thirst was lower in the glucose solution group than that in the carbohydrate-rich drink group.

CONCLUSIONS

Gastric emptying of carbohydrate-rich drink is slower than that of 5% glucose solution but the residual gastric fluid volume is low one hour after ingestion of 5 mL kg^-1 of either fluid.

Real fasting times and incidence of pulmonary aspiration in children: Results of a German prospective multicenter observational study

BACKGROUND

Prolonged fasting before anesthesia is still common in children. Shortened fasting times may improve the metabolic and hemodynamic condition during induction of anesthesia and the perioperative experience for parents and children and simplify perioperative management. As a consequence, some centers in Germany have reduced fasting requirements, but the national guidelines are still unchanged.

AIMS

This prospective multicenter observational study was initiated by the Scientific Working Group for Pediatric Anesthesia of the German Society of Anesthesiology and Intensive Care Medicine to evaluate real fasting times and the incidence of pulmonary aspiration before a possible revision of national fasting guidelines.

METHODS

After the Ethics Committee's approval, at least 3000 children were planned to be enrolled for this analysis. Patient demographics, real fasting times, anesthetic and surgical procedures and occurrence of regurgitation or pulmonary aspiration were documented using a standardized case report form. Results were presented as median [interquartile range] (range) or incidence (percentage).

RESULTS

At ten pediatric centers, 3324 children were included between October 2018 and May 2019. The real fasting times for large meals were 14 [12.2-15.6] (0.5-24) hours, for light meals 9 [5.6-13.3] (0.25-28.3) hours, for formula milk 5.8 [4.5-7.4] (0.9-24) hours, for breast milk 4.8 [4.2-6.3] (1.3-25.3) hours and for clear fluids 2.7 [1.5-6] (0.03-22.8) hours. Prolonged fasting (deviation from guideline >2 hours) was reported for large meals in 88.3%, for light meals in 54.7%, for formula milk in 44.4%, for breast milk in 25.8% and for clear fluids in 34.2%. Eleven cases (0.33%) of regurgitation, four cases (0.12%) of suspected pulmonary aspiration and two cases (0.06%) of confirmed pulmonary aspiration were reported; all of them could be extubated after the end of the procedure and recovered without any incidents.

CONCLUSION

This study shows that prolonged fasting is still common in pediatric anesthesia in Germany that pulmonary aspiration with postoperative respiratory distress is rare and that improvements to current local fasting regimens and national fasting guidelines are urgently needed.

Perioperative fasting: A review

Preprocedural/preoperative fasting is a key part of preparing a patient for undergoing sedation or anaesthesia to minimise the risk of pulmonary aspiration of gastric contents. As part of caring for elective surgical patients it is important that healthcare staff in the perioperative environment have a good understanding of both the current guidelines and underpinning evidence so that they can effectively manage preoperative patients. This article looks to summarise the latest guidelines regarding perioperative fasting for adult and paediatric patients, the underlying evidence behind these guidelines and finally review current literature which will inform future practice. This article therefore looks to reinforce best practice, to ensure that the safety and comfort of patients in the perioperative period is optimised.

Perioperative fluid management in children: can we sum it all up now?

PURPOSE OF REVIEW

The composition and type of intravenous fluids during paediatric anaesthesia have been subjects of debates for decades. Errors in perioperative fluid management in children may lead to serious complications and a negative outcome. Therefore, in this review, historical and recent developments and recommendations for perioperative fluid management in children are presented, based on physiology and focused on safety and efficacy.

RECENT FINDINGS

Optimized fasting times and liberal clear fluid intake until 1 h improve patient comfort and metabolic and haemodynamic condition after induction of anaesthesia. Physiologically composed balanced isotonic electrolyte solutions are safer than hypotonic electrolyte solutions or saline 0.9% to protect young children against the risks of hyponatraemia and hyperchloraemic acidosis. For intraoperative maintenance infusion, addition of 1-2% glucose is sufficient to avoid hypoglycaemia, lipolysis or hyperglycaemia. Modified fluid gelatine or hydroxyethyl starch in balanced electrolyte solution can safely be used to quickly normalize blood volume in case of perioperative circulatory instability and blood loss.

SUMMARY

Physiologically composed balanced isotonic electrolyte solutions are beneficial for maintaining homeostasis, shifting the status more towards the normal range in patients with preexisting imbalances and have a wide margin of safety in case of accidental hyperinfusion.

Quality improvement project to reduce pediatric clear liquid fasting times prior to anesthesia

BACKGROUND

Unnecessarily long preprocedural fasting can cause suffering and distress for children and their families. Institutional fasting policies are designed to consistently achieve minimum fasting times, often without regard to the extent to which actual fasting times exceed these minimums. Children at our hospital frequently experienced clear liquid fasting times far in excess of required minimums.

AIMS

The aim of this study was to utilize quality improvement methodology to reduce excess fasting times, with a goal of achieving experienced clear liquid fasting times ≤4 hours for 60% of our patients.

METHODS

This quality improvement project was conducted between July 2017 and August 2018. A multidisciplinary team performed a series of Plan-Do-Study-Act cycles focused on children undergoing elective procedures at a large children's hospital. Key drivers for clear liquid fasting times and relevant balancing measures were identified. Data were analyzed using control charts and statistical process control methods.

RESULTS

Approximately 16 000 children were involved in this project. Over the course of the project, the percentage of children with goal clear liquid fasting times improved from the baseline of 20%-63%, with a change in the mean fasting time from 9 hours to 6 hours. There were no significant effects on balancing measures (case delays/cancellations and clinically significant aspiration events).

CONCLUSION

Using quality improvement methodology, we safely improved the duration of preoperative fasting experienced by our patients. Our results provide additional data supporting the safety of more permissive 1-hour clear liquid fasting minimums. We suggest other institutions pursue similar efforts to improve patient and family experience.

Ultrasound dynamics of gastric content volumes after the ingestion of coconut water or a meat sandwich. A randomized controlled crossover study in healthy volunteers

Background

Adequate preoperative fasting is critical in preventing pulmonary aspiration of gastric content. We proposed to study the sonographic gastric content dynamics after the ingestion of liquid or solid food in healthy volunteers and confront it with current guidelines for preoperative fasting times.

Methods

We performed a prospective, crossover, evaluator-blinded study involving 17 healthy volunteers of both sexes. Each participant fasted for 10 h and was subjected to a baseline gastric ultrasound, intake of 400 mL of coconut water or a 145 g, 355 kcal meat sandwich, and sonographic gastric evaluations after 10 min and every hour until the stomach was completely empty.

Results

At baseline, all subjects had an empty stomach. At 10 min, gastric content [mean + standard deviation (SD)] was 240.4 + 69.3 and 248.2 + 119.2 mL for liquid and solid foods, respectively (p > 0.05). Mean + SD gastric emptying times were 2.5 + 0.7 and 4.5 + 0.9 h for liquid and solid foods, respectively (p < 0.001). For the drink, the stomach was completely empty in 59% and 100% of the subjects after two and four hours, and for the sandwich, 65% and 100% of the subjects after four and seven hours, respectively.

Conclusions

Sonographic gastric dynamics for coconut water and a meat sandwich resulted in complete gastric emptying times higher and lower, respectively, than those suggested by current guidelines for preoperative fasting.

[Ultrasound dynamics of gastric content volumes after the ingestion of coconut water or a meat sandwich. A randomized controlled crossover study in healthy volunteers]

BACKGROUND

Adequate preoperative fasting is critical in preventing pulmonary aspiration of gastric content. We proposed to study the sonographic gastric content dynamics after the ingestion of liquid or solid food in healthy volunteers and confront it with current guidelines for preoperative fasting times.

METHODS

We performed a prospective, crossover, evaluator-blinded study involving 17 healthy volunteers of both sexes. Each participant fasted for 10h and was subjected to a baseline gastric ultrasound, intake of 400mL of coconut water or a 145g, 355kcal meat sandwich, and sonographic gastric evaluations after 10min and every hour until the stomach was completely empty.

RESULTS

At baseline, all subjects had an empty stomach. At 10min, gastric content [mean + standard deviation (SD)] was 240.4 + 69.3 and 248.2 + 119.2mL for liquid and solid foods, respectively (p>0.05). Mean + SD gastric emptying times were 2.5 + 0.7 and 4.5 + 0.9h for liquid and solid foods, respectively (p<0.001). For the drink, the stomach was completely empty in 59% and 100% of the subjects after two and four hours, and for the sandwich, 65% and 100% of the subjects after four and seven hours, respectively.

CONCLUSIONS

Sonographic gastric dynamics for coconut water and a meat sandwich resulted in complete gastric emptying times higher and lower, respectively, than those suggested by current guidelines for preoperative fasting.

Biopharmaceutical considerations in paediatrics with a view to the evaluation of orally administered drug products - a PEARRL review

OBJECTIVES

In this review, the current biopharmaceutical approaches for evaluation of oral formulation performance in paediatrics are discussed.

KEY FINDINGS

The paediatric gastrointestinal (GI) tract undergoes numerous morphological and physiological changes throughout its development and growth. Some physiological parameters are yet to be investigated, limiting the use of the existing in vitro biopharmaceutical tools to predict the in vivo performance of paediatric formulations. Meals and frequencies of their administration evolve during childhood and affect oral drug absorption. Furthermore, the establishment of a paediatric Biopharmaceutics Classification System (pBCS), based on the adult Biopharmaceutics Classification System (BCS), requires criteria adjustments. The usefulness of computational simulation and modeling for extrapolation of adult data to paediatrics has been confirmed as a tool for predicting drug formulation performance. Despite the great number of successful physiologically based pharmacokinetic models to simulate drug disposition, the simulation of drug absorption from the GI tract is a complicating issue in paediatric populations.

SUMMARY

The biopharmaceutics tools for investigation of oral drug absorption in paediatrics need further development, refinement and validation. A combination of in vitro and in silico methods could compensate for the uncertainties accompanying each method on its own.

CHANGING PARADIGMS IN PREOPERATIVE FASTING: RESULTS OF A JOINT EFFORT IN PEDIATRIC SURGERY

Background:

Current researches associate long fasting periods to several adverse consequences. The fasting abbreviation to 2 h to clear liquids associated with the use of drinks containing carbohydrates attenuates endocrinometabolic response to surgical trauma, but often is observed children advised to not intake food from 00:00 h till the scheduled surgical time, regardless of what it is.

Aim:

To evaluate the safety of a protocol of preoperative fasting abbreviation with a beverage containing carbohydrates, and early postoperative feeding in children underwent elective small/mid-size surgical procedures during a national task-force on pediatric surgery.

Methods:

Thirty-six patients were prospectively included, and for several reasons five were excluded. All 31 who remained in the study received a nutritional supplement containing 150 ml of water plus 12.5% maltodextrin 2 h before the procedure. Data of the pre-operative fasting time, anesthetic complications and time of postoperative refeeding, were collected.

Results:

Twenty-three (74.2%) were males, the median age was 5 y, and the median weight was 20 kg. The median time of pre-operative fasting was 145 min and the time of post-operative refeeding was 135 min. There were no adverse effects on the anesthetic procedures or during surgery. Post-operatively, two children (6.5%) vomited.

Conclusion:

The abbreviation of pre-operative fasting to 2 h with beverage containing carbohydrate in pediatric surgery is safe. Early refeeding in elective small/mid-size procedures can be prescribed.

Racional:

Trabalhos atuais associam longos períodos de jejum com diversas consequências adversas. A abreviação do jejum de 2 h para líquidos claros associado ao uso de bebidas contendo carboidratos atenua resposta endocrinometabólica ao trauma, porém frequentemente as crianças são orientadas a não ingerir alimentos a partir das 00:00 h do dia anterior à operação, independente do horário do procedimento cirúrgico.

Objetivo:

Avaliar a segurança de um protocolo de abreviação do jejum pré-operatório, com o uso de bebida contendo carboidratos, e realimentação precoce.

Métodos:

Foram avaliados prospectivamente 36 crianças submetidas a procedimentos cirúrgicos eletivos de pequeno e médio porte. Cinco foram posteriormente excluídos do estudo. Todos os 31 remanescentes receberam suplemento nutricional com maltodextrina 12,5% em 150 ml de água aproximadamente 2 h antes do procedimento. Foram coletados dados do tempo de jejum pré-operatório, complicações anestésicas e tempo de realimentação.

Resultados:

Vinte e três (74,2%) eram do gênero masculino, com idade mediana de cinco anos e peso mediano de 20 kg. O tempo mediano de jejum pré-operatório foi de 145 min e o tempo mediano para realimentação foi de 135 min. Não houve eventos adversos durante a anestesia ou operação. No período pós-operatório, duas (6,5%) crianças vomitaram.

Conclusão:

A abreviação de jejum pré-operatório para 2 h com uso de bebida contendo carboidratos, em operações eletivas de crianças, é seguro e não está associado ao maior risco de broncoaspiração pulmonar. Realimentação precoce pode ser prescrita nos procedimentos cirúrgicos analisados.