Ultrasound assessment of gastric volume in older adults after drinking carbohydrate-containing fluids: a prospective, nonrandomized, and noninferiority comparative study

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.

The safety of preoperative carbohydrate drinks in extremely elderly patients assessed by gastric ultrasonography: a randomized controlled trial

BACKGROUND

Modern perioperative guidelines encourage drinking oral carbohydrates 2 h before management. Nevertheless, research on the safety of preoperative carbohydrate drinks, particularly in extremely elderly patients is lacking. We aimed to evaluate the safety of carbohydrate drinks 2 h before surgery in extremely elderly patients (≥ 80 years) using gastric ultrasonography.

METHODS

We conducted a randomized prospective comparative study of 70 patients aged over 80 years who were scheduled for total knee arthroplasty, hip fracture or humerus fracture surgery. These patients were randomly assigned to the carbohydrate group (n = 35), which fasted from midnight, except for drinking 355 mL of a carbohydrate-containing fluid 2 h before surgery, or the fasting group (n = 35), which fasted from midnight and drank no fluid before surgery. The primary outcome of the study was the cross-sectional area (CSA) of the gastric antrum in the right lateral decubitus position (RLDP) before surgery. The secondary outcomes included CSA in the supine position, intraoperative blood glucose levels and their variability coefficients, Perlas grade, and the visual analog scale of subjective feelings.

RESULTS

The CSA in the RLDP and supine positions revealed no differences between the carbohydrate and fasting groups at 0 h preoperatively (P > 0.05). In the qualitative assessment, preoperative 0-h Perlas grading did not differ significantly between the groups (P > 0.05). From 2 h before surgery to transfer out of the post-anesthesia care unit, the average blood glucose level of patients in the carbohydrate group was significantly higher than that in the fasting group (P < 0.001) but remained within the normal range. Moreover, the blood glucose variability coefficient was significantly lower in the carbohydrate group than in the fasting group (P = 0.009). Oral intake of 355 mL carbohydrates before surgery significantly relieved patients' feelings (P < 0.001).

CONCLUSION

Preoperative consumption of carbohydrate drinks 2 h before surgery is safe in "healthy" extremely elderly patients. In addition, preoperative drinking has potential value in maintaining ideal blood glucose levels and stable blood glucose fluctuations perioperatively and improving subjective perceptions of preoperative preparation. This finding warrants further investigation in clinical practice.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (Registration Number ChiCTR1900024812), first registered on 29/07/2019.

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.

Physiologically based pharmacokinetic (PBPK) modelling of oral drug absorption in older adults - an AGePOP review

The older population consisting of persons aged 65 years or older is the fastest-growing population group and also the major consumer of pharmaceutical products. Due to the heterogenous ageing process, this age group shows high interindividual variability in the dose-exposure-response relationship and, thus, a prediction of drug safety and efficacy is challenging. Although physiologically based pharmacokinetic (PBPK) modelling is a well-established tool to inform and confirm drug dosing strategies during drug development for special population groups, age-related changes in absorption are poorly accounted for in current PBPK models. The purpose of this review is to summarise the current state-of-knowledge in terms of physiological changes with increasing age that can influence the oral absorption of dosage forms. The capacity of common PBPK platforms to incorporate these changes and describe the older population is also discussed, as well as the implications of extrinsic factors such as drug-drug interactions associated with polypharmacy on the model development process. The future potential of this field will rely on addressing the gaps identified in this article, which can subsequently supplement in-vitro and in-vivo data for more robust decision-making on the adequacy of the formulation for use in older adults and inform pharmacotherapy.

Differences in preoperative gastric ultrasound findings in elderly compared to the mid-aged surgical patients: A retrospective observational study

This study aimed to compare gastric ultrasound assessments between young and elderly patients, to determine whether the cross-section area (CSA) cutoff values for elderly and young patients should be different, and to suggest CSA cutoff values for elderly patients. This study evaluated the data of 120 patients who underwent elective surgery under general anesthesia between July 2019 and August 2020. Demographic and gastric ultrasound assessment data were retrieved. Patients were divided into the elderly group (n = 58, age: ≥65 years) and young group (n = 62, age: <65 years). The CSAs in the supine and right lateral decubitus positions (RLDP), semiquantitative 3-point Perlas grade (grades 0, 1, and 2), and gastric volume (GV) were determined. CSAs according to different Perlas grades were compared between the 2 groups. To compare normally and non-normally distributed continuous data, Student t test and the Mann-Whitney U test were used, respectively. Categorical data were compared using the chi-square test or Fisher exact test, as appropriate. The receiver operating characteristic (ROC) curves were built for the CSAs to predict pulmonary aspiration. The CSA cutoff values for predicting a high risk of pulmonary aspiration in both the groups were determined. Among patients with Perlas grade 0, the CSAsupine (P = .002) and CSARLDP (P = .002) were greater in the elderly group than in the young group. The specificity, positive predictive value, and accuracy of the CSA decreased when the CSA cutoff value for the young group was applied to the elderly group. The CSA cutoff values for the elderly group were: CSAsupine, 6.92 cm2 and CSARLDP, 10.65 cm2. The CSA of the empty stomach was greater in elderly patients than in young patients. We suggest that the following CSA cutoff values should be used for predicting pulmonary aspiration risk in elderly patients: CSAsupine, 6.92 cm2 and CSARLDP, 10.65 cm2.

Ultrasound assessment of residual gastric volume in older adults undergoing staged-bilateral total knee arthroplasty after consuming carbohydrate-containing fluids: a prospective observational study

BACKGROUND

We compared preoperative residual gastric volume (GV) between the first and second stages of total knee arthroplasty (TKA) in older adults after drinking carbohydrate-containing fluid 2 h prior to surgery.

METHODS

In this study, 36 patients, aged > 65 years, scheduled for staged bilateral TKA with one-week interval, were enrolled. The patients consumed 400 ml of carbohydrate-containing fluid 2 h prior to surgery. Before the induction of spinal anesthesia, the gastric antral cross-sectional area was measured at the first and second TKA using ultrasound, and the residual GV was calculated. The primary outcome was the residual GV. Qualitative GV (grades 0, 1, and 2) and analgesic consumption after the first TKA were assessed as secondary outcomes.

RESULTS

The GV (median [Q1, Q3]) was greater in the second-stage TKA (41.1 [22.5, 62.8] ml) than in the first-stage TKA (10.3 [0.0, 27.1] ml) (P < 0.001). In the qualitative assessment, the distribution was not different between the two stages of TKA (P = 0.219) and only one patient showed grade 2 gastric content in the second TKA. When opioid consumption was converted to an equivalent dose of morphine, an average of 53.9 mg of morphine was required after the first TKA.

CONCLUSIONS

Residual GV after drinking carbohydrate-containing fluid differed according to the stage of TKA, showing a larger residual GV in the second TKA than in the first one. In older adults scheduled to undergo bilateral staged TKA, caution is required in preoperative fasting practice, especially in second-stage surgery.