The influence of fasting and carbohydrate-enriched drink administration on body water amount and distribution: a volunteer randomized study

Morning or Afternoon Scheduling for Elective Coronary Artery Bypass Surgery: Influence of Longer Fasting Periods from Metabolic and Hemodynamic Perspectives

BACKGROUND

Prolonged preoperative fasting may worsen postoperative outcomes. Cardiac surgery has higher perioperative risk, and longer fasting periods may be not well-tolerated. We analysed the postoperative metabolic and hemodynamic variables in patients undergoing elective coronary artery bypass grafting (CABG) according to their morning or afternoon schedule.

METHODS

Single-centre retrospective study at University teaching hospital (1-year data collection from electronic medical records). Using a mixed-effects linear regression model adjusted for several covariates, we compared metabolic (lactatemia, pH, and base deficit [BD]) and haemodynamic values (patients on vasoactive support, and vasoactive inotropic score [VIS]) at 7 prespecified time-points (admission to intensive care, and 1st, 3rd, 6th, 12th, 18th, and 24th postoperative hours).

RESULTS

339 patients (n = 176 morning, n = 163 afternoon) were included. Arterial lactatemia and BD were similar (overall P = 0.11 and P = 0.84, respectively), while pH was significantly lower in the morning group (overall P < 0.05; mean difference -0.01). Postoperative urine output, fluid balance, mean arterial pressure, and central venous pressure were similar (P = 0.59, P = 0.96, P = 0.58 and P = 0.53, respectively). A subgroup analysis of patients with diabetes (n = 54 morning, n = 45 afternoon) confirmed the same findings. The VIS values and the proportion of patients on vasoactive support was higher in the morning cases at the 18th (P = 0.002 and p=0.04, respectively) and 24th postoperative hours (P = 0.003 and P = 0.04, respectively). Mean intensive care length of stay was 1.94 ± 1.36 days versus 2.48 ± 2.72 days for the afternoon and morning cases, respectively (P = 0.02).

CONCLUSIONS

Patients undergoing elective CABG showed similar or better metabolic and hemodynamic profiles when scheduled for afternoon surgery.

Effect of total fasting hours on the overall quality of recovery after surgery: An observational study

Context

Preoperative fasting is one of the pre-requisite for patients undergoing a surgery. Despite clear instructions, patients frequently fast for extended periods before elective surgeries. Longer periods of fasting may cause discomfort, thirst, hunger, and other physiological problems.

Aims

To assess the quality of postoperative recovery among adult patients having different preoperative fasting hours by using the postoperative Quality of Recovery40 (QoR40) score.

Settings and Design

This was an observational study that was conducted for adult patients undergoing elective surgery during four weeks between 19th September and 13th October 2022 at Security Forces Hospital Riyadh, Kingdom of Saudi Arabia.

Methods and Material

We excluded pediatric patients, patients undergoing spine or neurosurgery, emergency cases, or local anesthesia cases. Non-probability convenient sampling technique was used in this study. The postoperative quality of recovery-40 (QoR-40) questionnaire was distributed among 200 patients.

Statistical Analysis Used

All analyses were performed with Statistical Package for the Social Sciences software (SPSS) v25. Descriptive statistics (frequency, percentage, median, and IQR) were used for the questionnaire's variables. The difference between the variables was analyzed using Kruskal-Wallis, and a P value <0.05 was considered statistically significant.

Results

Out of 200 patients, 172 patients responded but 16 responses were excluded. A total of 156 adult patients' responses were included in this study. The majority were female (53%), 31% were older than 45 years. More than 50% of patients reported fasting for more than 6 hours for drinking and more than 8 hours for eating. On the positive scale, the comfort score was significantly affected by the fasting hours for drinking (P value = 0.045). On the negative scale of the questionnaire, the emotions were significantly affected by fasting hours for both drinking (P value = 0.027) and eating (P value = 0.043).

Conclusions

The study results showed better comfort for patients with lesser fasting hours for drinking. Moreover, the results strongly suggest the need of following the fasting guidelines without prolonging the fasting duration. However, further studies with larger sample sizes are recommended.

Acute Fluid Intake Impacts Assessment of Body Composition via Bioelectrical Impedance Analysis. A Randomized, Controlled Crossover Pilot Trial

Bioelectrical impedance analysis (BIA) has proven to be particularly useful due to its inexpensive and rapid assessment of total body water and body density. However, recent fluid intake may confound BIA results since equilibration of fluid between intra- and extracellular spaces may take several hours and furthermore, ingested fluids may not be fully absorbed. Therefore, we aimed to evaluate the impact of different fluid compositions on the BIA. A total of eighteen healthy individuals (10 females, mean ± SD age of 23.1 ± 1.8 years) performed a baseline measurement of body composition before they consumed isotonic 0.9% sodium-chloride (ISO), 5% glucose (GLU) or Ringer (RIN) solutions. During the visit of the control arm (CON), no fluid was consumed. Further impedance analyses were conducted every 10 min after the fluid consumption for 120 min. We found statistically significant interactions between the effects of solution ingestion and time for intra- (ICW, p < 0.01) and extracellular water (ECW, p < 0.0001), skeletal muscle mass (SMM, p < 0.001) and body fat mass (FM, p < 0.01), respectively. Simple main effects analysis showed that time had a statistically significant effect on changes in ICW (p < 0.01), ECW (p < 0.01), SMM (p < 0.01) and FM (p < 0.01), while fluid intake did not have a significant effect. Our results highlight the importance of a standardized pre-measurement nutrition, with particular attention to hydration status when using a BIA for the evaluation of body composition.

Perioperative carbohydrate loading in patients undergoing one-day surgery. A systematic review of randomized controlled trials

INTRODUCTION

It is suggested that preoperative carbohydrate loading may have beneficial effects, which is emphasised in Enhanced Recovery After Surgery protocols (ERAS). Recent data confirmed that carbohydrate loading shortens length of hospital stay.

AIM

In this systematic review we aimed to determine whether carbohydrate loading have positive effects in patients undergoing 1-day surgery.

MATERIAL AND METHODS

We searched 5 databases and identified some randomized controlled trials which were reviewed independently by two reviewers. In the end 6 RCTs were included, involving 411 patients. Studies compared effects of carbohydrate loading vs. fasting and/or placebo on the following outcomes: thirst, hunger, postoperative nausea and vomiting (PONV), fatigue, pain and postoperative insulin resistance. In most cases data are inconclusive as studies reported opposite results.

CONCLUSIONS

It seems that carbohydrate loading did not have a significant impact when compared to fasting or placebo. Preoperative carbohydrate loading seems not to have significant benefits over fasting or placebo in patients qualified for 1-day surgery.

Acute Water Supplementation Improved the Body Composition of Young Female Adults After Water Restriction of 12 h in Baoding, China: A Randomized Controlled Trial (RCT)

Insufficient intake of water may influence the balance of water in the human body. In this study, we explore the impacts of water supplementation on body composition indices among young adults after 12 h of water restriction, with the aim to determine the optimum volume of water for improving body water composition. A randomized controlled trial study was conducted among 64 young men and women in Baoding, China. After fasting overnight for 12 h, anthropometric measurements and urine and blood samples were collected as a baseline test at 8:00 a.m. of Day 2. Body composition was determined by measuring the ECW (extracellular water), ICW (intracellular water), and TBW (total body water) through bioelectrical impedance analysis (BIA). The participants were randomly divided into four groups, including water supplementation (WS) groups 1, 2, and 3, with 500, 200, and 100 mL of water, respectively, and a no water supplementation (NW) group. After 90 min, they were reassessed in a rehydration test (at 10:00 a.m. of Day 2). Repeated measurement ANOVA was used to assess the impact of water supplementation on body composition. Comparing the baseline and rehydration tests, interactions between time and volume were not significant among the men (all p > 0.05). Among women, a significant interaction was only found in ECW (p = 0.043), with TBW tending toward being significant (p = 0.055). Comparing the baseline and rehydration tests, the ECW in WS group 1, WS group 3, and the NW group all decreased (p = 0.028, p = 0.001, and p = 0.029), with reductions of 0.1, 0.3, and 0.2 kg, respectively; however, no significant decrease was observed in WS group 2 (p = 0.329). Furthermore, comparing the WS groups with the NW group in the rehydration test, the differences were not significant (p = 1.000, p = 1.000, and p = 0.288, respectively). Between men and women within groups, all of the body composition indices differed significantly, both at baseline and rehydration tests (all p < 0.05). Water supplementation led to changes in the distribution of the water content in young female adults in this study-but not men-after 12 h of water restriction, with no decrease in ECW. Finally, we found that 200 mL was the minimum volume capable of improving the water content distribution in participants in this study.

Trial Registration

[www.chictr.org.cn], identifier [ChiCTR-IOR-17011568].

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

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