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.

Preoperative anxiety is a common negative emotional state in children and has a higher incidence at 2–12 years of age [1]. One of the contributing factors to preoperative anxiety is the prolonged fasting period before surgery [2].

The preoperative fasting time for clear fluids such as water, and fruit juices without pulp, carbonated beverages, and carbohydrate-rich nutritional fluids in children is 2 h, according to the 2017 guideline published by the American Society of Anesthesiologists (ASA) [3]. The updated guideline on preoperative fasting time indicates that there is insufficient evidence to support a 1-h fasting period before surgery [4]. However, according to the European Society of Anesthesiology and Intensive Care (ESAIC) guideline, children can drink clear fluids up to 1 h before anesthesia induction for elective procedures [5].

The intake of carbohydrate fluids before surgery in adult patients has become more common in recent years. However, the effect of carbohydrate fluid given 1 h before surgery on anxiety levels and gastric volumes in children is still unknown.

The hypothesis of the study is that allowing children to consume clear fluids, including water and carbohydrate fluids, 1 h prior to surgery can lead to a decreased preoperative anxiety without increasing gastric volumes, as measured by the gastric residual fluid volume (GRV) and gastric antral cross-sectional area (CSA).

This study followed the Consolidated Standards of Reporting Trials (CONSORT) 2010 Statement: an updated guideline for reporting parallel-group randomized controlled trials [6]. This study was designed as a prospective, randomized, and controlled trial in children. The study was approved by the local Ethical Committee (decision no: 120/16 and date: March 2022) and registered with ClinicalTrials.gov (ref: NCT05592964). This study was conducted on children who underwent elective surgery by the Pediatric Surgery and Ophthalmology Departments between March and August 2022. During the preoperative visit, parents/legal guardians for all participants aged under 18 were informed about the study; written and verbal consent was obtained from those who agreed. Overall, 90 patients with ASA physical status I-II, aged 5–12 years, were included in the study. Exclusion criteria were pediatric patients with ASA scores of III-IV, gastrointestinal system diseases, severe liver, kidney, cardiac, or neurological diseases, those using proton pump inhibitors or histamine 2 receptor blockers, and parents who refuse to participate.

The patients were randomly allocated into three groups by a computer-generated randomization list: group F (n = 30): patients who fasted for 6 h before surgery, group W (n = 30): patients who received 5 mL/kg of water orally 1 h before surgery, group C: patients who received 5 mL/kg of carbohydrate-rich clear fluid orally, 1 h before surgery (n = 30). The total volume was limited to 250 mL [7]. The fluid contained 11 g/100 mL of carbohydrates and 201 kj/44 kcal per 100 mL and was a standard package of apple juice without fat or protein. The patients (or their parents) and the nurses responsible for the administration of the fluids were informed of the group assignment.

The children and their parents were taken to the preoperative anesthesia waiting room 1 h before the planned surgery. No premedication was given to any children.

All patients were taken to the operating room with their parents immediately after evaluation with modified Yale Preoperative Anxiety Scale (m-YPAS). Ringer Lactate 5–10 mL/kg was preferred for fluid management. After intubation, all patients were placed in the right lateral decubitus position, and gastric volumes were measured using ultrasound. After tracheal extubation, the patients were transferred to the postoperative recovery room. Patients with Modified Aldrete Recovery Score ≥9 points were sent to the ward.

Children’s anxiety levels were evaluated using the Turkish version of the m-YPAS score at baseline and 1 h later in the preoperative anesthesia waiting room. The m-YPAS is an observational behavioral checklist containing 22 items in 5 categories (activity, emotional expression, state of arousal, vocalization, and use of parents). The adjusted score is calculated by use of the following formula: (activity/4 + emotional expression/4 + the state of arousal/4 + use of parents/4 + vocalization/6) × 100/5. The cutoff score determined for Turkish version of the m-YPAS was 40 [8].

A convex ultrasound probe was used to visualize the left lobe of the liver and the superior mesenteric vein in the upper abdominal area in the sagittal plane. The gastric antral CSA was determined by measuring the anteroposterior (D1) and craniocaudal (D2) areas, and antral CSA was formulated as (D1 × D2) × π/4. The GRV was calculated using the formula: GRV = −7.8 + (3.5 × GAA) + 0.127 × age (months) [9]. The m-YPAS and gastric ultrasonography were performed by an anesthesiologist who was blinded to the groups.

Blood glucose levels were measured using a glucometer at the 20th minute of surgery. Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate (HR) values were recorded before induction and at 5-min intervals during the first 20 min after induction. Complications including vomiting and aspiration that may occur during anesthesia induction were recorded. Parental satisfaction (very good, good, or unsatisfactory) was evaluated in the recovery room.

Statistical Analysis

The sample size for each group was determined to be at least 11 patients based on a 0.65 effect size obtained from the pilot study for the change in m-YPAS score between groups, assuming a 5% error level and 90% power. G*Power 3.1.9.7 program for Windows was used for analysis. Data obtained were analyzed using the IBM SPSS 25 software program. Continuous variables were reported as mean ± standard deviation and median (1st quartile–3rd quartile), while categorical variables were reported as frequency and percentage. The one-way ANOVA test was used for group comparisons in series showing normal distribution, while the Kruskal-Wallis test was used for group comparisons in series that do not show normal distribution. If there was a significant difference between the groups, multiple comparison tests were applied to determine the source of the difference. The Wilcoxon signed-rank test was used to test the difference between two measurement results obtained from the same unit in series that do not show normal distribution. The relationship between categorical variables was examined using the χ2 test. All analysis results were considered statistically significant if the significance level was less than 0.05.

Overall, 102 patients were assessed for eligibility and 90 patients completed study (shown in Fig. 1). No significant difference was found in demographic data between the three groups (Table 1). Baseline m-YPAS scores were not different between the groups. However, the m-YPAS scores 1 h after fluid intake were significantly lower in group C than group F and W (p < 0.001). Additionally, there was a statistically significant difference between the baseline m-YPAS scores and the m-YPAS scores 1 h later for each group (p < 0.001) (Table 2).

Fig. 1.

CONSORT flow diagram of the groups. CONSORT, Consolidated Standards of Reporting Trials.

Fig. 1.

CONSORT flow diagram of the groups. CONSORT, Consolidated Standards of Reporting Trials.

Close modal
Table 1.

Demographic data

Group F (n = 30)Group W (n = 30)Group C (n = 30)p value
Age, months 96.8±32.1 84.9±30.2 99.5±31.0 0.22 
F/M, n (%) 18 (60)/12 (40) 25 (83.3)/5 (16.7) 24 (80)/6 (20) 0.08 
Weight, kg 30.8±14.3 26.4±8.7 28.7±11.7 0.71 
Height, cm 131.4±17.3 123.1±17.1 127.1±18.0 0.19 
BMI, kg/m2 17.6±4.2 16.69±3.0 17.2±3.1 0.87 
ASA I/II, n (%) 28 (93.3)/2 (6.7) 26 (86.7)/4 (13.3) 26 (86.7)/4 (13.3) 0.64 
Group F (n = 30)Group W (n = 30)Group C (n = 30)p value
Age, months 96.8±32.1 84.9±30.2 99.5±31.0 0.22 
F/M, n (%) 18 (60)/12 (40) 25 (83.3)/5 (16.7) 24 (80)/6 (20) 0.08 
Weight, kg 30.8±14.3 26.4±8.7 28.7±11.7 0.71 
Height, cm 131.4±17.3 123.1±17.1 127.1±18.0 0.19 
BMI, kg/m2 17.6±4.2 16.69±3.0 17.2±3.1 0.87 
ASA I/II, n (%) 28 (93.3)/2 (6.7) 26 (86.7)/4 (13.3) 26 (86.7)/4 (13.3) 0.64 

Values are presented as number (n), percentage (%), or mean ± SD.

ASA, American Society of Anesthesiologists; F, female; M, male; BMI, body mass index.

Table 2.

m-YPAS scores of the groups

Group F (n = 30)Group W (n = 30)Group C (n = 30)p valuea
Baseline m-YPAS 52.8±15.9 57.2±20.2 50.6±14.1 0.32 
50 [44.2–63.7] 56.7 [39.6–76.6] 49.2 [41.6–63.3] 
m-YPAS after 1 h 63.3±16.0 47.0±17.1* 31.6±8.5b <0.001 
65 [50–72.0] 48.3 [32.9–59.6] 28.3 [23.3–37.0] 
p valuec <0.001 <0.001 <0.001  
Group F (n = 30)Group W (n = 30)Group C (n = 30)p valuea
Baseline m-YPAS 52.8±15.9 57.2±20.2 50.6±14.1 0.32 
50 [44.2–63.7] 56.7 [39.6–76.6] 49.2 [41.6–63.3] 
m-YPAS after 1 h 63.3±16.0 47.0±17.1* 31.6±8.5b <0.001 
65 [50–72.0] 48.3 [32.9–59.6] 28.3 [23.3–37.0] 
p valuec <0.001 <0.001 <0.001  

Values are presented as mean ± SD and median (Q1, Q3).

aOne-way ANOVA, Kruskal Wallis.

bp < 0.001, compared with group F and W.

cWilcoxon signed-rank test.

*p < 0.001, compared with group A.

There were statistically significant differences in antral CSA values between group C and group F (p < 0.001), as well as between group W and group F (p < 0.001). However, no significant difference was found between the antral CSA values of group C and group W (p > 0.05). Furthermore, there was a statistically significant difference in the GRV values between group C and group F, as well as between group W and group F (p < 0.001). However, no significant difference was found between the GRV values of group C and group W (p > 0.05) (Table 3).

Table 3.

Antral CSA and GRV values

Group F (n = 30)Group W (n = 30)Group C (n = 30)p valuea
Antral CSA, cm2 4.0±1.9* 2.7±1.0 2.3±1.2 <0.001 
3.8 [2.9–4.7] 2.5 [2.0–3.4] 2.0 [1.5–2.5] 
GRV, mL 18.5±8.2* 12.9±5.0 12.7±6.2 <0.001 
16.7 [13.1–20.6] 11.8 [9.5–16.5] 11.4 [7.7–18] 
Group F (n = 30)Group W (n = 30)Group C (n = 30)p valuea
Antral CSA, cm2 4.0±1.9* 2.7±1.0 2.3±1.2 <0.001 
3.8 [2.9–4.7] 2.5 [2.0–3.4] 2.0 [1.5–2.5] 
GRV, mL 18.5±8.2* 12.9±5.0 12.7±6.2 <0.001 
16.7 [13.1–20.6] 11.8 [9.5–16.5] 11.4 [7.7–18] 

Values are presented as mean ± SD and median (Q1, Q3).

Antral CSA, antral cross-sectional area; GRV, gastric residual volume.

aKruskal Wallis.

*p < 0.001, compared with group W and group C.

Group W had significantly higher HR values than other groups at the 5th and 10th minutes and compared to group C at the 15th and 20th minutes (p < 0.001). No significant differences were found between the groups in hemodynamic parameters, including systolic blood pressure, diastolic blood pressure, and mean arterial pressure values.

Statistical analysis revealed significant differences in blood glucose levels between group C and group W, as well as between group C and group F (p < 0.05 and p < 0.001, respectively). However, no significant difference was observed in blood glucose levels between group W and group F (Table 4).

Table 4.

Glucose values

Group F (n = 30)Group W (n = 30)Group C (n = 30)p value
Glucose, mg/dL 112.8±23.3 101.7±14.6 90.9±12.8* <0.001 
109 [102.3–118.5] 97.5 [92–113] 90 [82–102.3] 
Group F (n = 30)Group W (n = 30)Group C (n = 30)p value
Glucose, mg/dL 112.8±23.3 101.7±14.6 90.9±12.8* <0.001 
109 [102.3–118.5] 97.5 [92–113] 90 [82–102.3] 

Values are presented as mean ± SD, median (Q1, Q3).

*p < 0.001, compared with group F and group W.

Complications related to vomiting and aspiration during anesthesia induction were not observed in any of the patients. Parental satisfaction was significantly higher in group C compared to other groups (p < 0.001).

This study demonstrated the effectiveness of providing carbohydrate-containing fluid 1 h before surgery in preventing anxiety. Furthermore, it was observed that GRVs were lower in children who received oral fluid 1 h before surgery compared to the fasted group, and no aspiration-related complications were observed in any of the patients.

A multicenter study conducted with 1,200 infants in China reported a lower incidence of crying during the perioperative period in patients who received carbohydrate solution at different volumes 2 h prior to surgery compared to the fasting group [10]. A recent study with 120 pediatric patients aged 2–18 years, scheduled for gastroscopy, found that preoperative carbohydrate loading 2 h before surgery might improve the comfort of children over 4 years old. However, there were no significant differences between the carbohydrate loading group and the fasting group [11]. The physiological mechanism for this result can be explained by the fact that carbohydrate foods cause an increase in serotonin levels, which contributes positively to stress management [12]. The activation of the autonomic nervous system has been linked to emotional states, and carbohydrates have been suggested as a possible mechanism for activation of the autonomic nervous system [13].

In regards to the consumption of beverages before surgery, it is crucial to consider the risk of pulmonary aspiration, which can be a frightening outcome. Frykholm et al. [5] have previously suggested that clear fluids can be safely administered up to 1 h prior to elective surgery in pediatric patients. However, Joshi et al. [4] have argued that the current evidence on this topic is insufficient and that further studies are necessary to establish clear guidelines for the preoperative administration of clear fluids in this population [4, 5]. In adult patients, studies have shown no significant difference in gastric volumes measured by ultrasound between patients who underwent standard fasting and those who received fluid [14, 15]. In contrast, studies involving children have shown that giving carbohydrate fluids reduces gastric volumes compared to standard fasting, which is consistent with our study [11, 16]. Our results suggest that clear fluid intake 1 h before surgery does not delay gastric emptying and can be safely done without aspiration complications.

Although intraoperative blood glucose values were normal in all groups, they were statistically lower in the receiving carbohydrate liquid group compared to the other groups. The literature presents conflicting results on the effect of carbohydrate fluids on blood glucose levels [10, 17]. Nevertheless, a study conducted by Akbuga et al. [18] highlighted that carbohydrate fluid intake reduces the stress response caused by fasting and surgical trauma, and postoperative blood glucose fluctuations, while suppressing catabolism. Based on our findings, we suggest that this result may be attributed to the positive effect of carbohydrates on reducing the increase in catabolism induced by surgical stress.

The HR values in the carbohydrate group were generally lower, which may be attributed to the numerical difference in the age-groups, although this difference was not statistically significant. Alternatively, Horiuchi et al. investigated the effect of carbohydrate-electrolyte fluids and water on HR in healthy individuals and reported that carbohydrate intake reduces HR [19].

There are few studies in the literature investigating the relationship between preoperative fluid intake and parental satisfaction. The administration of preoperative carbohydrate fluid can have a positive impact on children’s anxiety and subsequently increase parents’ satisfaction, indirectly reducing anxiety for both parents and children [16].

Our study has limitations. First, we did not evaluate previous medical experiences that have shown an effect on preoperative anxiety, as well as parental anxiety [20, 21]. Second, the long-term effects of preoperative anxiety including postoperative agitation, increased analgesic demand, increased infection rate, and behavioral changes (such as temper tantrums, lack of discipline, eating and sleep disorders, separation anxiety, enuresis, etc.) were not examined [22].

In conclusion, we believe that the widespread utilization of clear fluid intake from non-pharmacological methods, particularly carbohydrate fluids, in clinic settings can be advantageous in reducing preoperative anxiety in children. Moreover, in contrast to conventional fasting practices, oral fluid intake decreases GRV, debunking the misconception that it increases the risk of pulmonary aspiration.

The study was approved by the Cukurova University Faculty of Medicine Non-Invasive Clinical Research Ethics Committee (approval number: 120/16 and date: March, 2022) and registered with ClinicalTrials.gov (ref: NCT05592964). During the preoperative visit, parents/legal guardians for all participants aged under 18 were informed about the study; written and verbal consent were obtained from those who agreed.

The authors have no conflicts of interest to declare.

This study was not supported by any sponsor or funder.

Burcu Bozoglu Akgun and Zehra Hatipoglu: conceptualization, formal analysis, data curation, investigation, methodology, writing – original draft, and writing – review and editing. Ersel Gulec, Mediha Turkmans, and Dilek Ozcengiz: investigation, methodology, and supervision.

Data are not available due to their containing information that could compromise the privacy of research participants but are available from the corresponding author (B.B.A.). Further inquiries can be directed to the corresponding author.

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