Effect of Preoperative Oral Carbohydrate Loading on Body Temperature During Combined Spinal-Epidural Anesthesia for Elective Cesarean Delivery

Trends in preoperative carbohydrate load practice: A systematic review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Effect of early oral carbohydrate intake after elective Cesarean delivery on maternal body temperature and satisfaction: a randomized controlled trial

PURPOSE

Although the Enhanced Recovery After Cesarean Delivery (ERAC) consensus statement provides recommendations for early postoperative drinking and eating, evidence from high-quality clinical research directly addressing parturients is sparse. Our objective was to assess if early oral carbohydrate intake after elective Cesarean delivery improves maternal recovery.

METHODS

In this randomized controlled trial, we enrolled parturients undergoing elective Cesarean delivery under spinal anesthesia with tympanic membrane temperatures ≤ 36.5 °C immediately upon arrival at the postanesthesia care unit. Parturients were randomized to either 100 mL of oral complex carbohydrate intake (group CC) or 10 mL of water (group C). The primary outcome was maternal tympanic membrane temperature. Other outcomes included maternal thermal comfort score, degree of shivering, satisfaction, degree of thirst and hunger, and gastric emptying assessed by ultrasonography.

RESULTS

We included 90 participants in the final analysis. The mean (standard deviation [SD]) maternal body temperature at 120 min after ingestion was 36.7 (0.3) °C in group CC and 36.6 (0.3) °C in group C (difference in means, 0.14 °C; 95% confidence interval, 0.02 to 0.26; P = 0.02). Furthermore, using repeated measure models, the linear trends of temperature changes over time between groups CC and C were significantly different (P = 0.04). The thermal comfort scores at 120 min after ingestion were higher in group CC than in group C (P = 0.02), and the linear trends of shivering score changes over time between groups CC and C also were different (P = 0.003). The mean (SD) visual analogue scale scores for maternal satisfaction were 84 (13) mm in group CC and 47 (20) mm in group C (P < 0.001). Nevertheless, at 90 and 120 min after ingestion, there were no differences between the two groups in the number of participants with a gastric antrum cross-sectional area > 10.3 cm2.

CONCLUSIONS

Early oral carbohydrate intake after Cesarean delivery helped to restore maternal body temperature postoperatively and improve maternal satisfaction. Nevertheless, the clinical importance of these finding is unclear, given that most of the differences were small. In addition, there was no delay in maternal gastric emptying after consumption of a complex carbohydrate beverage in the early post-Cesarean period.

STUDY REGISTRATION

www.chictr.org.cn (ChiCTR2000031085); first submitted 13 November 2022.

The Effect of Preoperative Oral Carbohydrate on the Incidence of Complications in PACU After General Anesthesia: A Prospective Cohort Study

PURPOSE

This study aimed to investigate the effect of preoperative oral carbohydrate (POC) loading on the occurrence of complications in the postanesthesia care unit (PACU) after general anesthesia.

DESIGN

Prospective observational cohort study METHODS: Patients who were scheduled for abdominal surgery under general anesthesia at our institution were divided into the POC group and control group based on whether they drank carbohydrate solution 2 hours before surgery. POC loading of the patients was decided by the responsible surgeon. In PACU, the occurrence of postoperative complications including delayed emergence, emergence agitation, hypoxemia, hypertension, hypotension, moderate to severe postoperative pain, nausea and vomiting, hypothermia, shivering, and time to awakening, time to extubation, length of PACU stay were recorded.

FINDINGS

Data from 307 patients (n = 154 in POC group and n = 153 in control group) were included in the final analysis. Compared to the control group, POC led to a near-significant reduction in the overall incidence of complications in PACU after surgery (37.0% vs 47.7%, P = .058). The POC group had a lower incidence of hypothermia and shorter mean time to awakening when compared to control group (6.5% vs 16.3%, P = .007 and 19 min vs 21 min, P = .007, respectively). No statistical differences were detected in other outcome measurements between the POC group and the control group.

CONCLUSIONS

POC is associated with a trend to decrease the overall incidence of complications during recovery period after general anesthesia in patients who underwent abdominal surgery. Moreover, POC could reduce the risk of hypothermia in PACU and shorten the time to awakening.

The effect of preoperative oral carbohydrate on the time to colostrum and amount of vaginal bleeding after elective cesarean section

OBJECTIVE

To investigate the effect of oral carbohydrate at 2 h before elective cesarean section on postoperative recovery indicators such as the time to colostrum and vaginal bleeding.

METHODS

Women undergoing elective cesarean section under spinal-epidural anesthesia, aged 20-40 years, with a body mass index (BMI) of 19-30 kg/m² and an American Society of Anesthesiology (ASA) score of II were randomized to the oral carbohydrate group (the OC group), the oral placebo group (the OP group), or the control group (the C group). The OC group underwent oral carbohydrate preloading (300 mL/bottle), the OP group orally consumed 300 mL of distilled water, and the C group was forbidden from drinking or eating on the day of the operation. The time to colostrum, vaginal bleeding, time to exhaust, and complications were recorded.

RESULTS

A total of 38 participants in the OC group, 37 in the OP group, and 37 in the C group completed the study. Compared with the OP group and the C group, the OC group produced colostrum significantly earlier, had a lower amount of 24-h vaginal bleeding, and had a higher 24-h consumption of analgesics. Compared with OP and OC groups, the C group took longer to exhaust. No significant intergroup difference was observed for any other indicator.

CONCLUSION

Oral carbohydrates loading 2 h before elective cesarean section significantly reduces the time to produce colostrum and the amount of vaginal bleeding, which contributes to postoperative recovery.