Influence of different preoperative fasting times on women and neonates in cesarean section: a retrospective analysis

A retrospective study of pre-operative fasting times prior to elective or emergency cesarean birth in a large maternity hospital: Lessons to be learned to minimize the fasting time

INTRODUCTION

When managing elective and emergency cesarean births in the same operating room, unpredictable variations in the start times of the cesareans can prolong fasting periods.

METHODS

The fasting times were retrospectively analyzed on 279 consecutive cesarean births at Helsinki University Women's Hospital, Finland, during January-February 2023. The fasting times were compared between the urgency groups and for elective cesareans according to their scheduled order on the operation list. The primary outcome was the difference in the fasting times for food and drink, while the secondary outcome was fasting for both food >12 h and fluids >4 h. The fasting times were compared by one-way ANOVA and chi-squared test, respectively. Dichotomous data are presented as unadjusted odds ratios (OR with 95% CI).

RESULTS

Increasing urgency was associated with shorter fasting times. Fasting times for elective cesareans increased with the scheduled order on the daily list. The mean fasting periods (SD) increased from 10.55 h (SD=1.57) to 14.75 h (SD=2.02) from the first to the third cesarean of the day (p<0.01). The unadjusted odds ratio (95% CI) for fasting of the scheduled cesareans to exceed 12 h for solid foods and 4 h for clear fluids was 6.53 (95% CI: 2.67-15.9, p<0.001), for the third and fourth cesareans compared to the first two cesareans of the day.

CONCLUSIONS

When elective and emergency cesareans are performed by the same team, the woman undergoing the third elective surgery of the day should be advised to have breakfast before 5 a.m. at home. While waiting for the operation, a carbohydrate drink should be offered to limit the fast.

Preoperative fasting and the risk of pulmonary aspiration-a narrative review of historical concepts, physiological effects, and new perspectives

In the early days of anaesthesia, the fasting period for liquids was kept short. By the mid-20th century 'nil by mouth after midnight' had become routine as the principles of the management of 'full stomach' emergencies were extended to include elective healthy patients. Back then, no distinction was made between the withholding of liquids and solids. Towards the end of the last century, recommendations of professional anaesthesiology bodies began to reduce the fasting time of clear liquids to 2 h. This reduction in fasting time was based on the understanding that gastric emptying of clear liquids is rapid, exponential, and proportional to the current filling state of the stomach. Furthermore, there was no evidence of a link between drinking clear liquids and the risk of aspiration. Indeed, most instances of aspiration are caused by failure to identify aspiration risk factors and adjust the anaesthetic technique accordingly. In contrast, long periods of liquid withdrawal cause discomfort and may also lead to serious postoperative complications. Despite this, more than two decades after the introduction of the 2 h limit, patients still fast for a median of up to 12 h before anaesthesia, mainly because of organisational issues. Therefore, some hospitals have decided to allow patients to drink clear liquids within 2 h of induction of anaesthesia. Well-designed clinical trials should investigate whether these concepts are safe in patients scheduled for anaesthesia or procedural sedation, focusing on both aspiration risk and complications of prolonged fasting.

Association between pregnant women fasting duration and neonatal hypoglycemia: A prospective cohort study

OBJECTIVE

To evaluate the association between maternal fasting time before delivery and the occurrence of hypoglycemia in neonates immediately after birth.

METHODS

This prospective single-center cohort study included pregnant women who delivered at the study institution between October 2021 and January 2023 and their neonates. The primary outcome was the incidence of neonatal hypoglycemia after birth, defined as a blood glucose level less than 47 mg/dL. Fasting time was categorized into quartiles, and the association between maternal fasting time and neonatal hypoglycemia was investigated. The crude or adjusted odds ratios of maternal fasting time for neonatal hypoglycemia were calculated using logistic regression analysis.

RESULTS

The study included 663 pregnant women and 696 neonates. Compared with the reference group with a short fasting time of 4.3 h or less, the adjusted odds ratios for neonatal hypoglycemia were 1.47 (95% confidence interval [CI] 0.70-3.20) for middle fasting time (4.3-9.8 h), 4.05 (95% CI 2.02-8.56) for long fasting time (9.8-14.6 h), and 4.99 (95% CI 2.59-10.25) for very long fasting time (>14.6 h). In the subgroup analysis, the association between maternal fasting time and neonatal hypoglycemia showed different trends according to the mode of delivery.

CONCLUSION

Maternal fasting time over 9-10 h before delivery was associated with the occurrence of neonatal hypoglycemia. Obstetrical management, considering not only maternal safety but also neonatal hypoglycemia prevention, is required.

Preoperative free access to water compared to fasting for planned cesarean under spinal anesthesia: a randomized controlled trial

BACKGROUND

Contemporary guidance for preoperative feeding allows solids up to 6 hours and clear fluids up to 2 hours before anesthesia. Clinical trial evidence to support this approach for cesarean delivery is lacking. Many medical practitioners continue to follow conservative policies of no intake from midnight to the time of surgery, especially in pregnant women.

OBJECTIVE

This study aimed to evaluate the pragmatic approach of permitting free access to water up to the call to dispatch to the operating theater vs fasting from midnight in preoperative oral intake restriction for planned cesarean delivery under spinal anesthesia on perioperative vomiting and maternal satisfaction.

STUDY DESIGN

A randomized controlled trial was conducted in the obstetrical unit of the University of Malaya Medical Centre from October 2020 to May 2022. A total of 504 participants scheduled for planned cesarean delivery were randomized: 252 undergoing preoperative free access to water up to the call to dispatch to the operating theater (intervention group) and 252 undergoing fasting from midnight (fasting arm). The primary outcomes were perioperative vomiting and maternal satisfaction. Analyses were performed using t test, Mann-Whitney U test, and chi-square test, as appropriate.

RESULTS

Of note, 9 of 252 patients (3.6%) in the intervention group and 24 of 252 patients (9.5%) in the control group had vomiting at up to 6 hours after completion of cesarean delivery (relative risk, 0.38; 95% confidence interval, 0.18-0.79; P=.007), and the maternal satisfaction scores (0-10 visual numerical rating scale) were 9 (interquartile range, 8-10) in the intervention group and 5 (interquartile range, 3-7) in the control group (P<.001). Assessed before dispatch to the operating theater, feeling of thirst was reported by 69 of 252 patients (27.4%) in the intervention group and 134 of 252 patients (53.2%) in the control group (relative risk, 0.52; 95% confidence interval, 0.41-0.65; P<.001), capillary glucose levels were 4.8±0.7 mmol/L in the intervention group and 4.9±0.8 mmol/L in the control group (P=.048), and preoperative intravenous fluid hydration was commenced in 49 of 252 patients (19.4%) in the intervention group and 76 of 252 patients (30.2%) in the control group (relative risk, 0.65; 95% confidence interval, 0.47-0.88; P=.005). In the operating theater, ketone was detected in the catheterized urine in 38 of 252 patients (15.1%) in the intervention group and 78 of 252 patients (31.0%) in the control group (relative risk, 0.49; 95% confidence interval, 0.25-0.59; P<.001), and the numbers of doses of vasopressors needed to correct hypotension were 2.3±1.7 in the intervention group and 2.7±2.2 in the control (P=.009). The recommendation rates for preoperative oral intake regimen to a friend were 95.2% (240/252) in the intervention group and 39.7% (100/252) in the control group (relative risk, 2.40; 95% confidence interval, 2.06-2.80; P<.001), in favor of free access to water. Other assessed maternal and neonatal outcomes were not different.

CONCLUSION

Compared with fasting, free access to water in planned cesarean delivery reduced perioperative vomiting and was strongly favored by women. In addition, several pre- and intraoperative secondary outcomes were improved. However, postcesarean delivery recovery and neonatal outcomes were not different.

Development of a prediction model for neonatal hypoglycemia risk factors: a retrospective study

Background

It's challenging for healthcare workers to detect neonatal hypoglycemia due to its rapid progression and lack of aura symptoms. This may lead to brain function impairment for the newborn, placing a significant care burden on the family and creating an economic burden for society. Tools for early diagnosis of neonatal hypoglycemia are lacking. This study aimed to identify newborns at high risk of developing neonatal hypoglycemia early by developing a risk prediction model.

Methods

Using a retrospective design, pairs (470) of women and their newborns in a tertiary hospital from December 2021 to September 2022 were included in this study. Socio-demographic data and clinical data of mothers and newborns were collected. Univariate and multivariate logistic regression were used to screen optimized factors. A neonatal hypoglycemia risk nomogram was constructed using R software, and the calibration curve and receiver operator characteristic curve (ROC) was utilized to evaluate model performance.

Results

Factors integrated into the prediction risk nomogram were maternal age (odds ratio [OR] =1.10, 95% CI: 1.04, 1.17), fasting period (OR=1.07, 95% CI: 1.03, 1.12), ritodrine use (OR=2.00, 95% CI: 1.05, 3.88), gestational diabetes mellitus (OR=2.13, 95% CI: 1.30, 3.50), gestational week (OR=0.80, 95% CI: 0.66, 0.96), fetal distress (OR=1.76, 95% CI: 1.11, 2.79) and neonatal body mass index (OR=1.50, 95% CI: 1.24, 1.84). The area under the curve (AUC) was 0.79 (95% confidence interval [CI]: 0.75, 0.82), specificity was 0.82, and sensitivity was 0.62.

Conclusion

The prediction model of this study demonstrated good predictive performance. The development of the model identifies advancing maternal age, an extended fasting period before delivery, ritodrine use, gestational diabetes mellitus diagnosis, fetal distress diagnosis and an increase in neonatal body mass index increase the probability of developing neonatal hypoglycemia, while an extended gestational week reduces the probability of developing neonatal hypoglycemia.

Patient Satisfaction With General Anesthesia Compared to Spinal Anesthesia for Cesarean Section: A Multicenter Observational Study

Background Satisfaction in patients undergoing cesarean section (CS) is of great importance in every hospital. There are big differences between spinal and general anesthesia for CS in terms of outcome, recovery times, and quality of service. Methods This multicenter observational study included 1443 patients who had elective (n=622) or emergency (n=821) CS in five medical centers over the period of 16 months. Bauer questionnaire was used for measuring patient satisfaction after CS. The questionnaire contained 15 questions about anesthesia-related discomfort and satisfaction with anesthesia care. Results During the study period, 1161 (80%) patients underwent CS under general anesthesia (GA) and 282 of them (20%) received spinal anesthesia (SA) for CS. The most frequently reported anesthesia-related discomfort was pain at the surgical site (>70%), drowsiness (68%), and thirst (60%). The data on patient satisfaction showed high satisfaction that exceeded 90%. Anesthesia side effects were less frequent and the general satisfaction rate was higher in the SA group compared to the GA group (P < .001). Conclusion SA for CS had less frequent side effects and a better satisfaction rate compared to GA for CS. Hospitals need to make room for improvement of postoperative acute pain control and introduction to Enhanced Recovery After Surgery (ERAS) protocols for elective CS.

The Effect of Various Pre-Cesarean Fasting Times on Maternal and Neonatal Outcomes

Background

Although it is currently recommended that patients avoid solid food for 6-8 h and liquid for 2 h before cesarean section, longer restrictions still apply in many centers. Since studies on the duration of fasting before cesarean section is scarce, we aimed to investigate the effect of different fasting times before cesarean section on maternal and neonatal complications.

Materials and methods

This descriptive study was performed on 405 candidates for cesarean section. These women were divided into five groups due to the length of time they did not consume clear liquid and solid food. Then, maternal and neonatal outcomes were compared using Kruskal-Wallis and Chi-square tests.

Results

The rate of nausea during surgery was lower in the groups who ate solid food between 2 and 8 h and clear liquid <2 h before surgery (P = 0.04). Also, abdominal distension in the first 6 h after surgery in the group that did not eat solid food for <6-8 h and clear liquid for <2 h was more than in the other groups (P < 0.05). The prevalence of hypoglycemia was significantly lower in women who ate solid food for <6 h and drank clear liquid for <2 h (P < 0.05).

Conclusion

Prolonged fasting time before cesarean section not only reduce complications but also may have undesirable consequences. The results of this study showed that it is better to use less strict measures in patients who are candidates for cesarean section and in patients with labor pains who are likely to have a cesarean section.

The impact of oral carbohydrate-rich supplement taken two hours before caesarean delivery on maternal and neonatal perioperative outcomes -- a randomized clinical trial

Background

To evaluate the impact of oral carbohydrate-rich (Ch-R) supplement taken 2 hours before an elective caesarean delivery (CD) on maternal and neonatal perioperative outcomes.

Methods

Ninety pregnant women undergoing elective CD were randomized into the Ch-R group, placebo group and fasting group equally. Participants’ blood was drawn at three time points, before intervention, immediately after and 1 day after the surgery to measure maternal and neonatal biochemical indices. Meanwhile women’s perioperative symptoms and signs were recorded.

Results

Eighty-eight pregnant women were finally included in the study. Women who had drunk Ch-R supplement had lower postoperative insulin level (β = − 3.50, 95% CI − 5.45 to − 1.56), as well as postoperative HOMA-IR index (β = − 0.74, 95% CI − 1.15 to − 0.34), compared with women who had fasted. Additionally, neonates of mothers who were allocated in the Ch-R group also had a higher glucose level, compared with neonates of mothers in the fasting group (β = 0.40, CI 0.17 to 0.62).

Conclusion

Oral Ch-R solution administered 2 hours before an elective CD may not only alleviate maternal postoperative insulin resistance, but also comfort women’s preoperative thirst and hunger, compared to fasting. Additionally, it may increase neonatal glucose level as well.

Trial registration

Chinese Clinical Trial Registry, ChiCTR2000033163.

Data of Registration: 2020-5-22.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04155-z.

Enhanced Recovery after Surgery: Benefits for the Fetal Surgery Patient

BACKGROUND

The fetoscopic approach to the prenatal closure of a neural tube defect (NTD) may offer similar advantages to the newborn compared to prenatal open closure of a NTD, with a reduction in maternal risks. Enhanced recovery after surgery (ERAS) protocols have been applied to different surgical procedures with documented advantages. We modified the perioperative care of patients undergoing in utero repair of myelomeningocele with the goal of enhancing the recovery. A retrospective study comparing traditional management to the ERAS protocol was conducted.

AIMS

Primary aim was to evaluate the length of stay (LOS). Secondary outcomes included pain scores, time to oral intake, opioid-induced side effects, and respiratory complications.

METHODS

Thirty patients who underwent a mid-gestation fetoscopic closure of a NTD were included. Data analyzed include demographics, comorbidities, LOS, anatomical location of the NTD, magnesium sulfate doses and duration of administration, oxygen requirements, duration of the postoperative epidural infusion, duration of surgery and anesthesia, incidence of postoperative nausea and vomiting, respiratory complications, time to oral intake, pain scores, and sedation scores. Differences between the treatment groups were compared using the independent sample t-test or Mann-Whitney Ʋ test.

RESULTS

Of the 30 patients, 10 patients were managed according to the ERAS protocol and 20 patients according to the traditional management (1:2 ratio). The mean gestational age at the time of intervention for the traditional and ERAS groups was 24.9 ± 0.5 weeks and 24.8 ± 0.5 weeks, respectively. Compared to the traditional group, the LOS was reduced in the ERAS group to 112.5 ± 12.6 h (4.7 ± 0.5 days) from 179.7 ± 87.9 h (7.5 ± 3.7 days) (p = 0.012). The time to oral intake was also shorter 502.6 ± 473.4 min versus 1015.6 ± 698.2 min; p = 0.049. Oxygen requirements were prolonged in the traditional group (1843.7 ± 1262.6 min vs. 1051.7 ± 1078.1 min p = 0.052). The total duration of magnesium sulfate was longer for patients in the traditional group (2125.6 ± 727.1 min vs. 1429.5 ± 553.8 min; p = 0.006). No statistically significant difference in pain scores was observed between the groups.

CONCLUSIONS

Establishing an ERAS protocol for fetoscopic in utero repair of NTDs approach is feasible with the advantages of decreased postoperative LOS, reduced oxygen requirements, lower duration of magnesium sulfate infusion, and facilitation of earlier oral intake without compromising the pain scores.

Safety and feasibility of oral carbohydrate consumption before cesarean delivery on patients with gestational diabetes mellitus: A parallel, randomized controlled trial

AIM

To investigate the safety and feasibility of taking low-concentration carbohydrate solution at 2 h before induction of anesthesia for gestational diabetes mellitus (GDM) patients.

METHODS

GDM patients undergoing cesarean section were randomly assigned to experimental group (n = 43) and control group (n = 42). Two hours before induction of anesthesia, participants in experimental group orally received 300 mL low-concentration carbohydrate solution, while those in control group received equivalent warm water. Blood glucose and serum insulin were measured at 2 h before induction of anesthesia, right before induction of anesthesia, and the morning of postoperative day 1. Neonatal blood glucose level was monitored at birth. Maternal gastrointestinal function and well-being were assessed perioperatively.

RESULTS

The levels of blood glucose and serum insulin right before induction of anesthesia in the experimental group were significantly higher than those in the control group. There were four cases with hypoglycemia in the experimental group and 19 cases in the control group right before induction of anesthesia (9.3% vs 45.2%, p < 0.001). The incidence of neonatal hypoglycemia was 2.3% in the experimental group and 7.1% in the control group with no significance. Hunger score of the participants between the two groups right before induction of anesthesia was significantly different. No aspiration, nausea, and vomiting occurred in both groups before, during, and after surgery. No significant difference was found in the time to the first flatus and abdominal distension between the two groups.

CONCLUSION

Taking low-concentration carbohydrate solution is safe and feasible for patients with GDM undergoing elective cesarean section.

Maternal Microbiota, Cortisol Concentration, and Post-Partum Weight Recovery are Dependent on Mode of Delivery

The importance of the maternal microbiota in terms of the initial bacterial seeding has previously been highlighted; however, little is currently known about the perinatal factors that could affect it. The aim of this study was to evaluate the effects of various delivery-related factors on the intestinal microbiome at delivery time and on post-partum weight retention. Data were collected from mothers (n = 167) during the first four months post-partum. A subset of 100 mothers were selected for the determination of the salivary cortisol concentration and microbiome composition at birth by 16S rRNA gene sequencing. The maternal microbiota was classified into two distinct clusters with significant differences in microbial composition and diversity. Maternal microbiota was also significantly influenced by the mode of delivery. Moreover, the salivary cortisol concentration was associated with some maternal microbiota genera and it was significantly higher in the vaginal delivery group (p = 0.003). The vaginal delivery group exhibited lower post-partum weight retention than the C-section (CS) mothers at four months post-partum (p < 0.001). These results support the hypothesis that the mode of delivery as well as the codominant hormonal changes could influence the maternal microbiota and possibly impact maternal weight recovery during the post-partum period.