Prise en charge des voies aériennes supérieures en obstétrique: enquête française de pratique

Prevalence and factors associated with high-risk gastric contents in women admitted to the maternity unit for childbirth: a prospective multicentre cohort study

BACKGROUND

This multicentre prospective observational study sought to determine the prevalence and the factors associated with high-risk gastric contents in women admitted to the maternity unit for childbirth, and to identify the clinical situations in which ultrasound assessment of gastric contents would be most helpful (i.e. when the prevalence of high-risk gastric contents is close to 50%).

METHODS

Ultrasound assessments of gastric contents were performed within the first hour after admission to the maternity unit. The prevalence of high-risk gastric contents was calculated and variables associated with high-risk gastric contents were identified using logistic regression analyses.

RESULTS

A total of 1003 parturients were analysed. The prevalence of high-risk gastric contents was 70% (379/544; 95% confidence interval: 66-74%) in women admitted in spontaneous labour and 65% (646/1003; 95% confidence interval: 61-67%) in the whole cohort. Lower gestational age, increased fasting duration for solids, and elective Caesarean delivery were independently associated with reduced likelihood of high-risk gastric contents. In women admitted in spontaneous labour and in the whole cohort, the prevalence of high-risk gastric contents ranged from 85% to 86% for fasting duration for solids <6 h, 63%-68% for fasting 6-8 h, 54%-55% for fasting 8-12 h, and 47%-51% for fasting ≥12 h.

CONCLUSIONS

Around two-thirds of parturients had high-risk gastric contents within the first hour after admission to the maternity unit. Our results suggest that gastric emptying for solids continues in labouring women, and that gastric ultrasound would be most helpful when fasting duration is ≥8 h.

Ultrasound assessment of gastric antrum in term pregnant women before elective cesarean section

Background and objectives

Pregnant women are considered patients at risk for pulmonary aspiration of gastric contents. The study aim was to evaluate the gastric antral cross-sectional area using ultrasound.

Method

In this prospective study, 85 scheduled term pregnant women underwent gastric ultrasound. The outcomes were the measurement of the gastric antral cross-sectional area (main outcome), the estimated gastric volume, the incidence of pregnant women at risk for pulmonary aspiration, and the association between gastric antral cross-sectional area and clinical-demographic characteristics. Gastric antral cross-sectional area and gastric volume were compared according to body mass index <30 or ≥30.

Results

The median (IIQ) for gastric antral cross-sectional area was 4 cm² (2.8–6.3), for the estimated gastric volume it was 49.8 mL (33.7–87.2), and for the gastric volume estimated in mL.kg⁻¹ it was 0.62 mL.kg⁻¹ (0.39–0.95). The 95^th percentile [95% confidence interval (CI)] of the gastric antral cross-sectional area and the estimated gastric volume were ≤10.3 cm² (95% CI: 7.6–15.6) and 1.42 mL.kg⁻¹ (95% CI: 1.20–2.64), respectively. The incidence of pregnant women at risk for pulmonary aspiration was 3.5% (CI: 3.5 (1.2–9.8)). There was a positive correlation between gastric antral cross-sectional area and weight, p < 0.001 and body mass index <0.001. Patients with a body mass index ≥30 had a gastric antral cross-sectional area and an estimated gastric volume greater than those with a body mass index <30, respectively, p < 0.01 and p < 0.02.

Conclusion

Measuring the gastric antral cross-sectional area of pregnant women is feasible and easy. There was positive correlation between gastric antral cross-sectional area, body weight and body mass index. The estimation of gastric volume by measuring the gastric antral cross-sectional area can identify patients at risk for pulmonary aspiration. Obese patients had a gastric antral cross-sectional area and an estimated gastric volume greater than non-obese patients.

[Ultrasound assessment of gastric antrum in term pregnant women before elective cesarean section]

BACKGROUND AND OBJECTIVES

Pregnant women are considered patients at risk for pulmonary aspiration of gastric contents. The study aim was to evaluate the gastric antral cross-sectional area using ultrasound.

METHOD

In this prospective study, 85 scheduled term pregnant women underwent gastric ultrasound. The outcomes were the measurement of the gastric antral cross-sectional area (main outcome), the estimated gastric volume, the incidence of pregnant women at risk for pulmonary aspiration, and the association between gastric antral cross-sectional area and clinical-demographic characteristics. Gastric antral cross-sectional area and gastric volume were compared according to body mass index <30 or ≥ 30.

RESULTS

The median (IIQ) for gastric antral cross-sectional area was 4cm² (2.8-6.3), for the estimated gastric volume it was 49.8mL (33.7-87.2), and for the gastric volume estimated in mL.kg^-1 it was 0.62mL.kg^-1 (0.39-0.95). The 95^th percentile [95% confidence interval (CI)] of the gastric antral cross-sectional area and the estimated gastric volume were ≤ 10.3cm² (95% CI: 7.6-15.6) and 1.42mL.kg^-1 (95% CI: 1.20-2.64), respectively. The incidence of pregnant women at risk for pulmonary aspiration was 3.5% (CI: 3.5 (1.2-9.8). There was a positive correlation between gastric antral cross-sectional area and weight, p <0.001 and body mass index <0.001. Patients with a body mass index ≥ 30 had a gastric antral cross-sectional area and an estimated gastric volume greater than those with a body mass index <30, respectively, p <0.01 and p <0.02.

CONCLUSION

Measuring the gastric antral cross-sectional area of pregnant women is feasible and easy. There was positive correlation between gastric antral cross-sectional area, body weight and body mass index. The estimation of gastric volume by measuring the gastric antral cross-sectional area can identify patients at risk for pulmonary aspiration. Obese patients had a gastric antral cross-sectional area and an estimated gastric volume greater than non-obese patients.

Ultrasound assessment of gastric content in the immediate postpartum period: a prospective observational descriptive study

INTRODUCTION

Pulmonary aspiration of gastric contents in pregnant women undergoing general anesthesia or sedation/analgesia in the peripartum period is a feared complication in obstetric anesthesia. We assessed the changes in antral cross-sectional area (CSA) with ultrasonography in laboring women and in the immediate postpartum period.

PATIENTS AND METHODS

In an observational study in a university-affiliated maternity, gastric ultrasonography examinations were performed in non-consecutive laboring women, after epidural analgesia insertion and after childbirth. Assessment of antral CSA, difficulty of performance on a numerical scale, and factors that could influence gastric content were noted. A cut-off value of 381 mm² was taken for the diagnosis of empty stomach.

RESULTS

One hundred women were enrolled in the study. Median antral CSA was 469 mm² [25th-75th] [324-591] after epidural insertion and 427 mm² [316-574] after delivery. Antral CSA was ≥ 381 mm² in 59 of 90 women (65%) after epidural insertion vs. 48 of 100 women (48%) after delivery (P = 0.59). Median variation of antral CSA between two measurements was 36 mm² [-42 to 114]. Gastric ultrasonography was significantly more difficult to perform during labor than immediately post-delivery (median difficulty score 5 [2-7] vs. 2 [1-4], P < 0.0001). No risk factors (pain, anxiety, diabetes, smoking) were significantly associated with the occurrence of full stomach post-delivery.

CONCLUSION

This study demonstrated that 48% of parturients in the immediate postpartum period presented an antral CSA ≥ 381 mm² , cut-off being accepted for diagnosis of empty stomach and emphasizes the need for re-assessing before any general anesthetic procedure.