Gastric Ultrasound After Clear Fluid Intake in Diabetic and Non-Diabetic Pregnant Women

Pulmonary aspiration of gastric contents is one of the most feared complications of obstetric anesthesia and may lead to severe morbidity and mortality. Pregnancy is associated with physiological changes such as delayed gastric emptying, increased intra-abdominal pressure, and gastroesophageal reflux, all of which may increase the risk of aspiration during anesthesia. Diabetes mellitus may further affect gastric motility due to autonomic neuropathy, potentially leading to gastroparesis and increased gastric residual volume.

Preoperative fasting guidelines from major anesthesia societies recommend that patients may consume clear fluids up to two hours before anesthesia. However, the effect of preoperative oral clear fluid intake on gastric volume in diabetic pregnant patients remains controversial.

This single-center prospective observational study will be conducted in pregnant women scheduled for elective cesarean delivery. A total of 70 participants will be included and divided into two groups: diabetic pregnant women and non-diabetic pregnant women. All participants will receive 200 ml of water two hours before surgery according to standard fasting guidelines.

Gastric ultrasonography will be performed before fluid intake and two hours after fluid intake. The gastric antrum will be identified using anatomical landmarks including the left lobe of the liver, pancreas, aorta, and inferior vena cava. Measurements will be obtained in both the semi-recumbent and right lateral decubitus positions.

The gastric antral cross-sectional area will be calculated using the formula:

CSA = (D1 × D2 × π) / 4.

Gastric volume will be estimated using the Roukhomovsky equation. In addition to quantitative measurements, qualitative assessment of gastric contents will be performed using the Perlas grading system.

The primary objective of the study is to compare gastric volume between diabetic and non-diabetic pregnant women after preoperative clear fluid intake. Secondary objectives include qualitative evaluation of gastric contents and assessment of aspiration risk defined as gastric volume greater than 1.5 ml/kg.

Inclusion criteria

• Pregnant women aged 18-40 years
• Scheduled for elective cesarean section under spinal anesthesia
• Singleton pregnancy
• ASA physical status II
• Patients who provide written informed consent

Exclusion criteria

• Refusal to participate in the study
• Contraindication to spinal anesthesia
• Known allergy to study medications
• Multiple pregnancy
• Severe systemic disease (ASA III or higher)
• Pre-existing neurological disease
• Infection at the spinal puncture site