Ultrasound Assessment of Gastric Volume in Diabetic Versus Non-Diabetic Term Pregnant Women Undergoing Cesarean Section

Fasting is a mandatory requirement prior to elective anesthesia and is intended to reduce gastric fluid volume and the risk of aspiration of gastric contents and subsequent organ injury. Aspiration of gastric contents during perioperative period is a grave complication with significant morbidity and mortality and its severity depends upon the gastric volume and nature of the aspirate.

A high-risk stomach refers to a gastric volume associated with an increased risk of pulmonary aspiration and is defined in most published literature as the presence of any solid or liquid content >1.5 mL/kg Pregnant women have been considered to be at particular risk of aspiration syndromes as a consequence of physiological changes during pregnancy which lead to relaxation of lower oesophageal sphincter and mechanical upward displacement of the stomach by the enlarged uterus.

European Society of Anaesthesiology (ESA) recommends fasting for ≥2 hours after clear liquids and 6 hours after light meals before elective surgery, including in pregnant patients. In contrast, the American Society of Anesthesiology guidelines specifically exclude pregnant women and the Society for Obstetric Anesthesia and Perinatology taskforce recommended a fasting period of 6-8 hours, depending on the nature of food ingested.

Diabetic patients can present with diabetic gastropathy, an autonomic neuropathy associated with delayed gastric emptying in the absence of gastric outlet obstruction tend, predisposing them to increased risk of aspiration as compared to non-diabetic patients.

To date, standard fasting guidelines for people with diabetes are still up for debate.. European Society of Anaesthesiology (ESA) 2011 Fasting guidelines state that diabetic patients can follow the same guidelines as healthy adults, While American Society of Anesthesiologists (ASA) in 2017 fasting guidelines mentioned that the standard eight hours fasting may not apply or may need to be modified for patients with coexisting diseases or conditions that can affect gastric emptying or fluid volume.

With the advent of portable ultrasound machines, performing point-of-care ultrasound has become relatively easy and feasible. Gastric ultrasound examination is finding a place as a point-of-care tool for aspiration risk assessment. It can identify the nature and the volume of the gastric content, i.e., empty, clear fluid and solid and when clear fluid is present, its volume can be quantified.

In this study, we will analyse the stomach contents of Non-labouring term pregnant women after six and eight hours of fasting, using previously described qualitative and quantitative ultrasonographic assessments.