Ultrasound assessment of gastric contents and volume in patients before and after endoscopic endonasal transsphenoidal surgery: a prospective observational study

Abstract

Surgical procedures may affect the changes in gastric contents and volume, resulting in a potential risk of pulmonary aspiration. We aimed to assess the differences in preoperative and postoperative gastric contents and volume in patients undergoing endoscopic endonasal transsphenoidal surgery using ultrasound and determine the potential factors associated with intraoperative volume changes. This prospective study enrolled 71 adult patients diagnosed with pituitary adenoma. Semi-quantitative (Perlas score: grade 0, 1, or 2) and quantitative (cross-sectional area, CSA) ultrasound scans of the gastric antrum were performed before anaesthetic induction and postoperatively in semirecumbent and semirecumbent-right lateral positions. The postoperative median (interquartile [range]) antral CSA in both positions were 3.5 cm2 (3.3–3.7 [2.9–12.1]) and 3.7 cm2 (3.4–4.6 [2.9–26.6]), significantly higher than the preoperative values of 3.3 cm2 (3.1–3.4 [2.7–3.9]) and 3.4 cm2 (3.2–3.7 [2.8–5.7]), respectively (P = 0.001). The postoperative estimated gastric volume was 20.2 ml (2.2–42.7 [0–316.7]), significantly larger than the preoperative value of 14.5 ml (0–32.6 [0–66.4]) (P = 0.001). Seven (9.9%) patients showed significant volume changes, from preoperative grade 0 to postoperative grade 2 (estimated volume > 1.5 ml.kg− 1) (P = 0.02). Logistic regression analysis revealed that gastroesophageal reflux, intraoperative irrigation volume, and anaesthesia duration were independent risk factors for significant intraoperative volume changes (P<0.05). Our results show that significant change in gastric volume was presented in some patients because of the special surgical procedures and comorbidities. Anesthesiologists could use antral ultrasonography to prevent this potential risk of aspiration in patients after transsphenoidal procedures.