Characterization of gastroesophageal reflux in patients during anesthesia induction: a high-resolution impedance...

Upper gastrointestinal motility disorders are common during anesthesia induction and are closely related to reflux aspiration; however, there is a lack of research on gastroesophageal reflux during anesthesia induction. In this study, we applied high-resolution impedance measurement (HRIM) to characterize gastroesophageal reflux during anesthesia induction.

A total of 28 patients participated in this study, with 14 patients receiving anesthesia induction with propofol and succinylcholine, and 14 patients receiving anesthesia induction with propofol and rocuronium. A HRIM catheter was used to collect esophageal impedance and pressure data throughout the anesthesia induction process.

Prior to anesthesia induction, none of the 28 patients experienced gastroesophageal reflux. Within 10 min of anesthesia induction, 12 patients experienced gastroesophageal reflux (n = 12/28; 42.9%). A total of 16 reflux events occurred, all of which remained in the esophagus and did not enter the pharyngeal cavity. Within 5 min after anesthesia induction, 5 patients in the succinylcholine group experienced reflux (n = 5/14; 35.7%), with a statistically significant difference compared to before induction (95% confidence interval, CI 0.435-0.950, P = 0.02). While 4 patients in the rocuronium group experienced reflux (n = 4/14; 28.6%) within 5 min after anesthesia induction, with a statistically significant difference compared to before induction (95% CI 0.513-0.995, P = 0.049), there was no statistically significant difference between the two groups (95% CI 0.539-1.502, P = 0.500). Compared to baseline values, there was no significant decrease in barrier pressure (BrP) in both groups of patients during anesthesia induction. All 16 instances of gastroesophageal reflux during anesthesia induction were related to transient lower esophageal sphincter relaxation (TLESR).

Up to 42.9% of patients experienced reflux within 10 min of anesthesia induction, with the majority occurring within 5 min. The gastroesophageal reflux during anesthesia induction was related to TLESR, not to a decrease in gastroesophageal BrP.