A randomized, double-blind study of the ultrasound assessment of the effect of pharyngeal packing on perioperative gastric volume in nasal surgery

BACKGROUND: Pharyngeal packing (PP) is commonly performed to reduce the incidence of perioperative blood ingestion (PBI) in nasal surgery (NS), and thus the incidence and severity of postoperative nausea and vomiting (PONV). This study examined the effects of PP on the perioperative gastric volume (GV) and PONV in patients undergoing NS, by ultrasound assessment. METHODS: Patients undergoing elective NS [septoplasty, septo-rhinoplasty (SRP) and functional endoscopic sinus surgery (FESS)] were randomised to receive or not receive PP. In the PP group, pharyngeal packs were placed after the orotracheal intubation. Ultrasound assessments were performed for all patients preoperatively (before the anaesthesia induction) and postoperatively (before the extubation). The antero-posterior (AP) and cranio-caudal (CC) antral diameters, antral cross-sectional area (ACSA), and total GV were calculated. PONV incidence and severity were rated. These variables were compared between timepoints and groups, and in the subgroup analyses according to the surgery type. Pearson correlation analysis was performed to assess correlations between the variables. RESULTS: AP and CC diameters and ACSAs were greater postoperatively than preoperatively in the PP and non-PP groups (n = 44 each; all p < 0.05). Postoperative AP and CC diameters and the ACSA were greater in the non-PP than in the PP group (all p < 0.05). Postoperative AP diameters were greater than preoperatively in patients undergoing SRP and FESS, and the postoperative CC diameter and ACSA were greater than preoperatively in patients undergoing SRP (all p < 0.05). Surgery duration was correlated positively with postoperative AP diameter (r = 0.380, p < 0.05), CC diameter (r = 0.291, p < 0.05), and ACSA (r = 0.369, p < 0.05). Patients who underwent septoplasty surgery, PP was decreased PONV incidence and severity at the first four hours, postoperatively (p < 0.05). CONCLUSIONS: The study findings indicate that PP reduces the increase in the perioperative GV due to PBI in an elective NS. It is therefore a useful and safe means of reducing the risk of perioperative pulmonary aspiration in such surgeries. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCT), ACTRN12619000487112, 25/03/2019, Trial registration retrospectively registered.