Use of gastric residual volume measured by nasogastric feeding tubes for management of dogs and cats after gastrointestinal foreign body surgery: a retrospective study.

Gastrointestinal foreign body obstruction is a frequently diagnosed ailment in small animal medicine and postoperative ileus can be a challenging sequela to manage. Nasogastric feeding tubes can be utilized after surgery for both quantification of gastric residual volumes to identify ileus as well as nutritional management in anorexic patients. This single-institution retrospective study assesses the association of gastric residual volumes measured via nasogastric feeding tubes with gastrointestinal signs and complications in dogs and cats undergoing foreign body surgery, with and without temporary nasogastric tube placement for postoperative management. In this retrospective study, 469 dogs and cats that had foreign body surgery within a 3-year period were included. These were arranged into two groups for analysis, 210 patients that had a nasogastric tubes placed and 259 that did not. Signalment, presenting clinical signs, and surgical procedure(s) performed were similar between groups, however, nasogastric tube placement was more likely for patients that underwent enterectomy (85.2%, p < 0.001). Total average gastric residual volume in the first 12 h after surgery was 2.0 mL/kg (range 0.0-38.9 mL/kg) and was 5.4 mL/kg (range 0.0-64.1 mL/kg) for the first 24 h. Frequency of upper gastrointestinal signs associated with postoperative ileus (vomiting and regurgitation) did not statistically differ between groups (14.4% vs. 14.7%, p = 0.118), however, with statistical analysis controlled for drug administration, the odds of vomiting and regurgitation were reduced approximately 50-60% for patients having nasogastric tubes placed and aspirated consistently (every 4-6 h) compared to those without. A gastric residual volume cut of >12 mL/kg over the first 24-h period after gastrointestinal foreign body surgery was most significantly associated with increased risk of vomiting and regurgitation (p = 0.058). Nasogastric tube placement was associated with substantially longer hospital stays after surgery (p < 0.001). Cats were less likely to have a feeding tube placed compared to dogs (35.5% vs. 47.1%) and were significantly less likely to regurgitate than dogs (1.1% vs. 17.6%, p = 0.001) despite some having higher gastric residual volumes. Additionally, usage of methadone in the perioperative period was associated with lower frequency of vomiting and regurgitation (p = 0.024). There was a low rate of complications associated with nasogastric tube placement noted in this study (2.9%).