Ileus is a loss of coordinated electromechanical activity of the stomach and small intestine.1 Gastric distension occurs as a primary event or can be secondary to ileus as a result of a variety of gastrointestinal tract diseases, including proximal enteritis and POI,2 which can be a major life-threatening complication in horses. Postoperative ileus has a prevalence that ranges from 14% to 47%, with associated mortality rate as high as 83% to 86%.3,4 In horses with ileus, the loss of effective transit of gastrointestinal contents can lead to gastric distension and, eventually, gastric rupture and death. The most obvious clinical signs of gastric distension and impending gastric rupture in horses are high heart rate and signs of pain. If gastric distension is suspected, nasogastric intubation is indicated to determine whether distension is present and to relieve the distension by drainage of fluid from the stomach. Failure to obtain fluid from the nasogastric tube is commonly accepted as evidence of gastric decompression. However, in some affected horses, gastric rupture can occur without warning. Furthermore, nasogastric intubation may be an inadequate procedure to identify stomach distension,5 and determining the efficacy of nasogastric decompression via nasogastric tube is often difficult.6,7 Repeated nasogastric intubation or long-term indwelling nasogastric tube placement is often used in horses with ileus to ensure gastric decompression. However, there may be substantial risks associated with repeated or long-term intubation, which include pharyngeal or esophageal mucosal irritation, laceration or perforation, epistaxis, and inadvertent tracheal intubation.8–10 Less invasive methods for accurate identification of gastric distension with fluid and determination of the efficacy of nasogastric decompression are warranted. Transcutaneous ultrasonography is a noninvasive procedure that might be useful for identifying gastric distension and determining the efficacy of nasogastric decompression via nasogastric tube.
Transcutaneous ultrasonography of the equine abdomen is commonly used for evaluation of horses with acute signs of abdominal pain, and there are several reports11–14 on the use of TUS for evaluation of the stomach in horses. However, to the authors' knowledge, there is no information on the use of TUS for assessment of gastric distension or the estimation of gastric fluid volume. We hypothesized that TUS could be a useful diagnostic tool to estimate the volume of fluid in the stomach of horses.
The objectives of the study reported here were to develop a TUS methodology for measuring the location of the stomach during various levels of fluid distension and to evaluate any correlation between gastric fluid distension and position of the stomach in horses.
Rompum, Bayer Corp, Toronto, ON, Canada.
PENTAX VSB-2900, Pentax, Mississauga, ON, Canada.
Ultramar 9 ultrasound system with HDI technology, Advanced Technology Laboratories, Bothell, Wash.
SAS, version 9.1, SAS Institute Inc, Cary, NC.
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