[Preliminary application value of ultrasound contrast agent with enteral nutritional suspension as mixed medium in locating indwelling nasointestinal tube in critically ill patients].

Objective: To evaluate the value of ultrasound contrast agent with enteral nutrition suspension as mixed medium in locating indwelling nasointestinal tube in critically ill patients. Methods: Total of 45 critically ill patients had nasointestinal tube indwelled were collected from June 1,2018 to April 1,2019 in the Intensive Care Unit of Zhejiang Provincial People's Hospital, including 30 males and 15 females, with an average age of (63±17) years.Enteral nutritional suspension Peptisorb Liquid was used as research medium,with the ultrasonic imaging performance of it confirmed by in vitro and in vivo experiments.The optimal mixing ratio of microbubble ultrasound contrast agent and Peptisorb Liquid was confirmed by in vitro experiment, then the mixture was quietly placed and its stability was dynamically observed. The nasointestinal tube was confirmed in the digestive tract by conventional ultrasound and then the ultrasound contrast mode turned on. Ultrasound contrast agent with Peptisorb Liquid as mixed medium was injected into the nasointestinal tube and the tube direction and end position were observed and recorded in real time. Abdominal X-ray examination or CT was used as the gold standard for verifying the location of the nasointestinal tube and the same result represented successful positioning. Results: The in vitro and in vivo experiments showed that Peptisorb Liquid had good ultrasound imaging uniformity and penetrating power, which could clearly show the range and boundary of the filling intestine cavity; the in vitro experiment showed that the ultrasound contrast agent prepared with the microbubble ultrasound contrast agent and Peptisorb Liquid by the ratio of 1∶1 000 and 1∶500 which had the best imaging effect and the best distribution uniformity, with the best stability within 10 minutes after quietly placed. Nasointestinal tubes were successfully located by using ultrasound contrast agent with enteral nutritional suspension as mixed medium in 95.6%(43/45) of the patients collected in this study,including success at one attempt in 39 cases, the operating time was (1.6±0.5) minutes and 4 cases were successfully located after multiple operations with (5.1±0.5) minutes, the tube bent in the stomach in one case and flexed back into the stomach from the descending duodenum in another. The operation failed in 2 cases (4.4%). No significant complications occurred during the examination. Conclusion: The ultrasound contrast agent with enteral nutritional suspension as mixed medium has the advantages of both, which can conveniently, safely and effectively locate the direction and end position of nasointestinal tube in critically ill patients.