[Ultrasound evaluation of the nasogastric tube position in prehospital]

Objective: To assess the feasibility and actual performance of ultrasound control in verification of the correct positioning of a nasogastric tube in pre-hospital settings.

Study type: Prospective, observational, single-centre study.

Patients and methods: Correct positioning of nasogastric tubes in patients intubated in a pre-hospital setting was verified by ultrasound and routinely compared with the results of two pre-hospital tests, namely a test involving insufflation of air through a syringe coupled with epigastric auscultation and a test involving aspiration of gastric fluid with a syringe. Routine x-ray control was carried out and compared with the pre-hospital results.

Results: Ninety-six patients were included. Mean age was 52 years (median: 53.5 years, SD: 23 years). In 83% of the patients (n=80), the nasogastric tube was located by ultrasound immediately during the insertion procedure. The mean times to ultrasound confirmation of correct positioning of the nasogastric tube were 7s (median: 2s; SD: 16s) and 19s for the syringe tests (median 19s, SD: 5s). Eight ultrasound control tests were negative. Location coupled with insufflation of air through a syringe allowed detection of the nasogastric tube in the stomach but without providing confirmation of the actual gastric position. The pre-hospital ultrasound results were confirmed by subsequent radiological controls at the hospital.

Conclusion: The ultrasound test performed in our study to verify correct positioning of a nasogastric tube is feasible in a pre-hospital setting. This technique is rapid and non-irradiating and is more sensitive and specific than the syringe tests commonly used in pre-hospital settings, and it may be performed in place of the latter tests.