Ultrasonography Confirmation of Feeding Tube Placement in Critically Ill Patients

Patients who are indicated for feeding tube (FT) placement in ICU will be recruited in this study. Written informed consent will be obtained from next of kin.

Feeding tubes will be inserted by ICU oncall anaesthesiologist as per protocol. The FTof polyvinyl chloride with calibre of 12-16 French will be used. The Nose-Ear-Xiphoid method will be used to measure the tube insertion distance, adding the distance from tip of the patient's nose to the earlobe and from the earlobe to the xiphoid. The tip of tube lubricated prior to insertion in all cases. Orogastric tube placement will be done if nasal route placement is unsuccessful or contraindicated.

Once the correct placement is confirmed by auscultation and aspirate method, the tube will be secured to patient's nose with adhesive tape. For the purpose of this study, verification of tube placement will be done with bedside ultrasound prior to X-ray.

Ultrasound verification of tube placement will be done by a single investigator who received training on oesophageal and gastric ultrasound from radiologist. 'Sonosite SII' (by Fujifilm Sonosite, Inc) ultrasound machine will be used to conduct this study. A linear probe (L38xi, 10-5MHz) will be placed transversely at the anterior neck and focused on visible part of oesophagus which will be just below the left thyroid lobe. A curved probe (C35x, 8-3MHz) will be placed at subxiphoid area orientated towards left upper abdominal quadrant to visualize the stomach and by angulating the probe towards the left subcostal area, the gastric body can be identified in transversal plane just beside the left lobe of liver as internal landmark.

The ultrasound examination will be considered positive if the FT visualized as a hyperechogenic circle posterior to left thyroid lobe adjacent to trachea, and as a hyperechogenic point in the stomach. If the FT seen in the oesophagus and not in stomach, a 20mls of air will be injected through the FT using pine tip syringe while observing dynamic fogging in the stomach. FT is considered in the gastric body in the presence of fogging. Total duration of ultrasound confirmation of FT will be recorded. Following completion of ultrasound confirmation of FT, a chest x-ray will be done for all the patients as per usual. The chest x-ray will be reviewed by ICU team who are blinded from this study.