Date(s) - 25/06/2014
5:30 pm - 7:00 pm
Lakatos (LAK) 2.06
Speaker: Melody Zhifang Ni (Imperial, Medicine)
Time: 5:30pm – 7pm
Title: Risks in predicting the location of nasogastric tubes in adult patients (joint work with Oliver Priest, Larry Phillips and George Hanna)
We present a project in which we have applied Bayesian network (BN) to analyse risks associated with available bedside tests to verify position of nasogastric (NG) tubes. BNs are graphical tools for handling uncertainties. The use of NG feeding tubes are extremely common with however high incidence rates. Complications of feeding tube misplacement include malnutrition, pulmonary aspiration and even death. To populate the model, we retrieved probabilistic evidence on test validity (sensitivity and specificity) from the literature, through a systematic review. We obtained model structure from the NG feeding experts. Through a series of stakeholder meetings, we ascertained the aims of the project and the BN model. We analysed a total number of five bedside tests, i.e. magnetic guidance, aspirate pH, auscultation, aspirate appearance and capnography/colorimetry. Amongst these, the pH test with a cutoff of 4 was the safest in terms of preventing feeding into the oesophagus and lung, the two most hazardous sites. However, lowering the pH would also increase demand for chest x-rays. This eventually led to our recommendations not being adopted, despite the effort within the NHS to make NG tube feeding incidents a “never” event.