Radiology responsibilities post NPSA guidelines for nasogastric tubes: A single centre review 1 Kevin Flintham Bev Snaith

Background Risks associated with NG tube malposition including pneumothorax, tracheal perforation or vocal cord paralysis. If feeding takes place via an NG tube sited within the lung then complications including aspiration pneumonia and acute respiratory failure. In 2011 the UK National Patient Safety Agency (NPSA) 2 published an alert regarding NG tubes highlighting the issue of incorrect placement and risk from subsequent patient feeding. The NPSA alert confirmed the feeding of a patient through an incorrectly sited NG tube to be a ‘never event’. Trust guidelines established 2011 though working group (including radiologists and radiographers)

Standards – NG tube for feeding First line check of NG tube position should be pH of aspirate. Chest x-ray required where aspiration fails or is equivocal X-ray should be taken as soon as possible X-ray sufficient quality to visualise whole tube Immediate report where available Report to document actions (tube to be removed if patient still in radiology) Coded phrases established

Standards First line check of NG tube position should be pH of aspirate. Chest x-ray required where aspiration fails or is equivocal X-ray should be taken as soon as possible X-ray sufficient quality to visualise whole tube Immediate report where available Report to document actions (tube to be removed if patient still in radiology) Coded phrases established

Method Retrospective review of examinations demonstrating NG tube Consecutive sampling approach using all attendances from 1 July 2012 to 31 December 2012 where the clinical history or report text included the terms “NG tube”, “Nasogastric” and “feeding”. Data were collected from the departmental Radiology Information System (RIS) in terms of patient demographics; exposure; author status (radiologist or radiographer); NG tube location; report content and report turnaround time. Tube position and visibility was confirmed by two independent reviewers (KF and BS), blinded to the report text, on a PACS workstation in optimal viewing conditions.

Results - referrals 1179 reports included defined search terms – 42 excluded as no NG tube (NGT) present – 777 for NGT check 12.6% performed outside of guideline times – time of insertion uncertain Patient location NGT for feeding NGT position (+/- other lines) NGT not mentioned on referral Total Critical care (inc. Burns) Neonatal unit Theatre recovery Ward Emergency Department Other

Results - patients Age range was broad (mean 54.0 years; range <24hours -106years). Of the paediatric referrals : – The majority were <1 year (n=173/186; 84.9%) – Predominately represented neonatal unit referrals (n=134/186; 72.0%). Age Category Radiologist N (%) Radiographer N (%) Total Adult (17 – 64 yrs)151 (34.8)283 (65.2)434 Elderly (65 yrs +)157 (30.4)360 (69.6)517 Paediatrics (0 – 16 yrs)182 (97.8)4 (2.2)186 Total490 (43.1)647 (56.9)1137

Results – tube position 1.8% of NGT located in the respiratory tract – half did not specify ‘for feeding’. 8.6% located too proximal in the GI tract NG tube tip positionNo (%) Satisfactory Respiratory tract Right lung Left lung Pharynx GI tract Oesophagus Gastro-oesophageal junction Not seen 1016 (89.4) 9 (0.8) 3 (0.3) 8 (0.7) 33 (2.9) 65 (5.7) 3 (0.3) Total1137

Results – report content 18 cases discrepancy between the original report and the audit review –all regarding the interpretation of the gastro- oesophageal junction. 68 malpositioned tubes did not document communication with the referrer/ward Use of a coded phrase for NGT tip position in the radiology report is advocated in the trust protocol. 555 reports used phrase where possible (n=555 / 1016; 54.6%) – Significant difference between report author profession when code use is possible (95.1% radiographer v 2.3% radiologist).

Results – report turnaround 211 had a verified report available within 1 hour of attendance (n=211/1137; 18.6%). The x-rays with NGT in the respiratory tract report turnaround from <1 hours (n=5) to in excess of 7 days (n=1) The main delay (>7 days) appears to be incorrect allocation.

Results – tube visibility Visibility of the entire length of the NGT reduced with lower exposure index (low 76.3%; optimal 87.6%; high 90.2%). When not visualised along entire length (12.6% of cases): – Inverting the image helped in only 0.6% – Windowing tools demonstrated 6.0% – Entire length never visualised in 6.6% A higher exposure index did not appear to positively influence the visibility of the NGT on initial viewing or when using post- processing tools.

Conclusions Misplacement rate similar to published studies Proximal GI location – tube length needs reinforcing Report turnaround disappointing Incorrect allocation of reporting contributes to delays Report standardisation required Windowing improves tube visibility Exposure factors require further investigation, particularly with regards to new dual-processing software for enhanced line and tube visualisations

References 1. Snaith, B. and Flintham, K Radiology responsibilities post NPSA guidelines for nasogastric tubes: A single centre review. Radiography National Patient Safety Agency Reducing the harm caused by misplaced nasogastric feeding tubes in adults, children and infants. (Patient Safety Alert 2011) [Online]. Available from: