Reducing Risk of Misplaced Nasogastric Tube.pptx

Nasogastric tube insertion

1. Reducing the risk of feeding through a misplaced nasogastric tube How to analyse check X-rays accurately to detect correct tube placement

2. Introduction

3. Background The NPSA has published a list of ‘never events’ which are specific serious untoward incidents that can cause serious harm but should be avoidable if national guidance is followed (1) One Never Event relates to: ‘Naso or orogastric tubes placed in the respiratory tract rather than the gastrointestinal tract and not detected prior to commencing feeding or other use’ The Quarterly Data Summary estimates 271,000 nasogastric tubes are purchased by the NHS annually (2) Since the 2005 NPSA alert, the NRLS has received reports of a further 21 deaths and 79 cases of harm due to feeding into the lungs through misplaced nasogastric tubes. The main causal factor leading to harm was misinterpretation of X-rays. This was found in 45 incidents, 12 of which resulted in the death of the patient. This e-Learning module as been recommended in the March 2011 Alert (3)

4. Background Subjectively, from information gathered as part of an audit following a nasogastric feeding tube ‘never event’ at their Trust the authors concluded that formal instruction particularly to F1 and F2 medical practitioners regarding the interpretation of tube siting on check X-ray images is not wide spread http://www.nrls.npsa.nhs.uk/resources/collections/never-events/ [last accessed 21.10.10] National Patient Safety Agency. Incidents related to nasogastric tubes. August 2008. Quarterly Data Summary:9 National Patient Safety Agency Alert March 2011. http://www.nrls.npsa.nhs.uk/alerts/?entryid45=129640 [Last accessed 16.03.11]

5. Contraindications to blind nasogastric tube insertion Fluoroscopically guided intubation should be considered in the following cases: Base of skull fracture Nasal injuries Deviation of the nasal septum Hiatus hernia and gastro-oesophageal reflux - if severe the risk of aspiration may be high Functional problems such as loss of swallow or gag reflex Oesophageal or gastric abnormalities e.g. stricture, pharangeal pouch, pharangeal compression, perforation, fistula - may require fluoroscopically guided intubation Known oesophageal varices, ulceration or haemangioma (due to possibility of causing trauma) Postoperative patients who have had upper GI surgery, with or without an anastamotic leak Many contraindications are relative and a decision to place an NG tube in these patients and the mode of intubation may still be taken by more senior members of the team In some of these situations use of fluoroscopic guidance can make intubation safer

6. Using fine bore feeding tubes Acutely unwell patients are preferably fed through fine bore nasogastric tubes, provided they do not require gastric decompression with a larger Ryle’s tube This is because fine bore tubes are more easily tolerated Large bore tubes are associated with rhinitis, oesophageal reflux and strictures 1 However, this tolerance comes at a price - patients may tolerate accidental intubation of the trachea and bronchi without obvious distress 2 If the tube misplacement is not spotted, and feeding is commenced, the consequences can be serious, including 3 Pneumothorax Severe pneumonia Empyema Pulmonary haemorrhage Death, depending on response to the above Pearce CB, Duncan HD. Postgrad Med J 2002;78(918):198-204 de Aguilar-Nascimento JE, Kudsk KA. Curr Opin Clin Nutr Metab Care . 2007 May;10(3):291-6 Kawati R, Rubertsson S. Acta Anaesthesiol Scand 2005; 49(1):58-61

7. Problems with fine bore nasogastric tube insertion – a case example A seventy five year old woman with a past history of chronic obstructive airways disease and hiatus hernia was admitted under the care of the general surgeons with peritonitis secondary to a perforated sigmoid diverticula She underwent a Hartmanns procedure with an end colostomy, but unfortunately her abdominal wound dehisced She returned to theatre several times and was managed with an abdominal VAC dressing She then developed pneumonia and was managed on the High Dependency Unit (HDU) She had poor oral intake for a variety of reasons and her progress was slow Therefore, after a review by the dieticians, it was decided during the evening ward round that she ought to commence nasogastric feeding

8. Problems with fine bore nasogastric tube insertion – a case example Later on in that shift the nurse inserted the fine bore NG tube and asked the evening Senior House Officer (SHO) to order a portable X-ray to check its position The X-ray was reviewed by the night HDU SHO at 0100 It was thought the X-ray was a little rotated, but that the position was probably slightly altered due to the hiatus hernia Feeding was commenced The patient’s respiratory function deteriorated overnight When the patient was reviewed on the morning ward round, the X-ray was reviewed again and the team felt that the tube might be misplaced The tube was removed and the patient treated for aspiration of feed with bronchial lavage (which confirmed feed in the bronchi) and adjustment of her antibiotic regime

9. Problems with fine bore nasogastric tube insertion – a case example There are several factors within this scenario which contributed to the patient being fed via a misplaced tube They fall into five main categories: Human factors (e.g. difficulty interpreting X ray) Equipment factors (e.g. use of less radiopaque tubes rather than ones that are completely radiopaque) System factors (e.g. limited access to out-of-hours specialist radiology help) Environmental factors (e.g. workload issues leading to delays) Communication factors (e.g. documentation in the notes is often poor - when re-siting tubes it is important to know if there have been previous difficulties placing the tube)

10. Incidence of tube misplacements Difficult to determine due to limited number of studies in this area Has been variously reported as being between 1.3% and 50% 1 The National Patient Safety Agency (NPSA) reported 11 known deaths and 1 case of serious harm due to misplaced NG feeding tubes over a two year period (2003-2005) 2 Led to the issue of a safety alert in 2005 on how to ensure feeding tubes are placed correctly 2 Since the release of the alert, there have been a further 79 reported cases of feeding through misplaced nasogastric tubes 3 21 of these are thought to have directly contributed to the death of a patient Ellett ML. Online J Knowl Synth Nurs 1997;4:5 National Patient Safety Agency (NPSA). Patient Safety Alert 05 Fayaz A. BMJ Careers;doi : 10.1136/bmj.c3850. http://careers.bmj.com/careers/advice/view-article.html?id=20001226

11. Given the potential catastrophic consequences of tube misplacement, the NPSA designated feeding after NG tube misplacement as one of 8 ‘ never events ’ 1 This means there needs to be a system in place to help avoid the never event taking place This training package is part of that safety system 4. Misplaced naso or orogastric tube not detected prior to use Definition: Naso or orogastric tube placed in the respiratory tract rather than the intestinal tract and not detected prior to commencing feeding or other use Main care setting: All care settings NPSA ‘never events’ http://www.nrls.npsa.nhs.uk/resources/collections/never-events/ [last accessed 10.08.10]

12. Developing your own protocol to avoid tube misplacement ‘never events’

13. Are you 100% sure which patients need to have check X-rays and which you can confidently feed without? Are you confident you have a reliable system in place for reviewing X-rays after NG tube placement? Ask yourself

14. Protocol for using pH strips to check NG tube position pH testing pH testing of aspirate is the initial method of choice for checking tube position Ideally, use pH indicator strips that are CE marked, and have increments of measurement marked on NICE guidelines state that if the aspirate has a pH of 5.5 or less using pH indicator strips, then feeding can be commenced as the tube is in the stomach Litmus paper should never be used 1 Checks should be carried out: Following initial insertion Before starting each feed or giving medication As well as misplacement upon insertion, NG tubes that were inserted correctly initially can move out of the stomach at a later stage if the tube is dislodged Once-daily, during continuous feed Following vomiting, retching or coughing in case of displacement If the tape around the nose is loose, or the visible tube appears longer than previously documented MHRA medical device alert. 14 June 2004

15. When to proceed to check X-ray? Elevated pH If pH is >5.5, repeat after one hour with nothing running through NG tube during this time If pH is still >5.5 proceed to check position with X-ray Reasons for an elevated pH in a correctly placed tube include use of antacid medication or feed raising the pH by diluting gastric secretions (this is more common with continuous feed when checks are done during the period of feeding - in this case the feed should be switched off for one hour and the aspirate rechecked) However, never assume that an elevated pH is acceptable whatever the cause Always proceed to check X-ray Difficulty obtaining aspirate Turn patient onto side if possible Try injecting 10-20ml of air into tube and wait for 15 minutes then try again THIS IS NOT THE "WHOOSH" TEST. DO NOT USE THE "WHOOSH" TEST AT ANY TIME The Whoosh test is an old test, where air is injected into the tube and auscultation performed to listen for exit sound The NPSA issued an alert in 2005, stating this test should no longer be used, as it is not an accurate method of checking tube placement 1 Advance tube 10-20cm and try again If no aspirate is obtained in any of these situations – proceed to X-ray National Patient Safety Agency (NPSA). Patient Safety Alert 05

16. Interpretation of check x-rays The following slides will help you answer the important questions below Can you interpret an image that is tilted or rotated? Can you identify the carina? Can you see the tube bisect the carina? Can you identify the diaphragm and see the tube passing below it? Which way does the tube deviate below the diaphragm? Can you see the tip of the tube? Please note, this training package has been developed using X-ray images that have been anonymised Some of these images would be easier to interpret using the PACS viewing system due to the ability to change the density of the image - this function is not available on this training tracker

17. Taking rotation into account This diagram illustrates the orientation of the clavicles, 1 st ribs and thoracic spine in a non rotated chest X-ray NG Tube central Equal distance from clavicles Non rotated film

18. Taking rotation into account This X-ray demonstrates a non-rotated film Look for the relationship of the clavicles, 1 st ribs and spine

19. Taking rotation into account This diagram illustrates how to identify rotation from the relationship of the clavicles, first ribs and spine. A film demonstrating this appears on the next slide. The right shoulder is rotated forward and the left shoulder is rotated away from the observer This makes the thoracic spinal processes visible to the right The oesophagus lies slightly to the left therefore the NG tube can be seen more to the left of the vertebral bodies in a film rotated in this orientation

20. Feeding should not occur and this tube should be removed Taking rotation into account This film demonstrates the features illustrated in the previous diagram. Look for: Asymmetry in the clavicles and 1 st ribs Spinous processes projecting to the right Note: this tube deviates to the left at the level of the carina and is likely to be in the base of the left lung 1 3 2

21. Identifying the carina The carina (the point at which the trachea divides into the right and left main bronchi) usually lies at the level of the 4 th or 5 th thoracic vertebrae, although it can vary Sometimes the angle of the carina can be very acute and in other patients the carina may be splayed wider apart. The carina can usually be seen on a standard chest X-ray The image to the right is taken from a CT scan (in a patient without an NG tube) but it illustrates the x-ray appearance of the carina very clearly When checking NG tube position the tube should be seen to pass into the area underneath the carina thereby "bisecting" it This does not mean the tube has to pass precisely in the midline or divide the carina into equal halves The diagram on the next slide illustrates this

22. Identifying the carina This diagram illustrates how the carina appears to be bisected by the NG tube

23. Identifying the carina Can you identify the carina and whether the NG tube bisects it in this X-ray?

24. Identifying the carina This annotated diagram of the previous film highlights the carina The tube does bisect the carina. It passes over the left main bronchus

25. Identifying the carina This tube deviates at the level of the carina The trachea lies slightly to the right of the spine as the film is rotated The carina can be seen and the tube deviates to the right at this level – it does not bisect the carina From review of this X-ray it appears that this tube is likely to be in the right lung base In fact this patient has a right sided pneumothorax caused by forcing the NG tube against resistance through the lung parenchyma and into the pleural space Feeding should not occur and this tube should be removed 1 2

26. Beyond the carina Sometimes the carina can be a little unclear, particularly if there are other artefacts on X-rays that can cause confusion as in this example If you are unsure whether the tube bisects the carina or deviates to either side follow the tube further down Does it pass down the midline to the level of the diaphragm? When passing below the diaphragm does it deviate immediately to the left? If the answer to these questions is YES, the tube can be assumed to be in the stomach In this film the carina is not particularly clear It is also a little difficult to see the tube more inferiorly However, it does appear to pass down the midline, below the diaphragm and then deviates to the left It would be acceptable to feed this patient nasogastrically

27. Beyond the carina If the tube does not pass below the diaphragm feeding should not occur It may be possible to advance the tube if it is felt to be in the oesophagus In this situation aspirate may then be obtained meaning a further X-ray would be unnecessary Obviously sometimes tubes do not pass below the diaphragm due to being coiled higher up as in this example In this situation the tube should be removed and resited If there is a suspicion of any abnormal anatomy causing this (e.g. pharyngeal pouch) then fluoroscopic intubation should be considered

28. Beyond the carina If the tip of the tube cannot be seen because it passes further below the diaphragm than can be seen on the X-ray, there are three options It may be that the X-ray does not cover enough of the area below the diaphragm to see the tube and a further image is required Sometimes the body of the stomach extends quite inferiorly in the abdominal cavity, but the duodenum is relatively fixed. Therefore, if the tube is in the duodenum it can usually be seen to loop back superiorly and to the right before turning inferiorly and tracking back towards the midline again A tube that does not do this may well still be in the stomach. In this situation it is useful to use measurements The length of NG tube to be inserted as a minimum is the same as the distance from the nasal septum to the tragus of the ear and then to the xiphisternum If the tip of the tube cannot be seen but the length of tube in situ is this distance plus up to 15cm then it is acceptable to feed

29. Interpreting check X-rays – flow chart system To increase accuracy in determining position of feeding tube, use a feeding tube that is fully radiopaque In some cases, use of fluoroscopic guidance can make intubation safer Remember, if in doubt regarding tube position for any reason, do not feed The flow chart on the next slide demonstrates a system to increase accuracy when checking X-rays for correct NG tube position

30. Examples

31. Misplaced tube This tube appears to be below the level of the diaphragm therefore it could be incorrectly interpreted as being in the stomach However: The base of the lungs extend much more inferiorly posteriorly The tube deviates at the level of the carina 2

32. Misplaced tube And on this x-ray of the same patient a lateral film demonstrates that the NG tube is indeed in the base of the right lung

33. Would you feed this patient? This NG tube bisects the carina, passes down the midline and below the diaphragm to the left and is in a suitable position for feeding It would be acceptable to feed this patient nasogastrically

34. Would you feed this patient? This is another correctly sited tube It bisects the carina, passes down the midline and below the diaphragm deviating initially to the left (although it then curves round to the right following the curve of the stomach as would be expected) It would be acceptable to feed this patient nasogastrically

35. Would you feed this patient? This tube is in the stomach, but only just and it would be advisable to advance it slightly prior to feeding After advancing an aspirate might be more easily obtained, otherwise it could be reimaged

36. Would you feed this patient? This film is interesting. Sometimes NG tubes can have this appearance when they are in a hiatus hernia - particularly if it is incarcerated. This is uncommon The tube is in a hiatus hernia. The deviation is quite low, near the diaphragm. However, any deviation in the chest – particularly if extreme like this – should raise the question: Could this tube be in the lung? Be very wary of attributing any deviation in the thorax to a hiatus hernia and get a senior opinion. "If in doubt, take it out" is the bottom line

37. Summary Not everyone needs a check X-ray However if they do, it is important that the person interpreting it has a system of reading the X-ray in place as feeding down a misplaced tube can be catastrophic Use the flowchart demonstrated earlier in these teaching slides to decrease the likelihood of misinterpreting an X-ray (Flow Chart)

38. Multiple Choice Questions Welcome to the multiple choice questionnaire for healthcare professionals who have completed the E-learning module: Reducing the risk of feeding through a misplaced nasogastric tube: How to analyse check X-rays accurately to detect tube placement. To complete the questionnaire please click here (insert link to 2.2)