This training tool is designed to help minimise the risk of feeding patients through a misplaced nasogastric tube.

1
Reducing the risk of feeding through a misplaced
nasogastric tube

• This training tool is designed to help minimise
  the risk of feeding patients through a misplaced
  nasogastric tube.
• Please complete the learning module,at the end
  of which will be a multiple choice questionnaire
  which you must complete to gain your CME
  certificate.
• This training tool has been developed by
  Dr Rob Law, Consultant GI Radiographer and Dr
  Joanne Bennett, Research Fellow, North Bristol
  NHS Trust.
• It has been funded by Merck Serono

2
Reducing the risk of feeding through a misplaced
nasogastric tube

• How to analyse check X-rays accuratelyto detect
  correct tube placement

3
Introduction
4
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)

5
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 Summary9
• National Patient Safety Agency Alert March 2011.
  http//www.nrls.npsa.nhs.uk/alerts/?entryid451296
  40 Last accessed 16.03.11

6
Contraindications to blind nasogastrictube
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

7
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 Ryles tube
• This is because fine bore tubes are more easily
  tolerated
• Large bore tubes are associated with rhinitis,
  oesophageal reflux and strictures1
• However, this tolerance comes at a price -
  patients may tolerate accidental intubation of
  the trachea and bronchi without obvious distress2
• If the tube misplacement is not spotted, and
  feeding is commenced, the consequences can be
  serious, including3
• Pneumothorax
• Severe pneumonia
• Empyema
• Pulmonary haemorrhage
• Death, depending on response to the above

• Pearce CB, Duncan HD. Postgrad Med J
  200278(918)198-204
• de Aguilar-Nascimento JE, Kudsk KA. Curr Opin
  Clin Nutr Metab Care. 2007 May10(3)291-6
• Kawati R, Rubertsson S. Acta Anaesthesiol Scand
  2005 49(1)58-61

8
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 abdominalVAC dressing
• She then developed pneumonia and was managed on
  the High DependencyUnit (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

9
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 patients 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

10
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)

11
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 501
• 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 areplaced correctly2
• Since the release of the alert, there have been a
  further 79 reported cases of feeding through
  misplaced nasogastric tubes3
• 21 of these are thought to have directly
  contributedto the death of a patient

• Ellett ML. Online J Knowl Synth Nurs 199745
• National Patient Safety Agency (NPSA). Patient
  Safety Alert 05
• Fayaz A. BMJ Careersdoi 10.1136/bmj.c3850.
  http//careers.bmj.com/careers/advice/view-article
  .html?id20001226

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NPSA never events

• Given the potential catastrophic consequences of
  tube misplacement, the NPSA designated feeding
  after NG tube misplacement as one of 8 never
  events1
• This means there needs to be a system in place to
  help avoid the never eventtaking place
• This training package is part of that safety
  system

• http//www.nrls.npsa.nhs.uk/resources/collections/
  never-events/ last accessed 10.08.10

13
Developing your own protocol to avoid tube
misplacement never events
14
Ask yourself
15
Protocol for using pH strips to check NGtube
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 used1
• 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

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When to proceed to check X-ray?

• Elevated pH
• If pH is gt5.5, repeat after one hour with nothing
  running through NG tube during this time
• If pH is still gt5.5 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 checkingtube placement1
• 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

17
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

18
Taking rotation into account

• This diagram illustrates the orientation of the
  clavicles, 1st ribs and thoracic spine in a non
  rotated chest X-ray

NG Tube central
Equal distance from clavicles
Non rotated film
19
Taking rotation into account

• This X-ray demonstrates anon-rotated film
• Look for the relationship of the clavicles, 1st
  ribs and spine

20
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 rotatedforward and the
  left shoulderis rotated away fromthe observer
• This makes the thoracicspinal processesvisible
  to the right
• The oesophagus lies slightly to the left
• therefore the NG tube can be seenmore to the
  left of the vertebralbodies in a film rotated in
  this orientation

21
Taking rotation into account

• This film demonstrates the features illustrated
  in the previous diagram. Look for
• Asymmetry in the clavicles and1st ribs
• Spinous processes projecting tothe 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

22
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 4th or 5th
  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

23
Identifying the carina

• This diagram illustrates how the carina appears
  to be bisected by the NG tube

24
Identifying the carina

• Can you identify the carina and whether the NG
  tube bisects it inthis X-ray?

25
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

26
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 thatthis
  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

27
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

28
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 wouldbe 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

29
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

30
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

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(No Transcript)
32
Examples
33
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 ofthe carina

2
34
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

35
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

36
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
  wouldbe expected)

37
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

38
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

39
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 (insert link back to the
  flow chart)

40
Test to gain CME points

• Now that you have completed this educational
  module, please complete the following test to
  gain your CME points
• Within the test there are several images to
  review - sometimes you have to scroll down to see
  the bottom of the image, just beware of this as
  the bottom of the film sometimes contains very
  important information!