- All staff who place NGTs should be aware that signs and symptoms of misplacement could be immediate such as circumoral cyanosis or delayed or non-existent until the patient's condition deteriorates. Therefor staff need to be constantly alert for such signs, but not take their absense as confirmtaion the tube is correctly sited.
- All staff who read radiographs done to confirm NGT placement should be specifically trained in reading the radiograph using the 'four criteria' (seek expert radiologist advice for detail of local training, but in brief: Does the tube path follow the oesophagus/avoid the contours of the bronchi? Does the tube clearly bisect the carina or the bronchi? Does it cross the diaphragm in the midline? Is the tip clearly visible below the left hemi-diaphragm?) rather than solely viewing the tip of the NGT.
Institutional policies
- A mandatory reporting system should be instituted to capture the frequency of NGT misplacement, including patient outcome.
- Institutional procedures guiding NGT insertion and placement verification should be evidence based and should provide guidance to staff on when a patient is considered high risk for misplacement.
- Within that procedure, a comment should be added encouraging the use of critical thinking skills when assessing a patient during, immediately after or at any time the NGT in place and clinical deterioration occurs.
- When product changes occur, staff need education regarding the new NGT and how it is different from the previous product.
Tube placement
- To obtain an accurate measurement of insertion length, use the NEMU method (Nose→Earlobe→Mid-Umbilicus)
- Proper positioning of the patient, particularly of the head (into anatomic position) during the insertion procedure will make the procedure safer.
Confirmation of placement before first use
- Upon initial insertion of an NGT, a pH should be checked with the desired range being 1-5.0.
- Aspiration of 3-8 ml of gastric fluid should be withdrawn to obtain specimen for pH with stylet in place. Water can then be instilled after confirmation to remove the stylet.
- If unable to obtain an aspirate, turn the patient on the left side if possible and after 10-20 minutes, re-attempt to obtain fluid from the NGT.
- If still unable to obtain an aspirate within the required range, do not use the tube until a radiograph is done to confirm placement.
- Concomitant use of acid suppressing medications is not a contra-indication to pH measurement. If the pH is > 5.0, an abdominal radiograph is necessary.
- When a radiograph is obtained:
- It needs to follow the tube from the chest to below the diaphragm. The tip of the NGT needs to be visualized.
- The report needs to document all 'four criteria' (seek expert radiologist advice for detail of local training, but in brief: Does the tube path follow the oesophagus/avoid the contours of the bronchi? Does the tube clearly bisect the carina or the bronchi? Does it cross the diaphragm in the midline? Is the tip clearly visible below the left hemi-diaphragm?) along with a comment that the tube is appropriately placed for use.
- The reader of the radiograph needs to assure the radiograph being read is the correct patient and the most recent radiograph obtained.
- For adult patients and certain neonatal/pediatric patient, consider a radiograph even if pH is in the required range when:
- patient is severely obtunded
- have an endotracheal tube, or are
- clinically unstable after NGT re-insertion post resuscitation
- clinical deterioration occurs soon after NGT placement
Reconfirmation of NGT placement after initial use
- Tubes should initially be secured to the patient in such a way that the centimeter (cm) mark is visible at the nare. This mark should be documented in the medical record and used as a point of reference for other caregivers to gauge movement of the tube.
- pH can and should be used to re-confirm placement especially if:
- there has been a clinical indication the tube may have migrated such as vomiting or visible enteral formula in the oral cavity from an unwitnessed event.
- The securement device has become dislodged or the tube is not at the reference cm mark.
Practices that should NEVER be used
The following non-evidence based practices are misleading and should never be used as methods to verify NGT placement:
- Auscultation
- Visual inspection of fluid from the tube
- Observation of bubbles - this method is NOT reliable and should no longer be used
- Litmus paper - should NOT be used to determine NGT placement
Technology Plan
Methods of NGT placement confirmation reported in a recently published literature review1 are listed below. New literature and/or options may exist, please send information on any additional technologies, along with appropriate evidence, to
info@patientsafetysummit.org- The Gold Standard - X-ray is regarded as the gold standard for initial NGT placement however it is infeasible, unsafe and costly to perform X-ray before every NGT use. It is also not fool-proof. Between 2005 to 2010, 45% of all cases of harm caused by a misplaced NGT reported by the UK National Patient Safety Agency were due to misinterpreted X-rays, although it should be noted none of thee cases involved use of the 'four criteria' but had relied on viewing tip placement.
- First-line bedside method - pH testing should be regarded as the first-line method for bedside checking of NGT placement as studies show it has the highest sensitivity and specificity of all bedside tests when using a cut-off point of less than or equal to pH5.0
The AACN2 recommends using 2 or more bedside methods to predict tube location during insertion, before feeding, at four hourly intervals after feeding has started or if there is any interruption in feeding.
Supplementary checks on NGT placement (NOT to be used as confirmation of correct placement):
- Observe for signs of respiratory distress (e.g. coughing, choking, dyspnea etc) -- remove and re-insert tube if observed however its important to note that that the signs of respiratory distress may be absent when tubes are inadvertently positioned in the airway especially if the patient has an impaired level of consciousness.
- Observe for change in length of external portion of the tube -- feeding tubes may become dislocated during use due a number of factors. For this reason it is necessary to monitor tube location at regular intervals while the tube is being used for feeding and/or medication. Observing and recording the length of the external portion of the NGT may be helpful in detecting tube migration.
- Observe visual characteristics of aspirate ONLY for indications of migration from stomach to small bowel where the difference in appearance would be more marked. DO NOT try to distinguish between gastric and respiratory secretions as this can be visually confusing.
Methods with limited indication or unclear benefit requiring further research:
- Biochemical markers -- currently no bedside tests available but laboratory tests for bilirubin, pepsin and trypsin levels have been used together with pH to confirm placement.
- Capnography/colorimetric capnometry -- promising method however current evidence is on initial placement only so its reliability in recurrent testing is unclear. The presence of feed, gastric contents and some drinks/medications may interfere with the results.
- Ultrasound -- may be useful but with some reported difficulties. Useful to show progress of the tube through the oesophagus but issues reported verifying that the tip is in the stomach.
- Electromagnetic tracing -- EM trace only indicates NGT placement during insertion and cannot make subsequent confirmation. Deaths have been reported through reliance on EM devices to confirm placement \cite{nhs2013placement}. No studies of EM use to guide nasogastric tube placement in children have been published to date and only one study of its use to guide in adults \cite{NICE2016Cortrak}.
- Visualisation technology -- limited data exists although it may be useful for initial placement in sedated patients but less useful for subsequent checking of NGT placement.
- Manometer technique -- may be a promising method of NGT placement confirmation among intubated, critically ill and mechanically ventilated patients.
Metrics
Topic
Misplacement of Nasogastric or orogastric tubes
Outcome Measure Formula
Numerator: Number of misplaced nasogastric or orogastric tubes
Denominator: Total number of placed nasogastric or orogastric tubes
*Rate is typically expressed as numerator/denominator * XXXX
Metric Recommendations
Direct Impact:
Lives Spared Harm:
Data Collection:
In an ideal healthcare system where an integrated electronic health record system exists, it would be possible to a capture population based incidence of nasogastric/orogastric feeding tube misplacements as a percentage of all tubes placed. In addition to quantitative data on misplacements, qualitative data on patient outcomes could also be captured by the mortality and specific morbidity rates. At the current time, there is no mandate for healthcare institutions to report misplacements, although many do participate in a Patient Safety Organization that would track such events. Without a mandate from a regulatory agency to report nasogastric/orogastric feeding tube misplacements it is not possible to have accurate metrics for this safety initiative.