- If water was instilled in the tube prior to insertion, 3-8ml of fluid needs to be withdrawn prior to obtaining the specimen for pH as the pH of water will skew the results.
- 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, 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 > 5.5, 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 the placement of the tip 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 when:
o patient is severely obtunded
o have an endotracheal tube, or are
o clinically unstable after NGT re-insertion post resuscitation
o clinical deterioration occurs soon after NGT placement
- Other devices may be used to for NGT placement, such as electromagnetic device, IRIS camera or capnography but a pH and/or radiograph should also be done.
- For re-confirmation of NGT placement the following techniques can be used:
o 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.
o 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.
o The securement device has become dislodged or the tube is not at the reference cm mark.
- The following non-evidence based practices should never be used as methods to verify NGT placement:
o Auscultation
o Visual inspection of fluid from the tube
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.
- 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.
- Other common methods of confirming NGT placement:-
o 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.
o 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.
o Observe visual characteristics of aspirate - trying to differentiate between gastric and respiratory secretions can be visually confusing. This method should not be used in isolation and is may be more useful trying to determine when a tube has migrated from the stomach to small bowel where the difference in appearance would be more marked.
o Auscultation with insufflation of air -- although auscultation lacks evidence it may be useful for bedside confirmation in the absence of aspirate and alongside at least one other form of verification
- Methods with limited indication or unclear benefit: -
o Observation of bubbles -- this method is NOT reliable and should no longer be used
o Litmus paper -- should NOT be used to determine NGT placement. pH indicator sticks licensed for medical use should be used
o 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.
o 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.
o 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.
o Electromagnetic tracing -- EM trace only confirms NGT placement during insertion and cannot make subsequent confirmation.
o 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.
o Manometer technique -- may be a promising method of NGT placement confirmation among intubated, critically ill and mechanically ventilated patients.
Metrics
Topic
Include a brief description of metric integrity.
Topic Name
Topic description
Outcome Measure Formula
Numerator:
Denominator:
*Rate is typically
Metric Recommendations
Direct Impact:
Lives Spared Harm:
\(Lives\ =\ \left(Compliance\ Rate_{measurement}\ -\ Compliance\ Rate_{baseline}\right)\ x\ Healthcare-associated\ Infection\ Rate\ _{baseline}\)
Data Collection: