NG Study Guide 2020 PDF

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Nasogastric Tube Insertion Study Guide

Clinical Skills Teaching & Learning Centre Written by:

Reviewed by:

Clinical Skills Lecturing Team

Dr Jamie Fanning, Theme lead Clinical Examination & Procedural Skills

University of Liverpool

August 20

Contents

Glossary ...................................................................................................................................

Learning Objectives .................................................................................................................

Year 5 ...................................................................................................................................

Introduction ..............................................................................................................................

Indications for inserting NG tube............................................................................................ Surface Anatomy / Relevant Physiology ..................................................................................

Preparation ..............................................................................................................................

Contraindications for NG tube insertion .................................................................................

Complications associated with NG tube insertion ..................................................................

Patient safety ........................................................................................................................ Measuring tube length ..........................................................................................................

Equipment ............................................................................................................................

Procedure ................................................................................................................................ If you are unable to aspirate .................................................................................................

Post Procedure ........................................................................................................................ Documentation......................................................................................................................

Ongoing care for the patient: ................................................................................................. Removal of an NG tube ........................................................................................................ Bibliography & Further Reading ...............................................................................................

Picture Credits .........................................................................................................................

Glossary Charrière or Ch CSTLC Epistaxis Fr Gastroparesis GI Nasal Ala NBM Never Event

NEX NG NPSA PEG Post-operative ileus PPI Ryles “Whoosh” test Xiphisternum

French sizing 1 Ch = 0.33mm Clinical Skills Teaching and Learning Centre Nose bleed French gauge; 1 Fr =0.33mm This is a chronic condition where the stomach cannot empty normally Gastrointestinal Wing of the nose shaped by Alar cartilage Nil By Mouth An event that is classed as “serious incidents that are wholly preventable because guidance or safety recommendations providi strong systemic protective barriers are available at a national level and should have been implemented by all healthcare providers. (NHS Improvement 2018 (20) pg. 4) Nose, ear, xiphisternum Nasogastric National Patient Safety Alert Percutaneous gastrostomy A reduction or arrest of intestinal motility following surgery, causing distension, bloating, vomiting and failure to pass faeces or flatus. Proton Pump inhibitors Wide bore NG tube, often used for gastric decompression This is now considered poor practice and should not be done- Rap injection of air into NG tube whilst auscultating over the epigastrium The lowest part of the sternum; the xiphoid process

Learning Objectives Year 5 To understand the indications for inserting nasogastric (NG) tubes To understand the contraindications associated with NG tube insertion To understand the complications associated with NG tube insertion and be aware of the National Patient Safety Alert (NPSA) associated with the procedure To understand the different styles of tubes available, their uses and be able to carry out the insertion of a NG tube on a manikin

Introduction

A nasogastric (NG) tube is a long flexible polyurethane or silicone tube that is passed through the nose and through the nasopharynx and the oesophagus into the stomach. They are commonly inserted for various reasons.

There are 2 types of NG tube, there is a fine-bore nasogastric tube used for enteric feeding or administration of medication and a wide-bore used for drainage. This study guide will look at the indications and complications for inserting an NG tube and th procedure of inserting an NG tube safely under direct supervision.

Indications for inserting NG tube There are several reasons why an NG tube may be inserted, some of the reasons are listed below: 



Therapeutic indications  Gastric Decompression  Gastric Lavage  Enteral feeding or administration of medications Diagnostic indications  Administration of radiopaque mediums for X-ray studies

Gastric Decompression

Patients with gastric outflow problems may develop distension / dilatation of the stomach w associated pain and the vomiting of gastric secretions, bile, blood or faecal matter (dependant underlying pathology) may occur.

Decompression of the stomach may also be required following bag-mask hand ventilation, wh air can be forced into the stomach as well as the lungs. This will generally be follow endotracheal intubation and the orogastric or nasogastric tube can be inserted to decompress stomach and reduce the risk of regurgitation and aspiration of stomach contents. NG tu decompression can also improve ventilation by reduction of stomach volume and therefo elimination of any diaphragmatic splinting causing limited lung expansion.

Gastric Lavage Following the ingestion of a toxic substance gastric lavage may be required to reduce the amount of ingested substance to reduce physiological effects. The fluid used to lavage the stomach may include substances such as activated charcoal to improve the absorption and removal of the ingested substance. Gastric lavage can also be used in severely hypothermic patients when warming the patient with warm fluids.

Enteral Feeding / administration of medications

Patients who are unable to maintain adequate oral intake may require short term enteral feedi or administration of medication. This may be facilitated by the insertion of a nasogastric tube which delivers enteral nutrition into the stomach or small intestine. Nasogastric tube feeding should be a short term intervention with patients requiring long term intervention (>4 weeks) having a PEG tube inserted.

Administration of radio-opaque mediums for X-ray studies. An NG tube may be passed if the patient is unable to swallow the medium.

Surface Anatomy / Relevant Physiology

When inserting an NG tube you need to have knowledge of the anatomy of the nose, nasopharynx, oropharynx, oesophagus and stomach. For example, external appearances of t nasal cavity would suggest that the tube should be inserted pointing in an upwards direction. Knowledge of the anatomy, however, means that the tube should actually be inserted in a flat position, pointed directly towards the back of the nasal cavity, which allows the tube to pass along the base of the nasal cavity, parallel to the hard palate.

Not uncommonly, the tube can enter the trachea instead of the oesophagus and to help recognise this known complication, you must also know the relevant anatomy of the trachea a main bronchi and in particular, their location on a plain chest x-ray.

Figure 1

The tip of the NG tube should sit within the stomach (see figure 3) and to help ensure its corre positioning you will need to estimate the distance to the patient’s stomach. To facilitate this yo will need to be able to identify the patient’s xiphisternum, which is coloured purple in figure 2:

Figure 2

The NG tube will sit in the patient’s stomach, the tip has to be in stomach contents to facilitate drainage, see Fig 3. Due to the curvature of the stomach the tube can curl up on itself, or not in far enough.

Figure 3

pH

In order to confirm the correct position of an NG tube, the pH of stomach contents has to be assessed. When this is not possible, the position is then confirmed using an x-ray. The pH of gastric acid in healthy fasting patients is normally between 1 and 3. Patients who have recent consumed food may have an increase in pH (Simonian et al 2005) to 4-5. Whereas patients who have recently taken Omeprazole or Ranitidine can have a significantly raised pH (Atanassoff et al 1992) 6 or above (NHS improvement 2016).

Figure 4

Preparation Before you begin this procedure you must prepare the patient and be aware of the contraindications and complications associated with the insertion of an NG tube.

Contraindications for NG tube insertion Absolute contraindications You must not insert an NG tube if the patient has:   

Mid face trauma, due to risk of bleeding or a fracture of the base of skull. Had recent nasal surgery due to risk of bleeding. Refused to allow you to undertake the procedure.

Relative contraindications: There are certain cases where NG tube insertion is difficult or not advised, you must discuss cases with your supervisor and ensure that you have direct supervision. Some relative contraindications are listed below: 

  

Cases of ingestion of alkaline substances - because the cardioesophageal sphincter cannot fully close when the NG tube is in place, there is a risk of aspiration of the substance and reflux into the oesophagus causing damage or even rupture. Coagulation abnormalities- there is an increased risk of bleeding Oesophageal varices (untreated or recently banded/cauterised) Oesophageal strictures, patients are less likely to have a stricture if they are on PPI’s (Desai & Moustarah 2019)

In the presence of relative contraindications, the advantages and disadvantages of NG placement will have to be judged against the reason for tubing and the patient’s condition.

Complications associated with NG tube insertion There are a few complications associated with NG tube insertion: 1. 2. 3. 4. 5.

Misplaced tube Movement or dislodgment of tube Tissue trauma and ulceration Nose bleeds or nasal sores Throat irritation

1. Misplaced Tube

There have been several National Patient Safety Alerts in relation to NG tube misplacement th last in 2016: NHS/PSA/RE/2016/006. These warn of continued risk of death and severe harm from NG tube misplacement. The NPSA is in relation to fine-bore tubes only. If a tube enters the trachea instead of the stomach it can be removed, however if fluids or medication are introduced into the respiratory tract, this is classed as a “Never Event” and is reportable at a National level.

Most patients will cough or develop respiratory symptoms on insertion if the tube goes into the lungs, however if they have reduced consciousness or are sedated, this may not be the case. there is evidence of respiratory symptoms, you should stop and remove the tube before any further attempts.

pH testing of NG aspirate should be done routinely and is the only accepted way of confirming NG tube placement, litmus paper is not sufficient for testing pH (NHS Improvement 2016).

The “safe range” for pH is 1 to 5.5 and in contrast the pH of the lungs of a healthy patient tend to be between 7.38 and 7.42 (NHS Improvement 2016).

If no aspirate is obtained from the NG tube, or if the pH is not within the acceptable range, the an x-ray should be obtained to confirm placement as all tubes should be radio-opaque. If the is not within the safe range no medication or fluid should be administered until there is x-ray confirmation of placement. Only a senior clinician who is trained to do so can interpret the x-ra (Image of a normal placement Figure 40)

X-ray showing tube in left low lobe bronchus.

Figure 5

If fluids or medication had been administered the patient would develop an aspiration pneumonia which could potentially result in the patient’s death. In the period between Sept 20 and March 2016 there were 95 incidents with 32 deaths (NPSA 2016)

2. Movement or dislodgment of the tube

There have been reported incidents of dislodgement of the tube, normally if the patient or staf have accidently caught the tubing or a confused patient has tried to remove it. However the tu may also potentially move if the patient has been coughing or retching. There should be daily monitoring in place for the length of the tube at the patient’s nose and prior to feeding or administration of medication.

There are different methods of securing the NG tube to the patient, and if secured with tape, t can become wet and dislodge, considerations should be taken regarding how the tube is secured, and a bridle could be considered, (see Figure 23).

3. Tissue trauma and ulceration

Prabhakaran et al (2012) describe tissue trauma caused by NG tubes, these are mostly cause by misplacement, e.g. pneumothorax and there has been a reported case of intracranial placement. The NG tube can also cause perforation or ulceration of the sinuses, throat, oesophagus or stomach, so stop if there is any resistance.

4. Nose bleeds or nasal sores Mild nasal bleeding or severe epistaxis can arise from NG tube insertion, Vihesh et al (2013) discuss a case of life threatening epistaxis from NG tube insertion, with this case there was difficulty on insertion. When inserting the tube if you encounter resistance stop and reassess.

Nasal sores tend to arise following pressure from the tube or the tape holding the tube in plac Seyedhejazi et al (2011). Asti et al (2017) found that the prevalence of pressure sores was as much as 4.8% of patients developing pressure ulcers from NG tubes and fixation of tubes.

Right nasal ala pressure sore from an NG tube

Figure 6

Many areas are advocating the use of a nasal bridle to reduce sores and tube dislodgement, see Figure 23.

5. Throat irritation

Many patients complain of irritation to their throat, and occasionally it can cause irritation of th larynx (Marcus et al (2006).

Patient safety • • • • • • • • •

Introduce yourself Check the patient’s identity and allergies Explain what you want to do Gain informed consent Consider an appropriate chaperone Adequate exposure maintaining dignity Position the patient appropriately – consider moving and handling Wear Personal Protective Equipment as required. Wash your hands before and after you touch the patient (as per WHO guidelines)

1. On first meeting a patient introduce yourself, confirm that you have the correct patient with the name and date of birth, if available please check this with the name band, written documentation and the NHS/ hospital number/ first line of address. 2. Check the patient’s allergy status, and ask the patient if they have had nasal surgery or a deviated septum

3. Ensure the procedure is explained to the patient in terms that they understand, including explanation of how long this procedure will take, gain informed consent and ensure that yo are supervised.

4. Offer a chaperone as appropriate, it is often ideal to have one available to support the patient through this procedure as it is uncomfortable and a chaperone can offer the patient sips of water as required. 5. You may explain to the patient that “I will insert a fine tube in your nose that will go into yo stomach, it will feel a little uncomfortable going in and as it passes the back of your throat you may want to gag, however you can take a sip of water at that time to help the tube pas your throat. If you feel that you need to cough or you have difficulty breathing please let m know”. You should discuss a hand signal with the patient or how you want the patient to indicate if they want the procedure stopped or paused before you begin.

6. The patient does not need to get undressed but they are best sat at the position of 90 degrees, unless they are unconscious when their head should be raised to 30 degrees.

7. Don personal protective equipment as you are likely to come into contact with bodily fluids Be aware of hand hygiene and preventing the spread of disease, WHO (2009). 8. Please adhere to ANTT requirements, do not contaminate the tube.

Measuring tube length The tube length should be measured prior to insertion, if the tube is to short it may be in the oesophagus, conversely if it is too long it may curl around the stomach and back up the oesophagus or even into the duodenum.

In 2011 the NPSA recommended measuring the length of the NG tube prior to insertion as the same length as Nose Ear Xiphisternum (NEX): Since then there has been multiple articles stating that the NEX measurement isn’t long enough. Taylor et al (2014) recommended using NEX + 10cm.Various methods may be used in practice. The method of NEX + 10 will be used here, and a reminder that all positions need to be checked by pH. Follow local trust policy when in clinical practice. This will be done using a disposable tape measure measuring from the tip of the nose to the earlobe to the xiphisternum, and then adding 10 cm, see Figure 7.

Figu

Equipment Below is a list of equipment that you will need to consider: 1. Hand wash 2. Disposable tape measure 3. If compliant a cup of water with a straw. 4. Receiver 5. Wipes for receiver 6. NG Tube 7. Tissues 8. Syringe- to fit NG tube 9. Water based lubricant 10. Some way of disposing of the guide wire, eg: sharps bin 11. pH indicator strips 12. Hypo allergenic tape or securing device 13. Gloves & personal protective equipment 14. Cover for the patient 15. Suction or a drainage bag may be required

Fig

Some further information on the above 1. Wash hands with soap and water when possible and have hand gel available. 2. Single use disposable tape measure for measuring NEX + 10 (described above).

3. To aid insertion, if the patient is able to, it helps if they can take small sips of water with straw. 4. A kidney dish, receiver or tray, single use may be used. 5. Wipe the tray if it is not single use before and after use. 6. NG tube: The tube will depend on its use,and there are 2 types you will consider:

Fine bore NG tube: This is the narrow NG tube used for fluid and administration of medication. These tubes can have long or short term types, short term should be in for no more than 7-10 days and long term can be in for up to 3 months.

Fig

Each tube will have length markings along the tube in cm, please see figure 10.

Figure 10

You will need to check:  The expiry date  The size of the tube- The diameter of the tube is written in French gauge. 1 French gauge is equal to 0.33mm, and tubes for adults tend to be 5-12 French (FR) this is written on the packet. The choice of size will depend on the patient, the patient’s size and what needs to be de...