Indications for OGD
There are a number of reasons for performing an OGD:
• To visualise the lining of the oesophagus, stomach and start of the duodenum, to look for irritation, wounds, ulcers or tumours.
• To take samples (biopsies) and photographs of the lining. These can be used for tissue analysis (for example in detecting malignancy) and images can be used for later comparisons (to see if the pathology is progressing).
• OGDs are performed for the diagnosis of peptic ulcer disease, the investigation of haematemesis, melaena, dyspepsia and dysphagia, for biopsies for coeliac disease, and for biopsies and palliation of suspected/confirmed malignancies.
The advantage of OGD over Barium x-ray studies, is that the surface of the gut can be directly visualised, and biopsies can be taken.
How is it performed?
In a clinical scenario, always remember to do the basics first: introduce yourself, check the patient's identity and explain what you are going to talk to them about.
Preparation: In order to obtain a clear view, the stomach must be empty. The patient will therefore have to fast for at least 6 hours before the procedure. Any false teeth will have to be removed.
The procedure: The back of the throat will be sprayed with a local anaesthetic. This will numb the throat and may make it difficult to swallow for a short while after the procedure. Care must therefore be taken with hot food and drinks afterwards. The numbness will go away within a few hours. Sedation can also be used (it generally is these days, however some endoscopists do perform this procedure without sedation). This sedation, however, is not a 'full' anaesthetic. Tell patients that they will feel drowsy, but will still be conscious and aware. The sedation does cause amnesia, however, so they will not remember much of the procedure afterwards. The patient will be asked to lie down on their left side, and a plastic mouthpiece will be placed between their teeth to keep the mouth open. The telescope will then be placed into the mouth, and the patient will be asked to 'swallow' it (this feels a bit like swallowing a large piece of food). Some air may need to be put into the stomach to perform the examination effectively - this can cause discomfort or the need to belch. The procedure usually takes about 10 to 15 minutes.
After the test: The patient will be taken to the recovery room and left to rest for around 30 minutes (until the bulk of the sedation wears off). They can eat and drink after the swallow reflex is back to normal (after the anaesthetic wears off). This can take upto an hour. The back of your throat may feel sore for the rest of the day, and they may feel a little bloated. After sedation, they must not drink alcohol, drive or operate machinery until the next day. Patients will therefore need someone to collect them from the hospital.
After your explanation, always ask the patient if they have any further questions or concerns. Don't forget to discuss the complications.
Complications
As with most 'invasive' procedures, patients in the UK will be required to sign a standardised consent form prior to the procedure. In order to do this, the patient must be competent, the consent must be based upon comprehensive information, and must be free from coercion (should not be forced). Bear in mind though, that despite this (and rather bizarrely), a consent form is not a legally valid document! In any case, you should discuss the following risks with patients prior to an OGD:
Diagnostic gastroscopy is an 'outpatient' procedure, and is generally very safe. Minor complications (such as bleeding and infection) are uncommon and major complications (such as perforation) are very rare. They should, however, be mentioned to the patient.
