Bronchoscopy, bronchogram and optical coherence tomography studies

Information about bronchoscopy and bronchogram (B&B) studies and the optical coherence tomography (OCT) study, which can be carried out during the same procedure. It explains why these may be suggested and what to expect.

This combination of tests is carried out in the Interventional Radiology department.

Other forms of bronchoscopy studies are carried out in other departments at Great Ormond Street Hospital (GOSH).

A B&B is a combination of two tests.

Firstly, a camera contained in a flexible tube (bronchoscope) is inserted into the airway to look closely at the airway wall. This allows us to see if the lining of the airway is inflamed or compressed.

Secondly, a tiny amount of contrast – a substance that shows up well on X-rays – is put into the airway. X-rays are then taken from various angles to give us accurate measurements of the size of the airway.

An optical coherence tomography (OCT) test gives us images of the cartilage rings which make up the airway wall. A thin plastic tube containing a light at the end is passed into the airway and the images are video recorded.

A B&B is usually suggested if your child has breathing difficulties, such as a condition called tracheomalacia, where their trachea is floppy and collapses inwards during breathing. Sometimes, these tests might be suggested for children who are using a ventilator to help them breathe, if the doctors need to work out why they are having trouble breathing. A B&B may also be used to monitor your child’s progress after surgery or treatment for breathing difficulties, such as after surgery for tracheal stenosis.

An OCT may be suggested if your child has a narrow airway or is having difficulties breathing.

Your child may need to come to GOSH for a pre-admission assessment. This is to check that they are well enough to have the angiogram. This appointment may involve taking blood samples and other tests.

You will have already received an admission letter which contains more information on how to prepare for the procedure.

If your child takes regular medication, please speak to your child’s team about when to stop these before the procedure.

Your child needs to be fasted for the procedure for the general anaesthetic. As a general rule:

Food and milk:

• Breast-fed babies- can have their last feed three hours before the procedure. Breast milk is digested faster than solid food or formula.
• Bottle-fed babies and children- can have their last milk feed, food or milk drink, six hours before the procedure. They should not have any food or milk after this time.

Water:

• All babies and children can have a drink of water (but no other fluids), until one hour before the procedure.

Please follow these instructions carefully, otherwise your child’s procedure may be delayed or even cancelled.

Your child will need to be admitted to a bed on a ward.

The person bringing your child to the procedure should have ‘parental responsibility’ for them. Parental responsibility refers to the individual who has legal rights, responsibilities, duties, power and authority to make decisions for a child. If the person bringing your child does not have parental responsibility, we may have to cancel the procedure.

An anaesthetist will visit to talk to you about your child’s anaesthetic. A specialist will explain the procedure in more detail, discuss any questions you may have and ask you to sign a consent form giving permission for your child to have the studies. If your child has any medical problems, please tell the specialists.

A contrast liquid is used during the procedure to help make the images clearer. This is removed from the body through urination (weeing), so please tell the doctors if your child has any kidney problems.

You and your child will then be brought to the Interventional Radiology (IR) suite within the X-ray department for the anaesthetic and the procedure.

If your child is currently in intensive care on a ventilator they may be being given medicines to help them keep still. For these studies, the doctors may have to gradually reduce these medicines so that your child is able to breathe on their own. Your child will remain on the ventilator when they are being transferred to the IR department but will be taken off it briefly for the B&B studies. An experienced anaesthetist will stay with your child throughout the studies to monitor their airway.

The bronchoscopy is the first part of the study. This involves putting a camera inside a flexible tube into your child’s airway through the breathing tube. While the camera is in your child’s airway, the radiologist will record a video of your child’s breathing, which will either be used for analysis or to compare with previous or future recordings. Using the flexible tube, they may also wash out the area if it is full of mucus and take samples for examination.

The second part of the study is the bronchogram. This involves inserting a tiny amount of contrast into your child’s airway through the same breathing tube. The radiologist will watch your child’s breathing by recording a series of pictures for two to three breaths.

This gives them a real-time view of your child’s breathing and can show if they have tracheomalacia, for instance. If your child is having an OCT during the same procedure, this will be the final part. The bronchoscope will be removed from your child’s airway and a thinner tube containing an infra-red light will be inserted. This records a film of your child’s airway which can be examined closely after the study has been completed.

The B&B study takes around 30 minutes, and the OCT takes around five minutes. Depending on the results of the studies, the specialist may decide to treat your child’s breathing difficulties during the same procedure or plan treatment for another occasion.

If your child was in intensive care before the study, they will return there once stable on the ventilator again. The medicines to keep your child still may be restarted, depending on their condition.

If your child was not on a ventilator, they will return to the ward to recover from the general anaesthetic.

During the procedure, the doctors may have needed to put some local anaesthetic spray on your child’s vocal cords, so that the airway tube could be inserted safely. This makes your child’s throats numb and can make swallowing difficult. If your child has the local anaesthetic spray, they will not be able to eat for two hours after the procedure until the effects of the local anaesthetic have worn off and it is easier and safer to swallow.

Your child will return to the ward after they have recovered from the general anaesthetic. Some children feel sick and vomit after a general anaesthetic. Your child may have a headache or sore throat or feel dizzy, but these side effects are usually short-lived and not severe.

The specialists will come to check your child’s progress on the ward and will give you some information about what they have done during the procedure.

The pictures taken during the procedure need to be studied carefully by the specialist, who will write a report for your child’s doctor. The results will not be available straightaway and usually we will discuss them with you during the next few days if your child is staying in hospital or at the next clinic appointment.

A B&B is usually carried out under general anaesthetic. Although an anaesthetic carries a risk, this is extremely small.

This is a very safe test. It can cause a small amount of bleeding from the wall of the airway, which will stop on its own. It is also possible that your child may need to be on a ventilator for a short period of time following the procedure. This is extremely rare. If your child is already on a ventilator, the intensive care doctors may need to increase the settings for a short time. An experienced anaesthetist will stay with your child to monitor them throughout the study.

The procedure does involve the use of X-rays. The levels that are used are low dose and therefore low risk. If you have any concerns regarding the use of radiation, please discuss this with the person performing the procedure beforehand.

As the procedure involves the use of X-rays, legally, we have to ask anyone over the age of 12 whether there is any chance they might be pregnant.

We will also ask for the first date of their last period (if started). This is to protect babies in the womb from receiving unnecessary radiation.

A CT scan can show the structure of the airway but not how it functions during breathing. The advantage of a B&B study is that it gives a real-time view of how your child’s airway functions during breathing.

OCT is the only test which shows the detail of the cartilage in the airway wall.

If you have any questions, please speak to you child’s doctor or nurse or call Interventional Radiology.

Telephone: 020 7405 9200 extension 7943.

You can also contact us through MyGOSH.