Procedures and investigations
Specialist investigations performed by Dr Dakin.
Sleep study
A respiratory sleep study may be performed to investigate the possibility of obstructive sleep apnoea. This test is provided for patients who are seen by Dr Dakin for suspected sleep apnoea. It may also be provided without a consultation, if you have already seen another respiratory consultant and are awaiting this test on the NHS or elsewhere.
The test is performed in the comfort of your own home, without the need for hospital admission. Monitoring equipment is fitted in the clinic, which you take home and wear overnight. Although many specialists rely upon a single night of study, Dr Dakin always performs a two-night study as standard, as this provides more data and because sometimes people have a more typical night of sleep on the second night of study.
The monitoring equipment includes two belts (around the chest and abdomen), an airflow monitor at the bottom of the nose, a finger probe to measure blood oxygenation and ECG to monitor the heart. Other monitoring may be employed for individual cases, such as monitoring of the jaw muscles (for bruxism) or the legs (for periodic leg movements). Although people often worry that the monitoring equipment will prevent sleep, in practice this is rarely a problem.
After the monitoring equipment is returned to the clinic, the data is uploaded for analysis. A report is issued, with recommendations for treatment if needed.
Dr Dakin is one of a small number of accredited Somnologists in the UK, having passed the European examination of the European Sleep Research Society, of which he is a member.
Bronchoscopy
Bronchoscopy is an endoscopic procedure, in which a fibre-optic camera is introduced into the lungs to investigate various conditions. The operator may take samples through the bronchoscope, including samples of tissue (biopsies) or washings from within the lungs, seeking evidence of infection or inflammation.
Who needs bronchoscopy?
Bronchoscopy is sometimes performed by respiratory specialists for investigation of suspected cancer, if a CT scan suggests the presence of a tumour within one of the central airways. A tissue sample (biopsy) will be sent to the pathology lab, to provide confirmation and further characterisation of a tumour.
Bronchoscopy is also performed to take liquid samples (lavage or bronchial washings), by injecting a small volume of water down the bronchoscope, followed by suctioning back the water. The water captures a sample of cells and any bacteria which may be present. The fluid is then sent to the lab for analysis, including isolation of bacteria, which may be helpful for evaluation of more difficult cases of pulmonary infection. In this way, it may be possible to identify bacteria, even when sputum specimens are negative for infection. It may also assist identification of infection in subjects who are producing no sputum.
Liquid samples from the lungs may also be helpful to characterise interstitial lung diseases. In this scenario, a larger volume of water is instilled into the lungs, with the aim of taking a liquid sample from the periphery of the lungs, where the alveoli (gas-exchanging units) lie. The cellular composition of this fluid (broncho-alveolar lavage) gives important information about inflammation within the lung, which may help to characterise different interstitial lung diseases. Unfortunately, broncho-alveolar lavage is not available on the NHS in Guildford, but is routinely performed when needed in Dr Dakin’s private practice.
The procedure
Bronchoscopy is performed by Dr Dakin at either the Royal Surrey or Mount Alvernia Hospital. The procedure typically takes 20 minutes and is performed under sedation and local anaesthetic. Most people have little memory of the procedure after it is completed. After completion of the procedure, patients are looked after in the recovery area until ready for discharge, typically two hours later. It is necessary to be nil by mouth prior to the procedure, which is usually performed first thing in the morning.
Endobronchial ultrasound (EBUS)
EBUS is an endoscopic procedure which allows sampling of lymph nodes within the chest. Lymph nodes are filter stations within the tissue drainage channels (lymphatic vessels), which course throughout the whole body. Lymph nodes may become enlarged in various diseases and by taking a tissue sample, a diagnosis may be made.
Who needs an EBUS?
An EBUS may be performed by a respiratory specialist whenever a CT shows enlargement of lymph nodes within the chest, if the diagnosis is unclear. Lymph node enlargement is a feature of several conditions, including cancer, tuberculosis and sarcoidosis.
An EBUS is a more specialised form of bronchoscopy and most of the same information is applicable. It is performed with a combination of local anaesthetic and sedation. The difference from bronchoscopy is that the scope also has an ultrasound sensor, which allows for visualisation of the lymph nodes, which lie adjacent to, but outside, the airway wall.
EBUS procedures are performed by Dr Dakin at the Royal Surrey. The procedure usually takes 45–60 minutes.
