What is it?
A Non-Bronchoscopic Bronchioalveolar Lavage (NB-BAL) is procedure that is performed on a ventilated patient (a patient with an artificial airway who is on a breathing machine). The purpose of the procedure is to help in diagnosing pneumonia by obtaining a sputum specimen by ‘washing the airways’. Some clinicians favour this method of obtaining a sputum specimen, as they believe the specimen is less contaminated
When a patient has an artificial airway the tube routinely needs to be suctioned on a regular basis in order to remove secretions (tracheal aspirate) from the tube and upper airways. This ensures that the tube doesn’t block and that the patient has a clear passage for their breathing. This tracheal aspirate can also be sent to the laboratory for analysis however the specimen is often contaminated by organisms which have attached to the artificial airway (endotracheal tube).
A NB-BAL specimen collection involves passing a sterile suction catheter (thin flexible tube) down through the artificial airway until resistance is felt and then 20ml of normal saline is flushed into the catheter using a syringe which attaches to the side of the catheter. The catheter is then withdrawn while applying suction and the resulting specimen is collected in a sterile container (sputum trap) which is connected between the suction tubing and the suction catheter. This procedure is repeated 3 times and the resulting specimen sent immediately to the microbiology laboratory for processing.
What are the advantages?
It is an invaluable diagnostic tool, It is a simple, safe and effective method of rapidly identifying and evaluating ventilated patients with pneumonia.
Its main advantage is that it will often avoid the necessity to do a bronchoscopy, which is a much more invasive procedure. This involves passing a much larger tube called a bronchoscope down through the breathing tube into the lungs which is more likely to cause complications such as damage to the airways and low levels of oxygen in the bloodstream.
Of course, if you have any questions or concerns, please discuss them with the ICU nurses and doctors
What are the risks?
The patient is well sedated before the procedure so that they should not feel any discomfort. If they do show any sign of discomfort their sedation is increased and the procedure is delayed until the sedation takes effect.
The procedure can cause a drop in the level of oxygen in the patients blood. Increasing the amount of oxygen the patient receives prior to, during and for a short period after the procedure prevents this.
The patient is closely monitored throughout and after the procedure. If you have any concerns or questions the ICU nurses and doctors will be happy to discuss them with you.
Arora, S.C., Mudaliar, Y.M., Lee, C., Mitchell, D., Iredell, J. & Lazarus, R. 2002, ‘ Non-bronchoscopic broncheoalveolar lavage in the microbiological diagnosis of pneumonia in mechanically ventilated patients’, Anaesthesia and Intensive Care, vol.30, no.1, 11-20.
Duff, C, 2003 ‘NB-BAL Specimen Collection’, Evidence Based Practice Guidelines Westmead Intensive Care.
The information contained on this page is general in nature and therefore cannot reflect individual patient variation. In addition it reflects Australian intensive care practice which may differ from other countries. It is meant as a back up to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. ICCMU attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual patient. Please refer to the full disclaimer.
Non-Bronchoscopic Bronchi Alveolar Lavage Version 1
First published August 2008
Correspondence: ICCMU CNC