University Hospital of Wales Paediatric Intensive Care Unit Guideline Printed on Wed 23-jul-08
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Last updated March 7, 2019 8:21 AM

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Noah's Ark Childrens Hospital for Wales
Heath Park
CF14 4XW
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Respiratory samples obtained on PICU come in three forms – NBBAL, sputum sample and naso-pharangeal aspirate (NPA). The purpose of the following document is to give some guidance on the differences between NBBALs and sputum samples.

A Non-Bronchoscopic Broncho-Alveolar Lavage (NBBAL) is an invasive procedure to gain a deep lavage sample from the broncho-alveolar region of the lungs. In order to obtain a true NBBAL the patient must be adequately sedated and paralysed to inhibit the cough reflex, otherwise the sample becomes contaminated with secretions from the ETT. Please refer to separate guidelines on this which is available on the Cardiff PICU website. Staff, both senior nursing staff and senior physiotherapists are trained and have completed competencies before being able to perform on patients.
N.B This is not an emergency duty requirement for the on call physiotherapist.

A Sputum Sample is obtained during normal ETT suction where-by an inline sputum trap (see picture below) is placed in the suction circuit. This obtains secretions from both the lower airways and ETT. Suction is applied when indicated and not purely for the sake of obtaining the sample. If physiotherapy is indicated then it is advised that samples will be obtained during a physiotherapy treatment to ensure best sputum yield.


The decision of whether a NBBAL or sputum sample is required is made by the PICU consultant. It then needs to be clearly documented which sample is taken as this may have an implication on clinical management.



Non-bronchoscopic bronchoalveolar lavage (NBAL) Patients should be pre-oxygenated and sedation ensured.


Significant respiratory illness (requiring ventilation) as admission diagnosis Secondary respiratory (iatrogenic) illness in intubated and ventilated patient
Abnormal clinical course of known respiratory pathogen e.g. RSV
Diffuse radiological change
Unidentified sepsis
Immunocompromised patients
Research (recognised projects with ethical approval being conducted in PICU, UHW)

How to do a NBBAL

Katherine Ronchetti, our specialist physiotherapist has provided an excellent guide, aided by photographs, to remind you how to perform the procedure correctly - but remember you should only be doing it if you have had training to do so.

Obtaining a NBBAL


Trained staff only

Oscillated patients

Experienced staff only to perform procedure
Re-recruitment will be needed following procedure