Sputum
• Patient submits the first morning expectorated sample (optimal) with the following instructions:
• Clean mouth with several rinses of sterile saline or water.
• Cough out 2-5 ml of sputum (not saliva) in a wide-mouthed sterile container.
• In case of dry cough, perform sputum induction with hypertonic saline nebulisation.
• Acceptability of sputum is determined with a Gram stained smear (pus cells >25/LPF, epithelial cells and only representative samples are accepted.
• 24-hour sputum collections are not acceptable.
Tracheal Aspirate
• Tracheal aspirates are collected through an endotracheal tube and are subject to the same limitations as sputum specimens.
Non-Directed Bronchoalveolar Lavage
• This method provides a lower respiratory tract sample without the need for bronchoscopy.
• A trained physician passes a suction catheter down the endotracheal tube until resistance is met.
• Inject an aliquot of sterile saline and then aspirate at least 1 ml of secretions.
• Non-directed techniques have been found to give results comparable to bronchoscopic methods.
See also: