Are Tracheal Washes Ever Useful?

From Episode 176 on the Medicine Stream. With Prof Lynelle Johnson.

I don’t know about you, but I was led to believe that for diagnosing lung disease tracheal washes are kinda useless. Too many contaminants for culture or something along those lines. But in this conversation about eosinophilic lung disease Prof Lynelle disagreed, saying that there is definite value in tracheal washes. 

"I prefer to do bronchoscopy, but it wouldn't make me say 'don't do a tracheal wash’ when the owner can afford a BAL.”

Like for diagnosing eosinophilic lung disease, where even a trans-oral wash will give you your diagnosis. 

Here’s her quick ‘how to”guide: 

• GA with an ET tube. (Prof Lynelle likes Ketamine Valium, or Propofol with Midazolam.) 

• Pre-oxygenate. 

• Sternal positioning. 

• Measure to about the fourth intercostal space. (Especially important in small dogs so that you don’t accidentally do a lung biopsy!)  

• Pass a long sterile urinary catheter - either a rigid polypropylene or a red rubber catheter - to the measured depth. 

• Dribble 4-10ml (TOTAL) of sterile fluid into lungs. (Ensure you put air in the catheter as well, so that all the fluid is in the airway.)

• Might help to coupage the chest to encourage the secretions to mix and to help you retrieve fluid. 

• Aspirate. NB: Don't panic if you don't get any fluid back. Just inject another aliquot of fluid. (And remember that you won't get out the same volume that you put in. As long as you get at least 1ml you’re good.)

"I've put 80ml of fluid in the lung, and I didn't panic.”

• Send for aerobic and mycoplasma cultures and look at cytology.

For more clinical pearls, sign up for our free weekly Newsletter, or get all of our content on the go with our Clinical Podcasts.