Welcome back to the tasty morsels of critical care podcast.
So, from the ultra broad topic of AKI in the last podcast to the super specific question of when we should pursue an open lung biopsy in an ICU patient. The answer is probably – very rarely. But while this podcast is intended to be brief even I feel I owe the listener something more than this.
When would you consider such an invasive and complication ridden procedure in the ICU? Typically this would be in a patient with progressive respiratory failure with no cause found despite an extensive work up (eg radiology, bronch, micro, fancy acronym ridden blood tests)
The CXR will be usually diffuse bilateral infiltrates.
The differential in this scenario is fairly broad and includes
- infectious (bacteria, viral, fungal)
- inflammatory (COP, interstitial pneumonias, connective tissue disease)
- may also find end stage diseases (and a reason to stop life sustaining therapies) eg IPF or malignancy
If you’re going to do this then it’s probably best done within 1 week of ventilation. This can be challenging as you often want that week to get all your basic results back and to see if your empiric therapies are having an effect.
Given that you’re going to open this patients chest and cut out a wedge of lung tissue it’s probably worth going through the pluses and minuses of this approach.
- diagnosis (though you may not get one)
- decent accuracy
- can change treatment
- you’re taking a large section tissue – more likely to get answer than a simple needle biopsy.
- can be combined with other procedures eg empyema drainage
- ~1.5% mortality which comes in as one of the more solid disadvantages in this list.
- invasive and all the complications that come with it, particularly air leaks.
- may not get the right sample/section of tissue
- not clear if it changes mortality
Overall this is a rarely pursued strategy that probably does have a niche role. It should probably not be immediately dismissed out of hand unlike other “helpful” suggestions like “maybe it’s time for the bicarb?” Or the discerning intensivist’s favourite suggestion “hey why we don’t try some gelo?”
Ultimately the nihilist in me suspects the most useful role of a biopsy may well be in defining pathology without potential treatment, and using this info as a means to discuss with patient and relatives the concept of futility and limitation of life sustaining therapies.
References and rationalisations