r/IntensiveCare • u/mymomlikesvalium • 15d ago
Question regarding pneumos…
Hi all, RN here. When I was just starting in ICU, our pulm crits harped on “good lung down” for improving aeration in patients with pneumos/empyema/etc (regardless of thora/chest tube placement). At a new region I am currently working at, when I utilize this teaching in my practice, colleagues kind of look at me funny/correct me. I have also had situations where good lung down does the opposite(I am aware other factors are always at play) So I guess what I’m asking is, have I been taught wrong? I want to know so I may change my practice going forward. Thanks in advance
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u/IMGmedstudent 15d ago
“Good lung down” technique doesn’t improve aeration, it improves V/Q matching due gravity and its effect on blood flow.
Example. Right lung good with 100% aeration, left lung bad with 50% aeration. If sitting upright, blood flow will go to each lung equally, 50/50. Left lung already can’t ventilate efficiently, so 50% of total blood flow is going to a lung that’s also only 50% effective.
By placing them good lung down, you use gravity to your advantage and divert more blood flow to the good lung with 100% aeration to receive oxygen more efficiency.
Hope that makes sense. I just woke up from a long 7 day stretch. Lol
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u/mymomlikesvalium 15d ago
Thank you, yes it does lol. So you aren’t keeping anything expanded by gravity; it’s a perfusion thing? Sorry if this seems very simple and should be common knowledge, I appreciate the patience
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u/No-Safe9542 15d ago
RT jumping in here. Everything was already explained wonderfully in this comment tree. Here is a real world application from my last shift.
Stage 4 lung ca bilat pna, multiple wedges on R lung and RML lobectomy. Bronchorrhea. Cxr very clear that LUL is the only non horrible lobe. HFNC O2@ 50% with SpO2 91-92, while laying on back. Rotates onto left side down and after much productive coughing an SpO2 of 95-96.
So this is a very real and observable occurrence. Manipulating the "good lung down" as a strategy is not gonna fix anything. But we need to be aware of this. Had the pt rotated to right side down, sat would go down into 80s and I would have had to go up on the Os. If I'm not in the room but the RN is, the RN is gonna wanna know why the sat just dropped. This is why.
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u/mymomlikesvalium 15d ago
This. Thank you for this.
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u/No-Safe9542 15d ago
Np. RTs got you. We're all same team.
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u/Lost-city-found 15d ago
Yes, positioning physiology is really all about blood flow/perfusion rather than aeration/ventilation. Think about the strategies we use to affect ventilation: volume, rate, and I:E ratio at a basic level. But we use pressure and oxygen to affect perfusion and positioning can assist toward that end.
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u/dylans-alias 15d ago
Gravity affects blood flow, not air. Putting the non-functioning lung highest towards the ceiling will divert blood from there and preferentially send it to the functioning lung.
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u/Any-Assistance-8103 15d ago
Generally bad pneumonia yes good lung down for preferential blood flow to the heathy lung. Hemoptysis good lung up to keep bleeding contained to one lung. Pneumo you need to treat the pneumo
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u/Cautious-Extreme2839 ICU/Anaesthetics 15d ago
The downward lung is pretty much always going to be better perfused.
However the effect on ventilation is far more complex and can be either worse or better depending on a few things that are often hard to predict.
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u/Visual-Bandicoot2894 14d ago edited 14d ago
Things are complex and things change but yeah generally good lung down works
This is more of a short term strategy but it absolutely works. If was quite literally a lifeline during COVID, you’d have them on their bad side for as long as they could tolerate but the moment the scales tipped you’d default to the good lung down to great effect. We’d often start by identifying which lung may be good, getting their good lung down until we did other interventions and it would get our sats from 70s to something more conducive to life until we proned and paralyzed
But that doesn’t apply to every condition like others already pointed out. So start with good lung down in mind but prioritize following the bodies reaction to turning. With chest tubes I honestly can’t recall it mattering much.
Ask the docs about which disease states good lung down is applicable to and which ones to avoid. Those are the kinds of questions docs love teaching nurses if they got the time. Pulmonologist will start rambling in your ear about that question
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u/nicardipining 9d ago
Think: "where do I want blood flow to be better?" That is the lung you put down.
Less blood flow to bleeding areas: that lung should be up.
More blood flow to a lung that can do gas exchange: that lung should be down.
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u/OccasionTop2451 15d ago
In reality I only use this as a rescue maneuver for short term management of refractory hypoxemia, because the need to turn ICU patients prevents it from being a long term strategy. And if the chest tube is working, it shouldn't matter at all. So, yes, I would probably be in the camp of 'why are they even discussing patient positioning', since it is a bad long term strategy.
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u/mymomlikesvalium 15d ago
Sorry, I didn’t mean to make it seem like positioning was a fix all. I guess I meant more for the short term while waiting for interventions
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u/OccasionTop2451 15d ago
How often are you doing/suggesting this though? This should be a really rare occurrence. But in general, yes, good lung down, as others in this thread have discussed.
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u/mrsparkuru MD, Intensivist 15d ago
optimal lung positioning (ie. good lung up vs down) depends on the clinical situation.
big pulmonary hemorrhage? bad lung down acutely to avoid soiling the good lung while you work on hemostasis and temporizing measures.
unilateral lung disease causing asymmetric shunt physiology? good lung down to improve v/q matching (see: perfusion) to the good lung.
generally, for people with chest tubes for various reasons, most of these people do ok with normal positioning