Are ventilators causing more harm than good?
-
I saw some chatter about this on Twitter a few days ago.
https://www.statnews.com/2020/04/08/doctors-say-ventilators-overused-for-covid-19/
Even as hospitals and governors raise the alarm about a shortage of ventilators, some critical care physicians are questioning the widespread use of the breathing machines for Covid-19 patients, saying that large numbers of patients could instead be treated with less intensive respiratory support.
If the iconoclasts are right, putting coronavirus patients on ventilators could be of little benefit to many and even harmful to some.
What’s driving this reassessment is a baffling observation about Covid-19: Many patients have blood oxygen levels so low they should be dead. But they’re not gasping for air, their hearts aren’t racing, and their brains show no signs of blinking off from lack of oxygen.
That is making critical care physicians suspect that blood levels of oxygen, which for decades have driven decisions about breathing support for patients with pneumonia and acute respiratory distress, might be misleading them about how to care for those with Covid-19. In particular, more and more are concerned about the use of intubation and mechanical ventilators. They argue that more patients could receive simpler, noninvasive respiratory support, such as the breathing masks used in sleep apnea, at least to start with and maybe for the duration of the illness.
“I think we may indeed be able to support a subset of these patients” with less invasive breathing support, said Sohan Japa, an internal medicine physician at Boston’s Brigham and Women’s Hospital. “I think we have to be more nuanced about who we intubate.”
That would help relieve a shortage of ventilators so critical that states are scrambling to procure them and some hospitals are taking the unprecedented (and largely untested) step of using a single ventilator for more than one patient. And it would mean fewer Covid-19 patients, particularly elderly ones, would be at risk of suffering the long-term cognitive and physical effects of sedation and intubation while being on a ventilator.
None of this means that ventilators are not necessary in the Covid-19 crisis, or that hospitals are wrong to fear running out. But as doctors learn more about treating Covid-19, and question old dogma about blood oxygen and the need for ventilators, they might be able to substitute simpler and more widely available devices.
An oxygen saturation rate below 93% (normal is 95% to 100%) has long been taken as a sign of potential hypoxia and impending organ damage. Before Covid-19, when the oxygen level dropped below this threshold, physicians supported their patients’ breathing with noninvasive devices such as continuous positive airway pressure (CPAP, the sleep apnea device) and bilevel positive airway pressure ventilators (BiPAP). Both work via a tube into a face mask.
-
“I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.” ~Winston S. Churchill
-
“I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.” ~Winston S. Churchill
-
@Mik said in Are ventilators causing more harm than good?:
OK, now that I went out and educated myself on FiO2, what is the range there normally? Significantly higher than .21?
A ventilator can deliver anywhere from 21% to 100% FiO2.
However, anything about 50% carries risk, oxygen being a toxic substance (yeah, believe it or not).
So, the thinking is that if you can deliver adequate oxygenation with less than 50%, it's a good thing.
-
Primarily for Jolly and Bach...
A podcast from earlier this week discussing ventilator management, and how unlike typical ARDS this process is.
Bottom line, they're saying we're intubating and ventilating these people way to early. These people come in with serious lack of oxygenation, but they're not necessarily in distress. One of the docs talks about a guy who walked in with a sat of 50% (that's ridiculously low) who was in no distress, albeit he was tachycardic and tachypneic. She put him on high-flow oxygen and he improved to the 80s. Her point was that this is a patient she would absolutely have intubated 3 months ago.
https://www.aaem.org/resources/publications/podcasts/critical-care-in-emergency-medicine/episode-19
Fascinating stuff.
One of my surgeon friends forwarded a tweet to me about how our thinking might change with this disease, directing me to a tweet by a ICU doc.
I responded:
"However, my sense is that we’re not really sure that COVID-19 lung injury is really ARDS. ARDS is a non-specific lung response to some kind of injury, sepsis, shock, whatever. It has a distinctive x-ray appearance, and as the Italian guys say, associated changes in lung compliance.
COVID-19 gives the same x-ray, but x-rays aren’t physiology - they’re pictures and you infer the diagnosis from that. Decades of thinking that anything that looks like ARDS must be ARDS led the guy in New York to think a different way.
Now, he may be right, and we will not know for a long time, if ever, whether he is. Nevertheless I find his comment “they don’t need pressure, they need oxygen” to be simplistic. How, exactly, are you going to provide oxygen? When intubated, and people start to desaturate, what’s the course of action you’re going to take. Presumably increase the FiO2. How high will you go? 40%? 80%? 100%. Anything above 50% has its own inherent toxicity to pneumocytes, and perhaps you’re doing ancillary damage that way."
"Now look here, you Baltic gas passer... " - Mik, 6/14/08
The saying, "Lite is just one damn thing after another," is a gross understatement. The damn things overlap.
-
@George-K said in Are ventilators causing more harm than good?:
Primarily for Jolly and Bach...
A podcast from earlier this week discussing ventilator management, and how unlike typical ARDS this process is.
Bottom line, they're saying we're intubating and ventilating these people way to early. These people come in with serious lack of oxygenation, but they're not necessarily in distress. One of the docs talks about a guy who walked in with a sat of 50% (that's ridiculously low) who was in no distress, albeit he was tachycardic and tachypneic. She put him on high-flow oxygen and he improved to the 80s. Her point was that this is a patient she would absolutely have intubated 3 months ago.
https://www.aaem.org/resources/publications/podcasts/critical-care-in-emergency-medicine/episode-19
Fascinating stuff.
One of my surgeon friends forwarded a tweet to me about how our thinking might change with this disease, directing me to a tweet by a ICU doc.
I responded:
"However, my sense is that we’re not really sure that COVID-19 lung injury is really ARDS. ARDS is a non-specific lung response to some kind of injury, sepsis, shock, whatever. It has a distinctive x-ray appearance, and as the Italian guys say, associated changes in lung compliance.
COVID-19 gives the same x-ray, but x-rays aren’t physiology - they’re pictures and you infer the diagnosis from that. Decades of thinking that anything that looks like ARDS must be ARDS led the guy in New York to think a different way.
Now, he may be right, and we will not know for a long time, if ever, whether he is. Nevertheless I find his comment “they don’t need pressure, they need oxygen” to be simplistic. How, exactly, are you going to provide oxygen? When intubated, and people start to desaturate, what’s the course of action you’re going to take. Presumably increase the FiO2. How high will you go? 40%? 80%? 100%. Anything above 50% has its own inherent toxicity to pneumocytes, and perhaps you’re doing ancillary damage that way."
Standard at The Lady of The Lake is after they hit 5L, anything past goes to the vent. I don't know what the SaO2 has to be at that point.
Is that a universal standard or disease specific?
Always remember, Operation Valkyrie was an act of sedition.
Warning: I post things that interest me. Read and comment at your own discretion. -
@Jolly said
Standard at The Lady of The Lake is after they hit 5L, anything past goes to the vent. I don't know what the SaO2 has to be at that point.
Is that a universal standard or disease specific?
I'm quite far out of the ICU loop. The podcast talks about the ARDSNET protocol for intubation. The point is that this more like high-altitude sickness rather than ARDS.
http://www.ardsnet.org/files/ventilator_protocol_2008-07.pdf
For me one of the takeaways on this is that clinical judgment might prevail over protocols and flowcharts. How the patient looks might be just as important as the numbers he presents. Whenever I got called about a situation like this, one of my first questions was "How does the patient look?" These people's numbers are terrible, but they don't look that bad, at least in the early stages.
"Now look here, you Baltic gas passer... " - Mik, 6/14/08
The saying, "Lite is just one damn thing after another," is a gross understatement. The damn things overlap.
-
“I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.” ~Winston S. Churchill
-
"Now look here, you Baltic gas passer... " - Mik, 6/14/08
The saying, "Lite is just one damn thing after another," is a gross understatement. The damn things overlap.
-
Covid-19 had us all fooled, but now we might have finally found its secret.
First, the ventilator emergency needs to be re-examined. If you’re putting a patient on a ventilator because they’re going into a coma and need mechanical breathing to stay alive, okay we get it. Give ’em time for their immune systems to pull through. But if they’re conscious, alert, compliant — keep them on O2. Max it if you have to. If you HAVE to inevitably ventilate, do it at low pressure but max O2. Don’t tear up their lungs with max PEEP, you’re doing more harm to the patient because you’re treating the wrong disease.
I'm still of mixed thoughts on HCQ, but here's what this guy says:
All that hilariously misguided and counterproductive criticism the media piled on chloroquine (purely for political reasons) as a viable treatment will now go down as the biggest Fake News blunder to rule them all. The media actively engaged their activism to fight ‘bad orange man’ at the cost of thousands of lives. Shame on them.
How does chloroquine work? Same way as it does for malaria. You see, malaria is this little parasite that enters the red blood cells and starts eating hemoglobin as its food source. The reason chloroquine works for malaria is the same reason it works for COVID-19 — while not fully understood, it is suspected to bind to DNA and interfere with the ability to work magic on hemoglobin. The same mechanism that stops malaria from getting its hands on hemoglobin and gobbling it up seems to do the same to COVID-19 (essentially little snippets of DNA in an envelope) from binding to it. On top of that, Hydroxychloroquine (an advanced descendant of regular old chloroquine) lowers the pH which can interfere with the replication of the virus. Again, while the full details are not known, the entire premise of this potentially ‘game changing’ treatment is to prevent hemoglobin from being interfered with, whether due to malaria or COVID-19.
No longer can the media and armchair pseudo-physicians sit in their little ivory towers, proclaiming “DUR so stoopid, malaria is bacteria, COVID-19 is virus, anti-bacteria drug no work on virus!”. They never got the memo that a drug doesn’t need to directly act on the pathogen to be effective. Sometimes it’s enough just to stop it from doing what it does to hemoglobin, regardless of the means it uses to do so.Of note: that link above takes you to the Wayback Machine. I wonder if Medium took it down.
-
“I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.” ~Winston S. Churchill
-
-
@Mik said in Are ventilators causing more harm than good?:
Y'know, I have long thought for a layman I had pretty good medical knowledge, or at least enough to understand with a little research. This has really stretched the limits of my knowledge.
I find blood gases and all the ins and outs of proper therapy to scramble my brains. Not that it was ever my job. Thank God all I had to do was maintain, control and run the ABG machines.
-
@George-K said in Are ventilators causing more harm than good?:
@Jolly said
Standard at The Lady of The Lake is after they hit 5L, anything past goes to the vent. I don't know what the SaO2 has to be at that point.
Is that a universal standard or disease specific?
I'm quite far out of the ICU loop. The podcast talks about the ARDSNET protocol for intubation. The point is that this more like high-altitude sickness rather than ARDS.
http://www.ardsnet.org/files/ventilator_protocol_2008-07.pdf
For me one of the takeaways on this is that clinical judgment might prevail over protocols and flowcharts. How the patient looks might be just as important as the numbers he presents. Whenever I got called about a situation like this, one of my first questions was "How does the patient look?" These people's numbers are terrible, but they don't look that bad, at least in the early stages.
This is quite interesting. I shared it on FB.
-
And on that note, try running an ABG in the eye of a hurricane.
Ain't happening...
