Knicks

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The Step up to Step 2 book says it's not.

I remember reading elsewhere that it is.



And another question after that one's answered: if it IS a cause of post-operative fever, what's the mechanism?


Thanks in advance.
 

Rendar5

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there's so many processes out there that can cause fever including trauma; i'm not sure of the data out there but don't see why not. It passes the sniff test, but who knows if it passes the actual data test.
 

CAPiTAtwo

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What we were taught is that bronchial mucous plugs are a common source of post-op fever, and if that plug is large enough that it causes a total airway obstruction, it can cause a resorption atelectasis.
 
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For tests, the answer is yes. For real life, its usually much more complicated.
That's what I thought as well,, but when I saw in the Step Up to USMLE Step 2 book that it's NOT a cause of post-op fever, I decided to make this thread.
 

TarHeelEMT

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My understanding is that it used to be considered a source of post-op fever, but newer research shows that this was a misconception. Despite this, many surgeons still hold onto the notion.
 

45408

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My understanding is that it used to be considered a source of post-op fever, but newer research shows that this was a misconception. Despite this, many surgeons still hold onto the notion.
Post it up then.
 
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45408

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Sabiston says:
Presentation and Management

The most common cause of a postoperative fever in the first 48 hours after the procedure is atelectasis. The patients has a low-grade fever, malaise, and diminished breath sounds in the lower lung fields. Very often the patient is uncomfortable from the fever but has no other overt pulmonary symptoms. Atelectasis is so common postoperatively that a formal workup is not usually required.
If it's not atelectasis, I'd like the pulmonologists to tell us what is causing all of these spontaneously resolving fevers in patients with initially poor inspiratory volumes.

All of your other W's tend not to resolve spontaneously without intervention. You're also not going to have a UTI, pneumonia or wound infection 4-6 hours after the surgery ends.
* Wind (pulmonary causes: pneumonia, aspiration, and pulmonary embolism, but not atelectasis)
* Water (urinary tract infection)
* Wound (surgical site infection)
* Walking limited (deep vein thrombosis or pulmonary embolism)
* "What did we do?" (iatrogenic causes: drug fever, blood product reaction, infections related to intravenous lines)
 

dilated

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Sabiston says:


If it's not atelectasis, I'd like the pulmonologists to tell us what is causing all of these spontaneously resolving fevers in patients with initially poor inspiratory volumes.

All of your other W's tend not to resolve spontaneously without intervention. You're also not going to have a UTI, pneumonia or wound infection 4-6 hours after the surgery ends.
Inflammatory cytokines released by the stress of cutting someone and injuring a bunch of their tissue? Even the surgical intensivists are pretty eye rolling about fever=atelectasis at this point.
 

Instatewaiter

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Sabiston says:


If it's not atelectasis, I'd like the pulmonologists to tell us what is causing all of these spontaneously resolving fevers in patients with initially poor inspiratory volumes.

All of your other W's tend not to resolve spontaneously without intervention. You're also not going to have a UTI, pneumonia or wound infection 4-6 hours after the surgery ends.
The issue is that they correlated low lung volumes (which is going to happen because of pain post-op and the like) with the fevers when in fact it is a systemic inflammatory response that causes the fevers and there is correlation between the low lung volumes and fevers but not a causation.

From chest: http://chestjournal.chestpubs.org/content/107/1/81

Were atelectasis a true cause of fever, basically every medicine patient would have a fever. They all are atelectatic but only when you cut someone open and release those cytokines does fever occur
 
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Sooooo, Atelectasis is NOT a cause of post-operative fever.


I believe UW says that it is, so for Step 2 purposes, we should go with "Yes, it does cause fever", right?
 

45408

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Inflammatory cytokines released by the stress of cutting someone and injuring a bunch of their tissue? Even the surgical intensivists are pretty eye rolling about fever=atelectasis at this point.
So why doesn't everyone have a fever? They all got cut open and injured. There's not even a correlation (to my knowledge) with the magnitude of the surgery and the presence of a fever, which would support your assertion.

The issue is that they correlated low lung volumes (which is going to happen because of pain post-op and the like) with the fevers when in fact it is a systemic inflammatory response that causes the fevers and there is correlation between the low lung volumes and fevers but not a causation.

From chest: http://chestjournal.chestpubs.org/content/107/1/81

Were atelectasis a true cause of fever, basically every medicine patient would have a fever. They all are atelectatic but only when you cut someone open and release those cytokines does fever occur
Hot damn, your article wasn't published until 13 years after it was initially submitted :laugh: That never bodes well.

Anyways, it's only a study of 100 patients, all of whom had open heart surgery (hardly a representative sample of average post-surgical patients), half of whom were intubated for the first night. The diagnosis of atelectasis was made strictly radiographically - does the radiographic appearance and cytokine secretion pattern change for atelectasis in the early post-operative period? This is a fairly limited study, and I don't think you can broadly generalize it.

Seriously though, are their articles in surgical journals that support this? Because I couldn't find any.
 
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Tiger26

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Our SICU guys say atelectasis does not cause post-op fever. With that said, my colleague the Prowler is a surgeon and I defer as a mere ER doc
 

45408

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My point is just that the surgeons say yes, and pulmonary people say no. I'm biased, of course, but I feel like surgeons know post-operative patients much better than pulmonologists, even if it is their specialty organ system. If I'm wrong, I would just like to see the data and mechanism for post-operative fever.
 

thenursingstudent

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The Step up to Step 2 book says it's not.

I remember reading elsewhere that it is.



And another question after that one's answered: if it IS a cause of post-operative fever, what's the mechanism?


Thanks in advance.
It's now 2017, and I went to research this SAME question, thus finding myself here. Nursing students like myself are taught that on the 2nd day post-op, if a patient presents with a low grade fever, the first action should be to have the patient use the incentive spirometer, because early fever would usually be caused by atelectasis.

But when I researched journal articles, atelectasis as a causation for early fever was even questioned as far back as 1995 ( http://www.jwatch.org/jw199501310000004/1995/01/31/does-atelectasis-cause-fever )

Anyway thanks for the info that was discussed here.
 

sazerac

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It's not a cause of fever, and IS doesn't really work. There was a Cochran review a couple years back and a RCT in bariatrics patients last year.

Makes us feel good like we are doing something for people though.

Plus it gives us an excuse to ignore POD0-1 fevers which is all we really wanted anyways
For those too lazy to google:

Cochrane article from 2009: link
Cochrane article from 2012: link
Bariatric RCT study from January 2017: link

Analysis of the 2017 study: "...compelling data for continuing routine incentive spirometry may be found by a quick internet search using the keywords lawsuit and incentive spirometry."
 

MSTP18

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3rd Edition of First Aid For Surgery (which was released this year) says atelectasis does cause fever. Honestly, they're probably not going to quiz you on whether or not it's the atelectasis, just whether or not you need to do a full fever workup for a POD1 fever and the answer to that is definitely no.
 

CaptainSSO

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It's not a cause of fever, and IS doesn't really work. There was a Cochran review a couple years back and a RCT in bariatrics patients last year.

Makes us feel good like we are doing something for people though.

Plus it gives us an excuse to ignore POD0-1 fevers which is all we really wanted anyways
This. IS is bull****.

And it won't stop any time soon, because the surgical mindset is "take an action."
 
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dpmd

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Well, breathing deeply is probably a good thing for anyone and handing a postop (or preop) patient an incentive spirometer has pretty much no downside other than the cost (which is probably negligible) and the nursing time to show them how to use it (I liked describing it as taking a really good hit of a joint or bong, somehow I haven't run into someone who didn't understand what that meant). Also, it lets you end the phone call from the nurse about the early post op low grade fever with them feeling like you are doing something if you order one or just ask them to have the patient use the one they have more (otherwise you might have to spend a bunch of time explaining why you aren't worried about it), even if it does nothing for the fever and the cause of the fever is that you failed to do the correct antipyretic voodoo dance before they left the OR.
 

dpmd

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But that's kind of the whole point. There's a mounting body of data that the IS is worthless. And the collective response of the surgical community is "well it can't hurt and it makes us feel like we are doing something"

The cost is real, although admittedly small compared to other sources of waste in the hospital.

Much as the typical pattern goes, We practice EBM until we don't like the evidence.
It is a pretty cheap placebo though. Although nowadays I am not the one getting the calls since all my patients are admitted to hospitalists,which means there is a lot more pan culturing and inappropriate CT ordering for those fevers. Although I do try to give everybody an nsaid or tylenol round the clock to try to cut down on how many fevers are measured.
 
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Cyal

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It is a pretty cheap placebo though. ... there is a lot more pan culturing and inappropriate CT ordering for those fevers. Although I do try to give everybody an nsaid or tylenol round the clock to try to cut down on how many fevers are measured.
But what if the fever is from a legit cause and you miss it by round-the-clock antipyretics?
 

dpmd

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But what if the fever is from a legit cause and you miss it by round-the-clock antipyretics?
Unlikely the day of and the day after surgery. After that they are usually going to be home and not getting vitals checks anyway. So I rely on other things like the patient calling my office asking why their wound is red or leaking, or asking about diarrhea or increasing pain. Turns out fever isn't the only signal of a problem.
 

sazerac

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The studies I posted put the cost of incentive spirometer at a little more than $30,000 per year for a hospital. This cost could be more than made up for by preventing a few cases of pneumonia.

Except there is mounting evididence that it hasn't prevented a single case of pneumonia. Or affected a single blood gas measurement for that matter.
 

OnePunchBiopsy

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Basic Science sources say it can cause fever (UWORLD, ABSITE Review)
Clinical evidence of the association is heavily lacking
Lots of surgeons say it does.
Lots of pulmonologists say it doesn't.

For Step 1/2 I would say yes. In practice just say what your upper level/attending believes.

When you become the attending, form your own opinion based on the evidence.
 
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VA Hopeful Dr

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Yeah that's another thing - "oh it's just 30000, that's a drop in the bucket!"

That kind of attitude contributes to the culture of wasted money across the whole hospital. Just like unecessary labs, blood cultures, electrolyte supplements, etc.
Get those things fixed and I'll hop aboard the "stop IS" train. Until then, this seems a very minor hill to die on
 
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Crayola227

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"Inflammatory response from being cut up" vs "lungs are a little squished" always made more sense to me for mechanism for fever.
One is inflammatory, totally outside the realm of normal everyday bodily experience.
The other I was told I probably exhibit on xray after a lazy weekend in bed Netflixing.
Gee, I wonder which is causing fever in the post-op patient?
I never forget what an attending told me in assessing the evidence:
does the proposed mechanism of action/biology make sense given what you know of how the body works, and common sense? Numbers alone aren't enough.
(Example: in summer, as ice cream sales go up, so do drownings. How does that make sense?)

TLDR:
In any case, atelectasis and fever aside,
I'm confused, is there no good evidence of OTHER benefits to IS? Just curious.
 

Slack3r

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Basic Science sources say it can cause fever (UWORLD, ABSITE Review)
Clinical evidence of the association is heavily lacking
Lots of surgeons say it does.
Lots of pulmonologists say it doesn't.

For Step 1/2 I would say yes. In practice just say what your upper level/attending believes.

When you become the attending, form your own opinion based on the evidence.
Not sure you can quote review materials as "basic science sources."
 
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OnePunchBiopsy

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Not sure you can quote review materials as "basic science sources."
I know, it's a bit of a stretch. However when you click the source links of Qbanks it brings up material from textbooks, not clinical research articles.

Fiser ABSITE review says atelectasis & fever is mediated by "alveolar macrophages releasing IL-1, which acts on the hypothalamus." I consider this a basic science explanation.
 

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Atelectasis may be a cause in some individuals, just like hematoma reabsorption may be a cause in some surgeries. Some people have these as and then don't spike a fever, maybe they are elderly/multiple comorbidities and their physiology is out of wack. I think this is more complex then we would like it to be, sorta like Sepsis.

With IS I wonder if patients using it feel more confident in their recovery and are more likely to walk earlier/be compliant. Does it make patients feel like they are involved in their recovery and give them a sense of control in their healthcare? I dunno, just some things I was thinking about.


Sent from my iPhone using SDN mobile app
 

dpmd

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Atelectasis may be a cause in some individuals, just like hematoma reabsorption may be a cause in some surgeries. Some people have these as and then don't spike a fever, maybe they are elderly/multiple comorbidities and their physiology is out of wack. I think this is more complex then we would like it to be, sorta like Sepsis.

With IS I wonder if patients using it feel more confident in their recovery and are more likely to walk earlier/be compliant. Does it make patients feel like they are involved in their recovery and give them a sense of control in their healthcare? I dunno, just some things I was thinking about.


Sent from my iPhone using SDN mobile app
I know it gave me something to do and a goal to shoot for through the pain after my vats wedge resection.
 

thenursingstudent

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It's not a cause of fever, and IS doesn't really work. There was a Cochran review a couple years back and a RCT in bariatrics patients last year.

Makes us feel good like we are doing something for people though.

Plus it gives us an excuse to ignore POD0-1 fevers which is all we really wanted anyways
Wow.

And if I mentioned this to my nursing instructors, **** would hit the fan, IS benefits are believed and drilled in myself and classmates that much in each of my nursing classes (I'm in my 3rd year for BSN). I need to read a little more though because I still don't understand how IS wouldn't help to create that pressure gradient to help prevent alveoli from collapsing (I hope that is worded correct).

I need to read more in these med forums, wonder what else there is to learn!
 

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Wow.

And if I mentioned this to my nursing instructors, **** would hit the fan, IS benefits are believed and drilled in myself and classmates that much in each of my nursing classes (I'm in my 3rd year for BSN). I need to read a little more though because I still don't understand how IS wouldn't help to create that pressure gradient to help prevent alveoli from collapsing (I hope that is worded correct).

I need to read more in these med forums, wonder what else there is to learn!
Actually it would probably make the negative effects of alveolar collapse even worse
 
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