LP to r/o SAH but on effiant

[Boatswain2PA]

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Rural community hospital. 55 yo f presents with sudden onset severe HA after exertion (climbing stairs). This is the SECOND sudden onset HA, first one occurred 3 days ago and was also after exertion. CT and CTA are negative. Neurologically intact.

Pt is on effiant and full dose asa for stents (x4). Also uncontrolled diabetes on insulin, uncontrolled hypertension, obese, smoker.

Do you do the LP despite the effiant? Or just admit and repeat the CT tomorrow??

Thanks in advance for any advice/suggestions.

 

[deleted547339]

Rural community hospital. 55 yo f presents with sudden onset severe HA after exertion (climbing stairs). This is the SECOND sudden onset HA, first one occurred 3 days ago and was also after exertion. CT and CTA are negative. Neurologically intact.

Pt is on effiant and full dose asa for stents (x4). Also uncontrolled diabetes on insulin, uncontrolled hypertension, obese, smoker.

Do you do the LP despite the effiant? Or just admit and repeat the CT tomorrow??

Thanks in advance for any advice/suggestions.

I wouldn't LP....you're already talking risk of SAH <1/500-700. If your CT is <6h and negative and you have a negative CTA, the odds of SAH are truly low. I'm only a resident, but I'd probably consult nsgy on the pt and not LP.

 

[Birdstrike]

Tough one. Could try admit to neurosurg or Neuro for presumed SAH, or try to get rads to do an old school cerebral angio.

Bottom line: punt to specialist.

 

[Tiger26]

Your CTA is negative--you're done with the SAH workup

 

[Old_Mil]

Not going to LP this. Out of curiosity, I am wondering how many of you have actually diagnosed a SAH with a normal CT and + persistent RBCs/xanthochromia on LP?

 

[EvoDevo]

Not going to LP this. Out of curiosity, I am wondering how many of you have actually diagnosed a SAH with a normal CT and + persistent RBCs/xanthochromia on LP?

I have.. Once. But the presumed onset was greater than 12 hours.. Never had one with your scenario

 

[Apollyon]

Tough one. Could try admit to neurosurg or Neuro for presumed SAH, or try to get rads to do an old school cerebral angio.

Bottom line: punt to specialist.

I wouldn't LP....you're already talking risk of SAH <1/500-700. If your CT is <6h and negative and you have a negative CTA, the odds of SAH are truly low. I'm only a resident, but I'd probably consult nsgy on the pt and not LP.

Did you guys miss "rural community hospital"? Guess what there ain't out in the boonies...yep, neurology and - especially - neurosurgery.

In my rural hospital - there is not a neurologist or neurosurgeon within 50 miles in any direction. I don't even think there is even one "rural academic hospital".

 

[Boatswain2PA]

Tough one. Could try admit to neurosurg or Neuro for presumed SAH, or try to get rads to do an old school cerebral angio.

Bottom line: punt to specialist.

Neurosurgery? I've heard about those guys who live in far-away lands. I played college ball, but can't punt that far.

Thanks for everyone's input. Much appreciated...I learn a lot from you guys here.

 

[southerndoc]

Your CTA is negative--you're done with the SAH workup

No, not true. A small percentage of SAH patients will have initial negative CTA's because of vasospasm. I've seen it before, and our endovascular neuro guys say it happens more frequently than you'd expect.

LP on Effiant? No way. Our malpractice carrier issued a statement for guidelines. Effiant is wait 3 days after holding before doing the LP. Warfarin is reversal if strong suspicion, Pradaxa is like 2 weeks, etc. I don't have the info on hand, but basically if you're on a blood thinner (including Plavix) then you don't do the LP.

I would refer your patient to a endovascular neurosurgeon for further workup. I realize you're in a rural hospital, but you can refer them to the nearest comprehensive stroke center. If they are true sudden onset, then she still hasn't been ruled out for a SAH. It's a very small chance, but the possibility still exists.

 

[southerndoc]

Not going to LP this. Out of curiosity, I am wondering how many of you have actually diagnosed a SAH with a normal CT and + persistent RBCs/xanthochromia on LP?

Here recently, quite a few times.

 

[Groove]

LP? Too risky. Fat, obese female? Did you measure opening pressure? Any vision changes? Are you sure this wasn't a pseudotumor?

CTA is neg. They are safe for discharge from SAH standpoint and there is nothing neurosurgical. It sounds as if you have done an appropriate work up and are essentially now stuck with a status migrainosus vs pseudotumor which you could certainly admit to medicine for intractable pain if you can't get them under control.

 

[GeneralVeers]

Based on the numbers, we shouldn't even do LPs for negative CT scan AND low suspicion. If 1/700 patients with a normal scan have an SAH, I think it's insane to do 700 LPs just to find that one. If you have a negative CTA, although not rule-out, that 1/700 just got even lower. I would discharge home assuming pain is controlled.

 

[Birdstrike]

Based on the numbers, we shouldn't even do LPs for negative CT scan AND low suspicion. If 1/700 patients with a normal scan have an SAH, I think it's insane to do 700 LPs just to find that one. If you have a negative CTA, although not rule-out, that 1/700 just got even lower. I would discharge home assuming pain is controlled.

Isn't a lot of that data is based on retrospective studies that doesn't include potentially missed small bleeds?

 

[GeneralVeers]

Isn't a lot of that data is based on retrospective studies that doesn't include potentially missed small bleeds?

I don't know, would have to re-read the article. Even if the number is 1/500 or 1/250 that is too many LPs as far as I'm concerned. That essentially means I would have to LP almost every headache I see for 2-3 years just to pick up one bleed. I think the risk of MI is a lot higher in the "atypical" chest pain that gets sent home.

 

[TooMuchResearch]

Isn't a lot of that data is based on retrospective studies that doesn't include potentially missed small bleeds?

And newer CT scanners that smaller centers may not have. Also, who read those scans? Radiologist? Neuroradiologist?

 

[Groove]

I remember in training going over a lot of these studies with our NSGY dept. Essentially, you CAN have sentinel bleeds from "mainly" benign etiologies that are non aneurysmal (perimesencephalic, etc..) but the chances are low. I mean, as Veers said... you'd have a higher chance of sending out a missed MI. I think there's some studies that show a not insignificant subset of pt's with neg CTAs that have aneurysms so small that they get missed and show up on repeat CTAs but those are studies they do like 1-2 weeks later. Essentially, you have (I'd really have to look all of this back up) but it was something like 8% possible non aneurysmal SAH but pt's that NSGY would always send home with a neg CTA. LP is always gold standard but I always have a few who can't get an LP or don't want it and I'll always offer CTA and with a neg CTA I think there's enough evidence for an adequate work up unless your gestalt trumps the diagnostic data such as severe pain +/- neuro deficit and your hunch wins out. As southern doc said, you can have vasospasm which will obscure an aneurysm on CTA (small) but I've personally never seen it though I don't have as much time under my belt as some of the others.

Occasionally, I'll get a few of these and usually admit them for status migrainosus or intractable headache, etc.. and have neurology look at them. I've followed up on most and they usually get sent home with no further repeat studies.

 

[Birdstrike]

The problem is, Grade I SAH's that are walking/talking can progress to vasospasm and stroke. That equals a bad neurological outcome in a young person with high economic damages and a lifetime of medical bills. Be careful out there.

 

[GeneralVeers]

The problem is, Grade I SAH's that are walking/talking can progress to vasospasm and stroke. That equals a bad neurological outcome in a young person with high economic damages and a lifetime of medical bills. Be careful out there.

There are lots of really bad 1/500 or 1/1000 things that I could rule out with painful, invasive tests. I just don't think that doing that is justified. How many coronary angiograms would you have to do on unspecified chest pain to pick up severe CAD? Maybe 1/50, maybe 1/100 would show something significant. It's a slippery and inappropriate slope we go down if we can justify an LP on 700 healthy people to pick out one person who *might* have an SAH due to an aneurysm.

 

[Birdstrike]

There are lots of really bad 1/500 or 1/1000 things that I could rule out with painful, invasive tests. I just don't think that doing that is justified. How many coronary angiograms would you have to do on unspecified chest pain to pick up severe CAD? Maybe 1/50, maybe 1/100 would show something significant. It's a slippery and inappropriate slope we go down if we can justify an LP on 700 healthy people to pick out one person who *might* have an SAH due to an aneurysm.

Your 1/700 number refers to 700 who "might" have a SAH, to find one who does. I'm not telling you how to treat your patients, I'm just telling you the literature might be a little misleading in that area (which I'm sure you probably knew anyways.) We get paid a nice salary to make these decision. They are judgment calls, all of them. It's also something you can use with informed consent by telling quoting the statistic to a patient to help them give informed consent, or informed refusal. Some may want a zero miss rate and opt for an LP. Many (most in my experience) will take their chances on having a 699/700 chance that they don't have a SAH. Then you simply document informed refusal, in whatever form you're most comfortable with, to cover that 1/700 chance. This is not an exact science. It's not rocket science, or even brain surgery. It's only Demand Medicine (and emergentology), formerly known as "Emergency Medicine" (for those of you that are a little bit slow on the uptake.)

 

[DocEspana]

Isn't a lot of that data is based on retrospective studies that doesn't include potentially missed small bleeds?

Our center is publishing a study where we LP everyone who had a high CVA suspicion with negative CTA. I forget if the number is 300+ or 400+, but we are "zero-for-" on all of them. Not a single CVA found at LP or with months of follow up for missed CV.

 

[Birdstrike]

Our center is publishing a study where we LP everyone who had a high CVA suspicion with negative CTA. I forget if the number is 300+ or 400+, but we are "zero-for-" on all of them. Not a single CVA found at LP or with months of follow up for missed CV.

Well that's beautiful. Because if the number you're looking for is the 1 in 700 that's being quoted, you don't even have nearly a large enough sample size. Yet I'm sure it won't stop people for quoting it as unquestionable "data" for the next 15 years, or from some so-called expert in one of the textbooks from testifying it was a classic miss.

Do 1 in 700 15-yr-olds with chest pain have PEs?

http://www.epmonthly.com/features/c...-slippery-slope-for-dubious-expert-testimony/

 

[DocEspana]

Well that's beautiful. Because if the number you're looking for is the 1 in 700 that's being quoted, you don't even have nearly a large enough sample size. Yet I'm sure it won't stop people for quoting it as unquestionable "data" for the next 15 years, or from some so-called expert in one of the textbooks from testifying it was a classic miss.

Do 1 in 700 15-yr-olds with chest pain have PEs?

http://www.epmonthly.com/features/c...-slippery-slope-for-dubious-expert-testimony/

That's one in 700 *retrospective and on *low suspicion rule outs.

Don't need to hit 700 if this is a trial of expanding the extant "LP for low suspicion rule out is no longer standard of practice" and applying it to moderate or higher suspicion cases with negative CTA. Also of its applying it to the cohort as they walk in the door and meet criteria.

It will need to be repeated at large scale anyway.

 

[DocEspana]

Well that's beautiful. Because if the number you're looking for is the 1 in 700 that's being quoted, you don't even have nearly a large enough sample size. Yet I'm sure it won't stop people for quoting it as unquestionable "data" for the next 15 years, or from some so-called expert in one of the textbooks from testifying it was a classic miss.

Do 1 in 700 15-yr-olds with chest pain have PEs?

http://www.epmonthly.com/features/c...-slippery-slope-for-dubious-expert-testimony/

Unrelated note: every time I read about Rosen the jerkwad, I just want to switch to Tintinalli the book.

 

[kat82]

This is an interesting scenario. I would make the decision based on my pretest probability of SAH. If it was low enough, I'd be happy with a negative CTA (+/- a negative CT- if its been less than six hours). Thats often what I do with my patients who I am considering SAH but who refuse LP.

If my pretest probability is high despite a negative CT/CTA, I would consult with neurosurgery/neurointerventionalist to see if they would consider angiogram. Otherwise, what else could they offer the patient?? I guess if you are off in the sticks, you'd have to transfer them.

I would not do LP b/c of the bleeding risk. Plus, if you get a bloody tap (would the risk of that be higher in this setting?) you're back where you started

 

[ORL10]

I wouldn't LP this patient, it also sounds like they did not have a SAH from the basic story you are describing, and being on prasugrel makes it a no go.

As an aside, a negative CTA in a patient with subarachnoid blood DOES NOT MEAN they do not have an aneurysmal SAH as others have eluded to. Those patients get DSA frequently. Having worked in a neuro ICU it's not uncommon to see a negative CTA with a positive formal angio or other diagnsois (i.e; blister aneurysm etc).

 

[BJJVP]

On a side note, what do you guys consider a negative tap? I was taught that there had to be a "significant" drop in RBCs from tube 1 to tube 4. Or, very close to 0 RBCs in tube 1. If I understand correctly, most labs in the country don't have spectrophotometer analysis for xanthochromia and so I always understood that xanthochromia is an irrelevant consideration for most EDs. Ironically, our neurosurgeons don't get excited unless RBCs are in the 1000's range in tube 4. I've never been suspicious enough clinically with any pt to argue with them on this point. Btw, I have never, nor do I personally know anyone who has ever made the diagnosis of SAH from an LP. On my 7th year as an attending. Reading the above posts is making me nervous about my potential misses.

 

[kat82]

On a side note, what do you guys consider a negative tap? I was taught that there had to be a "significant" drop in RBCs from tube 1 to tube 4. Or, very close to 0 RBCs in tube 1. If I understand correctly, most labs in the country don't have spectrophotometer analysis for xanthochromia and so I always understood that xanthochromia is an irrelevant consideration for most EDs. Ironically, our neurosurgeons don't get excited unless RBCs are in the 1000's range in tube 4. I've never been suspicious enough clinically with any pt to argue with them on this point. Btw, I have never, nor do I personally know anyone who has ever made the diagnosis of SAH from an LP. On my 7th year as an attending. Reading the above posts is making me nervous about my potential misses.

I think the literature out there says that there is no reliable cutoff for % or absolute drop in RBCs or # RBCs in tube 4 (last I checked)

 

[MDzocdoc]

second that

 

[Birdstrike]

Normal. That's the reliable cut off.

 

[Arcan57]

Less than 5 RBCs would definitely eliminate my concern for SAH. Xanthochromia should be a late finding so unless patient is presenting with chief complaint of thunder clap headache 3-4 days ago I wouldn't get too excited. What bothers me is the idea that the LP has fantastic test characteristics and never leads to unnecessary testing. There may be someone that can feel the LP needle about to hit a vein and redirect around it, but in patients with generous soft tissue I haven't noticed a significant drop in rates of non-normal RBC counts. It no longer looks like I drew a type and screen but in BMI>30 I seem to always pick up at least 20-50 RBCs. IIRC, the stroke risk from a DSA is something in the low single digits which means that playing the odds you're more likely to cause someone to have a stroke then pick up a CT negative SAH.

 

[WilcoWorld]

Most "authorities" say that xanthochromia will develop by 12 hours after headache onset. The emerging literature suggests that a (high quality) CT preformed within 6 hours is very, very sensitive. So, it's arguably only the folks who you're tapping between 6 & 12 hours after onset where + RBC's and - xanthochromia should concern you.

"But what about patients who don't know when their headache started?" some might ask… Well, those patients don't have a subarachnoid, I'd reply.

 

[Arcan57]

Most "authorities" say that xanthochromia will develop by 12 hours after headache onset. The emerging literature suggests that a (high quality) CT preformed within 6 hours is very, very sensitive. So, it's arguably only the folks who you're tapping between 6 & 12 hours after onset where + RBC's and - xanthochromia should concern you.

"But what about patients who don't know when their headache started?" some might ask… Well, those patients don't have a subarachnoid, I'd reply.

Which is by the time pt makes it past the waiting room and gets their CT, you're usually somewhere in that window. The literature for onset of xanthochromia is not fantastic and I found 3 studies that pin it on everything from 9 h to 4 days.

 

[southerndoc]

Based on the numbers, we shouldn't even do LPs for negative CT scan AND low suspicion. If 1/700 patients with a normal scan have an SAH, I think it's insane to do 700 LPs just to find that one. If you have a negative CTA, although not rule-out, that 1/700 just got even lower. I would discharge home assuming pain is controlled.

The plaintiff's attorney would ask if their client is just a number to you. Unfortunately, until solid tort reform happens, an LP is still standard of care.

 

[southerndoc]

Our center is publishing a study where we LP everyone who had a high CVA suspicion with negative CTA. I forget if the number is 300+ or 400+, but we are "zero-for-" on all of them. Not a single CVA found at LP or with months of follow up for missed CV.

CVA=Cerebrovascular Aneurysm v. Cerebrovascular Accident? I'm assuming you're meaning aneurysms?

 

[GeneralVeers]

The plaintiff's attorney would ask if their client is just a number to you. Unfortunately, until solid tort reform happens, an LP is still standard of care.

If it gets to the point where you are being deposed or questioned by a Plaintiff's attorney, then you are screwed. You could be the most competent, caring physician in the world, and they will come up with questions that you can't answer which make you seem like the biggest uncaring a**hole in the world. No amount of defensive medicine can prevent that. BTW I would never cite a number like 1/700 in a court of law. I would simply say that given the history, negative CT, and low likelihood of SAH I thought a large painful needle stuck straight into the spine would be unnecessary.

 

[DocEspana]

The plaintiff's attorney would ask if their client is just a number to you. Unfortunately, until solid tort reform happens, an LP is still standard of care.

I'd argue that its not standard of care anymore. While there is no foolproof strategy when the deciding factor is who convinces the jury more, pretty much every complication in the world, including inducing meningitis and causing a paralysis (temporary or lasting) is much more likely than the 1 in 700 miss rate.

 

[Birdstrike]

I'd argue that its not standard of care anymore.

The "standard of care" is ultimately what a jury of non-nurses and non-physicians decides what it is. It is not defined you, me, your attendings, those people with their names on your textbooks, or anyone else. It's defined by a jury, sitting in judgement of you, that may have no experience in medicine at all, other than what they hear in a five-day crash-course lesson in your specialty, in a courtroom.

Routinely now, we are blessed with reports of malpractice cases that confuse those supposed standards, turns them on their heads, and sets a new legal (not medical or scientific) precedent.

 

[Tiger26]

I'd argue that the standard of care depends on how much a famous text book author wants to earn that day in court ......

 

[Birdstrike]

I'd argue that the standard of care depends on how much a famous text book author wants to earn that day in court ......

Yes, that guides it, but doesn't really decide it. It carries weight only if the jury votes a verdict in favor of the testimony, right? Yes, expert opinion can be bought, but the jury has to pass a verdict in agreement, for it to make any difference. If the physician on trial ultimately wins, and such "bought testimony" is ignored, it's much different than if dubious testimony is supported by a guilty verdict. That's the rub. The so-called experts can argue all they want about what's the "standard" but the jury votes guilty or not, ultimately siding with one side's expert or the other. Therefore, it's the jury's vote that determines the standard, isn't it?

For example, if you spend your career thinking a negative CT angio without LP rules out SAH as "standard of care," all the textbooks say it's "standard of care," your expert witness says it's "standard of care," yet you are judged guilty of malpractice by a jury vote for missing a SAH by not doing an LP, then hasn't the standard been changed to "must do an LP to rule out SAH"?

If a jury renders you guilty, then it doesn't really matter at all who claims to be determiner of what "standard of care" is other than those few people on the jury. I don't care if your real name is on a textbook cover or chapter right now or in the future, the jury decides.

 

[DocEspana]

Yes, that guides it, but doesn't really decide it. It carries weight only if the jury votes a verdict in favor of the testimony, right? Yes, expert opinion can be bought, but the jury has to pass a verdict in agreement, for it to make any difference. If the physician on trial ultimately wins, and such "bought testimony" is ignored, it's much different than if dubious testimony is supported by a guilty verdict. That's the rub. The so-called experts can argue all they want about what's the "standard" but the jury votes guilty or not, ultimately siding with one side's expert or the other. Therefore, it's the jury's vote that determines the standard, isn't it?

For example, if you spend your career thinking a negative CT angio without LP rules out SAH as "standard of care," all the textbooks say it's "standard of care," your expert witness says it's "standard of care," yet you are judged guilty of malpractice by a jury vote for missing a SAH by not doing an LP, then hasn't the standard been changed to "must do an LP to rule out SAH"?

If a jury renders you guilty, then it doesn't really matter at all who claims to be determiner of what "standard of care" is other than those few people on the jury. I don't care if your real name is on a textbook cover or chapter right now or in the future, the jury decides.

Disagree. This above is why God created appellate courts. For people are idiots sometimes, but equilize to acceptable over repeated attempts.

 

[e30ftw]

"There but for the grace of God go I."

any patient you see could end up winning a successful suit against you no matter what you do.

there are things we can do to reduce our exposure, ordering more tests, documenting dc conversation, practicing good medicine, etc.

but ultimately we see sick, high-risk, undifferentiated patients all day long and, let's be honest, often times have no idea what is going on even after an appropriate work up. we have vague feelings of "this person is safe to go home." and "this person needs to be admitted but I don't know why.." and try to follow these instincts but will be wrong.

bad things happen to people and they die. their families get upset and want to blame someone, so the physician gets sued.

LP for SAH in anyone but the most textbook history > 12 hrs out seems a bit barbaric, classic "more procedures are better" medicine. I document my discussion with the patient offering them a needle in their back and usually they "request to go home and refuse further invasive procedures to rule out SAH/meningitis/etc".

 

[Raryn]

No, not true. A small percentage of SAH patients will have initial negative CTA's because of vasospasm. I've seen it before, and our endovascular neuro guys say it happens more frequently than you'd expect.

LP on Effiant? No way. Our malpractice carrier issued a statement for guidelines. Effiant is wait 3 days after holding before doing the LP. Warfarin is reversal if strong suspicion, Pradaxa is like 2 weeks, etc. I don't have the info on hand, but basically if you're on a blood thinner (including Plavix) then you don't do the LP.

I would refer your patient to a endovascular neurosurgeon for further workup. I realize you're in a rural hospital, but you can refer them to the nearest comprehensive stroke center. If they are true sudden onset, then she still hasn't been ruled out for a SAH. It's a very small chance, but the possibility still exists.

2 weeks for Pradaxa? Given that the standard of care for surgery is 2-3 days (you can do 4 if the patient has really bad CKD) and that it has a fairly short half-life and is completely out of your system within that time period, that's simply ridiculous. I've never even heard of the neurosurgeons saying wait more than 5, and they are usually way more conservative than the evidence would support.

 

[emergentmd]

The studies with missed SAH on CT is probably from old studies with early generation CTs. The current CTs are much better and thus I suspect the miss rate is much less.

I essentially stopped doing LPS for SAH. In 13 yrs, I have never had a positive SAH with neg CT even with high suspicion. If I am still concerned after a CT, then do a CTA and call it a day.

NSG would not touch this pt unless you provide proof of a bleed. They will always tell you to do a CTA and call them if positive..