Low pretest probability SAH and a normal CTA Brain...

[deleted109597]

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Wow, that's nice. How is gross negligence different from negligence? Unfortunately in my state the standard is plain old negligence which is just another way of saying breach of the standard of care.

Standard of care is whatever the majority of the people in the area around your practice site would do in a similar situation, unfortunately.

Gross negligence is willful and wanton typically. Simple negligence is basically carelessness.


Also, when did FDNewbie become an attending? I thought he/she was a resident last week.

 

[ERDude]

FD, I think you should strongly reconsider using CTA to rule out spontaneous SAH. I have never heard of anyone doing that. Ask your colleagues if they are doing that. It is certainly not the standard of care or even an idea I have ever heard suggested by anyone. This could get you into big trouble because in the courtroom you will be judged by the standard of care. You are better off with a non con CT head and a good MDM note about why your suspicion is low.

If you are looking to rule out spontaneous SAH, you need to do an LP and that is non-negotiable. If you are looking for an aneurysm, then fine do a CTA. A patient without an aneurysm is extremely unlikely to have a spontaneous SAH, and that is where it could help you. This algorithm for working up headaches is also not the standard of care, but at least it actually makes some sense.

At my community shop I would say the standard of care (definitely among the docs working in my ED and as advocated by all of our NSG consultants) does include the CT + CTA algorithm. Now, if I'm really concerned I'll definitely go forward with the LP, but if the story is so/so (but I still have some concern) or after discussion with the pt they prefer CTA over LP, I don't think it is unreasonable (provided they understand the limitations of CTA vs LP).

If you have a negative head CT and no aneurysm on CTA, the chance of a spontaneous SAH is pretty damn low (particularly one that is going to kill them within days/weeks). Personally, if I ever had an new onset, severe headache I'd want to know if I had an intracerebral aneurysm - incidental or otherwise.

 

[dotcb]

The point which I tried to make earlier, which I will repeat for the sake of repetition, is that ACEP clearly has a published policy statement on this topic. It's CT + LP. So if someone takes you to task (or to court) on this is issue, it is likely you will lose.

Now you might say CT/CTA is "reasonable," but I think a court might respond it's most reasonable to follow the guidelines recommended by our professional college.

 

[Rendar5]

At my community shop I would say the standard of care (definitely among the docs working in my ED and as advocated by all of our NSG consultants) does include the CT + CTA algorithm. Now, if I'm really concerned I'll definitely go forward with the LP, but if the story is so/so (but I still have some concern) or after discussion with the pt they prefer CTA over LP, I don't think it is unreasonable (provided they understand the limitations of CTA vs LP).

If you have a negative head CT and no aneurysm on CTA, the chance of a spontaneous SAH is pretty damn low (particularly one that is going to kill them within days/weeks). Personally, if I ever had an new onset, severe headache I'd want to know if I had an intracerebral aneurysm - incidental or otherwise.

If it was an incidental aneursym, would you want coiling, clipping, or regular MRI's to assess for growth? Me? I'd rather avoid the worry, the insurance issues, and the potential thousands of dollars in medical costs on what amounts to an incidentiloma by not rolling the dice (which is what a CTA is in this setting, you hope it comes up negative, but it's not always going to). Just tell me if I'm bleeding or not and let the neurologist tell me if I need to look for an aneurysm as an outpatient if I'm not bleeding.

 

[ERDude]

If it was an incidental aneursym, would you want coiling, clipping, or regular MRI's to assess for growth? Me? I'd rather avoid the worry, the insurance issues, and the potential thousands of dollars in medical costs on what amounts to an incidentiloma by not rolling the dice (which is what a CTA is in this setting, you hope it comes up negative, but it's not always going to). Just tell me if I'm bleeding or not and let the neurologist tell me if I need to look for an aneurysm as an outpatient if I'm not bleeding.

Yeah, I'd still want to know. If I ever had a headache that was severe enough to bring to me to the ED (granted I've only been to the ER as a patient x1 in my life and that was as a kid) I'd straight up ask for the CT/CTA. If no blood on CT and + aneurysm on CTA then I'd prefer to consult with a NSG I trusted and discuss options from there. Personal preference, I suppose.

 

[Rendar5]

Yeah, I'd still want to know. If I ever had a headache that was severe enough to bring to me to the ED (granted I've only been to the ER as a patient x1 in my life and that was as a kid) I'd straight up ask for the CT/CTA. If no blood on CT and + aneurysm on CTA then I'd prefer to consult with a NSG I trusted and discuss options from there. Personal preference, I suppose.

Would you want an LP if you had a neg CT and a pos CTA? I'm genuinely curiuos, not arguing a viewpoint now.

 

[ERDude]

Would you want an LP if you had a neg CT and a pos CTA? I'm genuinely curiuos, not arguing a viewpoint now.

Depends a bit. If I was a patient at the ED where I work and it wasn't 3am, I'd probably call my favorite neurosurgeon and ask him to look at the scans, talk to him about the situation, and proceed from there. But that's kind of cheating.

Under other circumstances:
If the CT was within 6 hours onset on a new generation scanner and no blood, even with a + CTA I'd probably skip the LP.

If > 6hr to CT or old scanner, then I'd take the LP after a + CTA b/c I'm going to want to know if that thing is leaking right now.

 

[neusu]

Depends a bit. If I was a patient at the ED where I work and it wasn't 3am, I'd probably call my favorite neurosurgeon and ask him to look at the scans, talk to him about the situation, and proceed from there. But that's kind of cheating.

Under other circumstances:
If the CT was within 6 hours onset on a new generation scanner and no blood, even with a + CTA I'd probably skip the LP.

If > 6hr to CT or old scanner, then I'd take the LP after a + CTA b/c I'm going to want to know if that thing is leaking right now.

The point of the LP is to assess bleeding. A ruptured aneurysm is far more dangerous than an unruptured. Likewise, if a patient arrives c/o sudden onset worst headache of life with a negative noncon CT and somehow gets a CTA prior to LP, we treat it as ruptured and secure it. Not sure if follow-up is appropriate in this scenario.

 

[ptarmigan]

Depends a bit. If I was a patient at the ED where I work and it wasn't 3am, I'd probably call my favorite neurosurgeon and ask him to look at the scans, talk to him about the situation, and proceed from there. But that's kind of cheating.

How can the neurosurgeon tell that the aneuriysm is not bleeding just by looking at the scans?

If the CT was within 6 hours onset on a new generation scanner and no blood, even with a + CTA I'd probably skip the LP.

Then why would you do the CTA?

 

[ERDude]

How can the neurosurgeon tell that the aneuriysm is not bleeding just by looking at the scans?



Then why would you do the CTA?

I would personally want a CTA because if it's negative (and presuming spontaneous SAH is what I was most concerned about having) then I'm skipping the LP and would feel comfortable doing so.

EDIT:
Actually I just re-read and better see your point. I changed my mind. If I ever go to the hospital with a sudden, severe headache I'm still asking for CT/CTA, but if I have the combo of negative plain CT and aneurysm on CTA (irrespective of time to CT or CT generation) I'm taking the LP. FINAL ANSWER!

I really hope I never have to see this play out...

 

[ERDude]

The point of the LP is to assess bleeding. A ruptured aneurysm is far more dangerous than an unruptured. Likewise, if a patient arrives c/o sudden onset worst headache of life with a negative noncon CT and somehow gets a CTA prior to LP, we treat it as ruptured and secure it. Not sure if follow-up is appropriate in this scenario.

I suppose this is an academic vs community difference, but the CT then CTA prior to LP approach doesn't just "somehow" happen, it happens all the time where I work. And this has been strongly advocated by ALL of our neurosurgeons (of which we have 6, between 2 groups. I work at a stroke-center hospital and neurosurgery referral center and they run very busy services and treat lots of spontaneous SAH). Best practice or not - in many places (and i'm sure it's more than just my shop) it's a common practice advocated by the specialists who definitively manage SAH.

Nonetheless your point is well taken. Thunderclap HA and aneurysm on CTA = assume worst and treat accordingly, no matter how you got there.

 

[Rendar5]

I suppose this is an academic vs community difference, but the CT then CTA prior to LP approach doesn't just "somehow" happen, it happens all the time where I work. And this has been strongly advocated by ALL of our neurosurgeons (of which we have 6, between 2 groups. I work at a stroke-center hospital and neurosurgery referral center and they run very busy services and treat lots of spontaneous SAH). Best practice or not - in many places (and i'm sure it's more than just my shop) it's a common practice advocated by the specialists who definitively manage SAH.

They may advocate it because it lets them do more procedures than CTand LP lets them do. If you look at the study FDNewbie posted earlier, in the place that did do CTA's on all their acute headaches, 5 or 6 aneurysms got clipped, despite only 3 bleeds being identified.

 

[deleted109597]

Quarterly bump.
http://www.epmonthly.com/features/current-features/lp-for-subarachnoid-hemorrhage-the-700-club/
The problem is, this still doesn't change the data. It's just that a low prevalence disease will necessarily have a high negative study rate if you want to have good sensitivity.

 

[southerndoc]

IIRC, the incidence of spinal epidural hematoma following lumbar puncture is 0.1%. So basically you're going to cause one for every 1.5 SAH's you pick up by LP.

 

[pinipig523]

I re-read this whole thread and a lot of good points and re-learned and learned new stuff. Great stuff guys.

So with the data that you catch 1 in 700 of high risk SAH patients and even a higher ration (1:1400 in lower risk patients)... what are you guys doing? Still CT+LP if say, they're 12-18h out?

Oh - and btw, what are your protocols for patients who you suspect SAH and are on coumadin - do you CT then if neg, recommend LP and reverse w/ ffp and admit to medicine for IR LP or LP later? It takes a while for us to get our 6u of ffp in the ER... holding a bed for that long seems to be anti-flow.

 

[southerndoc]

Oh - and btw, what are your protocols for patients who you suspect SAH and are on coumadin - do you CT then if neg, recommend LP and reverse w/ ffp and admit to medicine for IR LP or LP later? It takes a while for us to get our 6u of ffp in the ER... holding a bed for that long seems to be anti-flow.

It's not just warfarin... Our malpractice carrier analyzed data and advised us this:

Warfarin: wait 5-7 days and INR <1.4 (you can reverse with FFP to speed it up)

High-dose LMWH: wait 24 hours

Arixtra: wait 36 hours

Xarelto: wait 20 hours

Plavix/Effiant: wait 7 days, NOT reversed with platelets

Ticlid: wait 10 days, NOT reversed with platelets

Pradaxa/Danaparoid: unsafe, do not LP

This is based on their claims data, expert opinion by neurologists, etc. They will not cover claims where an LP occurs against their advice. They will also not cover claims for LP with platelets <50,000 (unless corrected), hemophilia (duh) or von Willebrand disease.

Makes one definitely think twice before LP'ing someone on an anticoagulant. Had a transfer recently of an LP gone awry: spinal epidural hematoma after LP while on warfarin with an INR of 1.6 (that they thought was safe to LP).

 

[tkim]

It's not just warfarin... Our malpractice carrier analyzed data and advised us this:

Warfarin: wait 5-7 days and INR <1.4 (you can reverse with FFP to speed it up)

High-dose LMWH: wait 24 hours

Arixtra: wait 36 hours

Xarelto: wait 20 hours

Plavix/Effiant: wait 7 days, NOT reversed with platelets

Ticlid: wait 10 days, NOT reversed with platelets

Pradaxa/Danaparoid: unsafe, do not LP

This is based on their claims data, expert opinion by neurologists, etc. They will not cover claims where an LP occurs against their advice. They will also not cover claims for LP with platelets <50,000 (unless corrected), hemophilia (duh) or von Willebrand disease.

Makes one definitely think twice before LP'ing someone on an anticoagulant. Had a transfer recently of an LP gone awry: spinal epidural hematoma after LP while on warfarin with an INR of 1.6 (that they thought was safe to LP).

So, this is interesting. If I suspect SAH and have a neg CT head, but can't LP because of any of the above meds or conditions, then since I don't have nsurg at my shop, would it now require transfer to a place with nsurg for evaluation?

Can't admit any of those people - the hospitalists would outright refuse if my reason for admitting is suspected SAH.

 

[southerndoc]

so, this is interesting. If i suspect sah and have a neg ct head, but can't lp because of any of the above meds or conditions, then since i don't have nsurg at my shop, would it now require transfer to a place with nsurg for evaluation?

Can't admit any of those people - the hospitalists would outright refuse if my reason for admitting is suspected sah.

cta

 

[tkim]

cta

neg CT, neg CTA would be enough to r/o SAH in the anticoagulated pt? I must be missing something.

 

[southerndoc]

neg CT, neg CTA would be enough to r/o SAH in the anticoagulated pt? I must be missing something.

Unless you want to go fishing for that 1 in 700.

 

[tkim]

Unless you want to go fishing for that 1 in 700.

It seems that we are obligated to do so, doesn't it? With an ACEP policy that states CT + LP to r/o SAH, plus it being the 'local' practice as well, I'm not sure CT/CTA is going to be enough. In the anticoagulated patient without the ability to quickly reverse I'd have to send the pt to a neurosurgeon for evaluation.

 

[Arcan57]

It seems that we are obligated to do so, doesn't it? With an ACEP policy that states CT + LP to r/o SAH, plus it being the 'local' practice as well, I'm not sure CT/CTA is going to be enough. In the anticoagulated patient without the ability to quickly reverse I'd have to send the pt to a neurosurgeon for evaluation.

The neurosurgeon would tell you that you should get a CTA and if that's negative send them home.

 

[tkim]

The neurosurgeon would tell you that you should get a CTA and if that's negative send them home.

So, there seems to be two standards depending on the specialty - CT/LP, and CT/CTA. I would much rather CT/CTA but I think I'd be held to my specialty standard, which is CT/LP.

Are people doing CT/CTA then d/c?

I'm familiar with the UBuffalo paper, as that was my residency and we had a presentation of it just prior to publication. Even that paper concludes 'more study'.

 

[southerndoc]

The neurosurgeon would tell you that you should get a CTA and if that's negative send them home.

Especially in a patient whom you cannot LP because of risk of complications. Simply document that and explain to the patient the importance of following-up. Outpatient follow-up with a negative CTA is appropriate.

 

[xaelia]

I'd probably say the medicolegal "standard of care" is CT->offer LP to r/o SAH. Now, when you're consenting for LP, you can use the numbers Newman quotes and tell the patient you're more likely to harm them with the needle in the back than to find the disease in question after a negative CT. Then, document, document.

My humble opinion is that CT cerebral angiogram only has a role when you can't get a negative LP &#8211; whether because it's contraindicated or because it's positive/traumatic. Thunderclap headache with a positive tap and an aneurysm on CTA makes for a valid neurosurgery consult. They'll be less excited about the CTA without the LP, but they'll still listen.

I also don't pursue SAH for the run-of-the-mill so-called "worst headache of life" &#8211; unless it's a truly severe atypical HA in a patient that doesn't usually have them or the classic "sudden, maximal at onset" HPI.

 

[dotcb]

This is long, but worth listening to:

http://www.smartem.org/podcasts/smart-sah-picture-worth-thousand-lps

I think I'm slowly changing my practice. Suggests that negative CTH likely brings us under the diagnostic threshold of 1-2%. I know people who've had cases of CT neg, LP+, but I've never personally had a case myself. I think we're starting to grasp the extremely low yield of the LP. I think I will still probably do them or recommend them in cases with high risk features, but I lean to the informed conversation and documentation model. I'm not sold on the CTA being helpful or necessary, just CTH.

The podcast suggest ACEP will be revising their practice statement.

 

[tkim]

I'd probably say the medicolegal "standard of care" is CT->offer LP to r/o SAH. Now, when you're consenting for LP, you can use the numbers Newman quotes and tell the patient you're more likely to harm them with the needle in the back than to find the disease in question after a negative CT. Then, document, document.

I've been instructed to never 'offer' but to 'recommend', as offering means that there's no consequence of choosing either/or, even with a long discussion with documentation thereof. It's stronger to recommend and have a refusal than offer and have the same refusal. "If the doctor had recommended the LP, then I would have said 'yes'".

 

[Brigade4Radiant]

Ok so lets say 3 hours after you have a pt with the worst HA of their lives the CT is negative and you give the HA cocktail and HA is resolved do you still go for CTA vs Lumbar puncture?

 

[deleted109597]

Ok so lets say 3 hours after you have a pt with the worst HA of their lives the CT is negative and you give the HA cocktail and HA is resolved do you still go for CTA vs Lumbar puncture?

Resolution of symptoms does not make it not a SAH. Don't fall into that trap.

 

[Old_Mil]

Also, never ask a patient "is this the worst headache of your life.". Ask how long ago it started what the pain level us now, what the pain level was when it started, and when the last time was they had a headache like this...

That eliminates quite a bit of it up front.

I have been in the CTH only if onset < 7 hours ago CTLP if not. I will get a CTA if I am 3-4 hours into a 4pph morning and I don't have time to set up and do procedures. Reality.

 

[gman33]

Resolution of symptoms does not make it not a SAH. Don't fall into that trap.

Agreed, but I think the question is really what do you do with somebody with a HA that started less than 6 hours ago?

For me to really push for an LP, you have to have a really good story.
I'll still have the discussion and let the patient decide.