Cardiology, Improving Throughput, Mythbusting

Yes, No, and Maybe – Magnesium for Afib RVR

I really, really, wanted this study to work.  Few things are more disheartening on an overnight observation shift than needing to place someone on a diltiazem drip after an inability to rate control. Ergo, I have been known to give a few grams of magnesium to try to decrease the likelihood of that happening. Therefore, on the surface, this study seems promising – it looks at standard of care for Atrial fibrillation with rapid ventricular response (dealer’s choice, metoprolol, diltiazem, or digoxin) given in combination with either one of 3 treatments: placebo, 4.5g of magnesium, or 9g of magnesium; with about 150 patients in each arm. This study took 5 years (!) over 3 academic centers in Tunisia, who’s ED’s service 90,000-110,000 patients per year. Patients needed to have a heart rate over 120 bpm, have a systolic BP >90 mmHg, and without: renal impairment, wide-complex tachycardia, decompensated CHF, acute myocardial infarction, or an impaired level of consciousness. All seems fair.

The results, at face value, seem great if you’re a magnesium believer: rate control at 24h of 83.3% for placebo, 97.9% for 4.5g MgSO4, and 94.1% for 9g of MgSO4. This is a great example of completely reading a paper before you start to fight about giving magnesium.

First, all groups used digoxin around 50% of the time for rate control.  This clearly does not mimic US practice. Nor does giving 4.5-9g of magnesium over 30 minutes.  Then the authors sneak this one in:

In a secondary analysis including only patients receiving beta blockers and calcium channel blockers, the obtained results were not significantly different compared to those found in the overall group.

This is sandwiched between mentions of adverse drug reactions (4% flushing in the 4.5g arm vs 12% in the 9g arm vs <1% in the placebo arm, and otherwise there was no significant difference between the 3 arms), and the discussion of 24h rate control. I am not 100% certain what they meant by this statement – were they referring to ADRs? Were they implying that there was no difference between metoprolol and diltiazem treated patients and placebo at 24 hours?  With only about 50% of patients per arm (~75 patients in total/arm) being treated with these agents, it would be hard to show a meaningful improvement.  Not to mention the fact that the actual data for this secondary analysis is nowhere to be found in this paper.  Nor have the authors responded to my email asking for it.

Then, of course, there are the prior trials with less than 60 patients / arm comparing diltiazem to metoprolol showing >90% efficacy with diltiazem.

And, of course, there is the next question, of are we doing any good?  Since rate control has not always shown to be in the patients best interest – a 6 fold higher rate of adverse events– and none of the ED AFib RVR magnesium studies look further out than 24 hours, perhaps we should cautiously, if at all, recommend magnesium, or even suggest waiting until long term outcomes are further elucidated.  Since this study took 5 years to complete, I do not see the desired study happening anytime soon.

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Improving Outcomes, Improving Throughput

POCUS guided Flexor Tenosynovitis

It feels good to be back! Now, fresh off the inaugural AAPA18 iScan ultrasound event, its only right that my next post is on two of my favorite things- POCUS and infectious disease.

This is a review of 73 patients presenting to an emergency hand clinic (!) over the course of 3.25 years with a pyogenic flexor tenosynovitis.  Yep, a whole 22 patients a year… at an emergency hand clinic.

All patients underwent a resident and attending surgeon eval as well as labs including CRP and films. 16 confirmed pyogenic flexor tenosynovitis patients were excluded (these were the slam dunk obvious ones)- while the remaining 57 underwent POCUS while pending labs. POCUS was done by either a resident with 2 years experience in MSK sono, an attending surgeon with sono training, or senior radiologist.  Suffice to say, that this isnt exactly us work-a-day EM providers.

Of the remaining 57 patients, there were 29 were ultrasound negative (non-thickened tendon sheath without hyperemia and no peritendonous effusion); all were given PO antibiotics and discharged with every other day follow up until symptom resolution; only one required OR intervention.

Of the 27 patients with positive ultrasound findings- 17 of these had either a positive OR culture or significant purulence seen at the time of OR washout.  While this results in a decreased PPV of 63%, and a decreased specificity of 74% – I maintain POCUS is actually much better; keep in mind these numbers do not include the 16 slam dunks on clinical exam.  It doesnt take into account the rapid sterilization after a single dose of antibiotics seen in CSF and ascites; nor the 30% negative OR-culture rate seen in other pyogenic flexor tenosynovitis studies.  Nor does it take into account that POCUS approaches MRI for sensitivity and specificity in prior studies.

Ultimately, it would be fantastic (and likely better medicine!) if, stateside, we could adopt an ultrasound first strategy (especially with a 97% NPV and 94% sensitivity!).  If POCUS negative, patients could get expedited follow up and oral antibiotics.  This is pretty much exactly what this group has done.  Presumably with this strategy, a small fraction of these more ugly “slam dunk” tenosynovitis cases may not require the OR (the group did not comment on positive OR-culture rates), and the patients in the middle ground could get expedited follow up or overnight observation and serial sonography.  It should be noted that “delayed” diagnoses which resulted in poor outcomes were >10 days out from the initiation of symptoms (!); so a day or two may not make much of a difference.  This study comes with the usual caveats- there are few MSK ultrasound courses in the USA (I contacted the Jefferson MSK fellowship, no dice for hand sonography!), different equipment than our usual sonosite machines, more training.  But that certainly does not mean we can not have something to aspire to.

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Improving Outcomes, Improving Throughput, Radiology

Parting the SEA with the almighty H&P (& rapid MRI).

Necessity is the mother of invention, and sometimes, necessity comes in the form of hospital administration after a bad outcome. The authors of this paper, essentially developed a rapid MRI protocol for suspected spinal epidural abscess after “several cases of SEA associated with delayed diagnoses and poor outcomes prompted the chairs of the departments of emergency medicine, neurosciences, medicine, and radiology, and members of the Division of Healthcare Quality, to develop a multidisciplinary, clinical decision support tool and imaging protocol with the goal of facilitating early recognition of SEA.”

Wow. Talk about moving mountains. If you’re department is anything like mine, it takes hours to agree on where we’re getting take out from; I cant imagine adding in 4 entire departments into the lunch-ordering mix, let alone all agree on a protocol.

They took a relatively simple approach – if you have new or worsening back/neck pain AND a history of spinal abscess or current/recent (6 months) bacteremia, straight to MRI. I think the recent bacteremia often gets lost in the work up, so I appreciate that they put this front and center. If there is no recent spinal infection or recent/current bacteremia, They looked at risk factors- and I’ll make this simple and break it into 2 categories: people putting things where they dont belong (IVDA, vascular catheters, spinal procedures/injections) and the recurrently ill: ED visit or antimicrobial treatment within 30 days or an infectious process elsewhere. If yes, head to MRI.

I’m torn a bit on this- while I want to applaud the authors for not dwelling on a variety of risk factors that only a small portion of the population has – alcoholism, HIV, severe COPD, the undomiciled, HepC, oncology patients, transplant patients, etc; to say that this group is pretty much captured in the recent ED visit category probably misses a fair amount of patients on the first go-round. And here is the problem of trying to find a needle in the haystack – its hard to increase sensitivity and specificity without causing a delay at some other portion of the food chain – every stat MRI for so many additional back pain patients pushes out another patient and potentially extends at least 1 other patients length of stay.

However.

Despite an increase from 56 MRI’s in the 7 months pre-intervention to 147 in the 7 months post-intervention, yield for a positive MRI (defined solely as SEA and not vertebral osteomyelitis or infectious discitis), went from 16.1% to 17.7%.

On first glance, that’s not a lot of improvement in yield, but they screened 3 times as many patients without losing yield! This is rather impressive. However, they tripled their ED MRI rate, and, even though they drastically cut turn around times from 8.6 hours to 4.4 hours from time of MRI order to radiology report, thats still well over 4 hours for patients with back pain in a highly optimized system. And while yes, they missed fewer SEAs, they probably still have a good percentage that they missed on first visit – the various forms of immunocompromised – the severe COPDer on repeated steroid prescriptions, the HepC patient, the elderly – these are likely missed on the first go round.

I think this is a great step towards creating a policy towards SEA workup. It needs some refinement, but is the best I’ve seen yet. It poses some issues for smaller facilities that do not have 24/7 MRI capabilities, as well as for consultants (neurology essentially becoming a house officer for ID and neurosurgery), and poses a big time crunch for the ED (again, neurology took control of these cases once the decision to MRI was performed, which the hospitalists must be thankful for!). In the end, there is no such thing as zero miss, but Baystate, with this study, demonstrates that, at least for one day, the H&P is not dead.

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Improving Outcomes, Improving Throughput, Neurology

Opiates beget Opiates – Headache edition.

This is a study comparing 3 EDs in my homeland of CT and their (mis)use of opiates for headaches over a 14 month period. This compared an academic tertiary care center with an approximate 110,000 annual patient volume; an urban hospital with an approximate 85,000 patient annual volume, and a community ED that sees approximately 19,000 patients annually. A total of 1,222 visits were included for final analysis.

Results? Opiates, are not good, mmmmkay?

Patients given opioids as first line treatment had a 37.7% increase in visits over the study period compared to those who were not given opioids. If you were given opioids as first line, 36.0% required rescue treatment compared to 25.1% in those who were not given opioids. Strangely, female patients were significantly more likely to have opioids ordered than male patients (38.2% vs 24.2%).

Need more reason not to give opiates? Patients not given opioids had a 30.3% reduction in length of stay.

I’m surprised these numbers are so high.  As a community EM AP, I’m embarrassed at these numbers – A shocking 58% of headaches in a community setting were given opiates as first line compared to 6.9% of those at the academic center). Then again, opiates beget opiates.  Opiates lead to repeat visits, more rescue meds, and an increased length of stay, without an improvement in patient satisfaction with opiates.  I question how often those in the community ED just gave opiates to avoid conflict.

Just.  Stop.  Giving.  Opiates.  For.  Headaches.  NOW.

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Improving Outcomes, Mythbusting, Radiology, Radiology

Spinal Abscess: The Baystate Review

This is a review of all spinal abscesses at Baystate (total 162), from 2005 – 2015.  They compare 88 randomly selected controls whom had similar ICD-codes less the spinal abscess plus an MRI that was negative for acute infectious process. 

Interesting take home points, much of which is consistent with prior (albeit scant) literature:

-73% of patients are over age 50.

-more likely to have their second visit (50.6% vs 29.6% of controls) – though this 50.6% of patients with a second visit is surprisingly low for me – no word on how many were sent home from the ED, and had an MRI as an outpatient that were not included in this calculation.; or maybe we’re getting better at finding the needle in the haystack?  Or maybe we’re MRI’ing everyone?

-Many received antibiotics within the month: (35.2% vs 6.8% of controls) – this signifies a huge red flag for me.  If a patient revisits the ED and recently had pyelo (or anything infectious really), and now presents with back pain, probe a bit more for the possibility of vertebral osteo or discitis. 

-percentage of patients with history of IVDA: 20.4% vs 4.6% … this number seems low, but also is somewhat in line with prior studies – thus making me wonder how many I’ve missed…

– percentage of patients with alcoholism with a spinal abscess: 19% vs 8% – the more I get interested in ID, the more I realize that alcoholism is basically a form of immunosuppression.

-percentage of spinal abscess patients with obesity 21.6% vs 2.3%; I’m surprised only 2.3% of controls were obese.  Not sure what role this plays as being a diabetic in and of itself was not associated with a higher increased risk in this study.

-fever was present 62.4% in those with a spinal abscess vs 13.6% of those without; this includes self reported fever, which I have to wonder how often we sweep this aside when the patient is afebrile in the ED.

-16% had no identifiable risk factors; a third of the patients  presented with back pain, fever, neurologic deficits vs 6%

-Other symptoms and signs related to potential spinal cord impingement were seen with similar frequencies and of similar durations among cases and controls- meaning, focal deficits seen in both groups.

-noncontiguous co-infection: 53.7% of time (pneumonia, distant osteo, endocarditis… of those with a co-infection, 20% had more than one).

-blood cultures were positive 63.4% of the time, and >75% of the time it was staph Aureus. 

-Majority of lesions were found in the L-spine at 56.2%  – which means almost half are elsewhere!

-while “admits” for spinal abscess were up from 2.5 to 8 in 10,000 admissions from 2005 to 2015, I have to believe that number is somewhat inflated as admits like chest pain, pneumonia and renal colic probably decreased, while MRI became more readily available. 

All in all, this paper is pretty much in line with others on this topic, and strengthens the signal a bit for certain key points: a good number of spinal abscesses are not in the L-spine; many patients are older than you think, and, among other things: its more than just IVDA. 

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Cardiology, Cardiology, Critical Care, Improving Outcomes, Improving Throughput, Mythbusting, Pulmonary, Radiology, Radiology

Probing the dyspneic patient.

For undifferentiated dyspnea, how would you like to have an accurate diagnosis in 24 minutes?

I love this study.

Basically, for all dyspneic patients (not trauma related, and over age 18), 10 EP’s were given an H&P, vital signs, and an EKG, as well as access to a Chest X-Ray, Chest CT, cardiologist performed echo, and labs including an ABG.

These same 2,683 patients, in tandem, had point of care ultrasound testing (lung, IVC, echo). Here’s the catch – the ultrasonographers were only provided the H&P, vital signs, and EKG then asked to make a diagnosis. The treating provider was blinded to POCUS diagnosis.

These numbers for diagnostic accuracy of POCUS are astounding.

+LR for acute HF? 22 (-LR 0.12)

+LR for ACS? 105 !!!

+LR for pneumonia? 10.5 (-LR 0.13)

+LR for pleural effusion? 95 (-LR 0.23)

+LR for pericardial effusion? 325!!! (-LR 0.14)

+LR for COPD/asthma? 22 (-LR 0.14)

+LR for PE? 345!!!

+LR for pneumothorax? 4635!!! (-LR 0.12)

+LR for ARDS? 90

Yes, for certain things like pneumonia, the difference in p-values between tradition means and POCUS diagnosis was not significantly different, but what about volume status? I cant imagine blindly giving 30 cc/kg would benefit the patient with a plethoric IVC and pleural effusion. There is some elegance a play here.

Additionally, sure, ED diagnosis for ACS had a higher LR, but they also had a cardiologist performing and interpreting echos in the ED (a rather rare siting in a US ED I would imagine) – without much improvement in their -LR (0.53 vs 0.48). For PE, the -LR of POCUS was predictably mediocre if not outright bad (0.6), while the -LR for ED diagnosis of PE, with the benefit of chest CT, was -0.10.

Now look, I get that these EP’s were quite sono-savvy. They all had 2+ years of experience, over 80 hours of ultrasound lessons & training, with at least 150 lung and 150 ED echo’s under their belt. The diagnosis was made in 24 minutes with POCUS in comparison to 186 minutes for traditional means. And while most of us can not do a year+ ultrasound fellowship, and neither can we all be as savvy with the probe as these authors (or Matt, Mike, Jacob, Resa, Laleh, etc) – it does not mean we shouldnt try. You can still greatly increase your yield just by practicing. To boot, the cognitive offload you experience by saving yourself a few hours by (correctly!) knowing which direction you are heading with a patient is an immense boon to both your mental heath & your patients well being.

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Improving Throughput, Mythbusting

More No-Value Care: pre-procedure INR for cirrhotics

You have a cirrhotic patient in front of you. They need a procedure. You reflexively order a cbc, comprehensive metabolic panel, and PT/INR because you’d like to know about their platelets/ liver enzymes / coagulation ability.

Or maybe it’s a consultant who refuses to do a procedure the patient needs until you order these tests.

And then the platelets come back at 40; or maybe the INR returns at 1.4. Now what?

Do we need to transfuse platelets or FFP? Well, this case series looked at 852 consecutive cirrhotics from Jan ’11 – March ’14 who needed an invasive procedure the decision to transfuse PLT / FFP at attending discretion. Here’s a breakdown of their patient demographics:

screen-shot-2017-02-18-at-7-47-52-pm

And the number of complications:

screen-shot-2017-02-18-at-7-48-04-pm

Now, sadly, despite discussing the World Health Organization classification for bleeding events, they did not really get into the severity of bleeding events. With that said, complications were unrelated to platelet count, INR, CHILD classes, and MELD score. Only 1 in 379 paracentesis had a bleeding event, and only 2 of 228 TIPS/ CVC/ PICC/ hemodialysis/ I&D procedures had an event.

Perhaps most importantly, while attempts to normalized PLT and INR values, PLT/FFP transfusions barely affected the corresponding abnormalities, the scheduled invasive investigations were carried out in the presence of still subnormal parameters- with no or only a few bleeding complications.

Ergo, I agree with the authors, – “we have verified clinically the futility of this recommendation.”

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