April 8, 2016

Urine Drug Screen False Positives

Urine drug screens aren't completely useless, but they have a number of limitations. Here is a table where I have compiled all of the false positive causing drugs I could find (pdf):

Update 4/22/2016:
Here are my sources:

I started with this paper which was I originally heard on EM Abstracts (Jan 2011):

Brahm NC, Yeager LL, Fox MD, Farmer KC, Palmer TA.
Commonly prescribed medications and potential false-positive urine drug screens.
Am J Health Syst Pharm. 2010 Aug 15;67(16):1344-50.

Special thanks to Jon Cole from Hennepin who made this fantastic video.

Other sources include:
UMHS Guidelines for Clinical Care May 2009

Standridge JB, Adams SM, Zotos AP.
Urine drug screening: a valuable office procedure.
Am Fam Physician. 2010 Mar 1;81(5):635-40.

Reisfield GM, Haddad J, Wilson GR, Johannsen LM, Voorhees KL, Chronister CW, Goldberger BA, Peele JD, Bertholf RL.
Failure of amoxicillin to produce false-positive urine screens for cocaine metabolite.
J Anal Toxicol. 2008 May;32(4):315-8.

Ly BT, Thornton SL, Buono C, Stone JA, Wu AH.
False-positive urine phencyclidine immunoassay screen result caused by interference by tramadol and its metabolites.
Ann Emerg Med. 2012 Jun;59(6):545-7.
doi: 10.1016/j.annemergmed.2011.08.013

Swift RM, Griffiths W, Cammera P.
False positive urine drug screens from quinine in tonic water.
Addict Behav. 1989;14(2):213-5.

Updates 5/1/2016
Reordered alphabetically
Added lamotragine -> PCP
Geraci MJ, Peele J, McCoy SL, Elias B. Phencyclidine false positive induced by lamotrigine (Lamictal®) on a rapid urine toxicology screen. Int J Emerg Med. 2010 Dec; 3(4): 327–331.

Added a few more -> PCP
Phencyclidine (PCP) Test Systems Executive Summary. Chemistry and Toxicology Devices. FDA
2013 Apr 25, Link.

December 30, 2015

And I Didn't Know It

Inspired by Saurabh Jha:
Not exactly op notes, but some ED limericks I wrote:

Mr. Jones ate some bad guacamole
press on his belly, he shouts "holy moley!"
we did a CT
and what could it be?
then he went for a lap'r'scopic chole

Mrs. Smith was awoke from her nappy
her belly was feeling quite snappy
white count? twasn't high
a fever? tad shy…
but the CT, of course, showed an appy

there once was a man from Bologna
thought he had caught a touch of pneumonia
he seemed like whiner
and he got a d dimer
no PE; just some bad allodynia

Of course the cake goes to:

November 16, 2015

Roc vs Sux Revisited: Cochrane Update

I’m not going to reinvent the wheel, so a sweeping summary:
Traditionally, succinylcholine has been the paralytic of choice for RSI. However, succinylcholine can (rarely) lead to hyperkalemia, particularly in patients with chronic neurological problems.* Proponents of rocuronium for RSI suggest avoiding potentially fatal hyperkalemia by routinely using roc, summarized superbly by Reuben Strayer here. When dosed properly (1.2 mg/kg or higher), time of onset and intubating conditions are equivalent to between rocuronium and succinylcholine.

Defenders suggest that succinylcholine's shorter duration of paralysis is an advantage: if you can’t get the tube, the patient starts breathing. Unless the patient critically desaturates before return to an unparalyzed state:

Note the title of the source of this familiar graph: Critical Hemoglobin Desaturation Will Occur before Return to an Unparalyzed State following 1 mg/kg Intravenous Succinylcholine (Benumof, Dagg, Benumof. Anesthesiology. 1997 Oct;87(4):979-82.)

In the original 2008 Cochrane review, the authors (including Perry & Wells) find that time of onset and intubating conditions are inferior to succinylcholine… when dosed inadequately. Cochrane just released another update and reached the same conclusion with mostly same data, but again, note that when dosed appropriately, rocuronium is just as good as succinylcholine, with a p-value of 1.00.

Of course that’s only 86 patients dosed at 1.2 mg/kg, but the results were identical. The Cochrane authors further find that even some lower doses of rocuronium (down to 0.9 mg/kg) are just as good:

but then come to the same conclusion:

This is a bit odd. When I can’t intubate or ventilate a patient, they don’t nicely wake up in 9 minutes. In fact, more paralysis may even be preferred, particularly to optimize further attempts at mask ventilation, including EGD placement. And more importantly, to stop a panicking, suffocating patient from stopping me from stabbing them in the neck. But the bottom line is that if the succinylcholine has worn off, then they’ve probably already critically desaturated.

A number of Very Smart People (including Rob Huang, Minh Le Cong, Chris Nickson, and Reuben Strayer) have all pointed out that Cochrane is supposed to summarize the data, not editorialize:
There are some situations where I still reach for succinylcholine, primarly when I don’t want to lose my neuro exam for an extra half hour, mostly severe head trauma and status epilepticus. Also, if I can’t get a line or an IO and need to use IM drugs for RSI, rocuronium is probably too dilute.**

Ultimately, this isn't that big deal. Hyperkalemia is bad, but rare. But if we can avoid it without worsening time to onset or intubating conditions, why not?

My biggest problem with rocuronium? It comes in 50 mg vials. One*** great tip I learned from Reuben Strayer : when I ask a nurse for rocuronium, I always clearly specify that I need 2 (or 3) vials.

*Most of which are fairly rare and I (fortunately) don’t need to intubate very frequently. But when that relative zebra is really sick, I have enough on my mind and I don’t want to have to think to hard about which drugs may be dangerous. Note that in MG, you can use succinylcholine but have to use more; you can use a lower dose of rocuronium but a normal dose will just paralyze them longer, which is much safer than me having to remember this whole paragraph and do math when the chips are about to hit the fan.

**Bad day for everyone. Not ideal but I prefer to have my quiver more full than my diaper.

***One of too numerous to count. Read and watch everything at emupdates.com

Special thanks to Minh Le Cong & Reuben Strayer for their prepublication peer review.

Also from Twitter::

October 25, 2015

Tweet-in-Brief: Do the Right Thing

October 21, 2015

Get What You Pay For & Pay for What You Get

This post is co-authored by Seth Trueger & Cedric Dark and also appears on Policy PrescriptionsSee also the related post on Narrow Networks (PolicyRx).

Andrew Sprung and I had a great conversation about Republican presidential candidate Donald Trump's claim that premiums are rising (see the Storify below). Our view: premiums are generally flat. There is a lot of variation around this, mostly geographic, and also largely based on whose premiums you're talking about. Comparing premiums from before Obamacare to today’s is like comparing 1995 and 2015 cell phone plans. [caption id="attachment_5826" align="alignleft" width="300"]Source: Lauren (Flickr/CC) Source: Lauren (Flickr/CC)[/caption] Yes, some people who were insured on the non-group market prior to the ACA saw their premiums go up significantly. But this is a meaningless critique. First, the fraction of people who had non-group plans prior to the ACA is (and still is) pretty small - about 5% in 2011 [source: KFF]. Second, remember that most people who have individual plans only have them for a fairly short period of time; most only enroll in a plan for 6-18 months, such as for a few months while searching for a job and until their next employer-sponsored plan kicks in (see this post for example). And while some were happy with their coverage, remember the two most important caveats to pre-ACA nongroup premiums:
  1. What did these plans cover?
  2. Who didn't these plans cover?
The first of these big problems: people who ostensibly had insurance would find that it didn't help them when they needed it, because they hit annual or lifetime benefits limits; certain medical problems or services weren't covered; or, the insurer cancelled their plan when they made a claim. Even in the best-case situation, remember how frustrating it is to deal with actually getting an insurance claim paid.
"If you think government healthcare is bad, wait until Comcast runs it." - Seth
Personal example #1: I (Seth) had cheap private insurance for a few years in med school after getting kicked off my parents plan well before age 26 (Thanks, Obama) and I paid $60+ a month for essentially useless coverage that didn't really cover anything. Fortunately, I never got sick and I only really needed my insurance to satisfy my school’s requirement (and, maybe, piece of mind. But not really). While we don't know how many people were "happy" with their pre-ACA plan, we can estimate. Per Andrew Sprung, about half of the 16% of people in the non-group market now have grandfathered plans... which is roughly 1/2 of 1/6 of 1/20 of the insurance market, so 1 in 240 insurance plans. The second of these major issues that arises when comparing premiums before and after the ACA: preexisting conditions. How many people were completely blocked from getting insurance because of a preexisting medical problem? And relatedly, how many people were either charged higher premiums because of a preexisting condition? Or, were only given a plan that didn’t cover anything remotely related to their preexisting condition? ("You can buy insurance from us but we won't cover surveillance or treatment for a relapse of your Hodgkin's Lymphoma.") Personal example #2: My (Seth’s) wife was previously charged more (plus had to do a ton of frustrating paperwork) for the preexisting condition of "having a pre-cancerous benign mole removed." Remember: private insurance companies aren’t incentivized to keep us healthy; they are incentivized to keep us healthy until we turn 65. While a small fraction of individuals now pay a little more for their premiums, their insurance actually now has to cover stuff; and, they aren't getting a discount by excluding all the people who have serious health problems (or benign moles). Given all these caveats, it's really remarkable that premiums are pretty much flat at all. Let’s consider one last thing. “Premium price" can mean a lot of things. Is it subsidized or unsubsidized? Subsidized premiums are most likely pretty flat, and are what individuals actually pay. Unsubsidized premiums have gone up, but not by as much as people like Trump claim. I'm the first to admit that probably the biggest question the ACA poses is: will premium subsidies simply cost too much? And so far, it doesn't seem like it.
We have a great review forthcoming from Laura Medford-Davis on this issue. Stay tuned! - Cedric
Premium subsidies are simply the price we pay for insuring millions and millions of Americans in a functioning market for non-group insurance. And let’s not forget the quasi-secret but much, much, larger subsidies we already provide to people insured through their employers. We shouldn’t decry subsidies for insurance bought on the market while spending hundreds of billions of dollars subsidizing employer-sponsored insurance.

October 13, 2015

Narrow Networks: The Result of Competition, not the Barrier

Source: geralt (Pixabay/Public Domain)
Source: geralt (Pixabay/Public Domain)
This post is co-authored by Seth Trueger & Cedric Dark and also appears on Policy Prescriptions. See also the related post on premiums before & after ACA (PolicyRx).

This fantastic article by Dan Diamond in Forbes on Republican presidential candidate Donald Trump’s gibberish on health care during his 60 Minutes interview sparked some great discussion on Twitter – see the Storify below. Dan makes an amazing analogy:
Blaming Obamacare for insurance companies’ behavior is like saying Trump’s responsible for how America nominates its presidents.
Dan’s piece did, however, clumsily brush over one important issue, saying:
Trump has returned time and again to the idea that there’s not enough competition in the health insurance market. And you know what? He’s probably right. More than 40% of the doctor networks available through Obamacare exchanges are narrow network plans. Around half of all hospital networks on ACA plans are narrow networks, too.
This isn’t so much wrong as it is non sequitur. Narrow network plans aren’t evidence of insufficient competition in the health insurance market; narrow network plans are the result of competition and negotiation in the health insurance market.

Insurers try to find the best provider network (providers include both hospitals and doctors, which are negotiated separately) for their plan at the lowest cost, mostly using their enrollees as leverage. Insurers try to negotiate a discount by bringing volume. Plans basically say to providers, “Take this price and look how many patients we will bring you!”

Hospitals and doctors negotiate for the highest prices and the largest volume of patients they can get, leveraging their quality and brand name (i.e. desirability).

The main “market interaction” in the insurer-provider market is defining the network for the plan. This is primarily how premiums and other costs are determined (in addition to deciding which benefits are covered by the plan).

Incidentally, this is pretty much why selling plans across state lines doesn’t magically fix anything. Consider this example.

An insurer in Illinois still has to negotiate a completely separate provider network if it were to try to sell a plan in another state like Indiana or Georgia. That’s where all the work exists. It’s not the regulatory burden; it’s the provider network negotiation.

There is, in fact, a lot of competition in health markets, primarily in the negotiations between insurers and providers. All Obamacare did was make it so that for insurers to complete against each other they had to come up with new ways of making profits while keeping premiums and cost sharing competitive. Instead of the pre-ACA race to see which insurer could exclude the riskiest people, now insurers fight over patients by cutting costs while maintaining required coverage — and the primary way to do that is by narrowing networks and excluding providers that don’t (as Trump would say) “cut a deal.”