Every test we get should be reasoned and supported by evidence to the best of our ability. Based on that, I haven't seen evidence of the value of an EKG as a screening tool prior to the initiation of an antipsychotic. In the absence of personal or family cardiac history, it's simply not useful. QTc is only a surrogate marker for what we really care about, and there isn't a direct correlation between QT prolongation and incidence of TdP. An EKG can prevent the use of a safe and effective medication, and that would be a problem.
Now here I'm confused. A UDS is useful. It can tell you if patients have or have not taken drugs they do or do not claim to have used (sometimes they lie or exaggerate, sometimes they don't know what they're taking). Sure, it might not help you in the ED, but it helps us figure out what to do on the psych floor, and a UDS can't be delayed or else we'd miss too much.
Ok. So, you're suggesting that we should forgo a reasonable test such as an EKG (which I don't routinely obtain, mind you, but do not get in a huff if it is requested) but *should* obtain a test which is not designed for clinical use?
The UDS is a test battery which is based on preemployment testing needs with a bit of the DoT and SAMHSA thrown in; not clinicians. Furthermore, a "negative" UDS does not exclude drug use (just means you have an inappropriately timed sample OR a drug which is not reliably detected) and a "positive" result does not prove actual drug use.
If you want to argue that the UDS is beneficial for managing dual-diagnosis patients, then fine. However, it does not change ED management in the least; and delaying appropriate psych dispo until the patient urinates is inane. If the patient does not manifest symptoms consistent with ingestion of an illicit substance, then it's not on board to any appreciable extent and ought not change the disposition (with the notable exception of ethanol, but that's not the matter here, and nor is it illicit).
As to your assertion that the EKG is a poor marker for QTc issues, I will agree. However, until someone develops and markets an assay for cardiac iKr polymorphism, and knowing that certain AP's have differing effects on said channel, I feel it's not unreasonable to acquiesce to this request if made (as even manufacturers such as Pfizer recommend one before initiating long-term treatment with ziprasidone).
To your assertion that it would preclude administration of a useful drug, well I disagree. We're not getting EKGs on the ones who need to be treated rapidly, so a priori I will have no knowledge of their QTc & it will not change my decision to use an AP. If you're arguing that it will preclude long-term use of the medication on the back end, well, read the preceding paragraph & confer with your malpractice carrier, then tell me you wouldn't CYA?
tl;dr -
Agree with Birdstrike, we do lots of things that are of questionable utility in the ED proper. Some are CYA, others are beneficial downstream. If something is reasonable, minimally invasive, or minimally risky; then go ahead & do it, if for no other reason than to keep your department moving & your consultants happy. But if there is no good justification for something ridiculous, then call BS on it & fight the good fight.
-d
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