A recent study by Parmar et al posited that mandatory screening tests provided little value in medically clearing psychiatric patients. (West J Emerg Med 2012; 13:388.) The basis for Parmar's argument is simple: only one of 191 patients (0.5%) who had ancillary testing ordered (a high acetaminophen level) by the psychiatry service resulted in a change in disposition (medicine admission for N-acetylcysteine treatment), and mandatory testing to clear all psychiatric patients medically would be wasteful.
Importantly, the results in Parmar indicate that ancillary testing ordered by the psychiatric service is wasteful, but patients who the EPs felt needed testing to be medically cleared were excluded from the study. The Parmar study did not analyze decision-making of EPs in medically clearing psychiatric patients. But this encapsulates the more interesting question: how did the EP miss the patient with acetaminophen toxicity? That was a bona fide missed diagnosis because the high acetaminophen level prevented the patient from being medically cleared.
The Elephant in the Room: Diagnostic errors were the most common, the most costly, and the most deadly of medical mistakes found in reviewing 25 years of paid medical malpractice claims in the National Practitioner Data Bank. (BMJ Qual Saf 2013 Apr 22 [Epub ahead of print].) This Newman-Toker study found that 28.6 percent (100,249) of the 350,706 paid claims reviewed were caused by diagnostic errors, which were defined as missed, wrong, or delayed diagnoses. Diagnostic errors constituted the largest proportion of paid claims (35.2%), and more often than any other cause resulted in death (40.9%). This study does not analyze why these errors occurred. Another study by Kachalla et al found that 58 percent of missed and delayed diagnoses for 122 closed ED malpractice claims were from failure to order a test; 33 percent were caused by failure to order an adequate consultation. (Ann Emerg Med 2007;49:196.) Cognitive factors — clinical judgment, knowledge, or vigilance or memory — contributed the most to missed diagnosis (96%). Multiple breakdowns were also common, revealing that missed diagnoses were often multifactorial.
So we are in a conundrum. The Parmar study demonstrates that knee-jerk mandatory testing applied to clear all psychiatric patients medically is too costly, but “mandatory” testing prevented missing the patient with a high acetaminophen level. This study minimizes the impact of missing this diagnosis by characterizing it as only 0.5 percent of patients with an abnormal ancillary test, but the cost savings in preventing liver failure, transfer to a transplant center, and possibly avoiding litigation is significant. The Newman-Toker study emphasizes the need to prevent missed diagnoses while the Kachalla study provides insight about the cause of missed diagnoses in emergency medicine: physician cognitive factors, with contribution from multiple external factors.
A Case Example: A patient presented to the County Mental Health Department hospital for treatment of a pre-existing psychotic disorder, and he was referred to the emergency department for medical clearance. (Jackson v. East Bay Hospital, 246 F.3d 1248, C.A.9 [Cal. 2001].) The emergency physician, noting that the patient was experiencing hallucinations, dizziness, and unsteadiness, diagnosed him with acute psychosis after ordering a screening blood test, and arranged follow-up with mental health. Two days later, the patient returned, this time complaining of chest pain, difficulty breathing, and dry heaves. A second emergency physician ordered additional tests, and again the patient was medically cleared with a diagnosis of “chest contusions, hypertension, and psychosis.” (Jackson v. East Bay Hospital, 1252.)
The urine tox screen was positive for tricyclic antidepressants, but the patient's medication list included clomipramine and lorazepam. Early the next morning, the patient's wife brought the patient into the emergency department again because he was wandering in the road agitated. He was given haloperidol and diphenhydramine, and subsequently transferred to a psychiatric hospital. Later that day, the patient went into cardiac arrest and died. Autopsy determined the cause of death as clomipramine toxicity.
The plaintiff in Jackson filed medical negligence and EMTALA claims in federal district court, which found for the defendant hospital. The Ninth Circuit affirmed the district court ruling on appeal, holding that the hospital satisfied EMTALA's screening requirement because the doctors and nurses screened the patient under the hospital's guidelines in a non-disparate manner. The Ninth Circuit acknowledged that negligence might still provide the basis for a medical malpractice claim, but the Ninth Circuit no longer had supplemental jurisdiction on the state-based medical negligence claim because the federal EMTALA claim was dismissed.
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© 2013 by Lippincott Williams & Wilkins