Tox Screens =========== 1. Ashbourne JF, Olson KR, Khayam-Bashi H Value of rapid screening for acetaminophen in all patients with intentional drug overdose Ann Emerg Med 1989; 18 1035-8 We performed a prospective study to determine the incidence of missed, potentially toxic acetaminophen poisoning in all patients with any type of intentional drug ingestion presenting to two large, county hospital emergency departments. Of 486 patients with drug ingestion seen during a five-month period, 114 (23.5%) were suspected of having ingested acetaminophen. Of these, 71 (62.3%) had insignificant acetaminophen levels (false-positive history). Of the 365 patients who were not suspected of having acetaminophen ingestion, seven patients (1.9%) were found to have elevated levels on rapid screening (false-negative history). Of these, only one patient had a potentially hepatotoxic level. We conclude that the incidence of missed, potentially serious acetaminophen overdose is very low in our study population. *** Drug company foorah to sell the rapid test. 2. Brett AS Implications of discordance between clinical impression and toxicology analysis in drug overdose Arch Intern Med 1988; 148 437-41 Two hundred nine cases of intentional drug overdose were reviewed to determine the importance of discordance between drugs identified by toxicology analysis and those suspected clinically. The laboratory agreed exactly with the clinical impression in 47% of cases. Clinically unsuspected drugs were identified by the laboratory in 27% of cases; the characteristics of these patients did not differ significantly from those of other patients. Unexpected toxicology findings led to changes in therapy in only three cases, and none of these changes appeared to have a major impact on outcome. Although routine comprehensive toxicology screening frequently may identify unsuspected drugs, it is likely that a policy of more selective use of the laboratory would not compromise the care of patients with drug overdose. *** A very poor study -- but bottom line is that drugs screens made little clinical difference. --KC 3. Henneman PL, Mendoza R, Lewis RJ Prospective evaluation of emergency department medical clearance [see comments] Ann Emerg Med 1994; 24 672-7 STUDY OBJECTIVE: To analyze a standardized medical evaluation of alert, adult emergency department patients with new psychiatric symptoms. DESIGN: Prospective, descriptive case series. SETTING: Urban, county hospital. PARTICIPANTS: One hundred consecutive, alert patients, aged 16 to 65 years, seen over 9 months, with new psychiatric symptoms. Excluded patients included those with obvious alcohol or drug intoxication, psychiatric patients with previously diagnosed abnormal behavior, psychiatric patients with medical complaints, and overdose or suicide patients. INTERVENTIONS: The following evaluation was performed: medical history, physical examination, complete blood count, SMA-7 (electrolytes, blood urea nitrogen, creatinine, and glucose), prothrombin time, calcium, oxygen saturation, creatine phosphokinase (CPK) if there was possible myoglobulinuria, alcohol level, urine drug screen (for cocaine, amphetamine, and phencyclidine), cranial computed tomography, lumbar puncture if febrile, and psychiatric evaluation when appropriate. Results were considered significant when they diagnosed the cause of the symptoms or resulted in medical admission. RESULTS: Sixty-three of the 100 patients had an organic etiology of their symptoms. The medical history was significant in 27, physical examination in 6, CBC in 5, SMA-7 in 10, CPK in 6, alcohol and drug screen in 28, computed tomography scan in 8, and lumbar puncture in 3. CONCLUSION: Most alert, adult patients with new psychiatric symptoms have an organic etiology. We recommend performing a medical history, physical examination, SMA-7, calcium, CPK if there is possible myoglobinuria, alcohol and drug screens, computed tomography scan, and lumbar puncture as part of the medical clearance of these patients. *** A bunch of unwarranted conclusions from an extremely poor, uncontrolled study with unclear objectives. 4. Olshaker JS, Browne B, Jerrard DA, Prendergast H, Stair TO Medical clearance and screening of psychiatric patients in the emergency department Acad Emerg Med 1997; 4 124-8 OBJECTIVES: To study the frequency of medical complaints and need for routine ED medical, laboratory, and toxicologic clearance for patients presenting with psychiatric chief complaints. METHODS: A retrospective, observational analysis of psychiatric patients seen in an urban teaching hospital ED over a 2-month period was performed. The individual sensitivities of history, physical examination, vital signs, and complete blood counts and chemistry panels for identifying medical problems were determined. The sensitivities and predictive values of patient self-reporting of recent illicit drug and ethanol use were also determined. RESULTS: 352 patients were seen with psychiatric chief complaints. A complete data set was available for 345 patients (98%). Of those with complete data, 65 (19%) had medical problems of any type. History, physical examination, vital signs, and laboratory testing had sensitivities of 94%, 51%, 17%, and 20%, respectively, for identifying these medical problems. Screening without universal laboratory testing would have missed 2 asymptomatic patients with mild hypokalemia. Patient self-reporting had a 92% sensitivity, a 91% specificity, an 88% positive predictive value (PPV), and a 94% negative predictive value (NPV) for identifying those with a positive drug screen, and a 96% sensitivity, an 87% specificity, a 73% PPV, and a 98% NPV for identifying those with a positive ethanol level. CONCLUSION: The vast majority of medical problems and substance abuse in ED psychiatric patients can be identified by initial vital signs and a basic history and physical examination. Universal laboratory and toxicologic screening of all patients with psychiatric complaints is of low yield. *** A weak study, but argues somewhat that a good H+P is what you need, not a set of lab work. However, didn't look at good H+P with labwork based on this vs. a simple protocol. 5. Sporer KA, Khayam-Bashi H Acetaminophen and salicylate serum levels in patients with suicidal ingestion or altered mental status Am J Emerg Med 1996; 14 443-6 Is universal screening of acetaminophen (APAP) and salicylate (SAL) necessary in patients with a suicidal ingestion or an altered mental status and suspected ingestion? This descriptive, retrospective chart review in an emergency department in a large urban county hospital examined all patients who presented with a history of suicidal ingestion or an altered mental status with a strong suspicion of ingestion from January 1992 through October 1993. APAP and SAL serum levels were measured in 1,820 patients, and charts of patients with APAP serum levels of > 1 microgram/mL or SAL serum levels of > 1 mg/dL were reviewed. The patient's history of ingesting APAP or SAL was recorded, as well as the clinician's interpretation of that level. Sixteen charts were not available. APAP levels of > 1 microgram/mL were found in 175 (9.6%) patients, 120 (6.5%) of whom were APAP history- positive and 55 (3%) APAP history-negative. None of the APAP history- negative group required therapy with N-acetylcysteine. Eight (0.3%) of the APAP history-negative group had potentially toxic levels of > 50 micrograms/mL. SAL levels of > 1 mg/dL were found in 155 (8.5%) patients, 44 (2.5%) of whom were SAL history-positive and 111 (6%) SAL history-negative. Three patients were SAL history-negative but had a significant chronic SAL intoxication. All these patients presented with an altered mental status and had an anion gap of > 20 mEq/L. Universal screening found that 0.3% of suicidal ingestions had a potentially toxic APAP intoxication not suggested by history. This incidence of infrequent but potentially life: threatening overdose should prompt clinicians to screen all of their patients with a suspected ingestion. Salicylate screening found that 0.16% of suicidal ingestions had a toxic SAL intoxication not suggested by history, although such intoxication should be suggested by an elevated anion gap and an altered mental status. Since this less severe intoxication is less frequent and usually suggested by commonly obtained laboratory data, universal screening is not indicated, but a more selective approach to screening could be taken.