Emergency department (ED) patients with symptoms of cardiac ischemia often require a second cardiac troponin (cTn) measurement to rule out non–ST elevation myocardial infarction. We measured the total turnaround time and the component event times following the ordering of the second cTn level to ED discharge to identify root causes of delays.

We reviewed a random sample of ED discharges following a second normal cTn measurement and recorded associated event times. The central tendency of time intervals is reported as median and mean number of minutes with interquartile ranges (IQRs) and 95% confidence intervals, respectively.

From 9,656 eligible cases, we randomly selected 226 for data collection. The median number of minutes for each event are as follows: from ordering the second cTn measurement to the time of ED discharge was 90 minutes (IQR 65–120); for blood collection from the time the collection was ordered for was 0 minutes (IQR 212–0); from blood collection to the time the blood was transported to the laboratory was 9 minutes (IQR 2–19); laboratory process duration was 44 minutes (IQR 39–52); from when the results were available to the time the patient was discharged was 30 minutes (IQR 15–52).

For ED patients discharged following two normal cTn levels, the laboratory processing time and time from the result being available to the time of ED discharge represent the longest modifiable time periods to reduce ED length of stay.

This study assessed the use and clinical yield of diagnostic imaging (radiography, computed tomography, and medical resonance imaging) ordered to assist in the diagnosis of acute neck injuries presenting to emergency departments (EDs) in Kingston, Ontario, from 2002–2003 to 2009–2010.

Acute neck injury cases were identified using records from the Kingston sites of the Canadian National Ambulatory Care Reporting System. Use of radiography was analyzed over time and related to proportions of cases diagnosed with clinically significant cervical spine injuries.

A total of 4,712 neck injury cases were identified. Proportions of cases referred for diagnostic imaging to the neck varied significantly over time, from 30.4% in 2002–2003 to 37.6% in 2009–2010 (ptrend = 0.02). The percentage of total cases that were positive for clinically significant cervical spine injury (“clinical yield”) also varied from a low of 5.8% in 2005–2006 to 9.2% in 2008–2009 (ptrend = 0.04), although the clinical yield of neck-imaged cases did not increase across the study years (ptrend = 0.23). Increased clinical yield was not observed in association with higher neck imaging rates whether that yield was expressed as a percentage of total cases positive for clinically significant injury (p = 0.29) or as a percentage of neck-imaged cases that were positive (p = 0.77).

We observed increases in the use of diagnostic images over time, reflecting a need to reinforce an existing clinical decision rule for cervical spine radiography. Temporal increases in the clinical yield for total cases may suggest a changing case mix or more judicious use of advanced types of diagnostic imaging.

Cognitive forcing strategies (CFS)may reduce error arising from cognitive biases. This is the first experimental test to determine the effect of CFS training in medical students.

Students were allocated to CFS training or control during a 4-week emergency medicine rotation (n = 191). At the end of the rotation examination, students were tested using computer-based cases. Application of CFS could enable reduction of diagnostic error, as evidenced by identifying multiple correct diagnoses for the two cases prone to search satisficing bias (SSB) and uncommon diagnoses for the two cases prone to availability bias (AB). Two “false positive” cases were included to test for possible “oversearching.”

There were 145 students in the intervention and 46 in the control group. For the SSB cases, 52% of students with CFS training and 48% in the control group initiated a search for the second diagnosis (χ2 = 0.13, df = 1, p = 0.91). More than half (54%) correctly identified the second diagnosis in the CFS group, and 48% identified it in the control group. The difference was not significant (χ2 = 2.25, df = 1, p = 0.13). For the second diagnosis in the false positive cases, 64% of the CFS group and 77% of the control group incorrectly identified it. There were no significant differences between groups (χ2 = 2.38, df = 1, p = 0.12). In the AB cases, only 45% in each group identified the uncommon correct diagnosis (χ2 = 0.001, df = 1, p = 0.98).

The educational interventions suggested by experts in clinical reasoning and employed in our study to teach CFS failed to show any reduction in diagnostic error by novices.

Cardiac troponin elevation portends a worse prognosis in diverse patient populations. The significance of troponin elevation in patients discharged from emergency departments (EDs)without inpatient admission is notwell known.

Patients without a diagnosis of acute coronary syndrome discharged fromtwo EDs between April 1, 2006, and December 31, 2007, with an abnormal cardiac troponin (troponin positive [TP]) were compared to a troponin-negative (TN) cohort matched for age, sex, and primary discharge diagnosis. Outcomes were obtained by linking with a regional ED and a provincial vital statistics database and adjusted for the following: estimated glomerular filtration rate, do-not-resuscitate status, history of coronary artery disease, Canadian Triage and Acuity Scale, and left ventricular hypertrophy on electrocardiography. The primary outcome was a composite of death or admission to hospital within 1 year.

Our total cohort (n 5 344) consisted of 172 TP and 172 TN patients. In the univariate analysis, TP patients had a higher rate of the primary outcome (OR 3.2, 95% CI 2.1–5.0, p < 0.001) and both of its components (p < 0.001). After adjusting for covariates, positive troponin remained an independent predictor of the primary outcome (OR 2.1, 95% CI 1.3–3.4, p 5 0.005) and inpatient admission (OR 2.0, 95% CI 1.2–3.4, p 5 0.006). There was no significant difference in death (OR 1.3, 95% CI 0.6–2.9, p 5 0.5) after adjustment.

A positive troponin assay during ED stay in discharged patients is an independent marker for risk of subsequent admission. Our findings suggest that the prognostic power of an abnormal troponin extends to patients discharged from the ED.

Venous thromboembolism (VTE) is difficult to diagnose yet potentially life threatening. A low-risk pretest probability (PTP) assessment combined with a negative Ddimer can rule out VTE in two-thirds of outpatients, reducing the need for imaging. Real-life implementation of this strategy is associated with several challenges.

We evaluated the impact of introducing a standardized diagnostic algorithm including a mandatory PTP assessment and D-dimer on radiologic test use for VTE in our emergency department (ED). A retrospective review of all ED visits for suspected VTE in the year prior to and following the introduction of this algorithm was conducted. VTE diagnosis was based on imaging. Guideline compliance was also assessed.

ED visits were investigated for suspected VTE in the pre- and postintervention periods (n 5 1,785). Most D-dimers (95%) ordered were associated with a PTP assessment, and 50% of visits assigned a low PTP had a negative D-dimer. The proportion of imaging tests ordered for VTE in all ED visits was unchanged postintervention (1.9% v. 2.0%). The proportion of patients with suspected VTE in whom VTE was confirmed on imaging decreased postintervention (10.2% v. 14.1%).

In spite of excellent compliance with our algorithm, we were unable to reduce imaging for VTE. Thismay be due to a lower threshold for suspecting VTE and an increase in investigation for VTE combined with a high false positive rate of our D-dimer assay in low–pretest probability patients. This study highlights two common real-life challenges with adopting this strategy for VTE investigation.

Hemodynamic instability following emergent endotracheal intubation (EETI) is a potentially life-threatening adverse event. The objectives of this systematic literature review were to document the incidence of postintubation hemodynamic instability (PIHI), to determine the definitions for PIHI used in the available literature, and to examine factors associated with PIHI in adult patients who require EETI.

Articles published in Medline (1966–August 2012).

This systematic review included adult, inhospital studies of EETIs. Studies with nonemergent or pediatric patient populations were excluded.

Two authors independently performed data abstraction. Disagreements were resolved by a third party. The methodological quality of included studies was assessed with the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies.

We estimated the pooled prevalence of PIHI across studies using a random effects meta-analysis. Subgroups analyzed included study design, intubation setting, geographic location of the study, physician experience, medications used for sedation, neuromuscular blockade, and definition of PIHI. Eighteen studies were analyzed, with sample sizes from 84 to 2,833 patients. The incidence of PIHI ranged from 5 to 440 cases per 1,000 intubations, with a pooled estimate of 110 cases per 1,000 intubations (95% CI 65–167).

PIHI was found to occur in 110 cases per 1,000 in-hospital, emergent intubations. However, heterogeneity among the included studies limits the reliability of this summary estimate. Further investigation is warranted.