Appropriateness of Cardiac Troponin Testing: Insights from the Use of TROPonin In Acute coronary syndromes (UTROPIA) Study.

OBJECTIVE: Our objective was to examine the appropriateness of cardiac troponin (cTn) testing among patients with cTn increases. METHODS: This is a planned secondary analysis of the Use of TROPonin In Acute coronary syndromes (UTROPIA, NCT02060760) observational cohort study. Appropriateness of cTn testing was adjudicated for emergency department patients with cTn increases >99th percentile and analyzed using both contemporary and high-sensitivity (hs) cTnI assays according to sub-specialty, diagnoses, and symptoms. RESULTS: Appropriateness was determined from 1272 and 1078 adjudication forms completed for 497 and 422 patients with contemporary and hs-cTnI increases, respectively. Appropriateness of cTnI testing across adjudication forms was 71.5% and 72.0% for cTnI and hs-cTnI, respectively. Compared with emergency physicians, cardiologists were less likely to classify cTnI orders as appropriate (cTnI: 79% vs 56%, P < .0001; hs-cTnI: 82% vs 51%, P < .0001). For contemporary cTnI, appropriateness of 95%, 70%, and 39% was observed among adjudication forms completed by cardiologists for type 1 myocardial infarction, type 2 myocardial infarction, and myocardial injury, respectively; compared with 90%, 86%, and 71%, respectively, among emergency physicians. Similar findings were observed using hs-cTnI. Discordance in appropriateness adjudication forms occurred most frequently in cases of myocardial injury (62% both assays) or type 2 myocardial infarction (cTnI 31%; hs-cTnI 23%). CONCLUSIONS: Marked differences exist in the perception of what constitutes appropriate clinical use of cTn testing between cardiologists and emergency physicians, with emergency physicians more likely to see testing as appropriate across a range of clinical scenarios. Discordance derives most often from cases classified as myocardial injury or type 2 myocardial infarction.

Hypoglycemia as a complication of intravenous insulin to treat hyperkalemia in the emergency department.

INTRODUCTION: Complications associated with the emergency department (ED) management of hyperkalemia are not well characterized. The goals of this study were to describe the frequency of hypoglycemia following the use of insulin to shift potassium intracellularly and to examine the association of key variables with this complication. METHODS: Adult ED patients (≥18 years old) with hyperkalemia (>5.3 mmol/L) were identified in the electronic medical record over a 5-year period at the study site. Patient characteristics, laboratory results, and treatments in the ED were captured. A generalized estimating equation (GEE) model was utilized to determine independent associations with the development of hypoglycemia. RESULTS: 1307 encounters were identified where hyperkalemia was present. Hypoglycemia (defined as a glucose <70 mg/dL) occurred in 68/409 (17%) of patients given insulin, compared to 4% of patients who did not receive insulin. Lower glucose prior to insulin (adjusted odds ratio [aOR] 0.90; 95% confidence interval [95% CI] 0.85 to 0.96), higher doses of insulin (aOR 1.07; 95% CI 1.01 to 1.15) and lower doses of D50 (aOR 0.98; 95% CI 0.97 to 0.99) were independently associated with hypoglycemia in the multivariate analysis. Age, history of diabetes, and history renal failure were not independently associated. CONCLUSION: Hypoglycemia is a frequent complication of treatment with IV insulin in the ED. Interventions such as standardized protocols to assist with the ED management of hyperkalemia should be developed; their efficacy and safety should be compared.

Diagnostic Performance of High Sensitivity Compared with Contemporary Cardiac Troponin I for the Diagnosis of Acute Myocardial Infarction.

BACKGROUND: We examined the diagnostic performance of high-sensitivity cardiac troponin I (hs-cTnI) vs contemporary cTnI with use of the 99th percentile alone and with a normal electrocardiogram (ECG) to rule out acute myocardial infarction (MI) and serial changes (deltas) to rule in MI. METHODS: We included consecutive patients presenting to a US emergency department with serial cTnI onclinical indication. Diagnostic performance for acute MI, including MI subtypes, and 30-day outcomes were examined. RESULTS: Among 1631 patients, MI was diagnosed in 12.9% using the contemporary cTnI assay and in 10.4% using the hs-cTnI assay. For ruling out MI, contemporary cTnI ≤99th percentile at 0, 3, and 6 h and a normal ECG had a negative predictive value (NPV) of 99.5% (95% CI, 98.6-100) and a sensitivity of 99.1% (95% CI, 97.4-100) for diagnostic and safety outcomes. Serial hs-cTnI measurements ≤99th percentile at 0 and 3 h and a normal ECG had an NPV and sensitivity of 100% (95% CI, 100-100) for diagnostic and safety outcomes. For ruling in MI, contemporary cTnI measurements had specificities of 84.4% (95% CI, 82.5-86.3) at presentation and 78.7% (95% CI, 75.4-82.0) with serial testing at 0, 3, and 6 h, improving to 89.2% (95% CI, 87.1-91.3) by using serial cTnI changes (delta, 0 and 6 h) >150%. hs-cTnI had specificities of 86.9% (95% CI, 85.1-88.6) at presentation and 85.7% (95% CI, 83.5-87.9) with serial testing at 0 and 3 h, improving to 89.3% (95% CI, 87.3-91.2) using a delta hs-cTnI (0 and 3 h) >5 ng/L. CONCLUSIONS: hs-cTnI and contemporary cTnI assays are excellent in ruling out MI following recommendations predicated on serial testing and the 99th percentile with a normal ECG. For ruling in MI, deltas improve the specificity. ClinicalTrials.gov Identifier: NCT02060760.

Type 1 and 2 Myocardial Infarction and Myocardial Injury: Clinical Transition to High-Sensitivity Cardiac Troponin I.

BACKGROUND: Studies addressing patients with type 2 myocardial infarction and myocardial injury, including the impact of using high-sensitivity (hs) cardiac troponin (cTn) assays on their incidence are needed. METHODS: Ours is a prospective, observational US cohort study. Consecutive emergency department patients with serial cTnI measurements were studied. Outcomes included 180-day mortality and major adverse cardiac events, including 2-year follow-up for those with myonecrosis. RESULTS: Among 1640 patients, using a contemporary cTnI assay, 30% (n = 497) had ≥1 cTnI >99th percentile, with 4.7% (n = 77), 8.5% (n = 140), and 17% (n = 280) classified as type 1 myocardial infarction, type 2 myocardial infarction, and myocardial injury, respectively. Compared with patients without myonecrosis, 180-day mortality was higher for type 2 myocardial infarction (4% vs 13%, P < .0001) (adjusted hazard ratio 2.7; 95% confidence interval, 1.6-4.8; P = .0005) and myocardial injury (4% vs 11%, P < .0001) (adjusted hazard ratio 1.8; 95% confidence interval, 1.1-3.0; P = .02), both with mortality >20% at 2 years. Predictors of 2-year mortality for type 2 myocardial infarction included age, congestive heart failure, and beta-blockers. Relative to the contemporary cTnI assay, hs-cTnI had less myonecrosis (30% vs 26%, P = .003) and acute myocardial infarction (13.2% vs 10.8%, P = .032), including fewer type 2 myocardial infarctions (8.5% vs 6.3, P = .01), with no difference in myocardial injury (17% vs 15%, P = .1). CONCLUSIONS: cTnI increases are encountered in approximately a third of patients, the majority due to nonatherothrombotic conditions. Compared with patients without myonecrosis, type 2 myocardial infarction and myocardial injury have worse short-term outcomes, with mortality rates >20% at 2 years. hs-cTnI assay does not lead to more myocardial injury or infarction.

Discordance between ICD-Coded Myocardial Infarction and Diagnosis according to the Universal Definition of Myocardial Infarction.

BACKGROUND: International Classification of Diseases (ICD) coding is the standard diagnostic tool for healthcare management. At present, type 2 myocardial infarction (T2MI) classification by the Universal Definition of Myocardial Infarction (MI) remains ignored in the ICD system. We determined the concordance for the diagnosis of MI using ICD-9 coding vs the Universal Definition. METHODS: Cardiac troponin I (cTnI) was measured by both contemporary (cTnI) and high-sensitivity (hs-cTnI) assays in 1927 consecutive emergency department (ED) patients [Use of TROPonin In Acute coronary syndromes (UTROPIA) cohort] who had cTnI ordered on clinical indication. All patients were adjudicated using both contemporary and hs-cTnI assays. The Kappa index and McNemar test were used to assess concordance between ICD-9 code 410 and type 1 MI (T1MI) and type 2 MI (T2MI). RESULTS: Among the 249 adjudicated MIs using the contemporary cTnI, only 69 (28%) were ICD-coded MIs. Of 180 patients not ICD coded as MI, 34 (19%) were T1MI and 146 (81%) were T2MI. For the ICD-coded MIs, 79% were T1MI and 21% were T2MI. A fair Kappa index, 0.386, and a McNemar difference of 0.0892 (P < 0.001) were found. Among the 207 adjudicated MIs using the hs-cTnI assay, 67 (32%) were ICD coded as MI. Of the 140 patients not ICD coded as MI, 27 (19%) were T1MI and 113 (81%) were T2MI. For the ICD-coded MIs, 85% were T1MI and 15% T2MI. A moderate Kappa index, 0.439, and a McNemar difference of 0.0674 (P < 0.001) were found. CONCLUSIONS: ICD-9-coded MIs captured only a small proportion of adjudicated MIs, primarily from not coding T2MI. Our findings emphasize the need for an ICD code for T2MI.

Awakening and withdrawal of life-sustaining treatment in cardiac arrest survivors treated with therapeutic hypothermia*.

OBJECTIVES: To characterize the prevalence of withdrawal of life-sustaining treatment, as well as the time to awakening, short-term neurologic outcomes, and cause of death in comatose survivors of out-of-hospital resuscitated cardiopulmonary arrests treated with therapeutic hypothermia. DESIGN: Single center, prospective observational cohort study of consecutive patients with out-of-hospital cardiopulmonary arrests. SETTING: Academic tertiary care hospital and level one trauma center in Minneapolis, MN. PATIENTS: Adults with witnessed, nontraumatic, out-of-hospital cardiopulmonary arrests regardless of initial electrocardiographic rhythm with return of spontaneous circulation who were admitted to an ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The study cohort included 154 comatose survivors of witnessed out-of-hospital cardiopulmonary arrests who were admitted to an ICU during the 54-month study period. One hundred eighteen patients (77%) were treated with therapeutic hypothermia. The mean age was 59 years, 104 (68%) were men, and 83 (54%) had an initial rhythm of ventricular tachycardia or fibrillation. Only eight of all 78 patients (10%) who died qualified as brain dead; and 81% of all patients (63 of 78) who died did so after withdrawal of life-sustaining treatment. Twenty of 56 comatose survivors (32%) treated with hypothermia who awoke (as defined by Glasgow Motor Score of 6) and had good neurologic outcomes (defined as Cerebral Performance Category 1-2) did so after 72 hours. CONCLUSIONS: Our study supports delaying prognostication and withdrawal of life-sustaining treatment to beyond 72 hours in cases treated with therapeutic hypothermia. Larger multicenter prospective studies are needed to better define the most appropriate time frame for prognostication in comatose cardiac arrest survivors treated with therapeutic hypothermia. These data are also consistent with the notion that a majority of out-of-hospital cardiopulmonary arrest survivors die after a decision to withdrawal of life-sustaining treatment and that very few of these survivors progress to brain death.

Interunit handoffs of patients and transfers of information: a survey of current practices.

STUDY OBJECTIVE: We describe the current state of emergency department to inpatient handoffs and assess handoff best practices between emergency physicians and hospitalist medicine physicians. METHODS: A survey was distributed electronically to emergency medicine and internal medicine physicians at 10 hospitals across the United States. Descriptive and quantitative analysis was performed on survey results. Additionally, qualitative data were obtained from an expert focus group of both emergency medicine and hospital medicine clinicians. RESULTS: Seven hundred fifty of 1,799 physicians (42.2%) responded to our Web-based survey. Attending physicians (45%) described themselves as practicing emergency medicine (51%) or internal medicine (56%). Responding residents were 55% internal medicine, 43% emergency medicine, and 13% dual emergency medicine/internal medicine. Of the responding departments, use of standardized tools was reported by less than 20% and only one third of residents reported formal handoff training. Handoff factors identified as important include identifying "high-risk" patients, designating uninterrupted time to perform the handoff, and standardizing information provided during the handoff. Qualitative results mirrored these themes and acknowledged the importance of bedside handoffs. CONCLUSION: To our knowledge, this is the largest multispecialty survey to date, including both resident and attending physicians in emergency medicine and hospital medicine. Standardized tools are rarely used and training of residents in this critical task is uncommon. Physicians in both specialties agree on the important content and structure of handoff, including the ideal situation of face-to-face bedside discussion. A curriculum and assessment tool for this practice should be developed.

Point-of-care ultrasound to estimate central venous pressure: a comparison of three techniques.

OBJECTIVE: To determine the most accurate predictor of central venous pressure among three point-of-care venous ultrasound techniques. DESIGN: Cross-sectional study. SETTING: Medical ICU in an academic medical center. PATIENTS: Convenience sample of 67 spontaneously breathing patients who had an intrathoracic central venous catheter to allow measurement of central venous pressure. INTERVENTION: Measurement of the internal jugular vein height to width ratio (aspect ratio), the inferior vena cava diameter, and the percent collapse of the inferior vena cava with inspiration (collapsibility index) by ultrasound. MEASUREMENTS AND MAIN RESULTS: Complete data for analysis were available in 65 patients, as the inferior vena cava could not be visualized in two patients. A central venous pressure of 10 mm Hg was chosen a priori as a clinically significant cutoff. The range of central venous pressure values was 1-23 mm Hg with a median value of 7 mm Hg. The maximal inferior vena cava diameter correlated moderately with central venous pressure (R = 0.58), whereas the inferior vena cava collapsibility index and the internal jugular vein aspect ratio showed poor correlation (R = 0.16 and 0.21, respectively). The area under the receiver operating characteristics curve (area under the curve) to discriminate a low central venous pressure (< 10 mm Hg) was 0.91 for inferior vena cava diameter (95% confidence interval 0.84-0.98), which was significantly higher than the internal jugular vein aspect ratio (area under the curve 0.76; 95% confidence interval 0.65-0.89) or the inferior vena cava collapsibility index (area under the curve 0.66; 95% confidence interval 0.51-0.80) (p = 0.0001). An inferior vena cava diameter < 2 cm predicted a central venous pressure < 10 mm Hg with a sensitivity of 85% (95% confidence interval 69% to 94%), specificity of 81% (95% confidence interval 60% to 93%), and positive predictive value of 87% (95% confidence interval 71% to 95%). Inferior vena cava collapsibility index was not an independent predictor of central venous pressure after adjusting for inferior vena cava diameter in a multiple linear regression model. CONCLUSION: Among spontaneously breathing patients largely without vasopressor support, the maximal inferior vena cava diameter is a more robust estimate of central venous pressure than the inferior vena cava collapsibility index or the internal jugular vein aspect ratio.