Delta troponin does not distinguish acute coronary syndrome in emergency department patients with renal impairment and an initial positive troponin.

Background: In emergency department (ED) patients with renal impairment, troponin concentrations can be positive without myocardial ischemia. When there is clinical concern for acute coronary syndrome (ACS), guidelines recommend obtaining a delta troponin measurement to identify acute myocardial injury. However, evidence supporting the use of delta troponin to rule in or out ACS in patients with renal impairment and initial elevated troponin levels is limited. Methods: This retrospective, observational study assessed the diagnostic value of a 20% delta troponin cutoff in the prediction of ACS events in ED patients (estimated glomerular filtration rate [eGFR] <60 mL/min/1.72 m2) with renal impairment, clinical concern for ACS, and an initial positive troponin concentration using either conventional troponin (cTnT) or high-sensitivity troponin (hsTnT). Clinical concern for ACS was based on initial ED physician-reported diagnoses. Patients with an initial diagnosis of ST-elevation myocardial infarction were not included. A positive initial troponin was identified at a threshold of ≥0.06 ng/mL for cTnT and ≥52 ng/L for hsTnT, and delta troponin measurements were obtained within 24 h of the initial troponin. The primary composite outcome, termed ACS event, included (1) cardiac-related mortality, (2) coronary revascularization (or its recommendation), or a (3) clinically diagnosed type-1 myocardial infarction within 6 weeks of the ED presentation. Sensitivities, specificities, negative predictive values, positive predictive values, and negative and positive likelihood ratios were calculated for these 6-week ACS events. Results: A total of 608 ED patients with renal impairment, an initial positive troponin, and clinical concern for ACS were included in the study. Of these patients, 234 had an initial positive cTnT (median eGFR 18 mL/min/1.72 m2) and 374 had an initial positive hsTnT (median eGFR 25 mL/min/1.72 m2). The overall ACS event rate was 38% in the cTnT group and 33% in the hsTnT group. In those with a negative delta, the 6-week ACS event rate was 32% when using cTnT, compared to 24% using hsTnT. Conversely, a positive delta was associated with an ACS event rate of 47% when cTnT was utilized versus 61% when hsTnT was utilized. Conclusion: In this study, approximately one-third of ED patients with renal impairment who had an initial positive troponin and clinical concern for ACS developed ACS events at 6 weeks. A delta troponin did not appear to provide clinically meaningful assistance in the prediction or exclusion of 6-week ACS events in this cohort.

Right Ventricular "Bubble Time" to Identify Patients With Right Ventricular Dysfunction.

STUDY OBJECTIVE: We propose a novel method of evaluating right ventricular (RV) dysfunction in the emergency department (ED) using RV "bubble time"-the duration of time bubbles from a saline solution flush are visualized in the RV on echocardiography. The objective was to identify the optimal cutoff value for RV bubble time that differentiates patients with RV dysfunction and report on its diagnostic test characteristics. METHODS: This prospective diagnostic accuracy study enrolled a convenience sample of hemodynamically stable patients in the ED. A sonographer administered a 10-mL saline solution flush into the patient's intravenous catheter, performed a bedside echocardiogram, and measured RV bubble time. Subsequently, the patient underwent a comprehensive cardiologist-interpreted echocardiogram within 36 hours, which served as the gold standard. Patients with RV strain or enlargement of the latter found on an echocardiogram were considered to have RV dysfunction. Bubble time was evaluated by a second provider, blinded to the initial results, who reviewed the ultrasound clips. The primary outcome measure was the optimal cutoff value of RV bubble time that identifies patients with and without RV dysfunction. RESULTS: Of 196 patients, median age was 67 year, and half were women, with 69 (35.2%) having RV dysfunction. Median RV bubble time among patients with RV dysfunction was 62 seconds (interquartile range [IQR]: 52, 93) compared with 21 seconds (IQR: 12, 32) among patients without (P<.0001). The optimal cutoff value of RV bubble time for identifying patients with RV dysfunction was 40 or more seconds, with a sensitivity of 0.97 (95% CI 0.93 to 1.00) and specificity of 0.87 (95% CI 0.82 to 0.93). CONCLUSION: In patients in the ED, an RV bubble time of 40 or more seconds had high sensitivity in identifying patients with RV dysfunction, whereas an RV bubble time of less than 40 seconds had good specificity in identifying patients without RV dysfunction. These findings warrant further investigation in undifferentiated patient populations and by emergency physicians without advanced ultrasound training.

Doppler ultrasound peak systolic velocity versus end tidal carbon dioxide during pulse checks in cardiac arrest.

BACKGROUND: An accurate, non-invasive measure of return of spontaneous circulation (ROSC) is needed to improve management of cardiac arrest patients. OBJECTIVES: During a pulse check in Emergency Department (ED) cardiac arrest patients, we compared the correlation between 1) end tidal carbon dioxide (ETCO2) and systolic blood pressure (SBP), and 2) Doppler ultrasound peak systolic velocity (PSV) and SBP. Additionally, we assessed the accuracy of PSV ≥ 20 cm/sec in comparison to previously suggested ETCO2 ≥ 20 or ≥ 25 mmHg thresholds to predict ROSC with SBP ≥ 60 mmHg. METHODS: This was a secondary analysis of a previously published prospective observational study of ED cardiac arrest patients with an advanced airway and femoral arterial line in place. During each pulse check, highest SBP, highest PSV, and ETCO2 at the end of the pulse check were recorded. Spearman correlation coefficients were calculated and compared using a Fisher Z-transformation. Accuracy of previously determined PSV and ETCO2 thresholds for detecting ROSC with SBP ≥ 60 mmHg were compared using McNemar's tests. RESULTS: Based on data from 35 patients with 111 pulse checks, we found a higher correlation between PSV and SBP than ETCO2 and SBP (0.71 vs 0.31; p < 0.001). Diagnostic accuracy of PSV ≥ 20 cm/sec for detecting ROSC with SBP ≥ 60 mmHg was 89% (95% CI: 82%-94%) versus 59% (95% CI: 49%-68%) and 58% (95% CI: 48%-67%) for ETCO2 ≥ 20 and ≥ 25 mmHg, respectively. CONCLUSIONS: During a pulse check, Doppler ultrasound PSV outperformed ETCO2 for correlation with SBP and accuracy in detecting ROSC with SBP ≥ 60 mmHg.

The Association of Immediate-Use Steam Sterilization with the Incidence of Orthopaedic Surgical Site Infections: A Propensity Score-Matched Cohort Study.

BACKGROUND: Immediate-use steam sterilization (IUSS), formerly termed "flash" sterilization, has been historically used to sterilize surgical instruments in emergency situations. Strict guidelines deter its use, as IUSS has been theorized to increase the risk of surgical site infections (SSIs), leading to increased health-care costs and poor patient outcomes. We sought to examine the association between the use of IUSS and the rate of orthopaedic SSIs. METHODS: The cases of 70,600 patients who underwent orthopaedic surgery-total knee or hip arthroplasty, laminectomy, or spinal fusion-from January 2014 to December 2020, were retrospectively reviewed for IUSS use. Of this group, 3,526 patients had had IUSS used during surgery. A propensity score-matched (PSM) analysis was conducted to account for known predictors of SSIs and included a total of 7,052 patients. The risk difference (RD), relative risk (RR), odds ratio (OR), and McNemar test compared the SSI risk for patients whose procedure had included the use of IUSS and those whose procedure had not included IUSS. RESULTS: After propensity score matching, 111 (1.57%) of the 7,052 matched patients developed an SSI. Of the 111 patients, 61 (54.95%) were in the IUSS group and 50 (45.05%) were in the non-IUSS group. The estimated probability for developing an SSI was 1.42% for the patients in the non-IUSS group versus 1.73% for the patients in the IUSS group (RR = 0.82 [95% confidence interval (CI)]: 0.57 to 1.19], RD = -0.3% [95% CI: -0.9% to 0.27%]).There was no evidence that the proportion of SSI was greater in the IUSS group (McNemar test, p > 0.29). CONCLUSIONS: SSI rates were not significantly different between IUSS and non-IUSS patients undergoing orthopaedic surgery. Future prospective studies are warranted to further explore the utility of IUSS during orthopaedic procedures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.