Sharon Klim

Agreement between arterial and transcutaneous PCO2 in patients undergoing non-invasive ventilation

AIM Transcutaneous carbon dioxide (PtCO(2)) monitoring offers a potentially non-invasive and continuous means to determine the arterial carbon dioxide tension (PaCO(2)). ED studies of agreement between PtCO(2) and PaCO(2) have had conflicting findings and have not been targeted to subgroups with severe ventilatory disturbance such as those requiring non-invasive ventilation [NIV]. Our aim is to determine agreement between PtCO(2) and PaCO(2) for patients undergoing NIV for respiratory failure. METHODS This prospective observational study included a convenience sample of patients undergoing NIV for respiratory failure who required arterial blood gas analysis as part of their care. Data collected included patient demographics, indication for NIV, diagnosis, vital signs, and pH, PaCO(2) and PtCO(2). The outcome of interest was agreement between PaCO(2) and PtCO(2). Analysis was made using descriptive statistics, Bland-Altman techniques, Mann-Whitney U test and Fisher/Chi square tests. RESULTS 46 comparisons were analysed. Median age was 69 [IQR 65-79], 67% male; median PaCO(2) 60 mmHg [IQR 46-70] and median pH 7.35 [IQR 7.30-7.38]. Average difference between PaCO(2) and PtCO(2) was 6.1 mmHg with 95% limits of agreement -10.1-22.3 mmHg. Thirty seven comparisons [80%] were within 10 mmHg [95% CI 66-90%]. Difference >10 mmHg was associated with increasing PaCO(2) [p = 0.001; median difference 19.6 mmHg, 95% CI 9.2-30.4 mmHg]. All cases with difference >10 mmHg had PaCO(2) > 60 mmHg. CONCLUSION In patients undergoing NIV, agreement between PaCO(2) and PtCO(2) was sub-optimal, with unacceptably wide 95% limits of agreement. PtCO(2) cannot be recommended as a substitute for PaCO(2) testing in this group.

Impact of a modified nursing handover model for improving nursing care and documentation in the emergency department: A pre- and post-implementation study

The aim of this study was to evaluate whether implementation of a new nursing handover model led to improved completion of nursing care activities and documentation. A pre- and post-implementation study, using a survey and document audit, was conducted in a hospital ED in Melbourne. A convenience sample of nurses completed the survey at baseline (n = 67) and post-intervention (n = 59), and the audit was completed at both time points. Results showed significant improvements in several processes: handover in front of the patient (P < 0.001), patients contributed and/or listened to handover discussions (P < 0.001), and provision of adequate information about all patients in the department (P < 0.001). Nurses also reported a reduction in omission of vital signs (P = 0.022) during handover. Three hundred sixty-eight medical records were audited in the two study periods: 173 (pre-intervention) and 195 (post-intervention). Statistically significant improvements in the completion of two nursing care tasks and three documentation items were identified. The findings suggest that implementation of a new handover model improved completion of nursing care activities and documentation, and transfer of important information to nurses on oncoming shifts.

Is elevated troponin associated with in-hospital mortality in emergency department patients admitted with chronic obstructive pulmonary disease?

The aim of this study was to determine the prevalence and prognostic value of troponin elevation at emergency department (ED) presentation in patients admitted with an exacerbation of chronic obstructive pulmonary disease (COPD). A retrospective cohort study of ED patients with acute exacerbations of COPD who were admitted to hospital and in whom troponin was assayed at ED presentation. Other data collected included demographics, clinical characteristics, test results, and outcome. Outcome of interest was in-hospital mortality. A total of 252 patients were studied, median age 73 years, 61% men. In-hospital mortality was 4.4% [n=11; 95% confidence interval (CI) 2.5–7.7%]. Seventy-eight patients had elevated troponin of greater than 99th centile (31%, 95% CI 26–37%). Factors independently associated with mortality were troponin elevation [odds ratio (OR) 8.3, 95% CI 1.58–43.7], pH less than 7.2 (OR 12.7, 95% CI 1.86–86.4), and requirement for noninvasive ventilation (OR 8.09, 95% CI 1.61–40.8). In conclusion, troponin elevation is associated with increased in-hospital mortality in ED patients with acute exacerbation of COPD.

Prospective external validation of an accelerated (2-h) acute coronary syndrome rule-out process using a contemporary troponin assay

BackgroundRecently there have been efforts to derive safe, efficient processes to rule out acute coronary syndrome (ACS) in emergency department (ED) chest pain patients. We aimed to prospectively validate an ACS assessment pathway (the 2-Hour Accelerated Diagnostic Protocol to Assess Patients with Chest Pain Symptoms Using Contemporary Troponins as the Only Biomarker (ADAPT) pathway) under pragmatic ED working conditions.MethodsThis prospective cohort study included patients with atraumatic chest pain in whom ACS was suspected but who did not have clear evidence of ischaemia on ECG. Thrombolysis in myocardial infarction (TIMI) score and troponin (TnI Ultra) were measured at ED presentation, 2 h later and according to current national recommendations. The primary outcome of interest was the occurrence of major adverse cardiac events (MACE) including prevalent myocardial infarction (MI) at 30 days in the group who had a TIMI score of 0 and had presentation and 2-h TnI assays <99th percentile.ResultsEight hundred and forty patients were studied of whom 177 (21%) had a TIMI score of 0. There were no MI, MACE or revascularization in the per protocol and intention-to-treat 2-h troponin groups (0%, 95% confidence interval (CI) 0% to 4.5% and 0%, 95% CI 0% to 3.8%, respectively). The negative predictive value (NPV) was 100% (95% CI 95.5% to 100%) and 100% (95% CI 96.2% to 100%), respectively.ConclusionsA 2-h accelerated rule-out process for ED chest pain patients using electrocardiography, a TIMI score of 0 and a contemporary sensitive troponin assay accurately identifies a group at very low risk of 30-day MI or MACE.

Agreement between arterial and venous pH and pCO2 in patients undergoing non-invasive ventilation in the emergency department

Blood gas analysis is an important part of the assessment of ventilatory function in patients with respiratory distress. Traditionally, analysis of arterial blood has been used, but recently, there has been a move towards venous blood gas analysis for selected conditions. Arteriovenous agreement for pH and pCO2 in adult patients undergoing non‐invasive ventilation (NIV) has not been explored to date. The aim of this study was to address this question.

External Validation of the GRACE Freedom from Events Score

AIM Acute coronary syndrome (ACS) is a common life-threatening condition but the majority of patients are at low risk of acute adverse events. In 2005, the GRACE Freedom-from-Event score (GFFES) was developed to identify patients with a low risk of adverse in-hospital events. Our aim was to externally validate this score. METHODS A prospective observational cohort of patients was admitted to a cardiology service with admission diagnoses of chest pain, unstable angina or myocardial infarction (MI). Clinical and investigational data were collected. Defined major adverse cardiac events (MACE) were death, new MI, stroke, acute pulmonary oedema, cardiac arrest or sustained ventricular tachycardia, high degree atrioventricular block, cardiogenic shock, pacemaker or intra-aortic balloon pump insertion, assisted ventilation or new acute renal failure occurring during the index admission. The primary outcome of interest was the predictive performance of the GFFES for MACE, by ROC curve and clinical performance analysis. RESULTS 238 patients were studied; median age 67, 56.7% were male. Seventy-eight patients (32.8%) were classified as low risk by the score (GFFES score≥287). There were no MACE in the low risk group. The AUC for predictive performance of the GFFES was 0.74 (95% CI 0.62-0.86). Sensitivity was 100% (95% CI 71.7-100%), specificity 34.7% (95% CI 28.5-41.3%) and negative predictive value 100% (95% CI 94.2-100%). CONCLUSION In this single site prospective validation, GFFES showed good discrimination, sensitivity and negative predictive value. It may be a useful tool for assigning patients to appropriate levels of care based on risk.

What is the 30-day rate of adverse cardiac events in chest pain patients with ED troponin I assays≤99th centile using a contemporary sensitive assay? An exploratory analysis.

Aim For nonhigh-risk patients who ‘rule out’ for acute coronary syndrome, Australasian guidelines recommend further testing to identify coronary artery disease. Testing is usually performed as an outpatient procedure. This recommendation has not changed with the advent of sensitive biomarker assays. We aimed to determine the 30-day rate of adverse cardiac events in emergency department (ED) chest pain patients without known coronary artery disease who had ED troponin I (TnI) assays⩽99th centile using a contemporary troponin assay, stratified by the Heart Foundation (HF; Australia) risk group. Methods This study is a substudy of a prospective observational study. Clinical and investigational data were collected. The primary outcome of interest was the proportion of patients with ED TnI assays⩽99th centile who suffered a major adverse cardiac event (MACE; myocardial infarction, death, major arrhythmia) within 30 days, stratified by HF risk group. The secondary outcome was the rate of MACE or revascularization in non-HF high-risk patients. Results A total of 460 patients were studied. Among them, 388 had no TnI assay>99th centile. There was one MACE in this group [0.26%, 95% confidence interval (CI) 0.05–1.5%]: a non-ST segment elevation myocardial infarction in an HF high-risk patient. There were no MACEs among nonhigh-risk patients (0%, 95% CI 0–1.5%), and one patient had revascularization (0.4%; 95% CI 0.7–2.2%). Conclusion Among ED patients presenting with suspected acute coronary syndrome, adverse cardiac events at 30 days are rare in nonhigh-risk patients with contemporary TnI assays<99th centile.

What is the Yield of Testing for Coronary Artery Disease after an Emergency Department Attendance with Chest Pain

BACKGROUND Guidelines recommend testing for coronary artery disease (CAD) for emergency department (ED) patients with a negative workup for acute coronary syndrome (ACS). The rationale is that, although myocardial infarction has been ruled out, the presentation could still indicate cardiac ischaemia. Evidence supporting this recommendation is weak. METHODS Planned sub-study of prospective cohort study of ED chest pain patients with a negative ACS workup who were discharged. Primary outcome of interest was occurrence of major adverse cardiac events (MACE) within 30 days. Secondary outcomes were rate of combined MACE or revascularisation and rates and outcome of referral for CAD testing. Analyses were descriptive. RESULTS 742 patients were included; median age 56, 52% male. There were two MACE within 30 days (0.3%; 95% CI 0.07-1%). Two patients had revascularisation without ACS - combined MACE or revascularisation rate 0.5% (95% CI 0.2-1.4%). Seventy-five per cent of patients with adverse events had previously known CAD. There was no statistically significant difference in outcome between those referred for testing and those who were not. Age, TIMI score 0-1 and absence of known CAD performed well as potential discriminators for selective testing. CONCLUSIONS In our study the rate of MACE within 30 days was very low, coronary intervention was rare and most patients with MACE or revascularisation had previously known CAD. For young patients, those without known CAD and those with a low TIMI score, the risk of clinically significant CAD appears to be very low. It adds to the case for abandoning routine testing for CAD.

Asia, Australia and New Zealand Dyspnoea in Emergency Departments (AANZDEM) study: Rationale, design and analysis

Shortness of breath is a common reason for ED attendance. This international study aims to describe the epidemiology of dyspnoea presenting to EDs in the South East Asia‐Pacific region, to compare disease patterns across regions, to understand how conditions are investigated and treated, and to assess quality of care.

Epidemiology, prehospital care and outcomes of patients arriving by ambulance with dyspnoea: An observational study.

BackgroundThis study aimed to determine epidemiology and outcome for patients presenting to emergency departments (ED) with shortness of breath who were transported by ambulance.MethodsThis was a planned sub-study of a prospective, interrupted time series cohort study conducted at three time points in 2014 and which included consecutive adult patients presenting to the ED with dyspnoea as a main symptom. For this sub-study, additional inclusion criteria were presentation to an ED in Australia or New Zealand and transport by ambulance. The primary outcomes of interest are the epidemiology and outcome of these patients. Analysis was by descriptive statistics and comparisons of proportions.ResultsOne thousand seven patients met inclusion criteria. Median age was 74 years (IQR 61-68) and 46.1 % were male. There was a high rate of co-morbidity and chronic medication use. The most common ED diagnoses were lower respiratory tract infection (including pneumonia, 22.7 %), cardiac failure (20.5%) and exacerbation of chronic obstructive pulmonary disease (19.7 %). ED disposition was hospital admission (including ICU) for 76.4 %, ICU admission for 5.6 % and death in ED in 0.9 %. Overall in-hospital mortality among admitted patients was 6.5 %.DiscussionPatients transported by ambulance with shortness of breath make up a significant proportion of ambulance caseload and have high comorbidity and high hospital admission rate. In this study, >60 % were accounted for by patients with heart failure, lower respiratory tract infection or COPD, but there were a wide range of diagnoses. This has implications for service planning, models of care and paramedic training.ConclusionThis study shows that patients transported to hospital by ambulance with shortness of breath are a complex and seriously ill group with a broad range of diagnoses. Understanding the characteristics of these patients, the range of diagnoses and their outcome can help inform training and planning of services.