Global research highlights - March 2019

Every quarter, the African Journal of Emergency Medicine, in partnership with several other regional emergency medicine journals, publishes abstracts from each respective journal. Abstracts are not necessarily linked to open access papers, but where green access is available it is linked to.  Click 'Read More' to read further.

Oral Ondansetron Administration to Nondehydrated Children With Diarrhea and Associated Vomiting in Emergency Departments in Pakistan: A Randomized Controlled Trial
From: Friedman SB, et al. Ann Emerg Med. 2019;73(3):255-265
Study objective
We determine whether single-dose oral ondansetron administration to children with vomiting as a result of acute gastroenteritis without dehydration reduces administration of intravenous fluid rehydration.
Methods
In this 2-hospital, double-blind, placebo-controlled, emergency department-based, randomized trial conducted in Karachi Pakistan, we recruited children aged 0.5 to 5.0 years, without dehydration, who had diarrhea and greater than or equal to 1 episode of vomiting within 4 hours of arrival. Patients were randomly assigned (1:1), through an Internet-based randomization service using a stratified variable-block randomization scheme, to single-dose oral ondansetron or placebo. The primary endpoint was intravenous rehydration (administration of ≥20 mL/kg of an isotonic fluid during 4 hours) within 72 hours of randomization.
Results
Participant median age was 15 months (interquartile range 10 to 26) and 59.4% (372/626) were male patients. Intravenous rehydration use was 12.1% (38/314) and 11.9% (37/312) in the placebo and ondansetron groups, respectively (odds ratio 0.98; 95% confidence interval [CI] 0.60 to 1.61; difference 0.2%; 95% CI of the difference -4.9% to 5.4%). Bolus fluid administration occurred within 72 hours of randomization in 10.8% (34/314) and 10.3% (27/312) of children administered placebo and ondansetron, respectively (odds ratio 0.95; 95% CI 0.56 to 1.59). A multivariable regression model fitted with treatment group and adjusted for antiemetic administration, antibiotics, zinc prerandomization, and vomiting frequency prerandomization yielded similar results (odds ratio 0.91; 95% CI 0.55 to 1.53). There was no interaction between treatment group and age, greater than or equal to 3 stools in the preceding 24 hours, or greater than or equal to 3 vomiting episodes in the preceding 24 hours.
Conclusion
Oral administration of a single dose of ondansetron did not result in a reduction in intravenous rehydration use. In children without dehydration, ondansetron does not improve clinical outcomes.
​Reproduced with permission

---

Sex-specific high-sensitivity cardiac Troponin T cut-off concentrations for ruling out acute myocardial infarction with a single measurement
From: McRae A, et al. CJEM. 2019;21(1):26-33
Background
Sex-specific diagnostic cutoffs may improve the test characteristics of high-sensitivity troponin assays for the diagnosis of myocardial infarction (MI). The objective of this study was to quantify test characteristics of sex-specific cutoffs of a single hs-cTnT assay for 7-day MI in patients with chest pain. 
Methods
This observational cohort study included consecutive ED patients with suspected cardiac chest pain from four Canadian EDs who had a hs-cTnT assay performed within 60 minutes of ED arrival. The primary outcome was MI at 7 days. We quantified test characteristics (sensitivity, negative predictive value, likelihood ratios and proportion of patients ruled out) for multiple combinations of sex-specific rule-out cutoffs. We calculated the net reclassification index compared to universal rule-out cutoffs.
Results
In 7130 patients (3931 men and 3199 women), the 7-day MI incidence was 7.38% among men and 3.78% among women. Optimal sex-specific cutoffs (<8g/L for men and <7ng/L for women) were 98.5% sensitive for MI and ruled out MI in 55.8% of patients. This would enable an absolute increase in the proportion of patients able to be ruled out with a single hs-cTnT of 13.2-22.2%, depending on the universal rule-out concentration used as a comparator.
Conclusions
Sex-specific hs-cTnT cutoffs for ruling out MI at ED arrival may improve classification performance, enabling more patients to be safely ruled out at ED arrival. However, differences between sex-specific and universal cutoff concentrations are within the variation of the assay, limiting the clinical utility of this approach. These findings should be confirmed in other datasets.
​Reproduced with permission

---

Patients with acute heart failure discharged from the emergency department and classified as low risk by the MEESSI score (multiple risk estimate based on the Spanish emergency department scale): prevalence of adverse events and predictability
From: Miró O, et al. Emergencias. 2019;31:5-14
Objective
To determine the rate of adverse events in patients with acute heart failure (AHF) who were discharged from the emergency department (ED) after classification as low risk according to MEESSI score (multiple risk estimate based on the Spanish ED scale), to analyze the ability of the score to predict events, and to explore variables associated with adverse events.
Methods
Patients in the EAHFE registry (Epidemiology of Acute Heart Failure in EDs) were stratified according to risk indicated by MEESSI score in order to identify those considered at low risk on discharge. All-cause 30-day mortality and revisits related to AHF within 7 days and 30 days were recorded. The area under the receiver operating characteristic curve (AUC) was calculated for the MEESSI score's ability to predict these events. Associations between 42 variables and 7-day and 30-day revisits to the ED were analyzed by multivariable logistic regression.
Results
A total of 1028 patients were included. The 30-day mortality rate was 1.6% (95% CI, 0.9%–2.5%). The 7-day and 30-day revisit rates were 8.0% (95% CI, 6.4%–9.8%) and 24.7% (95% CI, 22.1%–25.7%), respectively. The AUCs for MEESSI score discrimination between patients with and without these outcomes were as follows: 30-day mortality, 0.69 (95% CI, 0.58–0.80); 7-day revisiting, 0.56 (95% CI, 0.49–0.63); and 30-day revisiting, 0.54 (95% CI, 0.50–0.59). Variables associated with 7-day revisits were long-term diuretic treatment (odds ratio [OR], 2.45; 95% CI, 1.01–5.98), hemoglobin concentration less than 110 g/L (OR, 1.68; 95% CI, 1.02–2.75), and intravenous diuretic treatment in the ED (OR, 0.53; 95% CI, 0.31–0.90). Variables associated with 30-day revisits were peripheral artery disease (OR, 1.74; 95% CI, 1.01–3.00), prior history of an AHF episode (OR, 1.42; 95% CI, 1.02–1.98), long-term mineralocorticoid receptor antagonist treatment (OR, 1.71; 95% CI, 1.09–2.67), Barthel index less than 90 points in the ED (OR, 1.48; 95% CI, 1.07–2.06), and intravenous diuretic treatment in the ED (OR, 0.58; 95% CI, 0.40–0.84).
Conclusions
Patients with AHF who are at low risk for adverse events on discharge from our EDs have event rates that are near internationally recommended targets. The MEESSI score, which was designed to predict 30-day mortality, is a poor predictor of 7-day or 30-day revisiting in these low-risk patients. We identified other factors related to these events.
​​Reproduced with permission

---

Comparison of the use of lung ultrasound and chest radiography in the diagnosis of rib fractures: a systematic review
From: Battle C, et al. Emerg Med J. 2019;36(3):185-190
​Introduction
It is well-recognised that the detection of rib fractures is unreliable using chest radiograph. The aim of this systematic review was to investigate whether the use of lung ultrasound is superior in accuracy to chest radiography, in the diagnosis of rib fractures following blunt chest wall trauma.
Methods
The search filter was used for international online electronic databases including MEDLINE, EMBASE, Cochrane and ScienceDirect, with no imposed time or language limitations. Grey literature was searched. Two review authors completed study selection, data extraction and data synthesis/analysis process. Quality assessment using the Quality Assessment of Diagnostic Accuracy Studies Tool (QUADAS-2) was completed.
Results
13 studies were included. Overall, study results demonstrated that the use of lung ultrasound in the diagnosis of rib fractures in blunt chest wall trauma patients appears superior compared with chest radiograph. All studies were small, single centre and considered to be at risk of bias on quality assessment. Meta-analysis was not possible due to high levels of heterogeneity, lack of appropriate reference standard and poor study quality.
Discussion
The results demonstrate that lung ultrasound may be superior to chest radiography, but the low quality of the studies means that no definitive statement can be made.
Reproduced with permission

---