Diagnostic accuracy of diaphragm ultrasound to predict weaning outcome: A systematic review and meta-analysis.

BACKGROUND: The accuracy of diaphragm ultrasound for predicting weaning outcome is still debated, despite the publication of numerous studies evaluating this issue. OBJECTIVE: The aim of this systematic review and meta-analysis was to assess the diagnostic accuracy of diaphragm ultrasound for predicting weaning failure in critically ill patients. DESIGN AND DATA SOURCES: MEDLINE, Science direct, Cochrane Library, EMBASE and CENTRAL were searched. Two investigators independently selected studies that met the inclusion criteria, and three extracted data and performed a bias analysis using the Quality Assessment of Diagnostic Accuracy Studies-2 instrument. A bivariate model was used to estimate the pooled results for sensitivity, specificity and diagnostic odds ratio. Sources of heterogeneity were explored, and subgroup analyses were performed. RESULTS: Twenty-eight studies were included in the systematic review, from which 16 studies (816 patients in total) were included in the meta-analysis. The pooled sensitivity, specificity and area under the summary receiver operator characteristic curve were 0.70 (95% CI 0.57-0.80), 0.84 (95% CI 0.73-0.91), and 0.82 (95% Cl 0.78-0.85) for diaphragm thickening fraction, respectively, and 0.71 (95% CI 0.61-0.79), 0.80 (95% CI 0.73-0.86), and 0.82 (95% Cl 0.79-0.86) for diaphragm excursion, respectively. There was substantial heterogeneity among the studies. Meta-regression highlighted significant effects of prevalence of extubation failure, cut-off and risk of bias in flow and timing of the study on diaphragm ultrasound accuracy. By excluding outlier and influential studies, sensitivity was lower and specificity higher for diaphragm thickening fraction. CONCLUSION: The specificity of diaphragm ultrasound for predicting the risk of extubation failure in critically ill patients was moderate-to-high. However, sensitivity was low because weaning is also affected by non-diaphragm-related factors. Further research in subgroups of critically ill patients applying a homogeneous definition of weaning and uniformly conducted measure is needed to assess the accuracy of diaphragm ultrasound. CLINICAL TRIAL REGISTRATION: Registered on http://www.crd.york.ac.uk/PROSPERO as CRD42017058028. Tweetable abstract: Diaphragm ultrasound predicts extubation failure with high specificity. Absence of diaphragm dysfunction does not imply no risk of extubation failure.

Diagnostic Accuracy of Seven Commercial Assays for Rapid Detection of Group A Rotavirus Antigens.

Seven commercial immunochromatographic assays intended for the detection of group A rotavirus antigens in human stool samples were evaluated. These assays showed similar levels of diagnostic accuracy and were suitable for the detection of rotavirus in patients with acute gastroenteritis but missed some asymptomatic rotavirus shedding identified by real-time reverse transcription-PCR.

N-acetylaspartate/creatine and choline/creatine ratios in the thalami, insular cortex and white matter as markers of hypertension and cognitive impairment in the elderly.

Our objective was to investigate the influence of hypertension on N-acetylaspartate (NAA) and choline (Cho) ratios in brain tissues in a community-dwelling elderly population. Brain flexibility was also evaluated with regard to the same metabolite ratios. Proton magnetic resonance spectroscopy (MRS) and the Trail Making Test (TMT) were performed in 80 subjects (75.7+/-4 years old) from the Three-City Study. Fifty-eight participants had hypertension. The NAA/creatine (Cr) and Cho/Cr ratios were obtained in the insular cortex, the thalami and the deep periventricular white matter. In addition, the B-A score of the TMT was evaluated. Uni- and multi-variate analyses were performed in order to examine the relationships among these data. In the insula and the thalami of the hypertensive group, NAA/Cr ratios were significantly lower (1.39+/-0.23 and 1.52+/-0.23, respectively; p=0.01) than those in the normotensive control group (1.52+/-0.25 and 1.70+/-0.19, respectively; p<0.0001), whereas no such reduction was observed in the periventricular white matter of older hypertensive brains. Moreover, the NAA or Cho ratios were significantly correlated with the TMT B-A scores at the level of the thalami, insula and periventricular white matter. These statistical results were confirmed by the multivariate analysis. In an elderly population, hypertension leads to a reduction in NAA/Cr ratios in the insula and the thalami, possibly due to a decrease in blood flow through small perforating and cortical arteries. The TMT B-A test appears to be relevant not only for the frontal areas but also for more remote areas such as the thalami, the insula and the deep periventricular white matter.