The Inter-Rater Reliability of Pediatric Point-of-Care Lung Ultrasound Interpretation in Children With Acute Respiratory Failure

Pragmatic evaluation of point of care lung ultrasound for the triage of COVID-19 patients using a simple scoring matrix: Intraclass-classification and predictive value

BACKGROUND

The value of routine bedside lung ultrasound (LUS) for predicting patient disposition during visits to the Emergency Department (ED) is difficult to quantify. We hypothesized that a simplified scoring of bedside-acquired LUS images for the triage of acute respiratory symptoms in the ED would be associated with patient disposition.

METHODS

For this observational pragmatic study, we reviewed prospectively-collected bedside LUS images from patients presenting to the ED with acute respiratory symptoms. We agreed on a simplified LUS scoring approach (0-3). At least three reviewers blindly assessed the available LUS images for each patient and determined the worst score for each patient and the presence of individual LUS findings. The worst LUS score was used to classify patients' LUS-suggested hospital admission risk. We evaluated the agreement between reviewers and the predictive value of LUS findings for patient disposition.

RESULTS

204 patients were eligible, and 126 sets of images were available and scored. The most common LUS finding were isolated B-lines (63.5 % of LUS images), pleural thickening/irregularity (48.4 %), and diffuse B-lines (43.7 %). The patients' worst LUS score were 2 (43.5 %), 3 (26.1 %), 1 (20.7 %), and 0 (9.8 %). There was good agreement among reviewers on the worst LUS score (intra-class correlation coefficient 0.830, 95 % confidence interval (0.772-0.875)) and the LUS-suggested disposition (ICC 0.882, 95 % CI (0.846, 0.911)).

CONCLUSION

A simplified scoring of bedside-acquired LUS images from patients with acute respiratory symptoms at the emergency department reliably predicts patient disposition.

Acute Respiratory Failure in Children: A Clinical Update on Diagnosis

Acute respiratory failure (ARF) is a sudden failure of the respiratory system to ensure adequate gas exchanges. Numerous clinical conditions may cause ARF, including pneumonia, obstructive lung diseases (e.g., asthma), restrictive diseases such as neuromuscular diseases (e.g., spinal muscular atrophy and muscular dystrophy), and albeit rarely, interstitial lung diseases. Children, especially infants, may be more vulnerable to ARF than adults due to anatomical and physiological features of the respiratory system. Assessing respiratory impairment in the pediatric population is particularly challenging as children frequently present difficulties in reporting symptoms and due to compliance and cooperation in diagnostic tests. The evaluation of clinical and anamnestic aspects represents the cornerstone of ARF diagnosis: first level exams (e.g., arterial blood gas analysis) confirm and evaluate the severity of the ARF and second level exams help to uncover the underlying cause. Prompt management is critical, with supplemental oxygen, mechanical ventilation, and the treatment of the underlying problem. The aim of this review is to provide a comprehensive summary of the current state of the art in diagnosing pediatric ARF, with a focus on pathophysiology, novel imaging applications, and new perspectives, such as biomarkers and artificial intelligence.

Comparison of chest radiograph and lung ultrasound in children with acute respiratory failure

PURPOSE

Chest x-ray (CXR) is the standard imaging used to evaluate children in acute respiratory distress and failure. Our objective was to compare the lung-imaging techniques of CXR and lung ultrasound (LUS) in the evaluation of children with acute respiratory failure (ARF) to quantify agreement and to determine which technique identified a higher frequency of pulmonary abnormalities.

METHODS

This was a secondary analysis of a prospective observational study evaluating the sensitivity and specificity of LUS in children with ARF from 12/2018 to 02/2020 completed at the University of Wisconsin-Madison (USA). Children > 37.0 weeks corrected gestational age and ≤ 18 years of age admitted to the PICU with ARF were evaluated with LUS. We compared CXR and LUS completed within 6 h of each other. Kappa statistics (k) adjusted for maximum attainable agreement (k/kmax) were used to quantify agreement between imaging techniques and descriptive statistics were used to describe the frequency of abnormalities.

RESULTS

Eighty-eight children had LUS completed, 32 with concomitant imaging completed within 6 h are included. There was fair agreement between LUS and CXR derived diagnoses with 58% agreement (k/kmax = 0.36). Evaluation of imaging patterns included: normal, 57% agreement (k = 0.032); interstitial pattern, 47% agreement (k = 0.003); and consolidation, 65% agreement (k = 0.29). CXR identified more imaging abnormalities than LUS.

CONCLUSIONS

There is fair agreement between CXR and LUS-derived diagnoses in children with ARF. Given this, clinicians should consider the benefits and limitations of specific imaging modalities when evaluating children with ARF. Additional studies are necessary to further define the role of LUS in pediatric ARF given the small sample size of our study.

Comparison of the prognostic value, feasibility, and reproducibility among different scoring methods of 8‑point lung ultrasonography in patients with acute heart failure

There is no strong evidence that one of the B-line quantification approaches is clinically superior to the others, as the use of lung ultrasound (LUS) protocol becomes more commonplace in the treatment of heart failure (HF). This study, thus, aimed to evaluate to the prognostic value, feasibility, and reproducibility for selecting optimal B-line quantification methods. We enrolled patients with HF admitted to the emergency intensive care unit (EICU) in a single-center, prospective, observational study. LUS were performed before EICU discharge, and six B-line quantification methods were used to calculate scores. A total of 71 patients were enrolled. There was a moderately good discriminative value between six quantification methods and the composite outcome. The calibration curve of six B-line quantification methods for the probability of the composite outcome showed good agreement between prediction and observation. Decision curve presented that six B-line quantification methods presented similar net benefits at the entire range of threshold probabilities. Image interpretation time of Quantitative methods 1 and 2 was significantly less than that of other methods. Intraclass correlation coefficients (ICC) for B-pattern scoring systems (Quantitative methods 1 and 2) between two experts demonstrated the excellent level of clinical significance. Despite the similar discrimination, calibration and clinical usefulness, pattern-B scoring systems have the benefit of the feasibility and reproducibility over other methods.

Interrater Reliability of Point-of-Care Cardiopulmonary Ultrasound in Patients With Septic Shock: An Analysis of Agreement Between Treating Clinician and Expert Reviewers

BACKGROUND

Cardiopulmonary ultrasound (CPUS) is commonly used to assess cardiac function and preload status in patients with septic shock. However, the reliability of CPUS findings at the point of care is unknown.

OBJECTIVE

To assess interrater reliability (IRR) of CPUS in patients with suspected septic shock between treating emergency physicians (EPs) vs emergency ultrasound (EUS) experts.

METHODS

Single-center, prospective, observational cohort enrolling patients (n = 51) with hypotension and suspected infection. Treating EPs performed and interpreted CPUS for cardiac function parameters (left ventricular [LV] function and right ventricular [RV] function and size) and preload volume parameters (inferior vena cava [IVC] diameter and pulmonary B-lines). The primary outcome was IRR (assessed by Kappa values [κ] and intraclass correlation coefficient [ICC]) between EP and EUS-expert consensus. Secondary analyses examined the effects on IRR of operator experience, respiratory rate, and known difficult views on a Cardiology-performed echocardiogram.

RESULTS

IRR was fair for LV function, κ = 0.37, 95% confidence interval (CI) 0.1-0.64; poor for RV function, κ = -0.05, 95% CI -0.6-0.5; moderate for RV size, κ = 0.47, 95% CI 0.07-0.88; and substantial for B-lines, κ = 0.73, 95% CI 0.51-0.95 and IVC size, ICC = 0.87, 95% CI 0.2-0.99. Involvement of ultrasound-trained faculty was associated with improved IRR of RV size (p = 0.002), but not other CPUS domains.

CONCLUSIONS

Our study demonstrated high IRR for preload volume parameters (IVC size and presence of B-lines), but not for cardiac parameters (LV function and RV function and size) in patients presenting with concern for septic shock. Future research must focus on determining sonographer and patient-specific factors affecting CPUS interpretation in real-time.