Point of care diaphragm ultrasound in acute bronchiolitis: A measurable tool to predict the clinical, sonographic severity of the disease, and outcomes

Review of Point-of-Care Diaphragmatic Ultrasound in Emergency Medicine: Background, Techniques, Achieving Competency, Research, and Recommendations

ABSTRACT

The diaphragm is the major muscle of inspiration accounting for approximately 70% of the inspired tidal volume. Point-of-care diaphragmatic ultrasound offers the ability to quantitatively assess diaphragmatic function, perform serial evaluations over time, and visualize structures above and below the diaphragm. Although interest in point-of-care ultrasound (POCUS) of the diaphragm is developing in the emergency medicine, assessment of the diaphragm and its function is not recognized as a core application by national organizations or expert guidelines. As a result, it is infrequently performed, and its potential value in research or clinical practice may not be fully appreciated. The purpose of this review is to describe the developmental aspects of the diaphragm as it pertains to POCUS, discuss the POCUS techniques for evaluating diaphragmatic function, address competency acquisition in this POCUS application, summarize relevant research in the ED, and provide a summary of recommendations for further research and clinical utilization of POCUS in diaphragm evaluation.

Pleural line slope in point of care ultrasound assessment of paediatric wheeze may reflect respiratory effort

AIM

Asthma scoring systems rely on physical examination findings. Point of care ultrasound may provide an objective means to document improvement in the work of breathing in paediatric lower airway obstruction.

METHODS

Thirty children with wheeze on physical examination (cases) and 15 children presenting with abdominal pain (controls) were studied. Using point-of-care ultrasound, m-mode tracing of lung was recorded above the right hemidiaphragm at the midclavicular line. Pleural line slope and excursion were measured before and after treatment.

RESULTS

Twenty patients had a final slope measurement under 20°, and only three were admitted-one for hypoxia that resolved prior to ascending to the ward and another for poor compliance. Average decrease in pleural line slope after treatment was 43% and average decrease in pleural line excursion was 32%. Of the 10 children admitted, 8 had measurements over 25°. The correlation coefficient between pleural slope and pleural excursion was 0.67. All controls had a horizontal m-mode tracing at the pleural line.

CONCLUSION

Oscillation of the m-mode line at the pleura is seen in children with lower airway obstruction and is absent in controls. There appears to be a correlation between beta-agonist therapy and decreased pleural line slope and excursion.

Association of outcomes in point-of-care lung ultrasound for bronchiolitis in the pediatric emergency department

BACKGROUND

Acute bronchiolitis (AB) is the most common lower respiratory tract infection in infants. Objective scoring tools and plain film radiography have limited application, thus diagnosis is clinical. The role of point-of-care lung ultrasound (LUS) is not well established.

OBJECTIVE

We sought to characterize LUS findings in infants presenting to the pediatric ED diagnosed with AB, and to identify associations between LUS and respiratory support (RS) at 12 and 24 h, maximum RS during hospitalization, disposition, and hospital length of stay (LOS).

METHODS

Infants ≤12 months presenting to the ED and diagnosed with AB were enrolled. LUS was performed at the bedside by a physician. Lungs were divided into 12 segments and scanned, then scored and summated (min. 0, max. 36) in real time accordingly: 0 - A lines with <3 B lines per lung segment. 1 - ≥3 B lines per lung segment, but not consolidated. 2 - consolidated B lines, but no subpleural consolidation. 3 - subpleural consolidation with any findings scoring 1 or 2. Chart review was performed for all patients after discharge. RS was categorized accordingly: RS (room air), low RS (wall O2 or heated high flow nasal cannula <1 L/kg), and high RS (heated high flow nasal cannula ≥1 L/kg or positive pressure).

RESULTS

82 subjects were enrolled. Regarding disposition, the mean (SD) LUS scores were: discharged 1.18 (1.33); admitted to the floor 4.34 (3.62); and admitted to the ICU was 10.84 (6.54). For RS, the mean (SD) LUS scores at 12 h were: no RS 1.56 (1.93), low RS 4.34 (3.51), and high RS 11.94 (6.17). At 24 h: no RS 2.11 (2.35), low RS 4.91 (3.86), and high RS 12.64 (6.48). Maximum RS: no RS 1.22 (1.31), low RS 4.11 (3.61), and high RS 10.45 (6.16). Mean differences for all dispositions and RS time points were statistically significant (p < 0.05, CI >95%). The mean (SD) hospital LOS was 84.5 h (SD 62.9). The Pearson correlation coefficient (r) comparing LOS and LUS was 0.489 (p < 0.0001).

CONCLUSION

Higher LUS scores for AB were associated with increased respiratory support, longer LOS, and more acute disposition. The use of bedside LUS in the ED may assist the clinician in the management and disposition of patient's diagnosed with AB.

Lung ultrasound systematic review shows its prognostic and diagnostic role in acute viral bronchiolitis

AIM

Lung ultrasound (LUS) has not been included in the current guidelines for the diagnosis of bronchiolitis so far, even though data concerning its effectiveness have been published.

METHODS

A systematic literature review was carried out to determine the role of LUS scores in the diagnosis and prognosis of patients aged 0-2 years with bronchiolitis, using MEDLINE, Scopus and ScienceDirect databases from their inception to December 2021.

RESULTS

A total of 18 studies matching our eligibility criteria were analysed for the purposes of this review and 1249 patients with bronchiolitis were included. The sonographic and radiological findings were comparable and chest radiography was found to have a higher sensitivity in ruling out severe complications such as concomitant pneumonia. The LUS scores were correlated to the clinical course of bronchiolitis and it was able to predict the need of admission in paediatric intensive care unit, the duration of hospitalisation and the need for respiratory support.

CONCLUSION

This review suggests that LUS could have both a diagnostic and a prognostic role in bronchiolitis during first evaluation in the emergency department and hospitalisation. Physicians could adjust management according to sonographic findings as a useful adjunct to the clinical ones.

Point of care diaphragm ultrasound in mechanically ventilated children: A predictive tool to detect extubation failure

BACKGROUND

Children should be weaned from the ventilator once their clinical condition improves. Extubation failure is associated with poorer clinical outcomes in children. Predictive indicators of successful extubation are needed. This study aims to evaluate the predictive value of ultrasonographic diaphragm imaging could help predict weaning success.

METHODS

In this prospective, observational study conducted between March and December 2021, children between 1 month and 10 years of age who were mechanically ventilated for more than 48 h were included. Diaphragm ultrasound (DUS) examinations were performed at the end of 2-h extubation readiness test (ERT). The end-inspiratory thickness (DTi), end-expiratory thickness (DTe), diaphragmatic thickening fraction (DTF), diaphragmatic excursion (DE), inspiratory slope (IS), and expiratory slope (ES) were evaluated.

RESULTS

Twenty-four (60%) patients were successfully extubated, while 16 (40%) required invasive or noninvasive mechanical ventilation support which were classified as failed extubation group. Three of the sixteen patients in the failed extubation group required reintubation. DTF was significantly greater in the successful weaning group (55.05 ± 23.75% vs. 30.9 ± 10.38%) (p < 0.001). DE was significantly greater in the successful weaning group (14 ± 4.4 mm vs. 11.05 ± 3.25 mm) (p < 0.001). DTF and DE were found to have a sensitivity and specificity of 91.67%, 87.50%, 83.33%, and 81.25%, respectively.

CONCLUSION

Diaphragm ultrasound is a feasible and promising tool to guide physicians during weaning from invasive mechanical ventilation. Among all DUS measurements, the DE and DTF indexes showed better performance in extubation failure than other diaphragmatic parameters.

A narrative review of diaphragmatic ultrasound in pediatric critical care

The use of point of care ultrasound (POCUS) at the bedside has increased dramatically within emergency medicine and in critical care. Applications of POCUS have spread to include diaphragmatic assessments in both adults and children. Diaphragm POCUS can be used to assess for diaphragm dysfunction (DD) and atrophy or to guide ventilator titration and weaning. Quantitative, semi-quantitative and qualitative measurements of diaphragm thickness, diaphragm excursion, and diaphragm thickening fraction provide objective data related to DD and atrophy. The potential for quick, noninvasive, and repeatable bedside diaphragm assessments has led to a growing amount of literature on diaphragm POCUS. To date, there are no reviews of the current state of diaphragm POCUS in pediatric critical care. The aims of this narrative review are to summarize the current literature regarding techniques, reference values, applications, and future innovations of diaphragm POCUS in critically ill children. A summary of current practice and future directions will be discussed.