Point of care diaphragm ultrasound in infants with bronchiolitis

Diaphragmatic Ultrasound in Children With Asthma Exacerbations

OBJECTIVES

Asthma is a leading cause of pediatric emergency department visits, yet few tools exist to objectively measure asthma severity. Diaphragmatic ultrasound (DUS) is a novel method of assessing respiratory distress; however, data are lacking for children.Our primary aim was to determine if diaphragmatic excursion (DE), diaphragmatic thickening (DT), or diaphragmatic thickening fraction (TF) correlated with asthma severity as determined by the Pediatric Respiratory Assessment Measure (PRAM) score. Secondarily, we examined if these parameters correlated with need for respiratory support and evaluated interrater reliability.

METHODS

We conducted a prospective study of children 5-18 years presenting to a pediatric emergency department with an asthma exacerbation. Diaphragmatic ultrasound was performed by a trained pediatric emergency medicine sonologist in subcostal (DE) and midaxillary (DT). Thickening fraction was calculated from DT values as previously described in literature. To evaluate interrater reliability, a subset of subjects had DUS performed by a second sonologist.

RESULTS

We enrolled 47 subjects for a total of 51 encounters. The mean age was 9.1 ± 3.7 years. Twenty-five (49%) had mild, 24 (47%) had moderate, and 2 (4%) had severe asthma. There was a significant difference in midaxillary DT and TF between children with mild and moderate asthma (P = 0.02; mean difference, 0.2 mm; 95% confidence interval [CI], 0.03-0.4 and P = 0.02; mean difference, 0.11 mm; 95% CI, 0.02-0.2, respectively). No difference was found in subcostal DE (P = 0.43; mean difference, 1.4 mm; 95% CI, -2.1 to 4.8). No association was found between use of positive pressure and DUS parameters. Fourteen encounters had 2 sonologists perform DUS, with strong interrater reliability found for midaxillary DT (Pearson correlation, 0.56) and poor association for subcostal DE (Pearson correlation, 0.18).

CONCLUSIONS

In this pilot study, we conclude that DUS may be helpful in assessing severity of asthma. The midaxillary view assessment for DT and TF had the best correlation with asthma severity and the best interrater reliability. Future studies may benefit from focusing on the midaxillary view for DT and TF.

Sonographic evaluation of diaphragmatic thickness and excursion as a predictor for successful extubation in mechanically ventilated preterm infants

Sonographic assessment of diaphragmatic thickness and excursion has been found to be an accurate tool in predicting successful extubation of adult patients from invasive mechanical ventilation. We aimed to evaluate the accuracy of sonographic assessment of diaphragmatic thickness and excursion in predicting successful extubation of preterm infants from invasive conventional mechanical ventilation. Preterm infants less than 32 weeks gestation who required invasive conventional mechanical ventilation were evaluated by diaphragmatic sonography within 1 h of their planned extubation. Infants were classified into successful or failed extubation groups based on their ability to stay off invasive mechanical ventilation for 72 h after extubation. Inspiratory and expiratory thickness plus excursion of the right and left hemidiaphragm as well as diaphragmatic thickening fraction (DTF) measures were compared between groups. We included 43 eligible infants, of whom 34 infants succeeded and 9 infants failed extubation. Infants in the successful extubation group had a significantly higher expiratory thickness of the right and left hemidiaphragm, excursion of the right and left hemidiaphragm, inspiratory thickness of the left hemidiaphragm, and DTF of the left hemidiaphragm compared with infants who failed extubation. The receiver-operating characteristic curves showed that excursion of the right and left hemidiaphragm has the highest significant accuracy in predicting successful extubation of preterm infants among all diaphragmatic parameters (AUC is 0.98 and 0.96, respectively; p value < 0.001 for both).Conclusion: We conclude that diaphragmatic excursion is a useful indicator for successful extubation of preterm infants from mechanical ventilation. What is Known: • Invasive mechanical ventilation induces ventilator induced diaphragmatic dysfunction (VIDD) particularly when used for long time. • Assessment of diaphragmatic dimensions and functional activity has been a valuable tool in predicting successful extubation of adult patients from invasive mechanical ventilation. What is New: • Sonographic assessment of diaphragmatic dimensions can be used to predict successful extubation of preterm infants from mechanical ventilation. • Sonographic assessment of diaphragmatic excursion shows the highest sensitivity and specificity in predicting successful extubation of preterm infants.

Lung ultrasound findings in pediatric community-acquired pneumonia requiring surgical procedures: a two-center prospective study

BACKGROUND

Lung ultrasound (US) in the evaluation of suspected pediatric pneumonia is increasingly used and has a recognized role in evaluating pleural effusions, although there are no detailed studies specifically addressing its use in the pediatric population.

OBJECTIVES

To define lung US findings of severe pediatric community-acquired pneumonia that required surgical procedures during admission.

MATERIALS AND METHODS

Our prospective case-control study compared lung US findings in patients ages 1 month to 17 years admitted with community-acquired pneumonia that required surgical procedures from findings those who did not. Lung US was performed at admission and always before surgical procedures. Medical treatment, laboratory and microbiological findings, chest X-ray, computed tomography scan and surgical procedures are described.

RESULTS

One hundred twenty-one children with community-acquired pneumonia were included; of these, 23 underwent surgical intervention. Compared with the control group, children requiring a surgical procedure had a significantly higher rate of large consolidations (52.2%; 95% confidence interval [CI]: 30.6% to 73.2%), larger and complicated pleural effusions (100%; 95% CI: 85.2% to 100%), and both liquid and air bronchograms (73.9%; 95% CI: 51.6% to 89.8%).

CONCLUSION

Larger consolidations, larger and more complicated pleural effusions, and liquid and air bronchograms were associated with surgical treatment.

Ultrasound assessment of diaphragmatic function in type 1 spinal muscular atrophy

OBJECTIVE

To investigate ultrasound features of diaphragm motion and function in type 1 spinal muscular atrophy (SMA-1) patients.

DESIGN

Prospective study.

PATIENTS

The study cohort included SMA-1 children younger than 18-year-old. Control subjects included type 2 and type 3 SMA and other neuromuscular disorders younger than 18-year-old.

METHODOLOGY

Diaphragm ultrasound evaluating diaphragmatic excursion, speed of diaphragmatic contraction, duration of the respiratory cycle, inspiratory/expiratory relationship, end-inspiratory and -expiratory thickness, thickening fraction, and pattern of contractility. The interrater reliability for each variable was established by calculation of Cohen's k coefficient.

RESULTS

Twenty-three SMA-1 patients and 12 controls were evaluated. Diaphragm ultrasound values were within normal ranges in all study cohort patients and no difference was found with controls. There was a gradient of diaphragm function with SMA 1.9 subgroup having the best and SMA 1.1 having the worst parameters, particularly in end-inspiratory thickness and diaphragmatic excursion (P = .031 and P = .041, respectively). Seventy-four percent of SMA-1 patients had a dysmotility pattern of diaphragm contraction, mostly represented in SMA 1.9 subgroup (P = .001). This pattern was observed in 92.8% of children on noninvasive ventilation (NIV) for less than 16 hours/d of and in 20% patients with invasive ventilation or NIV for more than 16 hours/d (P = .027). The dysmotility pattern was never observed in the control group. The levels of interobserver agreement were high for "diaphragm irregularities," "inspiratory/expiratory relationship," and "diaphragm thickness," and good for the other variables.

CONCLUSIONS

Ultrasound can be used to evaluate diaphragm function and contractility in SMA-1 children, providing additional information to the clinical examination and functional respiratory tests, describing a characteristic contractility pattern in these patients. Longitudinal studies are needed to understand the impact of diaphragm dysmotility and other parameters on long-term outcome in SMA-1 patients.

Lung ultrasound in infants with bronchiolitis

Lung ultrasound (LUS) is nowadays a fast-growing field of study since the technique has been widely acknowledged as a cost-effective, radiation free, and ready available alternative to standard X-ray imaging. However, despite extensive acoustic characterization studies and documented medical evidences, a lot is still unknown about how ultrasounds interact with lung tissue. One of the most discussed lung artifacts are the B-lines [in all ages] and the subpleural consolidations (in young infants). Recently, LUS has been claimed to be able to detect pneumonia in infants with bronchiolitis, although this can be an overestimation due to the peculiar physiology of small peripheral airways of the pediatric lung (particularly in neonate/infants). Distinguishing consolidations from atelectasis in young infants with bronchiolitis can be challenging and those criteria well defined for adults and older children (size and bronchogram) cannot easily translated in this specific subset. Therefore, if decades of studies clearly defined the low risk of SBI in bronchiolitis, we need to be careful before stating that LUS may confirm pneumonia in such a high number of cases and, importantly, new and promising techniques such as LUS should give us new insights bringing us to improvements and not back to overuse of antibiotics. More studies are surely need on this topic.