B-Lines on Pediatric Lung Sonography: Comparison With Computed Tomography

Lung Ultrasound Induction of Pulmonary Capillary Hemorrhage in Rats With Consideration of Exposimetric Relationships to Previous Similar Observations in Neonatal Swine

OBJECTIVE

Lung ultrasound (LUS) has become an essential clinical tool for pulmonary evaluation. LUS has been found to induce pulmonary capillary hemorrhage (PCH) in animal models, posing a safety issue. The induction of PCH was investigated in rats, and exposimetry parameters were compared with those of a previous neonatal swine study.

METHODS

Female rats were anesthetized and scanned in a warmed water bath with the 3Sc, C1-5 and L4-12t probes from a GE Venue R1 point-of-care ultrasound machine. Acoustic outputs (AOs) of sham, 10%, 25%, 50% or 100% were applied for 5-min exposures with the scan plane aligned with an intercostal space. Hydrophone measurements were used to estimate the in situ mechanical index (MI_IS) at the lung surface. Lung samples were scored for PCH area, and PCH volumes were estimated.

RESULTS

At 100% AO, the PCH areas were 73 ± 19 mm² for the 3.3 MHz 3Sc probe (4 cm lung depth), 49 ± 20 mm² (3.5 cm lung depth) or 96 ± 14 mm² (2 cm lung depth) for the 3.0 MHz C1-5 probe and 7.8 ± 2.9 mm² for the 7 MHz L4-12t (1.2 cm lung depth). Estimated volumes ranged from 378 ± 97 mm³ for the C1-5 at 2 cm to 1.3 ± 1.5 mm³ for the L4-12t. MI_IS thresholds for PCH were 0.62, 0.56 and 0.48 for the 3Sc, C1-5 and L4-12t, respectively.

CONCLUSION

Comparison between this study and previous similar research in neonatal swine revealed the importance of chest wall attenuation. Neonatal patients may be most susceptible to LUS PCH because of thin chest walls.

To B or not to B. The rationale for quantifying B-lines in pediatric lung diseases

Lung ultrasound (LUS) is emerging as adjunct tool to be used during clinical assessment. Among the different hallmarks of LUS, B-lines are well known artifacts, which are not correlated with identifiable structures, but which can be used for pathological classification. The presence of multiple B-lines is a sonographic sign of lung interstitial syndrome. It has been demonstrated in adults that there is a direct correlation between the number of B-lines and the severity of the interstitial involvement of lung disease. Counting B-lines is an attempt to enrich the clinical assessment and clinical information, beyond obtaining a simple dichotomous answer. Semiquantitative or quantitative B-line assessment has been shown to correlate with fluid overload and demonstrated prognostic implications in specific neonatal and pediatric conditions. LUS with quantitative B-lines assessment is promising. Current evidence allows for quantification of B-lines in a limited number of neonatal and pediatric diseases.

Lung ultrasound findings in asymptomatic healthy children with asthma

BACKGROUND

Lung ultrasound (LUS) has been shown to be an effective tool to rapidly diagnose certain causes of pediatric respiratory distress. However, very little is known about LUS findings in pediatric asthma.

OBJECTIVES

The primary objective of this study was to characterize LUS findings in a cohort of pediatric patients with a definitive diagnosis of asthma, outside of an asthma exacerbation.

METHODS

Eligible patients, aged 6-17 years old and diagnosed with asthma, underwent LUS during an outpatient visit. LUS was conducted using a six-zone scanning protocol. Presence of a LUS artifact was defined by one or more of the following: ≥3 B-lines per intercostal space, pulmonary consolidation, and/or pleural abnormality. Images were interpreted by an expert sonographer blinded to patient clinical characteristics.

RESULTS

Fifty-two patients were included. 10/52 (19.2%) patients demonstrated the presence of LUS artifacts: 8 with ≥3 B-lines, 1 with consolidation >1 cm, and 7 with subpleural consolidations <1 cm, 1 with a pleural line abnormality. Artifacts were seen in the right anterior and lateral zones in 60% of participants and were limited to 1-2 intercostal space(s) within one lung zone in all participants. No association was found between presence of LUS artifacts and asthma control or severity.

CONCLUSION

To our knowledge, this is the first report of LUS findings in outpatient pediatric asthma. LUS artifacts in asthmatic children can be seen outside of acute exacerbations. Such baseline findings need to be taken into consideration when using LUS for the acute evaluation of a pediatric patient with asthma.

Image Human Thorax Using Ultrasound Traveltime Tomography with Supervised Descent Method

The change of acoustic velocity in the human thorax reflects the functional status of the respiratory system. Imaging the thorax’s acoustic velocity distribution can be used to monitor the respiratory system. In this paper, the feasibility of imaging the human thorax using ultrasound traveltime tomography with a supervised descent method (SDM) is studied. The forward modeling is computed using the shortest path ray tracing (SPR) method. The training model is composed of homogeneous acoustic velocity background and a high-velocity rectangular block moving in the domain of interest (DoI). The average descent direction is learned from the training set. Numerical experiments are conducted to verify the method’s feasibility. Normal thorax model experiment proves that SDM traveltime tomography can efficiently reconstruct thorax acoustic velocity distribution. Numerical experiments based on synthetic thorax model of pleural effusion and pneumothorax show that SDM traveltime tomography has good generalization ability and can detect the change of acoustic velocity in human thorax. This method might be helpful for the diagnosis and evaluation of respiratory diseases.

Ten Years of Pediatric Lung Ultrasound: A Narrative Review

Lung diseases are the most common conditions in newborns, infants, and children and are also the primary cause of death in children younger than 5 years old. Traditionally, the lung was not thought to be a target for an ultrasound due to its inability to penetrate the gas-filled anatomical structures. With the deepening of knowledge on ultrasound in recent years, it is now known that the affected lung produces ultrasound artifacts resulting from the abnormal tissue/gas/tissue interface when ultrasound sound waves penetrate lung tissue. Over the years, the application of lung ultrasound (LUS) has changed and its main indications in the pediatric population have expanded. This review analyzed the studies on lung ultrasound in pediatrics, published from 2010 to 2020, with the aim of highlighting the usefulness of LUS in pediatrics. It also described the normal and abnormal appearances of the pediatric lung on ultrasound as well as the benefits, limitations, and possible future challenges of this modality.

Lung Ultrasound versus Pulmonary Auscultation in Detecting Pulmonary Congestion in the Critically Ill

BACKGROUND: In critically ill patients, auscultation might be challenging as dorsal lung fields are difficult to reach in supine-positioned patients, and the environment is often noisy. In recent years, clinicians have started to consider lung ultrasound (LUS) as a useful diagnostic tool for a variety of pulmonary pathologies, including pulmonary edema. AIM: The aim of this study was to compare LUS versus pulmonary auscultation for detecting pulmonary edema in critically ill patients. PATIENTS AND METHODS: Sixty-one patients were included in this study, all included patients underwent clinical examination, chest auscultation of anterior and lateral (axillary) chest wall and back in each hemithorax in supine position was done, followed by LUS using Bedside LUS in Emergency (BLUE) protocol. LUS score was recorded; abnormal auscultation was defined as the presence of rales or wheezes. Laboratory tests were done on admission such as pro-BNP, renal function, and blood gases. Pro-BNP was used as diagnostic tool for volume overload and was correlated with LUS and stethoscope for detecting pulmonary edema. Pneumonia was excluded with normal total leukocyte counts, C-reactive protein, and absence of fever. RESULTS: This study included 61 patients with diagnosis of pulmonary edema, all data were recorded on admission and showed that there was statistically significant good positive correlation between LUS and Pro-BNP (p < 0.05), and Pearson correlation between LUS and Pro-BNP among the studied patients is statistically significant at the 0.01 level (two-tailed). Furthermore, we found that both LUS and Pro-BNP were statistically significant higher among patients with rales (p < 0.05) only 36 (59%) patients were positive as pulmonary edema with pulmonary auscultation (presence of rales) and 25 (41%) patients were negative for pulmonary edema (NO RALES) while they were positive for pulmonary edema with LUS (high LUS score)and pro-BNP. CONCLUSION: Pulmonary auscultation has poor sensitivity for pulmonary congestion while LUS had statistically significant higher sensitivity for pulmonary edema.

Use of Point-of-Care Ultrasound for Evaluation of Extravascular and Intravascular Fluid Status in Pediatric Patients Maintained on Chronic Hemodialysis

AIMS

Traditional methods that use clinical parameters to determine dry weight in hemodialysis patients are inaccurate. This study aimed to compare clinical assessment of fluid status to sonographic parameters of fluid status in pediatric patients undergoing chronic hemodialysis.

METHODS

In a prospective observational study, pediatric patients maintained on chronic hemodialysis (ages 2.3-20 years) were evaluated clinically and sonographically before and after dialysis at 6 consecutive sessions. Sonographic parameters examined were number of lung B-lines as a measure of extravascular volume and inferior vena cava (IVC)/aorta ratio as a measure of intravascular volume. Clinical assessment of fluid status was compared to sonographic assessment.

RESULTS

Twelve patients were evaluated during 72 dialysis sessions. Sonographic parameters were significantly lower post-dialysis than pre-dialysis (B-lines number 4.5 ± 5 vs. 7.69 ± 7.46, p < 0.0001; IVC/aorta ratio 0.9 ± 0.2 vs. 1.1 ± 0.2, p < 0.0001, respectively). Ultrafiltration volume correlated with change in B-lines number during dialysis (r = 0.39, p < 0.01). Percent of blood volume drop correlated with post-dialysis IVC/aorta ratio (r = 0.48, p < 0.001). A higher percent of symptomatic episodes occurred with post-dialysis IVC/aorta ratio <0.8 versus ≥0.8 (39.1 vs. 15.2%, p = 0.036). Four patients were hypertensive, a clinical parameter implying fluid overload, in only one sonographic evaluation indicated fluid overload. Eight patients were clinically determined to be euvolemic, in three of them sonographic evaluation discovered covert fluids.

CONCLUSION

Bedside ultrasound is a single modality that can be used to assess both extravascular and intravascular fluid status. It may contribute to clinical decisions differentiating fluid-related versus fluid-unrelated hypertension and identifying patients with covert fluids.

Effect of upper respiratory infection on anaesthesia induced atelectasis in paediatric patients

Upper respiratory tract infection (URI) symptoms are known to increase perioperative respiratory adverse events (PRAEs) in children undergoing general anaesthesia. General anaesthesia per se also induces atelectasis, which may worsen with URIs and yield detrimental outcomes. However, the influence of URI symptoms on anaesthesia-induced atelectasis in children has not been investigated. This study aimed to demonstrate whether current URI symptoms induce aggravation of perioperative atelectasis in children. Overall, 270 children aged 6 months to 6 years undergoing surgery were prospectively recruited. URI severity was scored using a questionnaire and the degree of atelectasis was defined by sonographic findings showing juxtapleural consolidation and B-lines. The correlation between severity of URI and degree of atelectasis was analysed by multiple linear regression. Overall, 256 children were finally analysed. Most children had only one or two mild symptoms of URI, which were not associated with the atelectasis score across the entire cohort. However, PRAE occurrences showed significant correspondence with the URI severity (odds ratio 1.36, 95% confidence interval 1.10–1.67, p = 0.004). In conclusion, mild URI symptoms did not exacerbate anaesthesia-induced atelectasis, though the presence and severity of URI were correlated with PRAEs in children.

Trial registration: Clinicaltrials.gov (NCT03355547).

Modified pediatric lung ultrasound score compared with computed tomography for assessment of lung aeration in children

BACKGROUND

Lung ultrasound can be used to assess lung density and aeration at the bedside. Few authors have investigated scores based on the ultrasonographic interstitial syndrome for this purpose, but none have compared them with the gold standard computed tomography in children.

METHODS

Children <10 kilograms undergoing a chest computed tomography for clinical purposes at a tertiary hospital Pediatric Intensive Care Unit were enrolled in the study. An ultrasound scan was performed shortly after computed tomography. Each hemithorax was divided in six zones, and each zone was scored: 1, no B lines; 2, <3 B lines; 3, >3 well separated B lines; 4, crowded, coalescent B lines; 5, white lung; 6, consolidation. The pediatric lung ultrasound score was obtained by adding all zones. Interobserver variation for two separate operators was calculated.

RESULTS

Ten children, median age 95 days (range 23-721) were enrolled. Mean pediatric lung ultrasound score had a significant correlation with lung density (r=0.68) and percentage of hypoaerated lung (r=0.51). Median density and percentage of hypoaerated lung increased along the ultrasound patterns values (P<0.05) although not all patterns were significantly different from adjacent ones in the pairwise comparison. Interobserver variability in scoring of ultrasonographic patterns was moderate.

CONCLUSIONS

The pediatric lung ultrasound score correlates with lung density and percentage of hypoaerated lung measured with computed tomography.

Lung ultrasound in children: What does it give us?

Lung ultrasound (LUS), a non-invasive non-ionizing radiation tool, has become essential at the bedside in both adults and children, particularly in the critically ill. This manuscript reviews normal LUS patterns and the most important pathologies that LUS allows to diagnose. Normal LUS is represented by the pleural line, the lung-sliding and the A-lines and B-lines. These two last findings are artifacts derived from the pleural line. Pleural effusion appears as an anechoic collection. Pneumothorax is suspected when only A-lines are present, without lung-sliding and B-lines. Alveolo-interstitial syndrome is characterized by different degrees of confluent B-lines and can be present in different pathologies such as pulmonary edema and acute respiratory distress syndrome. The distribution of B-lines helps to differentiate between them. LUS is useful to evaluate the response to lung recruitment in pathologies such as acute respiratory distress syndrome or acute chest syndrome. The distribution of B-lines also appears to be useful to monitor the response to antibiotics in pneumonia. However, further studies are needed to further ascertain this evidence. LUS is also useful to guide thoracocentesis.

Lung Ultrasound in Children with Respiratory Tract Infections: Viral, Bacterial or COVID-19? A Narrative Review

Respiratory tract infections (RTIs) are common complaints among patients presenting to the pediatric emergency department. In the diagnostic assessment of children with RTIs, many patients ultimately undergo imaging studies for further evaluation. Point-of-care lung ultrasound (LUS) can be used safely and with a high degree of accuracy in differentiating etiologies of RTIs in pediatric patients. Ultrasonographical features such as an irregular pleural line, subpleural consolidations, focal and lobar consolidation and signs of interstitial involvement can be used to distinguish between several pathologies. This work offers a comprehensive overview of pediatric LUS in cases of the most common pediatric RTIs including bacterial and viral pneumonia, bronchiolitis, and COVID-19.

Variation of Diagnostic Ultrasound-Induced Pulmonary Capillary Hemorrhage with Fraction of Inspired Oxygen

Pulmonary capillary hemorrhage induction by diagnostic ultrasound (DUS-PCH) was investigated with respect to the influence of the fraction of inspired oxygen (FiO₂). Sprague-Dawley rats were anesthetized with Telazol only (TO) or Telazol plus xylazine (TX), which can enhance DUS-PCH. A linear array probe (10 L, GE Vivid 7 Dimension) was used in B-mode at 7.5 MHz to expose the right lung. FiO₂ at 10%, 20%, 60% and 100% was delivered through a nose cone. On the ultrasound images, the PCH effect was observed as growing comet tail (B-line) artifacts and as subpleural consolidated segments at higher FiO₂. PCH for TO with 20% and 60% FiO₂ were significantly greater (p < 0.05) than for the 10% FiO₂. PCHs with TX at 10% and 20% FiO₂ were significantly greater (p < 0.02) than those for TO anesthesia. Added xylazine and high percentages of FiO₂ reduced PCH thresholds, but xylazine and high percentages of FiO₂ together did not lower the PCH threshold further. The lowest threshold observed, 1.4 MPa, corresponded to an in situ mechanical index of 0.5.

Diagnostic Ultrasound Safety Review for Point-of-Care Ultrasound Practitioners

Potential ultrasound exposure safety issues are reviewed, with guidance for prudent use of point-of-care ultrasound (POCUS). Safety assurance begins with the training of POCUS practitioners in the generation and interpretation of diagnostically valid and clinically relevant images. Sonographers themselves should minimize patient exposure in accordance with the as-low-as-reasonably-achievable principle, particularly for the safety of the eye, lung, and fetus. This practice entails the reduction of output indices or the exposure duration, consistent with the acquisition of diagnostically definitive images. Informed adoption of POCUS worldwide promises a reduction of ionizing radiation risks, enhanced cost-effectiveness, and prompt diagnoses for optimal patient care.

Lung ultrasound-a new diagnostic modality in persistent tachypnea of infancy

Lung ultrasound (LUS) has been increasingly used in diagnosing and monitoring of various pulmonary diseases in children. The aim of the current study was to evaluate its usefulness in children with persistent tachypnea of infancy (PTI). This was a controlled, prospective, cross-sectional study that included children with PTI and healthy subjects. In patients with PTI, LUS was performed at baseline and then after 6 and 12 months of follow-up. Baseline results of LUS were compared to (a) baseline high-resolution computed tomography (HRCT) images, (b) LUS examinations in control group, and (c) follow-up LUS examinations. Twenty children with PTI were enrolled. B-lines were found in all children with PTI and in 11 (55%) control subjects (P < .001). The total number of B-lines, the maximal number of B lines in any intercostal space, the distance between B-lines, and pleural thickness were significantly increased in children with PTI compared to controls. An irregularity of the pleural line was found in all patients with PTI and in none of the healthy children. There were no significant changes in LUS findings in patients with PTI during the study period. The comparison of HRCT indices and LUS findings revealed significant correlations between the mean lung attenuation, skewness, kurtosis and fraction of interstitial pulmonary involvement, and the number of B-lines as well as the pleural line thickness. LUS seems to be a promising diagnostic tool in children with PTI. Its inclusion in the diagnostic work-up may enable to reduce the number of costly, hazardous, and ionizing radiation-based imaging procedures.

Lung ultrasound in pediatric radiology - cons

In the 1990s, intensivists suggested a new type of sonography: lung ultrasound, based on artefacts that receive information even from physical acoustic phenomena not directly convertible into images of the human body. They compared the artefacts from the lung zones with no acoustic window with various computed tomography (CT) patterns. They used and still use US as a tool to evaluate patients bedside, i.e. monitoring of lung recruitment. They included Lung ultrasound in what was termed POCUS (Point-of-Care Ultrasound). Lung ultrasound has been progressively extended to paediatrics in general. The most appealing novelty has been the diagnosis of pneumothorax. Lung ultrasound was developed as a support tool for critical patients. Extrapolation with mass diffusion, in the absence of appropriate training, has led to misunderstandings and dangerous therapeutic diagnostic drifts.

Should the ultrasound probe replace your stethoscope? A SICS-I sub-study comparing lung ultrasound and pulmonary auscultation in the critically ill

Background

In critically ill patients, auscultation might be challenging as dorsal lung fields are difficult to reach in supine-positioned patients, and the environment is often noisy. In recent years, clinicians have started to consider lung ultrasound as a useful diagnostic tool for a variety of pulmonary pathologies, including pulmonary edema. The aim of this study was to compare lung ultrasound and pulmonary auscultation for detecting pulmonary edema in critically ill patients.

Methods

This study was a planned sub-study of the Simple Intensive Care Studies-I, a single-center, prospective observational study. All acutely admitted patients who were 18 years and older with an expected ICU stay of at least 24 h were eligible for inclusion. All patients underwent clinical examination combined with lung ultrasound, conducted by researchers not involved in patient care. Clinical examination included auscultation of the bilateral regions for crepitations and rhonchi. Lung ultrasound was conducted according to the Bedside Lung Ultrasound in Emergency protocol. Pulmonary edema was defined as three or more B lines in at least two (bilateral) scan sites. An agreement was described by using the Cohen κ coefficient, sensitivity, specificity, negative predictive value, positive predictive value, and overall accuracy. Subgroup analysis were performed in patients who were not mechanically ventilated.

Results

The Simple Intensive Care Studies-I cohort included 1075 patients, of whom 926 (86%) were eligible for inclusion in this analysis. Three hundred seven of the 926 patients (33%) fulfilled the criteria for pulmonary edema on lung ultrasound. In 156 (51%) of these patients, auscultation was normal. A total of 302 patients (32%) had audible crepitations or rhonchi upon auscultation. From 130 patients with crepitations, 86 patients (66%) had pulmonary edema on lung ultrasound, and from 209 patients with rhonchi, 96 patients (46%) had pulmonary edema on lung ultrasound. The agreement between auscultation findings and lung ultrasound diagnosis was poor (κ statistic 0.25). Subgroup analysis showed that the diagnostic accuracy of auscultation was better in non-ventilated than in ventilated patients.

Conclusion

The agreement between lung ultrasound and auscultation is poor.

Trial registration

NCT02912624. Registered on September 23, 2016.

Effect of Fluid Bolus Therapy on Extravascular Lung Water Measured by Lung Ultrasound in Children With a Presumptive Clinical Diagnosis of Sepsis

OBJECTIVES

Fluid bolus therapy for the treatment of sepsis may lead to the accumulation of extravascular lung water (EVLW) and result in respiratory dysfunction. We aimed to assess changes in EVLW using lung ultrasound (US) in children with a presumptive clinical diagnosis of sepsis after fluid bolus therapy and correlate these changes with respiratory signs.

METHODS

This work was a prospective observational study set in the emergency department of the Royal Children's Hospital. Children meeting international consensus criteria for sepsis receiving fluid bolus therapy were included. Respiratory signs were recorded, and lung US examinations were performed immediately before, 5 minutes after, and 60 minutes after fluid bolus therapy. A pediatric emergency physician blinded to the participants' identities and timing of US calculated an EVLW score from lung US. Results-Fifty fluid boluses were recorded in 41 children. The lung US score (range, 0-8) increased over the study period: median, 1 (interquartile range, 0-2) before fluid bolus therapy, 1 (interquartile range, 0-3) 5 minutes after fluid bolus therapy, and 3 (interquartile range, 1-4) 60 minutes after fluid bolus therapy. Respiratory effort, but not the respiratory rate or the presence of rales, increased over the study period and was correlated with the lung US score (ρ = 0.33; P = .02).

CONCLUSIONS

Extravascular lung water as measured by lung US increased after fluid bolus therapy in septic children and was correlated with an increase in the respiratory distress score. The respiratory rate and the presence of rales did not change over the study period. The role of lung US for titrating fluid bolus therapy in sepsis warrants further investigation.

Pediatric chest ultrasound: a practical approach

Chest ultrasonography is an important imaging adjunct for diagnosing and managing disease in children. Compared with CT and MRI, ultrasound is cheaper, portable and provides vascular or flow-related information that cannot otherwise be obtained noninvasively. The spatial and temporal resolution of ultrasound is excellent, particularly for superficial structures. In cases where a suspicious abnormality is found, tissue sampling can be performed percutaneously with US guidance. Ultrasound also excels at demonstrating and characterizing pleural fluid collections. As concerns about radiation exposure increase among laypersons and doctors alike, there is a compelling argument for making ultrasonography the initial imaging study of choice for many thoracic abnormalities in a child. In this review the authors discuss and illustrate the US findings of some of the more common chest complaints in children.

Correlation of B-Lines on Ultrasonography With Interstitial Lung Disease on Chest Radiography and CT Imaging

BACKGROUND

We prospectively identified B-lines in patients undergoing ultrasonographic (US) examinations following liver transplantation who also had chest radiography (CXR) or chest CT imaging, or both, on the same day to determine if an association between the presence of B-lines from the thorax on US images correlates with the presence of lung abnormalities on CXR.

METHODS

Following institutional review board (IRB) approval, patients who received liver transplants and underwent routine US examinations and chest radiography or CT imaging, or both, on the same day between January 1, 2015 through July 1, 2016 were prospectively identified. Two readers who were blinded to chest films and CT images and reports independently reviewed the US interreader agreement for the presence or absence of B-lines and performed an evaluation for the presence or absence of diffuse parenchymal lung disease (DPLD) on chest films and CT images as well as from clinical evaluation. Receiver operating characteristic (ROC) curves were constructed.

RESULTS

There was good agreement between the two readers on the presence of absence of B-lines (kappa = 0.94). The area under the ROC curve for discriminating between positive DPLD and negative DPLD for both readers was 0.79 (95% CI, 0.71-0.87).

CONCLUSIONS

There is an association between the presence of extensive B-lines to the point of confluence and "dirty shadowing" on US examinations of the chest and associated findings on chest radiographs and CT scans of DPLD. Conversely, isolated B-lines do not always correlate with abnormalities on chest films and in fact sometimes appear to be a normal variant.

Assessment of extravascular lung water by ultrasound after congenital cardiac surgery

BACKGROUND

Lung ultrasounds show vertical artifacts known as B-lines in the presence of increased extravascular lung water (EVLW). We aimed to investigate whether lung ultrasound could estimate EVLW after congenital cardiac surgery.

METHODS

This prospective observational study comprised 61 children (age range 3 days to 7.4 years) undergoing congenital cardiac surgery. We compared postoperative B-line scores from lung ultrasounds, early postoperative ultrasound as our primary interest, with corresponding postoperative chest radiography (CXR) lung edema scores, with static lung compliance, and with short-term clinical outcome interpreted as time on mechanical ventilation and length of pediatric intensive care unit (PICU) stay.

RESULTS

Our findings showed lung ultrasound B-line scores and CXR lung edema scores as correlating 1-6 hr postoperatively (r²  = 0.41, P < 0.0001), on the first postoperative day (r²  = 0.15, P = 0.004) and on the fourth postoperative day (r²  = 0.28, P = 0.008). The B-line score or CXR lung edema score showed no correlation with lung compliance. We found that in multivariable analyses, with length of perfusion and presence of postoperative complications as covariates, both lung ultrasound (P ≤ 0.02) and CXR (P ≤ 0.002) 1-6 hr postoperatively predicted the length of mechanical ventilation and PICU stay. The interobserver variability was less for lung ultrasound B-line score than for CXR lung edema score (P = 0.001).

CONCLUSIONS

Our results show that lung ultrasound in assessment of postoperative EVLW predicted length of mechanical ventilation and stay in the PICU, and it had less interobserver variability than CXR. Accordingly, lung ultrasound may complement CXR in assessment of lung edema after surgery for congenital heart defect. Pediatr Pulmonol. 2017;52:345-352. © 2016 Wiley Periodicals, Inc.

Lung ultrasound for the diagnosis of community-acquired pneumonia in children

Ultrasound (US) has been proposed as an alternative first-line imaging modality to diagnose community-acquired pneumonia in children. Lung US has the potential benefits over chest radiography of being radiation free, subject to fewer regulatory requirements, relatively lower cost and with immediate bedside availability of results. However, the uptake of lung US into clinical practice has been slow and it is not yet included in clinical guidelines for community-acquired pneumonia in children. The aim of this review is to give an overview of the equipment and techniques used to perform lung US in children with suspected pneumonia and the interpretation of relevant sonographic findings. We also summarise the current evidence of diagnostic accuracy and reliability of lung US compared to alternative imaging modalities in children and critically consider the strengths and limitations of lung US for use in children presenting with suspected community-acquired pneumonia.

Influence of Scan Duration on Pulmonary Capillary Hemorrhage Induced by Diagnostic Ultrasound

Diagnostic ultrasound can induce pulmonary capillary hemorrhage (PCH) in rats and display this as "comet tail" artifacts (CTAs) after a time delay. To test the hypothesis that no PCH occurs for brief scans, anesthetized rats were scanned using a 6-MHz linear array for different durations. PCH was characterized by ultrasound CTAs, micro-computed tomography (μCT), and measurements of fixed lung tissue. The μCT images revealed regions of PCH, sometimes penetrating the entire depth of a lobe, which were reflected in the fixed tissue measurements. At -3 dB of power, PCH was substantial for 300-s scans, but not significant for 25-s scans. At 0 dB, PCH was not strongly dependent on scan durations of 300 to 10 s. Contrary to the hypothesis, CTAs were not evident during most 10-s scans (p > 0.05), but PCH was significant (p = 0.02), indicating that PCH could occur without evidence of the injury in the images.

Finding covert fluid: methods for detecting volume overload in children on dialysis

BACKGROUND

Lung ultrasound is a novel technique for detecting generalized fluid overload in children and adults with end-stage renal disease (ESRD). Echocardiography and bioimpedance spectroscopy are established methods, albeit variably adopted in clinical practice. We compared the practicality and accuracy of lung ultrasound with current objective techniques for detecting fluid overload in children with ESRD.

METHODS

A prospective observational study was performed to compare lung ultrasound B-lines, echocardiographic measurement of inferior vena cava parameters and bioimpedance spectroscopy in the assessment of fluid overload in children with ESRD on dialysis. The utility of each technique in predicting fluid overload, based on short-term weight gain, was assessed. Multiple linear regression models to predict fluid overload by weight were explored.

RESULTS

A total of 22 fluid assessments were performed in 13 children (8 on peritoneal dialysis, 5 on haemodialysis) with a median age of 4.0 (range 0.8-14.0) years. A significant linear correlation was observed between the number of B-lines detected by lung ultrasound and fluid overload by weight (r = 0.57, p = 0.005). A non-significant positive linear correlation was observed between fluid overload by weight and bioimpedance spectroscopy (r = 0.43, p = 0.2), systolic blood pressure (r = 0.19, p = 0.4) and physical examination measurements (r = 0.19, p = 0.4), while a non-significant negative linear relationship was found between the inferior vena cava collapsibility index and fluid overload by weight (r = -0.24, p = 0.3). In multiple linear regression models, a combination of three fluid parameters, namely lung ultrasound B-lines, clinical examination and systolic blood pressure, best predicted fluid overload (R ²  = 0.46, p = 0.05).

CONCLUSIONS

Lung ultrasound may be superior to echocardiographic methods and bioimpedance spectroscopy in detecting volume overload in children with ESRD. Given the practicality and sensitivity of this new technique, it can be adopted alongside clinical examination and blood pressure in the routine assessment of fluid status in children with ESRD.