[Utility of the lung ultrasound in the intensive medicine unit]

Pleuropulmonary and diaphragmatic ultrasound in intensive care medicine

The usefulness of ultrasound for chest exploration was described in 1968. It was not until the 1990s, when its use became widespread in Intensive Care Units as a diagnostic, monitoring and procedural guide tool. The fact that it is a non-invasive tool, accessible at the bedside, with a sensitivity and specificity close to computerized tomography (CT) and with a short learning curve, have made it a mandatory technique in the management of critically ill patients. It is essential to know that there are different air/fluid ratio generated by different pathologies that gives rise to one echographic pattern or another. The identification of these patterns together with the clinical information will allow to make an accurate diagnosis in most settings of respiratory failure. Likewise, we must not forget the importance of evaluating diaphragmatic function by ultrasound during weaning from mechanical ventilation.

Point-of-care lung ultrasound in children with bronchiolitis in a pediatric emergency department

OBJECTIVES

This study assessed the association between findings of lung ultrasound (LUS) performed in the pediatric emergency department (PED) on infants with bronchiolitis and need for respiratory support.

METHODS

An observational study was carried out in the PED during the epidemic seasons in two consecutive years. Infants diagnosed with bronchiolitis who fulfilled the inclusion criteria were evaluated. A group of six pediatricians performed LUS and classified lung findings into four groups: normal pattern (A), moderate interstitial pattern (B1), severe interstitial pattern (B2), and isolated consolidation (C). The relationship between LUS findings and need for respiratory support was explored. An expert sonographer, blinded to the results, reviewed the ultrasound studies to determine the interobserver reliability.

RESULTS

A total of 200 infants were included (mean age 5.7 months±4.4 SD); 65 (32.5%) obtained moderate clinical scores, while 23 (11.5%) needed respiratory support at admission and 34 (17.0%) at 48h. The ultrasound findings in the PED were the following: A=89 (44.5%), B1=55 (27.5%), B2=34 (17%), and C=22 (11%). Age less than 6 weeks and moderate bronchiolitis were correlated with abnormal LUS (P<0.005). The severity of interstitial ultrasound pattern has some correlation with an increased need for respiratory support. The interobserver concordance was high (0.95, confidence interval: 0.92-0.98).

CONCLUSION

LUS is a feasible tool that may help to confirm the clinical impression and assess the need for respiratory support in children with bronchiolitis, but further multicenter studies are needed.

Current role of imaging in COVID-19 infection with recent recommendations of point of care ultrasound in the contagion: a narrative review

Radiological studies have an important role in the diagnosis and follow up of many infectious diseases. With current pandemic of Coronavirus disease 2019 (COVID-19) though the molecular analysis with reverse transcriptase polymerase chain reaction (RT-PCR) remains the cornerstone of diagnosis, the critical role of chest imaging including CT scan and baseline X-ray became apparent early in the course due to concern for less than optimal sensitivity of PCR testing. Delay in molecular diagnosis due to a shortage of testing kits and laboratory personnel also makes imaging an important modality in early diagnosis for appropriate triage and isolation decisions. CT scan technology is widely available in developed parts of the world but in developing countries, CT scanner is not widely available especially in rural settings. CT imaging usually requires patient movement to the radiology department and the scanner is not easy to disinfect. Point of care ultrasound (POCUS) has been used for many years in the assessment of critically ill patients in emergency departments and intensive care units. It is rapidly gaining popularity across many specialties and part of many general medicine training programs across the United States. It can be learned rapidly and with experienced hands, POCUS can help identify disease patterns in the lung parenchyma, and during the current pandemic has been gaining special attention. In this article, we review the most prominent imaging findings on chest X-ray and CT scan in patients with COVID-19. We also focus on the background and evolution of POCUS with studies showing the promising role of this diagnostic modality in COVID-19 infection. In addition, we describe step by step guidance on the use and disinfection of the portable ultrasound machine.

Lung ultrasound: an additional tool in COVID-19

Lung ultrasound is a well-defined diagnostic modality in the point of care emergency medicine concept. In the context of the coronavirus disease 2019 (COVID-19) pandemic, the lung ultrasound assumed an essential role in this disease, with a valid correlation of the imaging results with computed tomography. Recognize how the diagnostic possibilities of ultrasound in the approach of COVID-19 and its differential diagnoses are fundamental.

[Respiratory monitoring of pediatric patients in the Intensive Care Unit]

Respiratory monitoring plays an important role in the care of children with acute respiratory failure. Therefore, its proper use and correct interpretation (recognizing which signals and variables should be prioritized) should help to a better understanding of the pathophysiology of the disease and the effects of therapeutic interventions. In addition, ventilated patient monitoring, among other determinations, allows to evaluate various parameters of respiratory mechanics, know the status of the different components of the respiratory system and guide the adjustments of ventilatory therapy. In this update, the usefulness of several techniques of respiratory monitoring including conventional respiratory monitoring and more recent methods are described. Moreover, basic concepts of mechanical ventilation, their interpretation and how the appropriate analysis of the information obtained can cause an impact on the clinical management of the patient are defined.

[Basic lung ultrasound. Part 2. Parenchymal diseases]

In this second part, an analysis is made of the pathology of lung parenchyma. This text is structured into different sections, including the study of atelectasias, pneumonia and abscess, interstitial/alveolar or Blines patterns, and finally an analysis is made of pulmonary embolism. With this second part, the basic knowledge to develop lung ultrasound in the anesthesia department has been presented.

The Role of Lung Ultrasound in Diagnosis of Respiratory Distress Syndrome in Newborn Infants

BACKGROUND

Respiratory distress syndrome (RDS) is one of the most common causes of neonatal respiratory failure and mortality. The risk of developing RDS decreases with both increasing gestational age and birth weight.

OBJECTIVES

The aim of this study was to evaluate the value of lung ultrasound in the diagnosis of respiratory distress syndrome (RDS) in newborn infants.

MATERIALS AND METHODS

From March 2012 to May 2013, 100 newborn infants were divided into two groups: RDS group (50 cases) and control group (50 cases). According to the findings of chest x-ray, there were 10 cases of grade II RDS, 15 grade III cases, and 25 grade IV cases in RDS group. Lung ultrasound was performed at bedside by a single expert. The ultrasound indexes observed in this study included pleural line, A-line, B-line, lung consolidation, air bronchograms, bilateral white lung, interstitial syndrome, lung sliding, lung pulse etc.

RESULTS

In all of the infants with RDS, lung ultrasound consistently showed generalized consolidation with air bronchograms, bilateral white lung or alveolar-interstitial syndrome, pleural line abnormalities, A-line disappearance, pleural effusion, lung pulse, etc. The simultaneous demonstration of lung consolidation, pleural line abnormalities and bilateral white lung, or lung consolidation, pleural line abnormalities and A-line disappearance co-exists with a sensitivity and specificity of 100%. Besides, the sensitivity was 80% and specificity 100% of lung pulse for the diagnosis of neonatal RDS.

CONCLUSIONS

This study indicates that using an ultrasound to diagnose neonatal RDS is accurate and reliable too. A lung ultrasound has many advantages over other techniques. Ultrasound is non-ionizing, low-cost, easy to operate, and can be performed at bedside, making this technique ideal for use in NICU.

Lung ultrasonography for the diagnosis of neonatal lung disease

Ultrasound has recently become an important method for diagnostic examination and monitoring of lung disease. Many lung diseases, such as respiratory distress syndrome, transient tachypnea of the newborn, pneumonia, atelectasis and pneumothorax were diagnosed by chest X-ray or CT scan in the past, but can now easily be diagnosed with lung ultrasound. Lung ultrasound has many advantages over X-ray and CT scan including accuracy, reliability, low-cost and simplicity, as well as the fact that ultrasound incurs no risk of radiation damage. It is therefore feasible and convenient to perform at the bedside in a neonatal ward. This review focuses on features of bedside lung ultrasound and diagnosis features of common lung diseases in newborn infants, culminating in suggestions for improving the application of ultrasound in the neonatal field.

Detection of air trapping in chronic obstructive pulmonary disease by low frequency ultrasound

BACKGROUND

Spirometry is regarded as the gold standard for the diagnosis of COPD, yet the condition is widely underdiagnosed. Therefore, additional screening methods that are easy to perform and to interpret are needed. Recently, we demonstrated that low frequency ultrasound (LFU) may be helpful for monitoring lung diseases. The objective of this study was to evaluate whether LFU can be used to detect air trapping in COPD. In addition, we evaluated the ability of LFU to detect the effects of short-acting bronchodilator medication.

METHODS

Seventeen patients with COPD and 9 healthy subjects were examined by body plethysmography and LFU. Ultrasound frequencies ranging from 1 to 40 kHz were transmitted to the sternum and received at the back during inspiration and expiration. The high pass frequency was determined from the inspiratory and the expiratory signals and their difference termed ΔF. Measurements were repeated after inhalation of salbutamol.

RESULTS

We found significant differences in ΔF between COPD subjects and healthy subjects. These differences were already significant at GOLD stage 1 and increased with the severity of COPD. Sensitivity for detection of GOLD stage 1 was 83% and for GOLD stages worse than 1 it was 91%. Bronchodilator effects could not be detected reliably.

CONCLUSIONS

We conclude that low frequency ultrasound is cost-effective, easy to perform and suitable for detecting air trapping. It might be useful in screening for COPD.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01080924.