Lung ultrasound for pneumothorax in children: relevant limits

POCUS in the PICU: A Narrative Review of Evidence-Based Bedside Ultrasound Techniques Ready for Prime-Time in Pediatric Critical Care

Point-of-care ultrasound (POCUS) is an accessible technology that can identify and treat life-threatening pathology in real time without exposing children to ionizing radiation. We aim to review current evidence supporting the use of POCUS by pediatric intensivists with novice-level experience with bedside ultrasound. Current evidence supports the universal adoption of POCUS-guided internal jugular venous catheter placement and arterial line placement by pediatric critical care physicians. Focused cardiac ultrasound performed by PICU physicians who have completed appropriate training with quality assurance measures in place can identify life-threatening cardiac pathology in most children and important physiological changes in children with septic shock. POCUS of the lungs, pleural space, and diaphragm have great potential to provide valuable information at the bedside after validation of these techniques for use in the PICU with additional research. Based on currently available evidence, a generalizable and attainable POCUS educational platform for pediatric intensivists should include training in vascular access techniques and focused cardiac examination. A POCUS educational program should strive to establish credentialing and quality assurance programs that can be expanded when additional research validates the adoption of additional POCUS techniques by pediatric intensive care physicians.

Electrical impedance tomography to aid in the identification of hypoxemia etiology: Massive atelectasis or pneumothorax? A case report

Background

Bedside ultrasound is often used to determine the etiology of hypoxaemia, but not always with definitive results. This case reports the application of electrical impedance tomography (EIT) and saline injection to determine the etiology of hypoxaemia in a complex case that could not be identified by bedside ultrasound. The determination of the etiology of hypoxaemia by EIT and saline injection, regional ventilation and perfusion information can be used as a new clinical diagnostic method.

Case presentation

A post-cardiac surgery patient under prolonged mechanical ventilation for lung emphysema developed sudden hypoxemia in the intensive care unit (ICU). A line pattern and lung sliding sign abolishment were found in the left lung, but there was no evidence of a lung point sign on bedside ultrasound. Hence, the initial diagnosis was considered to be a massive pneumothorax. To further define the etiology, EIT and saline bolus were used to assess regional ventilation and perfusion. A massive ventilation defect was found in the left lung, in which regional perfusion was maintained, resulting in an intrapulmonary shunt in the left lung. Finally, the conjecture of a pneumothorax was ruled out considering the massive atelectasis. After the diagnosis was clarified, hypoxaemia was corrected by restorative ventilation of the left lung after changing the patient's posture and enhancing sputum drainage with chest physiotherapy.

Conclusions

This was the clinical case involving EIT and saline bolus to establish the differential diagnosis and guide clinical decisions for patients with acute hypoxemia. This study highlighted that combination regional ventilation, EIT perfusion, and saline bolus provided helpful information for determining the etiology of hypoxemia. The results of this study contribute to the development of emergency patient management.

Lung Ultrasound to Assess One Lung Ventilation: A Pediatric Case Series

Objectives: One lung ventilation (OLV) is the preferred ventilation technique for thoracoscopy as it provides a better exposure of the operative field and grants the protection of the healthy lung. Preoperative evaluation of lung exclusion is necessary and different methods are available. In recent years lung ultrasound (US) gained popularity and its use for monitoring the endotracheal tube position is widely reported. The existing evidence on adults addresses lung US as effective, yet only few data are available in children. Therefore, we present our experience with lung US as verification method for pediatric OLV. Methods: All patients undergoing OLV for video-assisted thoracoscopic surgery from January 2019 to May 2021 and for whom lung exclusion was confirmed through lung US were involved. Lung exclusion was considered effective when absence of lung motion and presence of lung pulse were encountered. When lung US did not match these criteria, repositioning of the endobronchial device followed by US verification was performed. When lung US met the exclusion criteria surgery was started and direct thoracoscopic observation was used to verify lung exclusion. Results: A total of 20 patients, accounting for 22 procedures, were involved. Absence of lung motion and presence of lung pulse were assessed in the operative-side lung for all patients. Lung exclusion was confirmed through thoracoscopy. Postoperative lung US proved the reappearance of lung motion in the previously excluded lung. Conclusions: In our center experience lung US resulted to be a safe, effective, and time-saving verification method for OLV. Further studies are needed to define its sensitivity and specificity.

Pediatric pneumothorax: Case studies and review of current literature

Pneumothorax is an abnormal collection of air between the lung and chest wall. Pneumothorax management guidelines put forth by the American College of Chest Physicians, European Respiratory Society, and British Thoracic Society are specific to adult patients. These guidelines' utility has not been addressed in pediatric populations, which causes significant management variation in younger patients. Additionally, pneumothorax management ranges from conservative to surgical treatment, but these approaches, timelines, and effectiveness have not been validated in significant numbers of pediatric patients. Here, we present three cases of pediatric pneumothorax with variable clinical courses—one with persistent air leak despite chest tube presence who underwent VATS and surgical resection of apical blebs. In contrast, the other two cases were managed more conservatively. We reviewed the current literature for diagnostic and management of pediatric patients with pneumothorax, which underscores the need for guidelines specific to this population.

Point-of-Care Lung Ultrasound to Diagnose the Etiology of Acute Respiratory Failure at Admission to the PICU

OBJECTIVES

Determine the sensitivity and specificity of point-of-care lung ultrasound in identifying the etiology of acute respiratory failure at admission to the PICU.

DESIGN

Prospective observational study.

SETTING

Tertiary PICU.

PATIENTS

Children older than 37 weeks gestational age and less than or equal to 18 years old admitted to the PICU with acute respiratory failure from December 2018 to February 2020.

INTERVENTION

Point-of-care lung ultrasound performed within 14 hours of admission to the PICU by physicians blinded to patient history and clinical course. Two physicians, blinded to all clinical information, independently interpreted the point-of-care lung ultrasound and then established a consensus diagnosis (ultrasound diagnosis). The ultrasound diagnosis was compared with an independent, standardized review of the medical record following hospital discharge (final diagnosis).

MEASUREMENTS AND RESULTS

Eighty-eight patients were enrolled in the study. Forty-eight patients had a final diagnosis of bronchiolitis/viral pneumonitis (55%), 29 had pneumonia (33%), 10 had status asthmaticus (11%), and one was excluded because of an inability to differentiate the final diagnosis. Point-of-care lung ultrasound correctly identified the etiology of acute respiratory failure in 56% of patients (49/87; 95% CI, 46-66%). It identified bronchiolitis/viral pneumonitis with 44% sensitivity (95% CI, 0.31-0.58) and 74% specificity (95% CI, 0.59-0.85), pneumonia with 76% sensitivity (95% CI, 0.58-0.88) and 67% specificity (95% CI 0.54-0.78), and status asthmaticus with 60% sensitivity (95% CI, 0.31-0.83) and 88% specificity (95% CI, 0.79-0.94).

CONCLUSIONS

In contrast to literature demonstrating high utility differentiating the cause of acute respiratory failure in adults, blinded point-of-care lung ultrasound demonstrates moderate sensitivity and specificity in identifying the etiology of pediatric acute respiratory failure at admission to the PICU among children with bronchiolitis, pneumonia, and status asthmaticus.