Tag Archives: lung

Recommendations for Improved Safety of Lung Ultrasound

Posted on by
Reply

Lung ultrasound (LUS) has been emerging as a vital clinical tool. LUS aids in diagnosing a range of conditions, from pneumonia to respiratory distress syndrome or pulmonary edema. LUS was also very significant at the height of the COVID-19 pandemic, when point-of-care lung monitoring modalities were crucial.  

Diagnostic ultrasound standards and safety guidelines were established in the late 20th century to ensure the safety of ultrasound imaging and avoid ultrasound bioeffects in tissues. The Thermal Index (TI) and Mechanical index (MI) are two ultrasound exposure indices that respectively indicate the risks of tissue heating and cavitation and which must be displayed in real time during scanning. However, the lung is a tissue like no other, and the bioeffects observed in animal studies (in mice, rabbits, pigs, and monkeys) are very different from the bioeffects observed in other tissues. Capillary pulmonary hemorrhage is a unique bioeffect that is correlated to the MI. In order to avoid such specific ultrasound bioeffects, a new safety paradigm must be created for LUS.

Despite guidelines recommending MI ≤ 0.4, recent research suggests that a further reduction to MI ≤ 0.3 for enhanced safety might be needed. In addition, it is critical to account for the actual MI in situ, which is influenced by the thickness of the chest wall. This is particularly concerning in neonatal LUS safety, due to thin chest walls and intensive use.

Existing safety education varies among practitioners, and surveys indicate a lack of knowledge regarding lung ultrasound safety. In the absence of an appropriate preset, pre-installed on all machines, for neonatal LUS guaranteeing an MI ≤ 0.3, the risk of error and exposure to higher MI is significant. In pediatric and adult patients with a thicker chest wall, a higher MI would be acceptable, as long as adherence to the “as low as reasonably achievable” (ALARA) safety principle is maintained.

Overall, the recommendations for Improved Safety  of Lung Ultrasound are:

  1. To install a preset on all ultrasound machines limiting MI to ≤ 0.3 for neonatal cases.
  2. To provide a user-friendly means for practitioners to select the safety preset without manual adjustments.
  3. To allow higher MI values for pediatric and adult patients when needed for optimal imaging, considering higher ultrasound attenuation in thicker chest walls.
  4. To guide practitioners in adhering to the As Low As Reasonably Achievable (ALARA) principle and by considering the chest wall attenuation for MI > 0.3.
  5. To develop a specific Mechanical Index for Lung (MIL). The creation of a unique MIL for LUS, displayed on-screen to estimate pleural exposure accurately would increase safety and safety awareness among practitioners.

Enhancing safety in LUS requires a multifaceted approach, encompassing preset implementation, practitioner education, and technological advancements. The proposed recommendations aim to address current safety challenges, ensuring the continued effectiveness and safety of lung ultrasound in diverse clinical settings and for diverse populations (from neonates to high BMI patients). By combining technological innovations with user-friendly controls, the proposed safety paradigm seeks to strike a balance between optimal imaging outcomes and patient safety in the evolving landscape of LUS.

For more information, see the “Statement and Recommendations for Safety Assurance in Lung Ultrasound” from the American Institute of Ultrasound in Medicine (AIUM)

Marie Muller, PhD, is an Associate Professor of Mechanical and Aerospace Engineering at NC State University.

Ultrasound in the Diagnosis and Management of Chronic Obstructive Pulmonary Disease

Posted on by
Reply

Chronic Obstructive Pulmonary Disease (COPD) is a prevalent and debilitating respiratory condition that affects millions of people worldwide. While traditional diagnostic methods like spirometry and imaging techniques such as CT scans have played a vital role in managing this disease, ultrasound is emerging as a powerful tool in both diagnosis and treatment.

The Basics of COPD

COPD is a progressive lung disease characterized by the restriction of airflow due to chronic bronchitis and emphysema. The primary symptoms include breathlessness, coughing, and excessive mucus production. It is typically associated with a history of smoking, but environmental factors also play a role. Diagnosing and monitoring the progression of COPD is crucial for effective management.

The Role of Ultrasound in Diagnosis

Sonographic Assessment of Lung Morphology: Ultrasound imaging offers a noninvasive and radiation-free approach to assess lung morphology. Studies published in the Journal of Ultrasound in Medicine have demonstrated the effectiveness of ultrasound in evaluating lung parenchyma,1 pleura,1 and diaphragm.2 By examining these elements, clinicians can identify changes in the lung structure and rule out other conditions that might mimic COPD symptoms.

Evaluation of Diaphragm Function: COPD often affects diaphragm function, resulting in respiratory muscle weakness. Ultrasound allows for real-time assessment of diaphragm movement, enabling clinicians to detect early signs of diaphragmatic dysfunction.2 This information is valuable in selecting the appropriate treatment strategy for each patient.

Ultrasound-Guided Thoracentesis

In some cases, COPD patients develop pleural effusion, a condition characterized by an abnormal buildup of fluid in the pleural cavity. Ultrasound can be used to guide thoracentesis, a procedure in which this excess fluid is drained. A Journal of Ultrasound in Medicine report has highlighted the accuracy and safety of ultrasound guidance during this procedure, minimizing complications and improving patient outcomes.3

Monitoring Disease Progression

Ultrasound is not limited to the initial diagnosis but also plays a crucial role in monitoring COPD progression. Repeat ultrasound examinations can help evaluate changes in lung structure, assess diaphragm function, and track the effectiveness of ongoing treatments. Regular ultrasound monitoring can lead to more tailored and effective care plans for COPD patients.

Point-of-Care Ultrasound in COPD

Point-of-care ultrasound (POCUS) is a valuable tool for quickly assessing COPD exacerbations in emergency situations. It allows healthcare providers to rapidly evaluate lung abnormalities, pneumothorax, and pleural effusion, guiding immediate treatment decisions.4

Future Implications

As technology continues to advance, ultrasound is likely to play an even more prominent role in the diagnosis and management of COPD. Developments in portable and handheld ultrasound devices are making it easier for clinicians to perform ultrasound examinations at the bedside, providing real-time information to aid in decision-making.

Conclusion

The use of ultrasound in the diagnosis and management of COPD is a promising and evolving field. It offers a noninvasive, safe, and cost-effective means of assessing lung morphology, diaphragm function, and pleural effusion. With continued research and technological advancements, ultrasound is likely to become an indispensable tool in the fight against this chronic respiratory disease, helping patients receive more accurate diagnoses and tailored treatment plans.

References:

1. Martelius L, Heldt H, Lauerma K. B-lines on pediatric lung sonography: comparison with computed tomography. J Ultrasound Med 2016; 35:153–157. doi: 10.7863/ultra.15.01092.

2. Xu JH, Wu ZZ, Tao FY, et al. Ultrasound shear wave elastography for evaluation of diaphragm stiffness in patients with stable COPD: A pilot trial. J Ultrasound Med 2021; 40:2655–2663. doi: 10.1002/jum.15655.

3. Lane AB, Petteys S, Ginn M, Nations JA. Clinical importance of echogenic swirling pleural effusions. J Ultrasound Med 2016; 35:843–847. doi: 10.7863/ultra.15.05009.

4. Copcuoglu Z, Oruc OA. Diagnostic accuracy of optic nerve sheath diameter measured with ocular ultrasonography in acute attack of chronic obstructive pulmonary disease. J Ultrasound Med 2023; 42:989–995. doi: 10.1002/jum.16106.

Cynthia Owens, BA, is the Publications Coordinator for the American Institute of Ultrasound in Medicine (AIUM).

Interested in learning more about lung ultrasound? Check out the following articles from the American Institute of Ultrasound in Medicine’s (AIUM’s) Journal of Ultrasound in Medicine (JUM). After logging into the AIUM, members of AIUM can access them for free. Join the AIUM today!