Chest
Volume 147, Issue 6, June 2015, Pages 1659-1670
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Recent Advances in Chest Medicine
BLUE-Protocol and FALLS-Protocol: Two Applications of Lung Ultrasound in the Critically Ill

https://doi.org/10.1378/chest.14-1313Get rights and content

This review article describes two protocols adapted from lung ultrasound: the bedside lung ultrasound in emergency (BLUE)-protocol for the immediate diagnosis of acute respiratory failure and the fluid administration limited by lung sonography (FALLS)-protocol for the management of acute circulatory failure. These applications require the mastery of 10 signs indicating normal lung surface (bat sign, lung sliding, A-lines), pleural effusions (quad and sinusoid sign), lung consolidations (fractal and tissue-like sign), interstitial syndrome (lung rockets), and pneumothorax (stratosphere sign and the lung point). These signs have been assessed in adults, with diagnostic accuracies ranging from 90% to 100%, allowing consideration of ultrasound as a reasonable bedside gold standard. In the BLUE-protocol, profiles have been designed for the main diseases (pneumonia, congestive heart failure, COPD, asthma, pulmonary embolism, pneumothorax), with an accuracy > 90%. In the FALLS-protocol, the change from A-lines to lung rockets appears at a threshold of 18 mm Hg of pulmonary artery occlusion pressure, providing a direct biomarker of clinical volemia. The FALLS-protocol sequentially rules out obstructive, then cardiogenic, then hypovolemic shock for expediting the diagnosis of distributive (usually septic) shock. These applications can be done using simple grayscale machines and one microconvex probe suitable for the whole body. Lung ultrasound is a multifaceted tool also useful for decreasing radiation doses (of interest in neonates where the lung signatures are similar to those in adults), from ARDS to trauma management, and from ICUs to points of care. If done in suitable centers, training is the least of the limitations for making use of this kind of visual medicine.

Section snippets

History

Lung ultrasound originally was not meant to be used in emergent care. Except for echocardiography used in cardiology and sonography used in obstetrics, ultrasound in general was a tool for radiologists, and the lung in particular was not considered suitable for this imaging technology.3 Since 1989, François Jardin's ICU explored, applied, and made lung ultrasound with a portable unit a standard of care in critically ill patients. Based on our 25 years of experience using lung ultrasound in the

Tools Used for the BLUE-Protocol

One application of lung ultrasound is the onsite exploration of acute respiratory failure: the bedside lung ultrasound in emergency (BLUE)-protocol. Although the new generation of intensivists benefits from a variety of excellent machines, we keep using our 1992 technology (last updated in 2008) for several reasons: We like its resolution; 32-cm width in settings where each lateral centimeter counts; 7-s start-up time; flat, easy-to-clean, fluid-proof design; 5-MHz microconvex probe allowing

Patients, Diseases, and Profiles in the BLUE-Protocol

The BLUE-protocol was developed based on the study of 300 consecutive adults with acute respiratory failure who were admitted to our ICU and given a diagnosis. The most frequent cause of respiratory failure was pneumonia (32%) followed by acute hemodynamic pulmonary edema (24%); exacerbated COPD (18%); severe asthma (13%); pulmonary embolism (8%); pneumothorax (4%); and countless rare causes, including easy-to-diagnose ones, such as massive pleural effusion (3%). We excluded rare, unknown, and

The BLUE-Protocol: When and How Is it Used, What Occurs Practically, With How Much Accuracy?

The BLUE-protocol is done each time the physician has clinical doubts after the physical examination. The machine is brought to the bedside, the probe applied at the anterior standardized points, and the BLUE-protocol begun (Fig 10), first searching for lung sliding. If lung sliding is present, the association with predominant A-lines defines the A-profile, and a venous scan is done following a sequential order.62 An A-profile associated with a DVT is 99% specific to pulmonary embolism. For

A Development of the BLUE-Protocol: Lung Ultrasound for Diagnosing Acute Circulatory Failure—the FALLS-Protocol

For this major concern, successive tools have been used, with echocardiography currently being one of the most popular.1, 2 Many others are competing, providing an impressive list of parameters when combined, suggesting that no gold standard is currently available. The fluid administration limited by lung sonography (FALLS)-protocol is not yet supported by clinical studies but should be considered as a potential source of help in difficult situations. It is based on sequential concepts:

How Can These Protocols Affect the Routine of Several Disciplines?

Lung ultrasound in critical care is a holistic tool. A concept is holistic when the understanding of each of its multiple components is necessary to fully understand the whole.45 The result generates a whole-body approach in addition to the main vital organ. This allows for simplification of expert domains such as echocardiography, if associated with lung ultrasound. In the case of suboptimal cardiac windows, the B-profile suggests pulmonary edema and the A-profile hypovolemia, schematically.

Conclusions

The BLUE-protocol and the FALLS-protocol, two main applications of LUCI, are simple to use at each step, beginning with the choice of equipment (one simple unit, one microconvex probe for the whole body). The BLUE-protocol directly scans the lung to assess the cause of a respiratory failure. The FALLS-protocol considers a direct marker of fluid overload at the lung surface in patients with septic shock. With these applications, lung ultrasound appears once again as a visual stethoscope (from

Acknowledgments

Financial/nonfinancial disclosures: The author has reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

Other contributions: The author thanks François Jardin, MD, who made everything possible, and Gilbert Mezière, MD, for precious advice. Additional material (videos) can be seen at www.CEURF.net, section BLUE-protocol.

References (85)

  • G Soldati et al.

    Occult traumatic pneumothorax: diagnostic accuracy of lung ultrasonography in the emergency department

    Chest

    (2008)
  • VE Noble et al.

    Ultrasound assessment for extravascular lung water in patients undergoing hemodialysis. Time course for resolution

    Chest

    (2009)
  • N Lerolle et al.

    Ultrasonographic diagnostic criterion for severe diaphragmatic dysfunction after cardiac surgery

    Chest

    (2009)
  • A Reissig et al.

    Lung ultrasound in the diagnosis and follow-up of community-acquired pneumonia: a prospective, multicenter, diagnostic accuracy study

    Chest

    (2012)
  • NP Oveland et al.

    Using thoracic ultrasonography to accurately assess pneumothorax progression during positive pressure ventilation: a comparison with CT scanning

    Chest

    (2013)
  • NW Rantanen

    Diseases of the thorax

    Vet Clin North Am Equine Pract

    (1986)
  • R Targhetta et al.

    Ultrasonographic approach to diagnosing hydropneumothorax

    Chest

    (1992)
  • DA Lichtenstein et al.

    A bedside ultrasound sign ruling out pneumothorax in the critically ill. Lung sliding

    Chest

    (1995)
  • DA Lichtenstein et al.

    Relevance of lung ultrasound in the diagnosis of acute respiratory failure

    Chest

    (2008)
  • DA Lichtenstein et al.

    A-lines and B-lines: lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill

    Chest

    (2009)
  • D Lichtenstein et al.

    Integrating lung ultrasound in the hemodynamic evaluation of acute circulatory failure (the fluid administration limited by lung sonography protocol)

    J Crit Care

    (2012)
  • KA Hendrikse et al.

    Low value of routine chest radiographs in a mixed medical-surgical ICU

    Chest

    (2007)
  • D Lichtenstein et al.

    The dynamic air bronchogram. A lung ultrasound sign of alveolar consolidation ruling out atelectasis

    Chest

    (2009)
  • F Jardin et al.

    Influence of positive end-expiratory pressure on left ventricular performance

    N Engl J Med

    (1981)
  • A Vieillard-Baron et al.

    Echocardiography in the intensive care unit: from evolution to revolution?

    Intensive Care Med

    (2008)
  • SE Weinberger et al.

    Diagnostic procedures in respiratory diseases

    (2005)
  • D Lichtenstein et al.

    Intensive use of general ultrasound in the intensive care unit. Prospective study of 150 consecutive patients

    Intensive Care Med

    (1993)
  • SA Dulchavsky et al.

    Thoracic ultrasound diagnosis of pneumothorax

    J Trauma

    (1999)
  • E Maury et al.

    Ultrasonic examination: an alternative to chest radiography after central venous catheter insertion?

    Am J Respir Crit Care Med

    (2001)
  • KR Rowan et al.

    Traumatic pneumothorax detection with thoracic US: correlation with chest radiography and CT—initial experience

    Radiology

    (2002)
  • A Reissig et al.

    Transthoracic sonography of diffuse parenchymal lung disease: the role of comet tail artifacts

    J Ultrasound Med

    (2003)
  • AW Kirkpatrick et al.

    Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST)

    J Trauma

    (2004)
  • M Blaivas et al.

    A prospective comparison of supine chest radiography and bedside ultrasound for the diagnosis of traumatic pneumothorax

    Acad Emerg Med

    (2005)
  • P Vignon et al.

    Quantitative assessment of pleural effusion in critically ill patients by means of ultrasonography

    Crit Care Med

    (2005)
  • M Balik et al.

    Ultrasound estimation of volume of pleural fluid in mechanically ventilated patients

    Intensive Care Med

    (2006)
  • B Bouhemad et al.

    Clinical review: bedside lung ultrasound in critical care practice

    Crit Care

    (2007)
  • R Copetti et al.

    The ‘double lung point': an ultrasound sign diagnostic of transient tachypnea of the newborn

    Neonatology

    (2007)
  • L Gargani et al.

    Early detection of acute lung injury uncoupled to hypoxemia in pigs using ultrasound lung comets

    Crit Care Med

    (2007)
  • R Copetti et al.

    Chest sonography: a useful tool to differentiate acute cardiogenic pulmonary edema from acute respiratory distress syndrome

    Cardiovasc Ultrasound

    (2008)
  • L Gargani et al.

    Ultrasound lung comets in systemic sclerosis: a chest sonography hallmark of pulmonary interstitial fibrosis

    Rheumatology (Oxford)

    (2009)
  • G Via et al.

    Whole lung lavage: a unique model for ultrasound assessment of lung aeration changes

    Intensive Care Med

    (2010)
  • B Bouhemad et al.

    Bedside ultrasound assessment of positive end-expiratory pressure-induced lung recruitment

    Am J Respir Crit Care Med

    (2011)
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