Bedside Ultrasound for the diagnosis of ALI ARDS
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Transcript of Bedside Ultrasound for the diagnosis of ALI ARDS
Bedside Ultrasound for the diagnosis of ALI ARDS
Chief of Medicine Conference10/29/2013
Cameron Bass, MD
Disclosures
• Mobisante ™ provided me with one of their smartphone based ultrasound devices for use in the study
• The UWMC pays my salary, so I suppose I’m less likely to say bad things about them publically
• I haven’t brushed my hair in almost a full year
Outline• Background on Cameron• Critical Illness in the resource limited setting• ARDS review• Ultrasound
– Basic review– Pulmonary ultrasound
• Pulse oximetry• Bedside Ultrasound for the diagnosis of ARDS
– Methods– Challenges– Future directions
• Brilliant and incisive Q&A
A Brief Introduction to Cameron
• Engineering
• Rwanda
Critical Illness in the Resource Limited Setting
• Resource allocation– Cost of Critical Care– Faith in the system1
– A lack of knowledge2
Critical Illness in the Resource Limited Setting
• Appropriate use of technology– Ventilators
– Ultrasound3
Critical Illness in the Resource Limited Setting
• Developing vs third world vs resource limited
Brief Introduction to ARDS
• Initial description in 1967 by Ashbaugh4
• New definition in 1994 by AECCC5
– P:F ratio– Bilateral infiltrates on CXR (“A pulmonary Edema pattern”)– PCWP < 18mm Hg
• Berlin definition in 20126
– Risk factors– Timing
Prevalence of ARDS
• In the united states– >150,000 cases per year7
• In the resource limited setting– Challenges to diagnosis
– Differences in etiology
• 1540 m/s
• You know what happens when you make an assumption? (Samuel L Jackson)
• Reverberation artifact• Comet tail artifact
How ultrasound works cartoon
Pulmonary Ultrasound
• A lack of Lung Sliding
Videos courtesy http://sonocloud.org
Thoracic Ultrasound
• Ease of teaching9
Thoracic Ultrasound
• Lichtenstein and the Blue protocol8
BLUE protocol8
Thoracic Ultrasound
• Specific studies for ARDS– BLUE protocol8
– FALLS protocol
– ARDS vs Acute Pulmonary Edema10
Arterial Blood Gasses• Cost of performing– Estimated at $110 cost to patient
• SpO2 to ABG– In adults11
• S/F = 64 + 0.84 x (P/F) [p < 0.0001; r = 0.89) • S/F of 235 ≈ P/F of 200• S/F of 315 ≈ P/F of 300
– In pediatrics12
• S/F = 76 + 0.62 x PF (p < 0.0001, R2 = 0.61)• S/F 201 ≈ P/F of 200• S/F 263 ≈ P/F of 300
Bedside Ultrasound for the diagnosis of ARDS
Study Design
Bedside Ultrasound for the diagnosis of ARDS
• Scanning– Technique
– Mobisante
Bedside Ultrasound for the diagnosis of ARDS
• Reviewing Data– Chest Radiographs
– Ultrasound scans
Bedside Ultrasound for the diagnosis of ARDS
• Statistical Analysis
– Lack of a Gold Standard• PPA• NPA• Kappa
Challenges
• Identifying Patients• Prevalence• Positioning• SpO2 measurements• IRB/HIPAA
Future Directions
• Cambodia/Rwanda
Citations1. Neill KJ Adhikari, Robert A Fowler, Satish Bhagwanjee, Gordon D Rubenfeld, Critical care and the global burden of critical illness in adults, The Lancet,
Volume 376, Issue 9749, 16–22 October 2010, Pages 1339-13462. Dünser MW, Baelani I, Ganbold L. “A review and analysis of intensive care medicine in the least developed countries.“Crit Care Med. 2006
Apr;34(4):1234-42.3. Sippel S, Muruganandan K, Levine A, Shah S. “Review article: Use of ultrasound in the developing world.” Int J Emerg Med. 2011 Dec 7;4:72. doi:
10.1186/1865-1380-4-72.4. Ashbaugh D, Bigelow D, Petty T, Levine B (1967). "Acute respiratory distress in adults". Lancet 2 (7511): 319–23.5. Bernard G, Artigas A, Brigham K, Carlet J, Falke K, Hudson L, Lamy M, Legall J, Morris A, Spragg R (1994). "The American-European Consensus
Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial 6. CV. Marco Ranieri, MD (2012). "The ARDS Definition Task Force*. Acute Respiratory Distress Syndrome: The Berlin Definition". JAMA 307 (23): 2526–
25337. Gordon D. Rubenfeld, MD, MSc; Margaret S. Herridge, MD, MPH, FCCP. “Epidemiology and Outcomes of Acute Lung Injury” Chest. 2007;131(2):554-
562. doi:10.1378/chest.06-19768. Lichtenstein et al. Relevance of lung ultrasound in the diagnosis of acute respiratory failure. The BLUE-protocol. Chest 2008;134:117-125 9. G Bedetti 1 , L Gargani 2 , A Corbisiero 3 , F Frassi 2 , E Poggianti 2 and G Mottola*“Evaluation of ultrasound lung comets by hand-held
echocardiography“ Cardiovascular Ultrasound10. Roberto Copetti* 1 , Gino Soldati 2 and Paolo Copetti . Chest sonography: a useful tool to differentiate acute cardiogenic pulmonary edema from
acute respiratory distress syndrome. Cardiovascular Medicine . 29 April 200811. Rice, Wheeler, bernard et al. ARDSNET “Comparison of the Sp O 2 /F IO 2 Ratio and the Pa O 2 /F IO 2 Ratio in Patients With Acute Lung Injury or
ARDS” CHEST 2007; 132:410–41712. Robinder G. Khemani, MD, MSCI; Neal R. Patel, MD, MPH; Robert D. Bart, III, MD; and Christopher J. L. Newth, MD “Comparison of the Pulse
Oximetric Saturation/Fraction of Inspired Oxygen Ratio and the Pa O 2 /Fraction of Inspired Oxygen Ratio in Children* CHEST 2009; 135:662-668