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

• Lung Sliding

Videos courtesy http://sonocloud.org

Pulmonary Ultrasound

• A lack of Lung Sliding

Videos courtesy http://sonocloud.org

Pulmonary Ultrasound

• A lines8

Videos courtesy http://sonocloud.org

Pulmonary Ultrasound

• B lines8

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