ARDS: What Works!

Todd M Bull MD Associate Professor of Medicine

Division of Pulmonary Sciences and Critical Care Division of Cardiology

Director Pulmonary Vascular Disease Center University of Colorado, Denver

A 42 year old female is admitted after a drug overdose complicated by emesis and aspiration. Intubation, mechanical ventilation, and neuromuscular blockade are initiated in the emergency department:

AC, Vt 680, RR 10, FiO2 100%, PEEP 5. She weighs 68kg Ht 6’ Vent mechanics include: PIP 52, Pplat 48, SpO2 86% P/F 54 ABG pH 7.38, PaCO2 36, PaO2 54, SpO2 86%

What interventions will improve this patients outcome A. Reduce tidal volume to 360 cc (6cc/kg) B. Early prone ventilation C. Diuresis when hemodynamically stable D. Early Neuromuscular blockade E. All of the above

Topics

•  New definition •  Breaths: Little or Big? •  Wet or Dry? •  Moving or Still? •  Upside down or Right side up?

Ashbaugh 1967

AECC 1994 (ARDS and ALI)

Berlin 2012 JAMA

ARDS

Jama Vol 307 2012

•  Acute Lung Injury is out •  Still Acute (7 days, most within 72 hrs) •  Bilateral opacities (CXR or CT) •  Do not need to exclude heart failure

–  “Not Explained” by CHF –  “Objective assessment” (echo) if no clear

trigger

3 Categories: Hypoxia Pa02/FI02 1) mild: P/F 201-300 2) moderate: P/F 101-200 3) severe: <= 100

Ventilator-induced lung injury

Ventilator induced lung injury – 5 minutes

Ventilator induced lung injury – 20 minutes

Topics

•  New definition •  Breaths: Little or Big? •  Wet or Dry? •  Moving or Still? •  Upside down or Right side up?

Multicenter RCT

861 patients

6 cc/kg vs. 12 cc/kg (Ideal Body Weight)

Pplat of 30 vs. 50 cm H20

New Eng J Med 2000; 342: 1301-1308.

ARDSnet Study

New Eng J Med 2000; 342: 1301-1308.

Mortality: 31% vs. 39%

Days on Vent: 11 vs. 12

Lung Protective Ventilation Clinical Trial Results: Survival Benefit

•  861 pts., 10 centers, stopped early for survival benefit •  Secondary Endpoints over 28 days: Lung protective Group Had - Less organ failure days

- more ventilator free days - Barotrauma no different NEJM 2000; 342:1301-8.

P = .007

31% 40%

NNT = 11

Lung Protective Ventilation Controversies

•  Implementation outside of tertiary hospitals in USA is poor

•  Implementation at tertiary hospitals outside of US is only fair

Topics

•  New definition •  Breaths: Little or Big? •  Wet or Dry? •  Moving or Still? •  Upside down or Right side up?

NEJM 2006: Oscar

N= 1000 pts ALI Conservative vs. Liberal Fluid Balance Day 7 -136 ml vs. 6992 ml

1◦- All cause mortality- day 60 25% vs. 28% p=0.3

2◦- Vent Free days: 14 vs. 12 p<0.001 ICU Free day: 13 vs. 11 p< 0.001

Topics

•  New definition •  Breaths: Little or Big? •  Wet or Dry? •  Moving or Still? •  Upside down or Right side up?

NEJM 2010: ACURASYS

N= 340 pts Severe ARDS P/F < 150

1◦- In hospital mortality- day 90 31% vs. 40% p=0.08 nnt = 25

28 day mortality 23% vs. 33% p=0.05

Topics

•  New definition •  Breaths: Little or Big? •  Wet or Dry? •  Moving or Still? •  Upside down or Right side up?

Prone Ventilation

Prone Ventilation in ARDS

SUPINE

PRONE

SUPINE AGAIN 1. AJRCCM 2001;164(1):131-40 2. NEJM 2001; 345(8):568-73 3. JAMA 2009;302(18):1977-84 4. JAMA 2004; 292;2379-87

•  Goal: Leverage nondependent, less involved lung parenchyma - ALI is regionally heterogeneous1

•  Improves oxygenation short term

•  But – Nondependent lung will succumb to the perils of being dependent

•  Randomized Clinical Trials2-4

-  Improves oxygenation (transient) -  Does not appear harmful, easy to do - But….Does not improve survival

NEJM 2001

JAMA 2009

N= 446 pts Enrolled by 36 hrs “Proned”: 16 hrs “De-proned”: 4 hours

1◦- All cause mortality- day 28 16% vs. 32% p< 0.001 nnt = 6

All cause mortality- day 90 23% vs. 41%

NEJM 2013 Proseva

Extracorporeal Membrane Oxygenation (ECMO) Principles

•  Veno-Venous route (V-V ECMO) for ARDS • Anticoagulation now becoming minimal for V-V ECMO •  “Ultra Lung Protective”

High Frequency Oscillation

Chest 2007;131:1907-16

• 3-5 cycles/second (Hertz) – 180-300 “breaths”/min •  Piston Deflection Setting (“Power” or “Wiggle”)

- 60-90 cm H20 •  No set peep, no set tidal volume

A 42 year old female is admitted after a drug overdose complicated by emesis and aspiration. Intubation, mechanical ventilation, and neuromuscular blockade are initiated in the emergency department:

AC, Vt 680, RR 10, FiO2 100%, PEEP 5. She weighs 68kg Ht 6’ Vent mechanics include: PIP 52, Pplat 48, SpO2 86% P/F 54 ABG pH 7.38, PaCO2 36, PaO2 54, SpO2 86%

What interventions will improve her outcome A. Reduce tidal volume to 360 cc (6cc/kg IBW) B. Early prone ventilation C. Diuresis when hemodynamically stable D. Early Neuromuscular blockade E. All of the above

A 42 year old female is admitted after a drug overdose complicated by emesis and aspiration. Intubation, mechanical ventilation, and neuromuscular blockade are initiated in the emergency department:

AC, Vt 680, RR 10, FiO2 100%, PEEP 5. She weighs 68kg Ht 6’ Vent mechanics include: PIP 52, Pplat 48, SpO2 86% P/F 54 ABG pH 7.38, PaCO2 36, PaO2 54, SpO2 86%

What interventions will improve this patients outcome A. Reduce tidal volume to 360 cc (6cc/kg) B. Early prone ventilation C. Diuresis when hemodynamically stable D. Early Neuromuscular blockade E. All of the above