Stephen Bernard shares his thoughts and the current evidence for using oxygen for cardiac arrest patients. Oxygen is ubiquitous in society! You can buy it in bottles and there are even oxygen cafes. This is especially true in hospitals where oxygen is used frequently and often without much thought. Oxygen is a natural substance. So surely, a short time on 100% oxygen can’t be harmful, right? Stephen wants to challenge that idea. In this talk he presents the data on why oxygen might be harmful to your patients, particularly following a cardiac arrest. Out-of-hospital cardiac arrest (OHCA) is common and carries a high mortality rate. In Victoria, Australia, approximately 50% of patients with an initial cardiac rhythm of VF achieve a return of spontaneous circulation (ROSC) and 30% overall survive to hospital discharge. The outcome for patients is improving. This is due mainly to faster ambulance response times and increased rates of bystander CPR. What is done in the hospital has altered the patient’s outcomes in the same way. Currently, OHCA patients who have achieved ROSC but who remain unconscious routinely receive 100% oxygen for several hours in the ambulance, ED, cardiac catheterisation laboratory until admission to ICU. However, there is now evidence from laboratory studies and preliminary observational clinical studies that the administration of 100% oxygen during the first few hours following resuscitation may increase both cardiac and neurological injury. Clinical trials are underway to test whether titrated oxygen to a target oxygen saturation of 90-94% in the immediate hours after ROSC results in improved outcomes compared with 100% oxygen. Join Stephen as he makes you think twice about blindly using oxygen for patients following a cardiac arrest.

1. First, do no oxygen
Stephen Bernard
MD FACEM FCICM FCCM ASM

2. First, a story……..

3. Warren
Zapol

7. Conclusion
A critical care physician can get
an arterial line in any artery ……

13. Dion Stub, Karen Smith, Stephen Bernard, Ziad Nehme, Michael
Stephenson, Janet E. Bray, Peter Cameron, Bill Barger, Andris H.
Ellims, Andrew J. Taylor, Ian T. Meredith, David M. Kaye for the
AVOID Investigators.
Circulation 2015; 131:2143-50
AVOID StudyAVOID Study
AAirir VVersusersus OOxygenxygen IIn ST-elevationn ST-elevation
MyocarMyocarDDial Infarctionial Infarction

14. Trial Design
Paramedics Assess Patient
Symptoms of STEMI <12 hours, O2 Sats ≥ 94%
ST-elevation ≥2 contiguous ECG leads
Intended for primary PCI
Stub et al. AHJ 2012;163;3;339-345
Clinicaltrials.gov NCT01272713
Exclusion Criteria
Oxygen saturation <94% measured on pulse oximeter
Oxygen administration prior to randomization
Altered conscious state
Planned transport to a non-participating hospital

15. Characteristic
Oxygen Arm
N=218
No Oxygen Arm
N=223
Status on arrival at the catheterization laboratory
Oxygen being administered, %† 95.9 7.7
Oxygen dose, median (IQR)† 8.0 (8.0, 8.0) 4.0 (2.0, 8.0)
Pain score, median (IQR) 2.0 (0.0-4.0) 2.0 (0.5-3.5)
Time from Paramedic on scene to
hospital arrival, median (IQR)
55.0 (46.0, 69.0) 56.5 (48.0, 68.8)
Cardiac arrest, % 4.6 3.6
Cardiogenic Shock, % 5.0 5.4
† P for difference <0.05
SpO2 in patients with STEMI
P trend <0.05

17. Resuscitation. 2012 Apr;83(4):417-22

18. Animal studies

20.  Multicenter retrospective cohort study
 120 US hospitals 2001-2005
 Non-traumatic cardiac arrest within 24 hours
of ICU admission
 Association between PaO2 of 1st
ABG in ICU
and in-hospital mortality
-Hyperoxia mortality rate 63%
-Hypoxia mortality rate 57%
-Normoxia mortality rate 45%

24. The EXACT pilot study
Reduction of oxygen after cardiac arrest
 Phase 2 study
 Post VF arrest with pulse oximeter >94%
 Paramedics randomise O2 to 2L/min or
>10L/min
 Increase to >10L/min if desaturation / re-arrest

25. The EXACT pilot study
Reduction of oxygen after cardiac arrest
 34 patients
 5/18 allocated to 2L/min desaturated <94%
 0/16 allocated to 10L/min desaturated <94%

26. The EXACT Phase 3 study
 NHMRC funded for 2016-2019
 3 States in Australia
 1,360 patients post cardiac arrest
 Sample size based on 35% to 44% survival
increase
 Paramedic randomisation to 4L/min then 2L/min
with target O2 sat 90-94%
 Continue allocation through to ICU

27. Thanks!
@AmbVicMedic
s.bernard@alfred.org.au