Survival after cardiac arrest is poor but some therapies can make a difference. This presentation discusses the evidence for therpauetic hypothermia, normoxia, management of blood pressure and early cardiac catherterisation. It also makes the case that these might be elements of a bundle of care.

1. Professor Anne-Maree Kelly
Western Health
@kellyam_jec

2.  This presentation may be reproduced in part or
whole for education purposes on the condition that
each reproduced slide contains the following:
‘Reproduced with permission of Professor Anne-
Maree Kelly, Joseph Epstein Centre for Emergency
Medicine Research @Western Health, Melbourne,
Australia’

3.  Support for this meeting and advisory boards from Astra Zeneca
 Travel support to speak at a conference (on blood gases) by Radiometer
 Advisory board membership MSD
 No relationships with manufacturers of hypothermia equipment
 Co-author of NHF guidelines for the management of ACS and addenda & of
some of the research mentioned in this talk
 Editorial boards of:
◦ Annals of Emergency Medicine
◦ Emergency Medicine Australasia
◦ Hong Kong Journal of Emergency Medicine

4.  My Colleagues Dr Stephen Bernard, Dr Karen Smith and
colleagues for the ongoing, world leading body of work in this
space

5.  To review the pathophysiology of post-cardiac arrest
syndrome
 To summarize the evidence for a variety of interventions to
improve outcome after out of hospital cardiac arrest
 To propose the concept of a bundle of care approach to
management of these patients

6.  72% in the home
 Age 64 years (mean)
 82% male
 Ventricular fibrillation 37%
 Pre-hospital -> advanced cardiac life support
 If return of pulse -> transport to nearest ED

7.  Ventilation on 100% oxygen
 Sedation to maintain ETT
 12 lead ECG
 Cardiology referral
 ICU referral
 Chest Xray
 Arterial line and ABG
 Bloods
 Bladder catheter
 Early (pessimistic) prognostication
ROSC rate = 24%
Survival to discharge =7.6%
Sasson et al. Circ Cardiovasc Qual Outcomes 2010:3:63-812.

8.  Cerebral and cardiac dysfunction due to prolonger whole
body ischaemia
 Elements
◦ Anoxia brain injury
◦ Myocardial dysfunction
◦ Systemic ischaemia/ reperfusion response
◦ Persistent precipitating pathology
 Contribution of the elements varies between individuals

9.  Ventilation
◦ 100% oxygen or normoxia?
◦ What pCO2 target?
 Blood pressure
◦ What target and how?
 Cath lab
◦ Just STEMI?
 Therapeutic hypothermia
◦ If ‘Yes’, how?

10.  High oxygen concentration may increase free radical
production
 Some observational data (from ICU) that higher oxygenation
is harmful
 Each 100mmHg increase in pO2 (on ICU admission) associated
with 24% increase in mortality
 Currently the subject of RCT proposals
Kilgannon et al. JAMA 2010;123:2717-2722

11.  Avoidance of both hyperoxia and hypoxia
 SpO2 target 94-96%
 Avoid hypocarbia as it:
◦ Causes cerebral vasoconstriction
◦ Hyperventilation decreases cardiac output

12.  Increased blood pressure may improve cerebral perfusion,
BUT
 Inotropes/ pressors may cause additional cardiac injury
 Observational data only suggesting ~30% improvement in
outcome with achievement of haemodynamic stability
 Studies used different targets
 MAP 80-100mmHg vs 65-70mmHg
 Optimal MAP target remains unclear
Gaieski et al. Resuscitation; 2009;80:418-24.
Sunde et al. Resuscitation 2007; 73:29-39.

13.  Aim for mean arterial pressure of 65-100mmHg
 Taken into consideration ‘usual’ BP and severity of
myocardial dysfunction

14.  Judicious fluid loading
 Inotropic drug therapy
 Mechanical support devices e.g.
◦ IABP
◦ ECMO

15.  Anoxic brain injury responsible for ~2/3rds of deaths
post cardiac arrest
 Therapeutic hypothermia is a major recent advance in
neuroprotection
 How it works?
◦ Multifactorial?
◦ Decreases cerebral oxygen demand
◦ ? Direct cellular effects
◦ Reduction in reactive oxygen species generation

16.  32 C-34 C for 12-24 hours
 24 hours is current recommendation
 In meta-analysis
 RR best cerebral performance categories 1.55 (95% CI 1.22-
1.96)
 RR survival to hospital discharge 1.35 (95% CI 1.10-1.65)
Arrich et al. Cochrane Database Syst Rev 2009; CD 004128

17.  Strong RCT evidence of OHCA with VF as initial rhythm


Evidence less clear for PEA/ Asystole
 Lower overall survival
 Not all are cardiac in origin (? ~50%)
 Some trend towards benefit (one study)
 Survival 19% vs 7%
 Good outcome13% vs. 0%
Study Survival Good neurological
outcome
HACA 59% vs 45% 55% vs 39%
Bernard 49% vs. 32% 49% vs. 26%
HACA. NEJM 2002;346:549-56
Bernard et al. NEJM 2002; 346:557-63
Haschimi-Idrissi et al. Resuscitation 2001; 51:275-81.

18.  Cooled IV fluids (40ml/kg)
 Surface cooling
 Intravascular cooling

19.  Persuasive animal data that the earlier the better
 Two RCT have demonstrated that pre-hospital cooling
using IV fluids is safe, feasible and effective
 No clinical outcome benefit shown compared to in-
hospital cooling (yet)
◦ Main (probable explanation): small difference in times

20.  STEMI unconscious post cardiac arrest were excluded from
PCI vs. thrombolysis trials
 Initial ECG shows STEMI in 30-60% of patients with ROCS after
OHCA
 Good evidence that early angiography with view to PCI
improves outcome for patients with STEMI (RCT and
observational)

21.  Recent study showed significant coronary lesions
present in up to 66% of patients with OHCA without
ST elevation.
 Registry data has reported primary PCI as an
independent predictor of survival regardless of initial
ECG (odds ratio, 2.06; 95% CI, 1.16 to 3.66).
Reynolds et al. J Intensive Care Med 2009; 24: 179-86.
Dumas et al. Circ Cardiovasc Interv 2010; 3:200-7.

22.  2902 post arrest patients in Victoria
 Transported to one of 70 hospitals
 1816 (63%) of patients were treated at hospitals with 24 hour
cardiac interventional services
 After adjusting for differences in baseline characteristics,
treatment at hospitals with 24 hour cardiac interventional
services was significantly associated with survival (odds ratio
1.40; 95% CI 1.12-1.74, p=0.003)
Stub D et al. Heart. 201197:1489-94.

23.  Bundles of care are a structured way of improving
processes of care and patient outcomes
 3-5 components performed collectively and reliably
 ALL OR NONE
 The power comes from the evidence-base and the
consistency of implementation
 Examples:
◦ Central line bundle IHI
◦ Goal-directed sepsis therapy

24.  Initiation of therapeutic hypothermia in ED (32-34 C).
 Maintain for 24 hours with slow re-warming
 Optimization of haemodynamic status (MAP 65-100mmHg)
 Transfer to cardiac catheter laboratory early
 Avoidance of hyperoxia (SpO2 94-96%)
A number of ‘before-and-after’ studies support
the concept.

25.  For patients with OHCA (?VF initial rhythm)
 SpO2 94-96%
 Core temperature <35 C
 MAP 65-100mmHg
 Transfer to cath lab within 110 mins.

26.  Systems of care for time critical illness improves
outcomes
 Emerging evidence of improved outcomes in OHCA in
specialized centres (Japan and Sweden)
◦ OR improved survival ~3.4
 Is this workable in the Australian context?