Cardiopulmonary Resuscitation (CPR)

Latest Guidelines

1. International Liaison Committee on Resuscitation (ILCOR). 2005 International Consensus Conference on Cardiopulmonary Resuscitation and Emergency Cardiac Care Science with Treatment Recommendations. Resuscitation 2005; 67: 157-342. [Reference]
2. European Resuscitation Council Guidelines for Resuscitation 2005. Adult, paediatric and neonatal resuscitation, and much more (see later). Resuscitation 2005; 67 (Suppl 1):S1-S190. [Reference]
   
3. American Heart Association (AHA). 2005 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2005; 112: IV-1 – IV-211. [Reference]
4. Australian Resuscitation Council (ARC) and New Zealand Resuscitation Council (NZRC) Local guidelines based on ILCOR 2005 for Adult Advanced Life Support, Paediatric Advanced Life Support, Neonatal Guidelines plus Guidelines for Airway, Breathing, Compressions and Cardiopulmonary Resuscitation.
   

What’s new in CPR

(Basic Life Support) (AHA)

• First rescuer to use ‘head tilt-chin lift’ if perceives absence of ‘normal’ breathing over 10 seconds.
• Emphasis on chest compression “push hard and fast“, at rate of 100 per min for all. Allow full chest recoil. Change ‘compressor’ every 2 minutes.
• Lay rescuer not to feel for a pulse, but to continue CPR until victim starts to move ‘signs of life’ / AED arrives / professional help arrives.
• Ratio of compressions:breaths is now 30:2 for all lone rescuers + with two rescuers in adults until airway isolated by ETT. Children two rescuers ratio of compressions:respirations remains at 15:2; neonates 3:1.
• Once advanced airway in place, compressions at 100/min (total) and respirations at 8-10/min.
• Cardiac compressions alone (no ventilations) recommended for adult, out-of-hospital primary cardiac arrest (not respiratory) if witnessed, and with shockable rhythm or short period (<4 minutes) of untreated arrest.

SOS-KANTO study group. Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-KANTO): an observational study. Lancet 2007;369:920-6. [Reference]

• Cardiac compressions alone also recommended if bystander not trained in CPR, or not confident in their ability.

Sayre M, Berg R, Cave D et al. Hands-only (compression-only) cardiopulmonary resuscitation: A call to action for bystander response to adults who experience out-of-hospital sudden cardiac arrest. Circulation 2008;117:2162-67. [Reference] (Editorial: Soar J, Nolan J. Cardiopulmonary resuscitation for out of hospital cardiac arrest. BMJ 2008;336:782-3.)

Advanced Life Support (AHA Editorial)

• Single universal algorithm maintained, splitting into two separate paths managing ‘shockable’ rhythms (VF/VT) or ‘non-shockable’ rhythms (asystole and PEA).
• Initial defibrillation is one shock and immediately resume CPR beginning with chest compressions. Only interrupt CPR to check patient’s rhythm after 5 cycles (ie. about 2 mins).
  • ARC still recommend when using a manual defibrillator stacked DC shocks x 3 for the first defibrillation attempts, for a witnessed arrest in VF. Otherwise single DC shocks as above.
• Thus, ALS is based on 5 cycles or 2 mins of uninterrupted CPR – pulse and rhythm checks no longer done after each defibrillation.
• Initial defibrillation dose for all modern (biphasic) defibrillators is device-specific ie. 120 J for rectilinear biphasic machines, or 150 – 200 J for biphasic truncated devices. If machine type unknown, start at 200 J and stay at this amount for all subsequent shocks. Defibrillation dose for all old (monophasic) defibrillators is now 360 J, with no escalation or ‘ramp up’ of joulage.
  • NZRC recommend maximum output up to 360 J for all manual defibrillators, whether biphasic or monophasic, given as rapid DC shock triplets separated by 2 min of CPR. AED devices to change to single shock biphasic defibrillators when available.
• Paediatric initial defibrillation dose is 2 J/kg first dose and then 4 J/kg. (ARC also 2,4,4 J/kg. ERC and NZRC 4 J/kg for all shocks;).
• Adrenaline (epinephrine) still given IV or IO (intraosseous) about every 3-5 minutes; or vasopressin 40 U once IV or IO to replace first or second dose of adrenaline (has longer half life of 10-20 minutes).
• Antiarrhythmics and bicarbonate have low priority – used after 2-3 shocks plus adrenaline, with continuous CPR. Amiodarone 300 mg then 150 mg IV or IO preferred to lignocaine (only indicated if amiodarone unavailable). Atropine 1mg repeated to 0.04 mg/kg for asystole remains.
• Important list of potentially reversible causes emphasised: ‘6Hs and 5Ts’: hypovolaemia, hypoxia, hydrogen ion (acidosis), hypo/ hyperkalaemia, hypoglycaemia (new), hypothermia; toxins (tablets), tamponade (cardiac), tension pneumothorax, thrombosis – coronary or pulmonary, trauma (new). NZRC go for ‘5Hs (including hyper / hypoglycaemia) and 4Ts’, while ARC and ERC stick with the old ‘4Hs and 4Ts’.
• Induced hypothermia cooled to 32-34 oC for 24 hours for unconscious adults with return of spontaneous circulation (ROSC) is recommended, when initial rhythm was VF. Use cooling blanket or external ice packs, or large-volume 40 mL/kg ice-cold 4oC saline.

Kim F, Olsufka M, Longstreth WT Jr, et al. Pilot randomized clinical trial of prehospital induction of mild hypothermia in out-of-hospital cardiac arrest patients with a rapid infusion of 4 degrees C normal saline. Circulation 2007; 115:3064-70 [Reference]

Jacobs I, Morley P. The Australian Resuscitation Council: new Guidelines for 2006. Crit Care Resuscitation 2006;8:87-8.

Parfitt A. Resuscitation guidelines. Lancet 2006;367:283-4. [Reference]

Hazinski MF, Nadkarni VM et al. Major changes in the 2005 AHA Guidelines for CPR and ECC. Circulation 2005;112:IV-206-IV-211. [Reference]

Chamberlain D. New international consensus on cardiopulmonary resuscitation. BMJ 2005;331:1281-2. [Reference]

Resuscitation Resource Documents

• European Resuscitation Council (ERC) and American Heart Association (AHA) reviews cover all aspects of cardiopulmonary resuscitation and emergency cardiac care. Australian Resuscitation Council (ARC) Guidelines are less extensive or comprehensive.
• ERC and AHA have included BLS, airway and ventilation, ALS, paediatric and neonatal life support, plus arrhythmia management; post-CPR care; management of ACS; stroke management; life-threatening electrolyte abnormalities; toxicology; drowning; hypothermia; near-fatal asthma; anaphylaxis; cardiac arrest in trauma and pregnancy; electrocution and lightning strike; and ethical aspects.

CPR Techniques and Devices

Techniques. These require additional equipment / training / personnel. So far none is superior to standard manual CPR. Clinical human data exist for:

• High-frequency chest compressions ie. 120/min.
• Open-chest CPR. Best considered for cardiac arrest early post-op or in trauma surgery. No prospective randomised comparison with standard ECM – and none likely!
• Interposed abdominal compression (IAC) CPR. Additional compression midway between xiphoid and umbilicus. Use in-hospital by two trained persons is supported, but not for out-of-hospital CPR.
• Cough CPR. Supported in conscious, monitored, supine, trained (!) patients who get VF.

CPR devices.

• Transport ventilators. Automatic and mechanical. No advantage over bag-valve-mask, especially over short distances. Some value if advanced airway in place. Tidal volume (TV) 6-7 mL/kg ie. 500 mL – 600 mL.
• Active compression-decompression (ACD) CPR. Hand-held suction device. None FDA approved and results mixed.
• Inspiratory impedance-threshold device. Valve limiting air entry into lungs during chest recoil between chest compressions, designed to reduce intra-thoracic pressure to enhance venous return. Combined with ACD CPR in OHCA did improve ROSC (but not long-term survival).
• Mechanical piston (plunger) device. Appears to work, but not better.
• Load-distributing band (LDB) or Vest CPR. Circumferential compression device with backboard. ? use in ‘difficult terrain’.
• Phased thoracic-abdominal compression-decompression (PTACD) CPR +hand held device. Combines IAC-CPR with ACD-CPR.
• Extra-corporeal / invasive techniques. More successful in post- cardiotomy patients. Also improved survival in severe hypothermia. Role will always be limited.

Part 6. CPR techniques and devices. Circulation 2005;112:IV-47 – IV-50. [Reference]

Factors affecting outcome after CPR

• Major survival determinant is time between VF onset and defibrillation, ranging from 70% (immediate) to <2-5% (beyond 12 minutes) survival rates.
• Other important factors include witnessed collapse, bystander CPR, presenting cardiac rhythm being VF/VT and early use of an AED.
• The addition of other ALS interventions to rapid defibrillation in an optimised EMS system does not improve outcome.
• Out-of-Hospital cardiac arrest (OHCA) survival rates vary from 4 – 34% for VF and rare/anecdotal for asystole ie. <1%. Likelihood of survival largely determined by return of spontaneous output by the time patient arrives in ED.

Stiell IG, Wells GA et al. Advanced cardiac life support in out-of-hospital cardiac arrest. NEJM 2004; 351:647-56. [Reference]

Meyer ADM, Cameron PA, Smith KL et al. Out-of-hospital cardiac arrest. MJA 2000; 172:73-6. [Reference]

• Induced hypothermia cooled to 32-34 degrees recommended in an unconscious adult with return of spontaneous circulation (ROSC) in OHCA when initial rhythm was VF. Start as soon as possible, with external and internal cooling techniques and continue for up to 24 hours (see 2. b) ix) above). Benefit not yet evaluated for in-hospital cardiac arrests, and non-VF.

Part 7.5: Postresuscitation support. Circulation 2005;112:IV-84-IV-88. [Reference]

Nolan JP, Morley PT, et al. Therapeutic hypothermia after cardiac arrest. Resuscitation 2003; 57:231-5. [Reference]

• In-hospital survival rates finally seem to be improving in adults, although mainly if witnessed arrest, initial VT/VF, pulse regained within first 10 minutes of CPR, and ideally defibrillated within 2 minutes!

Chan P, Krumholz H, Nichol G et bal. Delayed time to defibrillation after in-hospital cardiac arrest. NEJM 2008;358:9-17. [Reference]

• In-hospital survival rates worse at night and at weekends, even when adjusted for confounding characteristics.

Peberdy M, Ornato J, Larkin G et al. Survival from in-hospital cardiac arrest during nights and weekends. JAMA 2008;299:785-92. [Reference]

• Overall rates for ROSC vary, with survival rate to leave hospital from 42% to as low as 0%, most ranges between 15-20%. Co-morbidities relate to poor survival.

Sandroni C, Nolan J, Cavallaro F et al. In-hospital cardiac arrest: incidence, prognosis and possible measures to improve survival. Intens Care Med 2007;33:237-45. [Reference] [Reference]

Peberdy MA, Kaye W, Ornato JP et al. Cardiopulmonary resuscitation of adults in the hospital. A report of 14 720 cardiac arrests Resuscitation 2003; 58:297-308. [Reference]

Medical Emergency Team (MET)

• Medical Emergency Team (MET) should replace cardiac arrest team to rapidly identify and treat critical patients before full cardiopulmonary arrest. Some data show reduced CPR calls and reduced mortality in adults, and also in children.
• Validated call out criteria include “staff member worried” or acute changes in heart rate <40 or >130 /SBP <90 mmHg /resp rate <8 or >30 /pulse oximetry <90% despite oxygen / conscious level /urine output <50 mL in 4 hours.
• Important staffing, logistics, disposal and facility implications. There is also potential for abuse (excessive calling with abrogation of clinical responsibility).

Bellomo R, Goldsmith D et al. A prospective before-and-after trial of a medical emergency team. MJA 2003; 179:283-7. [Reference]

Buist M, Moore G et al. Effects of a medical emergency team on reduction of incidence of and mortality from unexpected cardiac arrests in hospital: preliminary study. BMJ 2002; 324:387-90. [Reference]

Hillman K, Parr M et al. Redefining in-hospital resuscitation: the concept of the medical emergency team. Resuscitation 2001; 48:105-110 [Reference]

• Unfortunately, MERIT Study randomised trial increased team call-outs, without reducing incidence of cardiac arrest, unexpected death or unplanned ICU admission. However, widely criticised as few medical patients had sufficient monitoring to trigger MET call, and even if triggered, calls were made unreliably.

MERIT Study Investigators. Introduction of the medical emergency team (MET) system: a cluster-randomised controlled trial. Lancet 2005: 365: 2091-7. [Reference]

GUIDELINES FOR NO-CPR ORDERS / DO-NOT-ATTEMPT-RESUSCITATION (DNAR) ORDER / NOT-FOR-RESUSCITATION (NFR) ORDER

• “A no-CPR order offers an opportunity to rethink the goals of therapy in the light of discussions with the critically ill patient and his or her family.”

Kerridge I. Guidelines for no-CPR orders. MJA 1994; 161:270-272. [Reference]

• Unfortunately many hospital staff fail to consider when resuscitation attempts are inappropriate or futile, including NFR, or this is not discussed and documented in advance.

Perkins G, Soar J. In hospital cardiac arrest. Missing links in the chain of survival. Resuscitation 2005;66:253-5. [Reference]

Parr MJ, Hadfield JH et al. The Medical Emergency Team: 12 month analysis of reasons for activation, immediate outcome and not-for-resuscitation orders. Resuscitation 2001;50:39-44. [Reference]