Stayin’  Alive  or  Another  One  Bites  the  Dust:  The  Science  

Behind  Good  CPRSco$  Gilmore,  MD,  EMT-‐P,  FACEP  

Medical  Director  St.  Louis  Fire  Department  

A  Li?le  Background

•  Incidence  of  cardiac  arrest  •  20  to  140  per  100,000  people  globally  

•  Survival  •  2%  to  11%  globally  •  Less  then  15%  in  the  United  States  

•  3.0%  to  16.3%  according  to  the  ResuscitaPon  Outcomes  ConsorPum  (ROC)  

CPR  is  a  lifesaving  interven-on  and  the  cornerstone  of  resuscitaPon  from  cardiac  

arrest.  

CPR  quality  has  significant  impact  on  survival.  

Current Knowledge

of CPR Quality

Optimal Implementation

Preventable Deaths

CPR  is  not  a  perfect  

subsPtute  for  a  beaPng  heart   But  it  is  the  best  

thing  that  we  can  do  in  the  out  

of  hospital  seWng  

Restore  spontaneous  circulaPon  as  quickly  as  possible.  

Five  Main  Components  of  High-‐performance  CPR

• Chest  compression  fracPon  (CCF)  • Chest  compression  rate  • Chest  compression  depth  • Chest  recoil  (residual  leaning)  • VenPlaPon  

Minimize  InterrupKons

• Goal  is  a  chest  compression  fracPon  greater  than  80%  

•  This  means  less  than  24  seconds  off  the  chest  every  2  minutes  

•  Lower  CCF  is  associated  with  decreased  ROSC  and  survival  to  hospital  discharge  

Chest  Compression  FracKon  and  Survival  In  Ventricular  FibrillaKon  Arrest

Christenson  J  et  al.  Chest  compression  fracPon  determines  survival  in  paPents  with  out-‐of-‐hospital  ventricular  fibrillaPon.  CirculaPon.  2009;120:1241-‐1247  

Chest  Compression  FracKon  and  Survival  In  Non-‐Ventricular  FibrillaKon  Arrest

Vaillancourt  C  et  al.  The  impact  of  increased  chest  compression  fracPon  on  return  of  spontaneous  circulaPon  for  out-‐of-‐hospital  cardiac  arrest  paPents  not  in  ventricular  fibrillaPon.  ResuscitaPon.  2011;82:1501-‐1507  

Manual  versus  AED  mode

Cheskes  S  et  al.  Perishock  pause:  an  independent  indicator  of  survival  from  out-‐of-‐hospital  cardiac  arrest.  CirculaPon.  2011;124:58-‐66  

Chest  Compression  Rates

•  2010  AHA  Guidelines  for  CPR  and  ECC  recommend  a  chest  compression  rate  ≥  100/minute  

Chest  Compression  Rate

Idris  AH  et  al.  RelaPonship  between  chest  compressions  rates  and  outcomes  from  cardiac  arrest.  CirculaPon.  2012;  125:3004-‐3012.  

• As  chest  compression  rates  fall,  a  significant  drop-‐off  in  ROSC  occurs  • Higher  chest  compression  rates  

•  May  reduce  coronary  blood  flow  •  Decrease  the  percentage  of  compressions  that  achieve  target  depth  

Chest  Compression  Depth

•  2010  AHA  Guidelines  for  CPR  and  ECC  •  ≥  2  inches  in  adults  •  At  least  one  third  of  the  anterior-‐posterior  dimension  of  the  chest  in  infants  and  children  

•  ≈1½  inches  or  4  cm  in  infants  •  ≈  2  inches  or  5  cm  in  children  

Push  Hard

SPell  IG  et  al.  What  is  the  role  of  chest  compression  depth  during  out-‐of-‐hospital  cardiac  arrest  resuscitaPon?  Crit  Care  Med.  2012;40:1192-‐1198  

Compression  Depth  and  Survival  to  Discharge  Rates

•  <  38  mm  compression  depth  •  Survival-‐to-‐discharge  rates  reduced  by  30%  

Perkins  GD,  Benny  R,  Giles  S,  et  al.  Do  different  ma$resses  affect  the  quality  of  cardiopulmonary  resuscitaPon?  Intensive  Care  Medicine.  29(12),  2330-‐5.  

Comparison  of  chest  compression  depth  over  Pme  on  4  different  surfaces  

Surfaces  Do  Ma?er

CPR  Feedback  Devices

• Accelerometer  Device   •  Field  InducPon  Device  

Perkins  GD,  Kocierz  L,  Smith  SCL,  McCulloch  RA,  Davies  RP,  Compression  feedback  devices  over  esPmate  chest  compression  depth  when  performed  on  a  bed,  ResuscitaPon,  80  (2009):  79–82  

Get  the  PaKent  to  the  Floor

Full  Chest  Recoil:  No  Residual  Leaning

• Decreases  blood  flow  throughout  the  heart  • Can  decrease  venous  return  and  cardiac  output  

Oxygen  Delivery  and  CPR

•  EssenPal  during  CPR  • Appropriate  Pmeframe  to  supplement  exisPng  oxygen  in  the  blood  

•  Varies  with  the  type  of  arrest  •  Arrhythmic  •  Asphyxial  

• Metabolic  demands  for  oxygen  are  reduced  in  cardiac  arrest  

•  Even  during  chest  compressions  

Sudden  arrhythmic  arrest  

• Oxygen  content  iniPally  sufficient  • High-‐quality  chest  compressions  can  circulate  oxygenated  blood  

•  Studies  suggest  compressions  without  venPlaPon  may  be  adequate  in  early  nonasphyxial  arrests  

Asphyxial  Cardiac  Arrest

• CombinaPon  of  assisted  venPlaPon  and  high-‐quality  chest  compressions  

•  CriPcal  to  ensure  adequate  oxygen  delivery  •  Studies  have  found  improved  outcomes  when  both  assisted  venPlaPon  and  high-‐quality  chest  compressions  are  delivered  

Goal  of  Assisted  VenKlaKon  During  Cardiac  Arrest• Providing  sufficient  oxygen  to  the  blood  without  impeding  perfusion  • PosiPve  pressure  venPlaPon  reduces  CPP  during  CPR  •  Synchronous  venPlaPon  requires  interrupPons  

•  Reduces  chest  compression  fracPon  • Compression-‐only  CPR  versus  standard  CPR  

•  Yielded  similar  survival  outcomes  •  Not  enough  evidence  to  define  when  or  if  venPlaPon  should  be  withheld  by  experienced  providers  

•  More  data  required  

VenKlaKon  Rate  <  12  Breaths  per  Minute

• No  data  showing  higher  rate  of  venPlaPon  is  beneficial  •  InflaPon  Pme  of  1  second  for  each  breath  with  a  compression  rate  of  100-‐120/min  

•  6  to  12  breaths  

Minimal  Chest  Rise

• VenPlaPon  volume  should  produce  no  more  than  visible  chest  rise  • PosiPve-‐pressure  venPlaPon  significantly  lowers  cardiac  output  

•  Spontaneous  circulaPon  •  CPR  

•  Lower  Pdal  volumes  during  prolonged  cardiac  arrest  was  not  associated  with  significant  differences  in  Pao2  

• PosiPve  pressure  venPlaPon  in  an  unprotected  airway  may  gastric  insufflaPon  

•  AspiraPon  of  gastric  contents  •  Lung  compliance  is  affected  by  compressions  during  cardiac  arrest  

CPR  in  a  Moving  Ambulance

•  The mean compression depth performed on the floor (39 ± 9mm)was greater than that on a moving stretcher (28±9mm) (p

DefibrillaKon  Failure

•  Longer  pre-‐shock  pauses  •  Shallow  chest  compressions  

Pre-‐Shock  Pauses  and  DefibrillaKon  Success

Edelson  DP  et  al.  Effects  of  compression  depth  and  pre-‐shock  pauses  predicts  defibrillaPon  failure  during  cardiac  arrest.  ResuscitaPon.  2006;71:137-‐145.  

Compression  Depth  and  Shock  Success  Rate

Edelson  DP  et  al.  Effects  of  compression  depth  and  pre-‐shock  pauses  predicts  defibrillaPon  failure  during  cardiac  arrest.  ResuscitaPon.  2006;71:137-‐145.