out - of - hospital cardiac arrest ( ohca ) in developed communities occurs more commonly and is a leading cause of death [ 1 , 2 ] .
recently , chan et al . reported a survival rate of 8.6  % in the united states . in the netherlands , reported survival rates are much higher , from 9  % even up to 43  % [ 4 , 5 ] .
importantly , determinants that effectively favour better survival outcome include witnessed arrest , bystander cardiopulmonary resuscitation , shockable rhythm , use of automated electrical defibrillator , early return of spontaneous circulation ( rosc ) and post - arrest care [ 2 , 68 ] . collectively , minimising time delays , resuscitation quality , intensive care , and treatment of the underlying cause of arrest increases survival outcome .
alternatively , extracorporeal cardiopulmonary resuscitation ( e - cpr ) has been reported to improve survival outcome and organ recovery in refractory cardiac arrest [ 911 ] .
moreover , expansions in extracorporeal technology such as portable devices , circuitry and access to systemic circulation have led to further curiosity of its potential application .
e - cpr application is reported to increase the chances of successful defibrillation , preventing re - arrest due to post - resuscitation myocardial dysfunction , thereby enabling subsequent interventions [ 11 , 13 ] .
nevertheless , e - cpr requires minimalisation of time delay to establish qualitative invasive cpr , and establish as a bridge to specific diagnostics and intervention .
therefore , we aimed to analyse the current outcome of adult patients with ohca following resuscitation in the maastricht region with the prospects of implementing e - cpr in the near future .
the observational study included adult ohca patients who survived to emergency department admission at maastricht university medical center , which lies in the southern part of the dutch province of limburg , between march 2012 and april 2014 .
the area is 203  km in size and has approximately 183,000 inhabitants ( statistics netherlands 2013 , www.cbs.nl ) . the maastricht area
is served by a university medical centre ( maastricht university medical center ) and a network of emergency medical services ( ems ) .
the local medical ethics review board approved the study with a waiver for obtaining the informed consent .
a call to the emergency number ( 112 ) alerts the regional ems and other trained first responders including civilian sms - alert responders and police personnel , equipped with an automatic external defibrillator ( aed ) in case of suspected ohca .
two ambulances are dispatched , along with the first responder to perform basic life support .
the ems personnel provide standardised , mechanical cpr with an auto - pulse device ( zoll , chelmsford , ma usa ) and advanced life support .
the data were collected by a researcher , who accessed the data collected and stored by the ambulance services , and by going through the electronic drive forms daily for resuscitations .
the data gathered included utstein - based recommendations on a form , while the ecg strips of the patients were attached to the drive forms of the patient . in case of aed use
, the information on the aed application was retrieved from the aed ( corpuls , gs elektromed , kaufering , germany ) and sent via an email to the researcher . when the sms alert responder had provided basic life support ,
pertinent data were sent to the researcher , which were compiled and verified with the patient records .
pre - existing cardiac risk factors , cardiac comorbidities and past cardiac interventions were retrieved from the hospital records .
data on post - resuscitation management ( diagnosis , therapeutic hypothermia or treatment such as percutaneous coronary interventions ( pci ) , coronary artery bypass graft , implantable cardioverter defibrillator ( icd ) or pacemaker ) were obtained from the hospital records .
survival was assessed at three time points , i.e. survival to emergency department , survival to hospital admission , and survival to hospital discharge .
individuals with a do - not - resuscitate status , with signs of prolonged death and cardiac arrest of non - cardiac origin ( for e.g. drowning , exsanguination ) , were excluded .
the ecgs analysed by aed or taken by ems paramedics were designated as the initial cardiac rhythm .
the rhythms were classified as shockable ( ventricular fibrillation , ventricular tachycardia ) , non - shockable ( asystole , pulseless electrical activity ) and non - threatening ( sinus bradycardia , sinus tachycardia or sinus rhythm ) .
rosc was recorded at the time of departure from the site of the arrest and arrival at the emergency department .
neurological outcome to determine brain injury was scored by charting the modified rankin scale instead of the standard cerebral performance score to clearly distinguish mild to moderate neurological disability .
the scoring was performed by assessing patient records at the time of discharge and at 1 month , 3 months , 6 months and 1 year follow - up .
the modified rankin scale scores are allocated as : 0no symptoms , 1no significant disability , 2slight disability , 3moderate disability , 4moderately severe disability , 5severe disability , 6dead .
data were subjected to normality distribution , and accordingly continuous data are presented as medians [ interquartile range ] and/or means  standard deviation .
comparisons between two groups of continuous variables were performed using the mann - whitney u - test .
categorical variables were compared using chi - square test with fisher s exact test and expressed as percentages .
analyses were two - sided and differences with p - values <  0.05 were considered statistically significant .
the analyses were carried out using the statistical package for social sciences version 21.0 ( ibm corp . , armonk , ny , usa ) .
the data were collected by a researcher , who accessed the data collected and stored by the ambulance services , and by going through the electronic drive forms daily for resuscitations .
the data gathered included utstein - based recommendations on a form , while the ecg strips of the patients were attached to the drive forms of the patient . in case of aed use
, the information on the aed application was retrieved from the aed ( corpuls , gs elektromed , kaufering , germany ) and sent via an email to the researcher . when the sms alert responder had provided basic life support ,
pertinent data were sent to the researcher , which were compiled and verified with the patient records .
pre - existing cardiac risk factors , cardiac comorbidities and past cardiac interventions were retrieved from the hospital records .
data on post - resuscitation management ( diagnosis , therapeutic hypothermia or treatment such as percutaneous coronary interventions ( pci ) , coronary artery bypass graft , implantable cardioverter defibrillator ( icd ) or pacemaker ) were obtained from the hospital records .
survival was assessed at three time points , i.e. survival to emergency department , survival to hospital admission , and survival to hospital discharge .
individuals with a do - not - resuscitate status , with signs of prolonged death and cardiac arrest of non - cardiac origin ( for e.g. drowning , exsanguination ) , were excluded .
the ecgs analysed by aed or taken by ems paramedics were designated as the initial cardiac rhythm .
the rhythms were classified as shockable ( ventricular fibrillation , ventricular tachycardia ) , non - shockable ( asystole , pulseless electrical activity ) and non - threatening ( sinus bradycardia , sinus tachycardia or sinus rhythm ) .
rosc was recorded at the time of departure from the site of the arrest and arrival at the emergency department .
neurological outcome to determine brain injury was scored by charting the modified rankin scale instead of the standard cerebral performance score to clearly distinguish mild to moderate neurological disability .
the scoring was performed by assessing patient records at the time of discharge and at 1 month , 3 months , 6 months and 1 year follow - up .
the modified rankin scale scores are allocated as : 0no symptoms , 1no significant disability , 2slight disability , 3moderate disability , 4moderately severe disability , 5severe disability , 6dead .
data were subjected to normality distribution , and accordingly continuous data are presented as medians [ interquartile range ] and/or means  standard deviation .
comparisons between two groups of continuous variables were performed using the mann - whitney u - test .
categorical variables were compared using chi - square test with fisher s exact test and expressed as percentages .
analyses were two - sided and differences with p - values <  0.05 were considered statistically significant .
the analyses were carried out using the statistical package for social sciences version 21.0 ( ibm corp . ,
a total number of 287 adult patients were identified with ohca in the maastricht region through the study period . after assessment of the records ,
1flow chart of patients with out - of - hospital cardiac arrest in maastricht region ( march 2012april 2014 ) .
ohca out - of - hospital cardiac arrest , dnr do not resuscitate , ed emergency department , ccu coronary care unit , icu intensive care unit ; other , ward flow chart of patients with out - of - hospital cardiac arrest in maastricht region ( march 2012april 2014 ) .
ohca out - of - hospital cardiac arrest , dnr do not resuscitate , ed emergency department , ccu coronary care unit , icu intensive care unit ; other , ward the study population included 195 patients , admitted to the emergency department with a cardiac cause of arrest .
patient demographics ( table  1 ) and pre - hospital resuscitation characteristics of ohca are shown in table  2 .
the patients were aged 66 [ 5775 ] years and predominantly ( 80  % ) male .
the cardiac arrest event occurred at home ( 56  % ) and was witnessed in 173 ( 89  % ) patients . subsequently 145 ( 74  % ) patients received bystander cpr , ems personnel initiated cpr in 26  % , and in 24  % cases an aed was applied .
the ems response time was 7 [ 59 ]  min , the advanced cardiac life support was provided for 24 [ 1831 ]  min , and at departure rosc was achieved in 70  % of the patients .
transport time to the emergency department was 12 [ 618 ]  min and 61 ( 58  % ) patients required continued resuscitation during transportation .
table 1patient demographics of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admissionsurvivors n  =  90non - survivors n  =  105 
 p - value 
 age ( years)0.01  mean  standard deviation63    1267    15  median [ interquartile range]63 [ 5572]70 [ 5879]male gender , n ( % ) 74 ( 82)83 ( 79)0.57cardiac risk factors , n ( % ) diabetes12 ( 14)22 ( 22)0.11hypertension29 ( 34)35 ( 37)0.66dyslipidaemia previous cardiovascular conditions , n ( % ) 14 ( 17)18 ( 19)0.64cerebrovascular accident4 ( 5)6 ( 6)0.67chronic heart failure6 ( 7)18 ( 18)0.02myocardial infarction22 ( 25)33 ( 32)0.25ventricular fibrillation3 ( 3)4 ( 4)0.84atrial fibrillation previous cardiac interventions , n ( % ) 7 ( 8)17 ( 17)0.07pci6 ( 7)14 ( 14)0.12cabg8 ( 9)8 ( 8)0.78pacemaker2 ( 2)0 ( 0)0.13icd1 ( 1)8 ( 8)0.03 
 pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 
 fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continous variables .
patient demographics of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admission 
 pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 

fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continous variables .
table 2pre - hospital resuscitation characteristics , aetiology and treatment of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admissionsurvivors n  =  90non - survivors n  =  105 
 p - value 
 location of arrest , n ( % ) 0.79home52 ( 59)60 ( 57)public36 ( 41)45 ( 43)witnessed arrest , n ( % ) 83 ( 92)90 ( 86)0.15bystander cpr , n ( % ) 68 ( 76)77 ( 73)0.72aed deployed , n ( % ) 22 ( 24)24 ( 23)0.80initial rhythm , n ( % ) <  0.01shockable81 ( 90)69 ( 67)non - shockable5 ( 6)31 ( 30)non - threatening 
 4 ( 4)3 ( 3)ems arrival time since call , min0.36mean  standard deviation7    68    9median [ interquartile range]6 [ 59]6 [ 49]defibrillation times , n ( % ) <  0.01mean  standard deviation1.8    2.02.7    2.9median [ interquartile range]1 [ 03]2 [ 04]auto - pulse , n ( % ) 44 ( 49)77 ( 73 ) <  0.01rosc at departure , n ( % ) 89 ( 99)48 ( 46 ) <  0.01continued resuscitation ,
n ( % ) 1 ( 1)57 ( 54)acls duration ( min ) , n ( % ) <  0.01mean  standard deviation22    823   
11median [ interquartile range]23 [ 1827]24 [ 1631]intubation , n ( % ) 44 ( 49)81 ( 77 ) <  0.01transport time , minmean  standard deviation17    1416    140.36median [ interquartile range]15 [ 922]12 [ 719]rosc on arrival , n ( % ) 88 ( 98)45 ( 43 ) <  0.01continued resuscitation , n ( % ) 2 ( 2)59 ( 56)cardiac arrest aetiology , n ( % ) <  0.01acute coronary syndrome53 ( 59)34 ( 32)chronic coronary artery disease7 ( 8)10 ( 10)congestive heart failure4 ( 4)12 ( 11)conduction disorders16 ( 18)8 ( 8)structural disorders7 ( 8)7 ( 7)unknown3 ( 3)34 ( 32)therapeutic hypothermia39 ( 43)21 ( 20 ) <  0.01intervention , n ( % ) pci47 ( 52)15 ( 14 ) <  0.01cabg10 ( 11)2 ( 2 ) <  0.01icd27 ( 30)1 ( 1 ) <  0.01pacemaker8 ( 9)3 ( 3)0.11 
 cpr cardiopulmonary resuscitation , aed automated external defibrillator , ems emergency medical services , rosc return of spontaneous circulation , acls advanced cardiac life support , pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 
 fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continuous variables . 

pre - hospital resuscitation characteristics , aetiology and treatment of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admission 
 cpr cardiopulmonary resuscitation , aed automated external defibrillator , ems emergency medical services , rosc return of spontaneous circulation , acls advanced cardiac life support , pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 

fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continuous variables . 

. tables  1and 2 show the characteristics of the survivors and the non - survivors admitted to the emergency department .
the non - survivors were relatively older compared with the survivors ( 70 [ 5879 ] years ) vs. 63 [ 5572 ] years , p  =  0.01 ) , and chronic heart failure was present in 18 vs. 7  % ( p  =  0.02 ) , respectively .
an initial shockable rhythm was recorded in 69 non - survivors ( 67  % ) vs. 81survivors ( 90  % ) , p  <  0.01 . among the non - survivors <  50  % achieved rosc at departure from the site and on arrival to the emergency department , while of the survivors
nearly 100  % achieved rosc at departure and arrival , p  <  0.01 , respectively .
there was no statistical significance compared with survivors in terms of gender , witnessed arrest , bystander cpr , or use of aed .
following admission to the emergency department , 50 ( 26  % ) patients died .
( 45  % ) of the patients , cardiac arrest was precipitated by acute coronary syndrome , 60 ( 31  % ) received therapeutic hypothermia and 62 ( 32  % ) patients underwent a pci . among the non - survivors , 21 ( 20  % ) received therapeutic hypothermia , acs was diagnosed in 34 ( 32  % ) and 15 ( 14  % ) underwent pci procedure .
ninety ( 46.2  % ) patients survived to hospital discharge after an average stay of 16 days following ohca .
sixty - four ( 71  % ) patients were discharged home and nine ( 10  % ) to a nursing facility .
table  3 illustrates the neurological outcome of the survivors at the time of hospital discharge and follow - up at the end of 1 month , 6 months and 12 months following ohca . the neurological outcome ( assessed by the modified rankin scale ) at hospital discharge was available for 61 ( 68  % ) patients
accordingly , 50  % could carry out normal daily activities , while six ( 10  % ) patients had moderately severe disability .
table 3the modified rankin scale scores at hospital discharge and follow - up at 1 , 6 and 12 monthsmodified rankin scaledischarge n  =  611 month n  =  436 months n  =  2512 months n  =  18030 ( 50  % ) 27 ( 63  % ) 14 ( 56  % ) 10 ( 56  % ) 113 ( 21  % ) 10 ( 23  % ) 7 ( 28  % ) 5 ( 28  % ) 29 ( 15  % ) 4 ( 10  % ) 1 ( 4  % ) 1 ( 6  % ) 33 ( 5  % ) 2 ( 5  % ) 3 ( 12  % ) 2 ( 11  % ) 46 ( 10  % ) ---5 - ---modified rankin scale : 0no symptoms , 1no significant disability , 2slight disability , 3moderate disability , 4moderately severe disability , 5severe disability , 6dead .
the modified rankin scale scores at hospital discharge and follow - up at 1 , 6 and 12 months modified rankin scale : 0no symptoms , 1no significant disability , 2slight disability , 3moderate disability , 4moderately severe disability , 5severe disability , 6dead .
a total number of 287 adult patients were identified with ohca in the maastricht region through the study period . after assessment of the records ,
1flow chart of patients with out - of - hospital cardiac arrest in maastricht region ( march 2012april 2014 ) .
ohca out - of - hospital cardiac arrest , dnr do not resuscitate , ed emergency department , ccu coronary care unit , icu intensive care unit ; other , ward flow chart of patients with out - of - hospital cardiac arrest in maastricht region ( march 2012april 2014 ) .
ohca out - of - hospital cardiac arrest , dnr do not resuscitate , ed emergency department , ccu coronary care unit , icu intensive care unit ; other , ward the study population included 195 patients , admitted to the emergency department with a cardiac cause of arrest .
patient demographics ( table  1 ) and pre - hospital resuscitation characteristics of ohca are shown in table  2 .
the patients were aged 66 [ 5775 ] years and predominantly ( 80  % ) male .
the cardiac arrest event occurred at home ( 56  % ) and was witnessed in 173 ( 89  % ) patients . subsequently 145 ( 74  % ) patients received bystander cpr , ems personnel initiated cpr in 26  % , and in 24  % cases an aed was applied .
the ems response time was 7 [ 59 ]  min , the advanced cardiac life support was provided for 24 [ 1831 ]  min , and at departure rosc was achieved in 70  % of the patients .
transport time to the emergency department was 12 [ 618 ]  min and 61 ( 58  % ) patients required continued resuscitation during transportation .
table 1patient demographics of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admissionsurvivors n  =  90non - survivors n  =  105 
 p - value 
 age ( years)0.01  mean  standard deviation63    1267    15  median [ interquartile range]63 [ 5572]70 [ 5879]male gender , n ( % ) 74 ( 82)83 ( 79)0.57cardiac risk factors , n ( % ) diabetes12 ( 14)22 ( 22)0.11hypertension29 ( 34)35 ( 37)0.66dyslipidaemia previous cardiovascular conditions , n ( % ) 14 ( 17)18 ( 19)0.64cerebrovascular accident4 ( 5)6 ( 6)0.67chronic heart failure6 ( 7)18 ( 18)0.02myocardial infarction22 ( 25)33 ( 32)0.25ventricular fibrillation3 ( 3)4 ( 4)0.84atrial fibrillation previous cardiac interventions , n ( % ) 7 ( 8)17 ( 17)0.07pci6 ( 7)14 ( 14)0.12cabg8 ( 9)8 ( 8)0.78pacemaker2 ( 2)0 ( 0)0.13icd1 ( 1)8 ( 8)0.03 
 pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 
 fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continous variables .
patient demographics of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admission 
 pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 

fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continous variables .
table 2pre - hospital resuscitation characteristics , aetiology and treatment of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admissionsurvivors n  =  90non - survivors n  =  105 
 p - value 
 location of arrest , n ( % ) 0.79home52 ( 59)60 ( 57)public36 ( 41)45 ( 43)witnessed arrest , n ( % ) 83 ( 92)90 ( 86)0.15bystander cpr , n ( % ) 68 ( 76)77 ( 73)0.72aed deployed , n ( % ) 22 ( 24)24 ( 23)0.80initial rhythm , n ( % ) <  0.01shockable81 ( 90)69 ( 67)non - shockable5 ( 6)31 ( 30)non - threatening 
 4 ( 4)3 ( 3)ems arrival time since call , min0.36mean  standard deviation7    68    9median [ interquartile range]6 [ 59]6 [ 49]defibrillation times , n ( % ) <  0.01mean  standard deviation1.8    2.02.7    2.9median [ interquartile range]1 [ 03]2 [ 04]auto - pulse , n ( % ) 44 ( 49)77 ( 73 ) <  0.01rosc at departure , n ( % ) 89 ( 99)48 ( 46 ) <  0.01continued resuscitation ,
n ( % ) 1 ( 1)57 ( 54)acls duration ( min ) , n ( % ) <  0.01mean  standard deviation22    823   
11median [ interquartile range]23 [ 1827]24 [ 1631]intubation , n ( % ) 44 ( 49)81 ( 77 ) <  0.01transport time , minmean  standard deviation17    1416    140.36median [ interquartile range]15 [ 922]12 [ 719]rosc on arrival , n ( % ) 88 ( 98)45 ( 43 ) <  0.01continued resuscitation , n ( % ) 2 ( 2)59 ( 56)cardiac arrest aetiology , n ( % ) <  0.01acute coronary syndrome53 ( 59)34 ( 32)chronic coronary artery disease7 ( 8)10 ( 10)congestive heart failure4 ( 4)12 ( 11)conduction disorders16 ( 18)8 ( 8)structural disorders7 ( 8)7 ( 7)unknown3 ( 3)34 ( 32)therapeutic hypothermia39 ( 43)21 ( 20 ) <  0.01intervention , n ( % ) pci47 ( 52)15 ( 14 ) <  0.01cabg10 ( 11)2 ( 2 ) <  0.01icd27 ( 30)1 ( 1 ) <  0.01pacemaker8 ( 9)3 ( 3)0.11 
 cpr cardiopulmonary resuscitation , aed automated external defibrillator , ems emergency medical services , rosc return of spontaneous circulation , acls advanced cardiac life support , pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 
 fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continuous variables . 

pre - hospital resuscitation characteristics , aetiology and treatment of out - of - hospital cardiac arrest of cardiac origin who survived to emergency department admission 
 cpr cardiopulmonary resuscitation , aed automated external defibrillator , ems emergency medical services , rosc return of spontaneous circulation , acls advanced cardiac life support , pci percutaneous coronary intervention , cabg coronary artery bypass grafting , icd implantable cardioverter defibrillator . 

fisher s exact or chi - square test for categorical variables ; mann - whitney u test for continuous variables . 

tables  1and 2 show the characteristics of the survivors and the non - survivors admitted to the emergency department .
the non - survivors were relatively older compared with the survivors ( 70 [ 5879 ] years ) vs. 63 [ 5572 ] years , p  =  0.01 ) , and chronic heart failure was present in 18 vs. 7  % ( p  =  0.02 ) , respectively .
an initial shockable rhythm was recorded in 69 non - survivors ( 67  % ) vs. 81survivors ( 90  % ) , p  <  0.01 . among the non - survivors <  50  % achieved rosc at departure from the site and on arrival to the emergency department , while of the survivors
nearly 100  % achieved rosc at departure and arrival , p  <  0.01 , respectively .
there was no statistical significance compared with survivors in terms of gender , witnessed arrest , bystander cpr , or use of aed .
following admission to the emergency department , 50 ( 26  % ) patients died .
( 45  % ) of the patients , cardiac arrest was precipitated by acute coronary syndrome , 60 ( 31  % ) received therapeutic hypothermia and 62 ( 32  % ) patients underwent a pci . among the non - survivors , 21 ( 20  % ) received therapeutic hypothermia , acs was diagnosed in 34 ( 32  % ) and 15 ( 14  % ) underwent pci procedure .
ninety ( 46.2  % ) patients survived to hospital discharge after an average stay of 16 days following ohca .
sixty - four ( 71  % ) patients were discharged home and nine ( 10  % ) to a nursing facility .
table  3 illustrates the neurological outcome of the survivors at the time of hospital discharge and follow - up at the end of 1 month , 6 months and 12 months following ohca . the neurological outcome ( assessed by the modified rankin scale ) at hospital discharge was available for 61 ( 68  % ) patients .
accordingly , 50  % could carry out normal daily activities , while six ( 10  % ) patients had moderately severe disability .
table 3the modified rankin scale scores at hospital discharge and follow - up at 1 , 6 and 12 monthsmodified rankin scaledischarge n  =  611 month n  =  436 months n  =  2512 months n  =  18030 ( 50  % ) 27 ( 63  % ) 14 ( 56  % ) 10 ( 56  % ) 113 ( 21  % ) 10 ( 23  % ) 7 ( 28  % ) 5 ( 28  % ) 29 ( 15  % ) 4 ( 10  % ) 1 ( 4  % ) 1 ( 6  % ) 33 ( 5  % ) 2 ( 5  % ) 3 ( 12  % ) 2 ( 11  % ) 46 ( 10  % ) ---5 - ---modified rankin scale : 0no symptoms , 1no significant disability , 2slight disability , 3moderate disability , 4moderately severe disability , 5severe disability , 6dead .
the modified rankin scale scores at hospital discharge and follow - up at 1 , 6 and 12 months modified rankin scale : 0no symptoms , 1no significant disability , 2slight disability , 3moderate disability , 4moderately severe disability , 5severe disability , 6dead .
in our out - of - hospital cardiac arrest observational study , covering the maastricht region , more than 46  % of the cardiac cohort admitted to the emergency department survived to hospital discharge .
evidently , shockable rhythm , rosc on departure from site of arrest and arrival to the emergency department , shorter advanced cardiac life support duration , and post - arrest resuscitation care were the main findings for good survival outcome in the present study .
reported a survival rate of 43  % in patients admitted to hospital due to cardiac and non - cardiac causes in the leiden region . in an earlier study reported from the amsterdam region ,
survival rate to hospital discharge was 9  % .the varying survival outcome has been ascribed to regional variations following resuscitation efforts for ohca and study design [ 1 , 7 , 8 ] .
these described variations include but are not limited to population demographics , culture , competing illness , but also post - arrest care . despite all these regional variations , a trend towards a better outcome reflects improvements in the  chain of survival , as compared with the approximate 6  % reported from an earlier study in the 1990s , from the maastricht region . in nearly 75  % of the non - ems
it is known that bystander cpr maintains a state of shockable rhythm , which could double the chances of survival .
this finding is high compared to other utstein reports [ 46 ] , which is probably due to public awareness and alert systems in the region .
we observed a shockable rhythm to be most evident among the survivors ( 90  % ) .
it is likely that an increased number of bystander cprs in the acute phase of a cardiac event maintained a shockable rhythm .
furthermore , a correlation between shockable rhythm and rosc has been described by sasson and colleagues .
they reported that with a shockable initial rhythm , rosc was achieved in 50  % of ohca . in the arrest study ,
waalewijn et al . observed that 43  % of patients with a shockable rhythm achieved rosc , while 13  % of patients with a non - shockable rhythm attained rosc .
therefore , the presence of a shockable rhythm might influence the duration of resuscitation and even the subsequent course of clinical management .
recently , structured post - arrest care and its effect on the ohca outcomes has been gathering attention , including the provision of therapeutic hypothermia , early cardiac intervention and neurological prognostication [ 1 , 3 , 18 ] . in our study 43  % of survivors
were cooled down with therapeutic hypothermia comparable with 47  % of the survivors in the study by boyce et al . .
further , 43  % of the patients admitted to hospital underwent an acute and/or sub - acute intervention . in the recent ohca study from the netherlands , 86  % of patients admitted to the icu or ccu underwent acute and/or sub - acute cardiac intervention . the disparity might be due to the number of patients who died in our emergency department .
a common understanding would be that patients with a reasonable chance to survive would receive further intervention .
potentially , early restoration of homeostasis with invasive cpr might serve as a bridge to definitive care in patient s refractory to continued resuscitation .
following recovery , at hospital discharge , 50  % of documented cases in the present study had a favourable neurological outcome .
plausibly , the presence of a shockable rhythm and early rosc with consequent post - arrest care in eligible patients led to a better neurological outcome in our observational study . one might wonder whether we could further optimise the chances of non - survivors towards better outcomes in the presented cohort .
it is impossible to save every patient as some determinants remain unchanged , such as e.g. age and comorbidities .
however , the modifiable determinant would be wider application of aed , thereby preventing a longer duration of no - flow ( collapse to first defibrillation ) , which worsens the chances of survival by progressing into a non - shockable rhythm [ 8 , 9 ] .
alternatively , the presence of a non - shockable rhythm among non - survivors ( 30  % ) might have been due to failure of icd , battery discharge following defibrillation or the duration of resucitation [ 19 , 20 ] .
since there has been limited resucitative and post - arrest care options for non - shockable rhythm , one can argue that implementation of e - cpr , restoring circulation and oxygenation , might prevent a state of non - shockable rhythm [ 11 , 12 ] . therefore , it is tempting to speculate that a certain number of non - survivors in our cohort with survival determinants , such as witnessed arrest , received bystander cpr , or in shockable rhythm , would have likely benefited from invasive cpr in the event of unsustained rosc , thereby , establishing a bridge to proven interventions .
e - cpr is considered in cardiac arrest patients with a brief no - flow period when the condition leading to cardiac arrest is reversible or amenable to heart transplantation .
additionally , e - cpr needs to be implemented in experienced centres , where the technique can be rapidly initiated [ 11 , 12 , 21 ] . in a prospective , observational study by chen et al .
an up to 42  % increase in survival rate was observed when e - cpr was implemented within 30  min of cardiac arrest .
the implementation of e - cpr in a site like the emergency room would establish whole - body perfusion , providing a bridge to diagnosis and treatment , including controlled therapeutic hypothermia , cardiac intervention or heart transplant [ 1113 , 21 , 22 ] .
however , applying e - cpr may be futile in patients with previous cardiac comorbidities , i.e. , chronic heart failure , structural heart disease or icd failure . in the event of poor neurological prognosis , a decision for organ donation ( based on advance directives and/or care provider s decision ) could improve the quality of organ donors as a secondary outcome .
therefore , assuming that refractory cardiac arrest may be caused by a treatable condition , engaging all temporising techniques to facilitate further diagnostics and therapy might be prospectively applied in a select patient population ; this might potentially improve survival rate and organ recovery
. limitations of our analysis include the lack of neurological scores for all survivors , this information was not available at the time of discharge and follow - up .
we reiterate that shockable rhythm , rosc , and post - arrest care improves survival outcome .
potentially , initiating e - cpr in patients refractory to standard care on - scene or at the arrival to the emergency department might be a prospect for even better survival outcome .
 aimthe current outcome of out - of - hospital cardiac arrest ( ohca ) patients in the maastricht region was analysed with the prospect of implementing extracorporeal cardiopulmonary resuscitation ( e - cpr).methodsa retrospective analysis of adult patients who were resuscitated for ohca during a 24-month period was performed.results195 patients ( age 66 [ 5775 ] years , 82  % male ) were resuscitated for ohca by the emergency medical services and survived to admission at the emergency department . 
 survival to hospital discharge was 46.2  % . 
 notable differences between non - survivors and survivors were observed and included : age ( 70 [ 5879 ] years ) vs. ( 63 [ 5572 ] years , p  =  0.01 ) , chronic heart failure ( 18 vs. 7  % , p  =  0.02 ) , shockable rhythm ( 67 vs. 99  % , p  <  0.01 ) , and return of spontaneous circulation ( rosc ) at departure from the site of the arrest ( 46 vs. 99  % , p  <  0.01 ) and on arrival to the emergency department ( 43 vs. 98  % , p  <  0.01 ) , respectively . 
 acute coronary syndrome was diagnosed in 32  % of non - survivors vs. 59  % among survivors , p  <  0.01 . 
 therapeutic hypothermia was provided in non - survivors ( 20  % ) vs. survivors ( 43  % ) , p  <  0.01 . 
 percutaneous coronary intervention ( pci ) was performed in 14  % of non - survivors while 52  % of survivors received pci ( p  <  0.01 ) . 
 no statistical significance was observed in terms of gender , witnessed arrest , bystander cpr , or automated external defibrillator deployed among the cohort . at hospital discharge , 
 moderately severe neurological disability was present in six survivors.conclusionthese observations are compatible with the notion that a shockable rhythm , rosc , and post - arrest care improve survival outcome . 
 potentially , initiating e - cpr in the resuscitation phase in patients with a shockable rhythm and no rosc might serve as a bridge to definite treatment and improve survival outcome . 
Introduction
Methods
Data collection
Definitions
Statistical analysis
Results
Patients
Pre-hospital characteristics of non-survivors in relation to survivors
Diagnosis and treatment
Survival and discharge destination
Neurological outcome and follow-up
Discussion
Conclusion
Funding
Conflict of interests