***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The purpose of this study was to evaluate the outcome of out-of-hospital cardiac arrest ( CA ) and cardiopulmonary resuscitation ( CPR ) in the city of Katowice , Pol and , during a period of 1 year prior to the planned reorganization of the national emergency system . Data were collected prospect ively according to a modified Utstein style . To ensure accurate data collection , a special method of reporting resuscitation events with the use of a tape-recorder was introduced . Patients were followed for a 1-year period . Between 1 July 2001 and 30 June 2002 , out-of-hospital cardiac arrest was confirmed in 1153 patients .  Cardiopulmonary resuscitation was attempted in 188 patients . Cardiac arrest of presumed cardiac aetiology ( 147 ) was byst and er witnessed in 105 ( 71 % ) cases and lay-byst and er basic life support was performed in 35 ( 24 % ) . In the group of byst and er witnessed arrest ventricular fibrillation ( VF ) or tachycardia was documented in 59 , asystole in 40 and other non-perfusing rhythms in six patients . Of 147 patients with cardiac aetiology , return of spontaneous circulation ( ROSC ) was achieved in 64 ( 44 % ) patients , 15 ( 10 % ) were discharged alive and 9 ( 6 % ) were alive 1 year later . Most of these patients had a good neurological outcome . Time to first defibrillatory shock was significantly shorter for survivors ( median 7 min ) compared to non-survivors ( median 10 min ) . The most important resuscitation and patient characteristics associated with survival were VF as initial rhythm , arrest witnessed , and lay-byst and er CPR BACKGROUND The aim of this research is to evaluate quality of out-of-hospital medical services in our country , using performance indicators and a new computerised data base . METHODS ( a ) EXPERIMENTAL DESIGN Data were collected prospect ively in three emergency dispatch centres for 90 days . Follow-up was evaluated at 1 day and 1 month after the event . This paper presents data on the cardiac arrest cohort only . ( b ) SETTING Three emergency dispatch centres in Lombardia . ( c ) PATIENTS One hundred and seventy-eight patients in non-traumatic cardiac arrest were enrolled . ( d ) INTERVENTIONS None . The study was observational only . RESULTS Mean interval between phone call and arrival on scene was 8.5+/-3.5 min . BLS manoeuvres were carried out from byst and ers only in 15 % of the cohort ; this was associated with significant mortality reduction ( 85.7 versus 95.8 % , chi(2 ) P<0.05 ) . One hundred and thirty-three patients ( 75 % ) received assistance from BLS crews while only 45 patients ( 25 % ) were assisted by ALS medical personel , with a significant mortality reduction ( ALS deaths 86.7 % , BLS deaths 97 % ) . Total 24 h survival was 9 % and survival at 1 month declined to 6.17 % . CONCLUSIONS Quality monitoring produces objective information on interventions and outcomes . Only with this information , is it possible to implement improvement programmes that are planned according to the data presented CONTEXT Out-of-hospital cardiac arrest is a major public health problem . OBJECTIVE To investigate whether the survival of patients with out-of-hospital cardiac arrest  would improve with minimally interrupted cardiac resuscitation ( MICR ) , an alternate emergency medical services ( EMS ) protocol . DESIGN , SETTING , AND PATIENTS A prospect i ve study of survival-to-hospital discharge  between January 1 , 2005 , and November 22 , 2007 . Patients with out-of-hospital cardiac arrests in 2 metropolitan cities in Arizona before and after MICR training of fire department emergency medical personnel were assessed . In a second analysis of protocol compliance , patients from the 2 metropolitan cities and 60 additional fire departments in Arizona who actually received MICR  were compared with patients who did not receive MICR  but received st and ard advanced life support . INTERVENTION Instruction for EMS personnel in MICR , an approach that includes an initial series of 200 uninterrupted chest compressions , rhythm analysis with a single shock , 200 immediate postshock chest compressions before pulse check or rhythm re analysis , early administration of epinephrine , and delayed endotracheal intubation . MAIN OUTCOME MEASURE Survival-to-hospital discharge . RESULTS Among the 886 patients in the 2 metropolitan cities , survival-to-hospital discharge increased from 1.8 % ( 4/218 ) before MICR training to 5.4 % ( 36/668 ) after MICR training ( odds ratio [ OR ] , 3.0 ; 95 % confidence interval [ CI ] , 1.1 - 8.9 ) . In the subgroup of 174 patients with witnessed cardiac arrest and ventricular fibrillation , survival increased from 4.7 % ( 2/43 ) before MICR training to 17.6 % ( 23/131 ) after MICR training ( OR , 8.6 ; 95 % CI , 1.8 - 42.0 ) . In the analysis of MICR protocol compliance involving 2460 patients with cardiac arrest , survival was significantly better among patients who received MICR than those who did not ( 9.1 % [ 60/661 ] vs 3.8 % [ 69/1799 ] ; OR , 2.7 ; 95 % CI , 1.9 - 4.1 ) , as well as patients with witnessed ventricular fibrillation ( 28.4 % [ 40/141 ] vs 11.9 % [ 46/387 ] ; OR , 3.4 ; 95 % CI , 2.0 - 5.8 ) . CONCLUSIONS Survival-to-hospital discharge of patients with out-of-hospital cardiac arrest increased after implementation of MICR as an alternate EMS protocol . These results need to be confirmed in a r and omized trial The results of the first epidemiological , prospect i ve , multicentric study on cardiac arrest in a geographical Italian region are reported . On 708 consecutive cardiac arrests , 438 underwent cardiopulmonary resuscitation ( CPR ) .  Of these , 344 were identified of cardiac aetiology . The underlying initial rhythm was : 166 asystole ( 48.3 % ) , 104 ventricular fibrillation ( 30.2 % ) , 74 pulseless electrical activity ( 21.5 % ) . The best outcome occurred in patients whose cardiac arrest was witnessed by the EMS ( 49 % return of spontaneous circulation ( ROSC ) , 21 % hospital discharge ) . When cardiac arrest was witnessed by lay people , 20.5 % had ROSC and 4.4 % were discharged alive from the hospital . When it was unwitnessed ROSC and hospital discharge were 8.6 and 1.7 % , respectively . Ventricular fibrillation was highly predictive of outcome . Both ROSC and hospital discharge correlated inversely with the delay of the first defibrillation . Overall , the highest probability of survival was achieved when CPR interventions were started within the first minutes after collapse . Basic Life Support ( BLS ) manoeuvres began after 9 min of untreated cardiac arrest were still followed by a ROSC , but none of these patients survived . The incidence of prehospital cardiac arrest in our population was estimated to be in proportion of 0.95/1000 per year with a survival rate of 6.7 % BACKGROUND Patients suffering out-of-hospital cardiac arrest ( OOHCA ) are generally transported to the closest ED , presumably to expedite a hospital level of care and improve the chances of return for spontaneous circulation ( ROSC ) or provide post-resuscitative care for patients with prehospital ROSC . As hospital-based therapies for survivors of OOHCA are identified , such as hypothermia and emergency primary coronary interventions ( PCI ) , certain hospitals may be design ated as cardiac arrest receiving facilities . The safety of bypassing non- design ated facilities with such a regional system is not known . OBJECTIVES To explore the potential ED contribution in OOHCA victims without prehospital ROSC and document the relationship between transport time and outcome in patients with prehospital ROSC . METHODS This was a prospect i ve , observational study conducted in a large , urban EMS system over an 18-month period . Data were collected using the Utstein template for OOHCA . The incidence of prehospital ROSC was calculated for patients who were declared dead on scene , transported but died in the ED , died in the hospital , and survived to hospital discharge . The relationship between transport time and survival was also explored for patients with prehospital ROSC . RESULTS A total of 1141 cardiac arrest patients were enrolled over the 18-month period . A strong association between prehospital ROSC and final disposition was observed ( chi-square test for trend p<0.001 ) . Only two patients who survived to hospital discharge did not have prehospital ROSC . Mean transport times were not significantly different for patients with prehospital ROSC who were declared dead in the ED ( 8.3min ) , died following hospital admission ( 7.8min ) , and survived to hospital discharge ( 8.5min ) . Outcomes in patients with prehospital ROSC who had shorter ( 7min or less ) versus longer transport times were similar , and receiver-operator curve analysis indicated no predictive ability of transport time with regard to survival to hospital admission ( area under the curve=0.52 ) . CONCLUSIONS In this primarily urban EMS system , the vast majority of survivors from OOHCA are resuscitated in the field . A relationship between transport time and survival to hospital admission or discharge was not observed . This supports the feasibility of developing a regional cardiac arrest system with design ated receiving facilities OBJECTIVE To determine the influence of electrocardiographically documented cardiac rhythm during sudden cardiac arrest on successful resuscitation among out-of-hospital deaths in Kaunas city . MATERIAL AND METHODS An observational prospect i ve study was conducted between 1 January , 2005 , and 30 December , 2005 , in Kaunas city with a population of 360,627 inhabitants . In this period , all cases of cardiac arrest were analyzed according to the guidelines of the Utstein consensus conference . Cardiac arrest ( both of cardiac and noncardiac etiology ) was confirmed in 72 patients during one year . Effective cardiopulmonary resuscitation was performed in 18 patients . RESULTS The total number of deaths from all causes in Kaunas during 1-year study period was 6691 . Sixty-two patients due to sudden death of cardiac etiology were resuscitated by emergency medical services personnel . Return of spontaneous circulation was achieved in 11 patients . Ventricular fibrillation was observed in 33 ( 53.2 % ) patients . Asystole was present in 11 ( 17.7 % ) and other rhythms in 18 ( 29.1 % ) cases . Patients with ventricular fibrillation as an initial rhythm were more likely to be successfully resuscitated than patients with asystole . CONCLUSIONS Ventricular fibrillation was the most common electrocardiographically documented cardiac rhythm registered during cardiac arrest in out-of-hospital setting s. Ventricular fibrillation as a mechanism of cardiac arrest was associated with major cases of successful resuscitation BACKGROUND Cardiac arrest with widespread cerebral ischemia frequently leads to severe neurologic impairment . We studied whether mild systemic hypothermia increases the rate of neurologic recovery after resuscitation from cardiac arrest due to ventricular fibrillation . METHODS In this multicenter trial with blinded assessment of the outcome , patients who had been resuscitated after cardiac arrest due to ventricular fibrillation were r and omly assigned to undergo  therapeutic hypothermia ( target temperature , 32 degrees C to 34 degrees C , measured in the bladder ) over a period of 24 hours or to receive st and ard treatment with normothermia . The primary end point was a favorable neurologic outcome within six months after cardiac arrest ; secondary end points were mortality within six months and the rate of complications within seven days . RESULTS Seventy-five of the 136 patients in the hypothermia group for whom data were available ( 55 percent ) had a favorable neurologic outcome ( cerebral-performance category , 1 [ good recovery ] or 2 [ moderate disability ] ) , as compared with 54 of 137 ( 39 percent ) in the normothermia group ( risk ratio , 1.40 ; 95 percent confidence interval , 1.08 to 1.81 ) . Mortality at six months was 41 percent in the hypothermia group ( 56 of 137 patients died ) , as compared with 55 percent in the normothermia group ( 76 of 138 patients ; risk ratio , 0.74 ; 95 percent confidence interval , 0.58 to 0.95 ) . The complication rate did not differ significantly between the two groups . CONCLUSIONS In patients who have been successfully resuscitated after cardiac arrest due to ventricular fibrillation , therapeutic mild hypothermia increased the rate of a favorable neurologic outcome and reduced mortality CONTEXT Identifying patients in the out-of-hospital setting who have no realistic hope of surviving an out-of-hospital cardiac arrest could enhance utilization of scarce health care re sources . OBJECTIVE To vali date 2 out-of-hospital termination-of-resuscitation rules developed by the Ontario Prehospital Life Support ( 
    Output:
    
Overall survival from OHCA has been stable for almost 30 years , as have the strong associations between key predictors and survival .