***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: CONTEXT Epinephrine is widely used in cardiopulmonary resuscitation for out-of-hospital cardiac arrest ( OHCA ) . However , the effectiveness of epinephrine use before hospital arrival has not been established . OBJECTIVE To evaluate the association between epinephrine use before hospital arrival and short- and long-term mortality in patients with cardiac arrest . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve , nonr and omized , observational propensity analysis of data from 417 188 OHCAs occurring in 2005 - 2008 in Japan in which patients aged 18 years or older had an OHCA before arrival of emergency medical service ( EMS ) personnel , were treated by EMS personnel , and were transported to the hospital . MAIN OUTCOME MEASURES Return of spontaneous circulation before hospital arrival , survival at 1 month after cardiac arrest , survival with good or moderate cerebral performance ( Cerebral Performance Category [ CPC ] 1 or 2 ) , and survival with no , mild , or moderate neurological disability ( Overall Performance Category [ OPC ] 1 or 2 ) . RESULTS Return of spontaneous circulation before hospital arrival was observed in 2786 of 15,030 patients ( 18.5 % ) in the epinephrine group and 23,042 of 402,158 patients ( 5.7 % ) in the no-epinephrine group ( P < .001 ) ; it was observed in 2446 ( 18.3 % ) and 1400 ( 10.5 % ) of 13,401 propensity-matched patients , respectively ( P < .001 ) . In the total sample , the numbers of patients with 1-month survival and survival with CPC 1 or 2 and OPC 1 or 2 , respectively , were 805 ( 5.4 % ) , 205 ( 1.4 % ) , and 211 ( 1.4 % ) with epinephrine and 18,906 ( 4.7 % ) , 8903 ( 2.2 % ) , and 8831 ( 2.2 % ) without epinephrine ( all P < .001 ) . Corresponding numbers in propensity-matched patients were 687 ( 5.1 % ) , 173 ( 1.3 % ) , and 178 ( 1.3 % ) with epinephrine and 944 ( 7.0 % ) , 413 ( 3.1 % ) , and 410 ( 3.1 % ) without epinephrine ( all P < .001 ) . In all patients , a positive association was observed between prehospital  epinephrine and return of spontaneous circulation before hospital arrival ( adjusted odds ratio [ OR ] , 2.36 ; 95 % CI , 2.22 - 2.50 ; P < .001 ) . In propensity-matched patients , a positive association was also observed ( adjusted OR , 2.51 ; 95 % CI , 2.24 - 2.80 ; P < .001 ) . In contrast , among all patients , negative associations were observed between  prehospital epinephrine and long-term outcome measures ( adjusted ORs : 1-month survival , 0.46 [ 95 % CI , 0.42 - 0.51 ] ; CPC 1 - 2 , 0.31 [ 95 % CI , 0.26 - 0.36 ] ; and OPC 1 - 2 , 0.32 [ 95 % CI , 0.27 - 0.38 ] ; all P < .001 ) . Similar negative associations were observed among propensity-matched patients ( adjusted ORs : 1-month survival , 0.54 [ 95 % CI , 0.43 - 0.68 ] ; CPC 1 - 2 , 0.21 [ 95 % CI , 0.10 - 0.44 ] ; and OPC 1 - 2 , 0.23 [ 95 % CI , 0.11 - 0.45 ] ; all P < .001 ) . CONCLUSION Among patients with OHCA in Japan , use of prehospital epinephrine was significantly associated with increased chance of return of spontaneous circulation before hospital arrival but decreased chance of survival and good functional outcomes 1 month after the event CONTEXT Intravenous access and drug administration are included in advanced cardiac life support ( ACLS ) guidelines despite a lack of evidence for improved outcomes . Epinephrine was an independent predictor of poor outcome in a large epidemiological study , possibly due to toxicity of the drug or cardiopulmonary resuscitation ( CPR ) interruptions secondary to establishing an intravenous line and drug administration . OBJECTIVE To determine whether removing intravenous drug administration from an ACLS protocol would improve survival to hospital discharge after out-of-hospital cardiac arrest . DESIGN , SETTING , AND PATIENTS Prospect i ve , r and omized controlled trial of consecutive adult patients with out-of-hospital nontraumatic cardiac arrest treated within the emergency medical service system in Oslo , Norway , between May 1 , 2003 , and April 28 , 2008 . INTERVENTIONS Advanced cardiac life support with intravenous drug administration or ACLS without access to intravenous drug administration . MAIN OUTCOME MEASURES The primary outcome was survival to hospital discharge . The secondary outcomes were 1-year survival , survival with favorable neurological outcome , hospital admission with return of spontaneous circulation , and quality of CPR ( chest compression rate , pauses , and ventilation rate ) . RESULTS Of 1183 patients for whom resuscitation was attempted , 851 were included ; 418 patients were in the ACLS with intravenous drug administration group and 433 were in the ACLS with no access to intravenous drug administration group . The rate of survival to hospital discharge was 10.5 % for the intravenous drug administration group and 9.2 % for the no intravenous drug administration group ( P = .61 ) , 32 % vs 21 % , respectively , ( P<.001 ) for hospital admission with return of spontaneous circulation , 9.8 % vs 8.1 % ( P = .45 ) for survival with favorable neurological outcome , and 10 % vs 8 % ( P = .53 ) for survival at 1 year . The quality of CPR was comparable and within guideline recommendations for both groups . After adjustment for ventricular fibrillation , response interval , witnessed arrest , or arrest in a public location , there was no significant difference in survival to hospital discharge for the intravenous group vs the no intravenous group ( adjusted odds ratio , 1.15 ; 95 % confidence interval , 0.69 - 1.91 ) . CONCLUSION Compared with patients who received ACLS without intravenous drug administration following out-of-hospital cardiac arrest , patients with intravenous access and drug administration had higher rates of short-term survival with no statistically significant improvement in survival to hospital discharge , quality of CPR , or long-term survival . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00121524 IMPORTANCE Among patients with cardiac arrest , preliminary data have shown improved return of spontaneous circulation and survival to hospital discharge with the vasopressin-steroids-epinephrine ( VSE ) combination . OBJECTIVE To determine whether combined vasopressin-epinephrine during cardiopulmonary resuscitation ( CPR ) and corticosteroid supplementation during and after CPR improve survival to hospital discharge with a Cerebral Performance Category ( CPC ) score of 1 or 2 in vasopressor-requiring , in-hospital cardiac arrest . DESIGN , SETTING , AND PARTICIPANTS R and omized , double-blind ,  placebo-controlled  , parallel-group trial performed from September 1 , 2008 , to October 1 , 2010 , in 3 Greek tertiary care centers ( 2400 beds ) with 268 consecutive patients with cardiac arrest requiring epinephrine according to resuscitation guidelines ( from 364 patients assessed for eligibility ) . INTERVENTIONS Patients received either vasopressin ( 20 IU/CPR cycle ) plus epinephrine ( 1 mg/CPR cycle ; cycle duration approximately 3 minutes ) ( VSE group , n = 130 ) or saline placebo plus epinephrine ( 1 mg/CPR cycle ; cycle duration approximately 3 minutes ) ( control group , n = 138 ) for the first 5 CPR cycles after r and omization , followed by additional epinephrine if needed . During the first CPR cycle after r and omization , patients in the VSE group received methylprednisolone ( 40 mg ) and patients in the control group received saline placebo . Shock after resuscitation was treated with stress-dose hydrocortisone ( 300 mg daily for 7 days maximum and gradual taper ) ( VSE group , n = 76 ) or saline placebo ( control group , n = 73 ) . MAIN OUTCOMES AND MEASURES Return of spontaneous circulation ( ROSC ) for 20 minutes or longer and survival to hospital discharge with a CPC score of 1 or 2 . RESULTS Follow-up was completed in all resuscitated patients . Patients in the VSE group vs patients in the control group had higher probability for ROSC of 20 minutes or longer ( 109/130 [ 83.9 % ] vs 91/138 [ 65.9 % ] ; odds ratio [ OR ] , 2.98 ; 95 % CI , 1.39 - 6.40 ; P = .005 ) and survival to hospital discharge with CPC score of 1 or 2 ( 18/130 [ 13.9 % ] vs 7/138 [ 5.1 % ] ; OR , 3.28 ; 95 % CI , 1.17 - 9.20 ; P = .02 ) . Patients in the VSE group with postresuscitation shock vs corresponding patients in the control group had higher probability for survival to hospital discharge with CPC scores of 1 or 2 ( 16/76 [ 21.1 % ] vs 6/73 [ 8.2 % ] ; OR , 3.74 ; 95 % CI , 1.20 - 11.62 ; P = .02 ) , improved hemodynamics and central venous oxygen saturation , and less organ dysfunction . Adverse event rates were similar in the 2 groups . CONCLUSION AND RELEVANCE Among patients with cardiac arrest requiring vasopressors , combined vasopressin-epinephrine and methylprednisolone during CPR and stress-dose hydrocortisone in postresuscitation shock , compared with epinephrine/saline placebo , result ed in improved survival to hospital discharge with favorable neurological status . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00729794 BACKGROUND There is little evidence from clinical trials that the use of adrenaline ( epinephrine ) in treating cardiac arrest improves survival , despite adrenaline being considered st and ard of care for many decades . The aim of our study was to determine the effect of adrenaline on  patient survival to hospital discharge in out of hospital cardiac arrest . METHODS We conducted a double blind r and omised placebo-controlled trial of adrenaline in out-of-hospital cardiac arrest . Identical study vials containing either adrenaline 1:1000 or placebo ( sodium chloride 0.9 % ) were prepared . Patients were r and omly allocated to receive 1 ml aliquots of the trial drug according to current advanced life support guidelines . Outcomes assessed included survival to hospital discharge ( primary outcome ) , pre-hospital return of spontaneous circulation ( ROSC ) and neurological outcome ( Cerebral Performance Category Score - CPC ) . RESULTS A total of 4103 cardiac arrests were screened during the study period of which 601 underwent r and omisation . Documentation was available for a total of 534 patients : 262 in the placebo group and 272 in the adrenaline group . Groups were well matched for baseline characteristics including age , gender and receiving byst and er CPR . ROSC occurred in 22 ( 8.4 % ) of patients receiving placebo and 64 ( 23.5 % ) who received adrenaline ( OR=3.4 ; 95 % CI 2.0 - 5.6 ) . Survival to hospital discharge occurred in 5 ( 1.9 % ) and 11 ( 4.0 % ) patients receiving placebo or adrenaline respectively ( OR=2.2 ; 95 % CI 0.7 - 6.3 ) . All but two patients ( both in the adrenaline group ) had a CPC score of 1 - 2 . CONCLUSION Patients receiving adrenaline during cardiac arrest had no statistically significant improvement in the primary outcome of survival to hospital discharge although there was a significantly improved likelihood of achieving ROSC CONTEXT The health and policy implication s of regional variation in incidence and outcome of out-of-hospital cardiac arrest remain to be determined . OBJECTIVE To evaluate whether cardiac arrest incidence and outcome differ across geographic regions . DESIGN , SETTING , AND PATIENTS Prospect i ve observational study ( the Resuscitation Outcomes Consortium ) of all out-of-hospital cardiac arrests in 10 North American sites ( 8 US and 2 Canadian ) from May 1 , 2006 , to April 30 
    Output:
    
In conclusion , in this systematic review and meta- analysis involving studies , the use of epinephrine result ed in a significantly higher likelihood of survival to hospital discharge and ROSC than the non-epinephrine administration , but , there was no significant between group difference in the rate of a favorable neurologic outcome