***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 
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    Input: AIMS To investigate the feasibility of delivering titrated oxygen therapy to adults with return of spontaneous circulation ( ROSC ) following out-of-hospital cardiac arrest ( OHCA ) caused by ventricular fibrillation ( VF ) or ventricular tachycardia ( VT ) . METHODS We used a multicentre , r and omised , single blind , parallel groups design to compare titrated and st and ard oxygen therapy in adults resuscitated from VF/VT OHCA . The intervention commenced in the community following ROSC and was maintained in the emergency department and the Intensive Care Unit . The primary end point was the median oxygen saturation by pulse oximetry ( SpO2 ) in the pre-hospital period . RESULTS 159 OHCA patients were screened and 18 were r and omised . 17 participants were analysed : nine in the st and ard care group and eight in the titrated oxygen group . In the pre-hospital period , SpO2 measurements were lower in the titrated oxygen therapy group than the st and ard care group ( difference in medians 11.3 % ; 95 % CI 1.0 - 20.5 % ) . Low measured oxygen saturation ( SpO2<88 % ) occurred in 7/8 of patients in the titrated oxygen group and 3/9 of patients in the st and ard care group ( P=0.05 ) . Following hospital admission , good separation of oxygen exposure between the groups was achieved without a significant increase in hypoxia events . The trial was terminated because accumulated data led the Data Safety Monitoring Board and Management Committee to conclude that safe delivery of titrated oxygen therapy in the pre-hospital period was not feasible . CONCLUSIONS Titration of oxygen in the pre-hospital period following OHCA was not feasible ; it may be feasible to titrate oxygen safely after arrival in hospital Background Traumatic brain injury ( TBI ) is one of the important causes of morbidity and mortality throughout the world , especially in young people . In recent years normobaric hyperoxia has become an important and useful step for recovery and improvement of outcome in TBI . Objectives The purpose of this study was to evaluate the effects of normobaric hyperoxia on clinical neurological outcomes of patients with severe traumatic brain injuries . We used the Glasgow outcome scale ( GOS ) , barthel index , and modified rankin scale ( mRS ) to measure the outcomes of patients with TBI . Patients and Methods Sixty-eight consecutive patients with severe TBI ( mean Glasgow coma scale [ GCS ] score : 7.4 ) who met the inclusion criteria were entered in this r and omized controlled clinical trial . The patients were r and omized into two groups , as follows : 1 ) experimental : received 80 % oxygen via mechanical ventilator in the first 6 hours of admission , 2 ) control : received 50 % oxygen by mechanical ventilator in the first 6 hours of admission and then st and ard medical care . We measured the GOS , Barthel Index , and mRS at the time of discharge from hospital and reassessed these measurements at the 6-month follow-up after injury . Results According to our study , there were no significant sex or age differences between the two groups ( P = 0.595 and 0.074 ) . The number of days in the intensive care unit ( ICU ) in the control group and experimental group were 11.4 and 9.4 days , respectively ( P = 0.28 ) , while the numbers of days of general ward admission were 13.9 and 11.4 days ( P = 0.137 ) respectively . The status of GOS at time of discharge were severe = 13 and 10 , moderate = 16 and 19 , and low = 5 and 5 in the control and experimental groups , respectively ( P = 0.723 ) ; 6 months after injury , the scores were as follows : moderate = 16 and 9 , low = 15 and 25 , and severe = 3 and 0 ( P = 0.024 ) . The Barthel index scores in the control and experimental groups were 59.7 and 63.9 at time of discharge ( P = 0.369 ) and 82.7 and 91.3 at 6 months after injury ( P = 0.018 ) , respectively . The mRS results were 2.6 and 2.3 at time of discharge ( P = 0.320 ) and 1.6 and 0.7 at 6 months after injury ( P = 0.006 ) for the control and experimental groups , respectively . Conclusions According to the results of this study , oxygen therapy by mechanical ventilator in the first 6 hours after injury in patients with severe TBI can improve the final GOS , Barthel index , and mRS scores . It could also improve long-term outcomes and enhance rehabilitation and the quality of life Background — Oxygen is commonly administered to patients with ST-elevation – myocardial infa rct ion despite previous studies suggesting a possible increase in myocardial injury as a result of coronary vasoconstriction and heightened oxidative stress . Methods and Results — We conducted a multicenter , prospect i ve , r and omized , controlled trial comparing oxygen ( 8 L/min ) with no supplemental oxygen in patients with ST-elevation – myocardial infa rct ion diagnosed on paramedic 12-lead ECG . Of 638 patients r and omized , 441 patients had confirmed ST-elevation – myocardial infa rct ion and underwent primary end-point analysis . The primary end point was myocardial infa rct size as assessed by cardiac enzymes , troponin I , and creatine kinase . Secondary end points included recurrent myocardial infa rct ion , cardiac arrhythmia , and myocardial infa rct size assessed by cardiac magnetic resonance imaging at 6 months . Mean peak troponin was similar in the oxygen and no oxygen groups ( 57.4 versus 48.0 & mgr;g/L ; ratio , 1.20 ; 95 % confidence interval , 0.92–1.56 ; P=0.18 ) . There was a significant increase in mean peak creatine kinase in the oxygen group compared with the no oxygen group ( 1948 versus 1543 U/L ; means ratio , 1.27 ; 95 % confidence interval , 1.04–1.52 ; P=0.01 ) . There was an increase in the rate of recurrent myocardial infa rct ion in the oxygen group compared with the no oxygen group ( 5.5 % versus 0.9 % ; P=0.006 ) and an increase in frequency of cardiac arrhythmia ( 40.4 % versus 31.4 % ; P=0.05 ) . At 6 months , the oxygen group had an increase in myocardial infa rct size on cardiac magnetic resonance ( n=139 ; 20.3 versus 13.1 g ; P=0.04 ) . Conclusion — Supplemental oxygen therapy in patients with ST-elevation – myocardial infa rct ion but without hypoxia may increase early myocardial injury and was associated with larger myocardial infa rct size assessed at 6 months . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT01272713 STUDY OBJECTIVE We conducted the first r and omized controlled study to assess the effects of short-term 28 % and 100 % oxygen on PaCO(2 ) and peak expiratory flow rate ( PEFR ) in patients with acute severe asthma . PATIENTS AND INTERVENTIONS Seventy-four patients ( mean age , 37.9 + /- 9.7 years [ + /- SD ] ; PEFR , 41.0 + /- 12.1 % of predicted ) from two emergency departments were r and omized to receive 28 % or 100 % oxygen during 20 min . RESULTS The administration of 100 % oxygen significantly increases PaCO(2 ) ( p = 0.03 ) and decreases PEFR ( p = 0.001 ) as compared with administration of 28 % oxygen .  PaCO(2 ) before and during oxygen administration correlated significantly ( p = 0.001 ) in both groups . Patients breathing 28 % oxygen experienced a PaCO(2 ) fall ; on the contrary , patients who received 100 % oxygen showed an increase in PaCO(2 ) , particularly those with PaCO(2 ) before oxygen treatment > 40 mm Hg . CONCLUSIONS This study confirmed previous observations that oxygen dose should be variable and based on achieving and maintaining target arterial oxygen saturation measured by pulse oximetry > or = 92 % rather than on prescribing predetermined concentrations or flow rates of inspired oxygen Objective Recent studies suggest that administration of O2 in patients with acute myocardial infa rct ion may have negative effects . With the use of cardiac MRI ( CMR ) , we evaluated the effects of supplemental O2 in patients with ST elevation myocardial infa rct ion ( STEMI ) accepted for acute percutaneous coronary intervention ( PCI ) . Material s and methods This study was a r and omized-controlled trial conducted at two university hospitals in Sweden . Normoxic STEMI patients were r and omized in the ambulance to either supplemental O2 ( 10 l/min ) or room air until the conclusion of the PCI . CMR was performed 2–6 days after the inclusion . The primary endpoint was the myocardial salvage index assessed by CMR . The secondary endpoints included infa rct size and myocardium at risk . Results At inclusion , the O2 ( n=46 ) and air ( n=49 ) patient groups had similar patient characteristics . There were no significant differences in myocardial salvage index [ 53.9±25.1 vs. 49.3±24.0 % ; 95 % confidence interval ( CI ) : −5.4 to 14.6 ] , myocardium at risk ( 31.9±10.0 % of the left ventricle in the O2 group vs. 30.0±11.8 % in the air group ; 95 % CI : −2.6 to 6.3 ) , or infa rct size ( 15.6±10.4 % of the left ventricle vs. 16.0±11.0 % ; 95 % CI : −4.7 to 4.1 ) . Conclusion In STEMI patients undergoing acute PCI , we found no effect of high-flow oxygen compared with room air on the size of ischemia before PCI , myocardial salvage , or the result ing infa rct size . These results support the safety of withholding supplemental oxygen in normoxic STEMI patients BACKGROUND The clinical effect of routine oxygen therapy in patients with suspected acute myocardial infa rct ion who do not have hypoxemia at baseline is uncertain . METHODS In this registry‐based r and omized clinical trial , we used nationwide Swedish registries for patient enrollment and data collection . Patients with suspected myocardial infa rct ion and an oxygen saturation of 90 % or higher were r and omly assigned to receive either supplemental oxygen ( 6 liters per minute for 6 to 12 hours , delivered through an open face mask ) or ambient air . RESULTS A total of 6629 patients were enrolled . The median duration of oxygen therapy was 11.6 hours , and the median oxygen saturation at the end of the treatment period was 99 % among patients assigned to oxygen and 97 % among patients assigned to ambient air . Hypoxemia developed in 62 patients ( 1.9 % ) in the oxygen group , as compared with 254 patients ( 7.7 % ) in the ambient‐air group . The median of the highest troponin level during hospitalization was 946.5 ng per liter in the oxygen group and 983.0 ng per liter in the ambient‐air group . The primary end point of death from any cause within 1 year after r and omization occurred in 5.0 % of patients ( 166 of 3311 ) assigned to oxygen and in 5.1 % of patients ( 168 of 3318 ) assigned to ambient air ( hazard ratio , 0.97 ; 95 % confidence interval [ CI ] , 0.79 to 1.21 ; P=0.80 ) . Rehospitalization with myocardial infa rct ion within 1 year occurred in 126 patients ( 3.8 % ) assigned to oxygen and in 111 patients ( 3.3 % ) assigned to ambient air ( hazard ratio , 1.13 ; 95 % CI , 0.88 to 1.46 ; P=0.33 ) . The results were consistent across all predefined subgroups . CONCLUSIONS Routine use of supplemental oxygen in patients with suspected myocardial infa rct ion who did not have hypoxemia was not found to reduce 1‐year all‐cause mortality . ( Funded by the Swedish Heart – Lung Foundation and others ; DETO2X‐AMI Clinical Trials.gov number , NCT01787110 . Two-hundred consecutive patients thought to have suffered a myocardial infa rct ion were admitted to a r and omised , double-blind controlled trial of oxygen or air administered by MC mask throughout the first 24 hours in hospital . Forty-three patients in whom myocardial infa rct ion was not subsequently confirmed were excluded from the analysis . The remaining air and oxygen groups were comparable except for a significantly higher PaO2 and serum aspartate aminotransferase level in the oxygen group . There was no significant difference in mortality , incidence of arrhythmias , use of analgesics , or systolic time intervals between the two groups , although a higher incidence of sinus tachy 
    Output:
    
Our results indicate that oxygen supplementation with higher versus lower fractions or oxygenation targets may increase mortality .
None of the trials reported the proportion of participants with one or more serious adverse events according to the ICH-GCP criteria , however we found that the trials reported an increase in the number of serious adverse events with higher fractions or oxygenation targets .