***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: Introduction Patients with distributive shock who require high dose vasopressors have a high mortality .  Angiotensin II ( ATII ) may prove useful in patients who remain hypotensive despite catecholamine and vasopressin therapy . The appropriate dose of parenteral angiotensin II for shock is unknown . Methods In total , 20 patients with distributive shock and a cardiovascular Sequential Organ Failure Assessment score of 4 were r and omized to either ATII infusion ( N = 10 ) or placebo ( N = 10 ) plus st and ard of care . ATII was started at a dose of 20 ng/kg/min , and titrated for a goal of maintaining a mean arterial pressure ( MAP ) of 65 mmHg . The infusion ( either ATII or placebo ) was continued for 6 hours then titrated off . The primary endpoint was the effect of ATII on the st and ing dose of norepinephrine required to maintain a MAP of 65 mmHg . Results ATII result ed in marked reduction in norepinephrine dosing in all patients . The mean hour 1 norepinephrine dose for the placebo cohort was 27.6 ± 29.3 mcg/min versus 7.4 ± 12.4 mcg/min for the ATII cohort ( P = 0.06 ) . The most common adverse event attributable to ATII was hypertension , which occurred in 20 % of patients receiving ATII . 30-day mortality for the ATII cohort and the placebo cohort was similar ( 50 % versus 60 % , P = 1.00 ) . Conclusion Angiotensin II is an effective rescue vasopressor agent in patients with distributive shock requiring multiple vasopressors . The initial dose range of ATII that appears to be appropriate for patients with distributive shock is 2 to 10 ng/kg/min . Trial registration Clinical trials.gov NCT01393782 . Registered 12 July 2011 While fluid management is established in controlled hemorrhagic shock , its use in uncontrolled hemorrhagic shock is being controversially discussed , because it may worsen bleeding . In the irreversible phase of hemorrhagic shock that was unresponsive to volume replacement , airway management and catecholamines , vasopressin was beneficial due to an increase in arterial blood pressure , shift of blood away from a subdiaphragmatic bleeding site towards the heart and brain and decrease of fluid resuscitation requirements . The purpose of this multicenter , r and omized , controlled , international trial is to assess the effects of vasopressin ( 10 IU IV ) vs. saline placebo IV ( up to 3 injections at least 5 min apart ) in patients with prehospital traumatic hemorrhagic shock that persists despite st and ard shock treatment . The study will be carried out by helicopter emergency medical service teams in Austria , Germany , Czech Republic , Portugal , the Netherl and s and Switzerl and . Inclusion criteria are adult trauma patients with presumed traumatic hemorrhagic shock ( systolic arterial blood pressure < 90 mmHg ) that does not respond to the first 10 min of st and ard shock treatment  ( endotracheal intubation , fluid resuscitation and use of vasopressors ) after arrival of the first emergency physician at the scene . The time window for r and omization will close after 30 min of shock treatment . Exclusion criteria are terminal illness , no intravenous access , age < 18 years , injury > 60 min before r and omization , cardiac arrest before r and omization , presence of a do-not-resuscitate order , untreated tension pneumothorax , untreated cardiac tamponade , or known pregnancy . Primary study end-point is the hospital admission rate , secondary end-points are hemodynamic variables , fluid resuscitation requirements and hospital discharge rate Introduction To provide up-to- date information on the prognostic factors associated with 28-day mortality in a cohort of septic shock patients in intensive care units ( ICUs ) . Methods Prospect i ve , multicenter , observational cohort study in ICUs from 14 French general ( non-academic ) and university teaching hospitals . All consecutive patients with septic shock admitted between November 2009 and March 2011 were eligible for inclusion . We prospect ively recorded data regarding patient characteristics , infection , severity of illness , life support therapy , and discharge . Results Among 10,941 patients admitted to participating ICUs between October 2009 and September 2011 , 1,495 ( 13.7 % ) patients presented inclusion criteria for septic shock and were included .  Invasive mechanical ventilation was needed in 83.9 % ( n = 1248 ) , inotropes in 27.7 % ( n = 412 ) , continuous renal replacement therapy in 32.5 % ( n = 484 ) , and hemodialysis in 19.6 % ( n = 291 ) . Mortality at 28 days was 42 % ( n = 625 ) . Variables associated with time to mortality , right-censored at day 28 : age ( for each additional 10 years ) ( hazard ratio ( HR ) = 1.29 ; 95 % confidence interval ( CI ) : 1.20 - 1.38 ) , immunosuppression ( HR = 1.63 ; 95%CI : 1.37 - 1.96 ) , Knaus class C/D score versus class A/B score ( HR = 1.36 ; 95%CI:1.14 - 1.62 ) and Sepsis-related Organ Failure Assessment ( SOFA ) score ( HR = 1.24 for each additional point ; 95%CI : 1.21 - 1.27 ) . Patients with septic shock and renal/urinary tract infection had a significantly longer time to mortality ( HR = 0.56 ; 95%CI : 0.42 - 0.75 ) . Conclusion Our observational data of consecutive patients from real-life practice confirm that septic shock is common and carries high mortality in general ICU population s. Our results are in contrast with the clinical trial setting , and could be useful for healthcare planning and clinical study design In septic shock , the alteration of the gut barrier contributes to the development of multiple organ failure . The aim of the study was to compare epinephrine with the combination of dobutamine and norepinephrine on gastric perfusion  in patients with septic shock Objectives : To compare the effects of dobutamine and dopexamine on systemic hemodynamics , lactate metabolism , renal function and the intramucosal-arterial PCO2 gap in norepinephrine-treated septic shock . Design : A prospect i ve , interventional , r and omized clinical trial . Setting : Adult medical/surgical intensive care unit in a university hospital . Patients : After volume resuscitation , 24 patients were treated with norepinephrine alone titrated to obtain a mean arterial pressure of 75 mmHg and a cardiac index greater than 3.5 l/min-1 · m-2 . Interventions : Patients were r and omized to receive an infusion of dobutamine ( n = 12 ) ( 5 μg/kg per min ) or dopexamine ( n = 12 ) ( 1 μg/kg per min ) . Measurements and main results : Baseline measurements included : hemodynamic parameters , renal parameters ( diuresis , creatinine clearance and urinary sodium excretion ) , gastric mucosal-arterial PCO2 gap , arterial and mixed venous gases and arterial lactate and pyruvate levels . These measurements were repeated after 1 ( H1 ) , 4 ( H4 ) and 24 ( H24 ) h. No difference was found between dobutamine and dopexamine among H0 and H1 , H4 and H24 values for hemodynamics  . Dobutamine and dopexamine at low doses had no significant effect on mean arterial pressure , heart rate , cardiac index , oxygen delivery , oxygen consumption and pulmonary artery occlusion pressure . No patients developed arrhythmia or electrocardiographic signs of myocardial ischemia . After 4 and 24 h lactate concentration decreased in the dobutamine group from 2.4 ± 1 mmol/l to 1.7 ± 0.7 mmol/l and 1.5 ± 0.4 mmol/l , respectively , while it increased in the dopexamine group from 2.3 ± 1 mmol/l to 2.7 ± 1 mmol/l after 4 h and returned to baseline values after 24 h ( 2.2 ± 0.6 ) . After 24 h the lactate/pyruvate ratio decreased in the dobutamine group from 15 ± 5 to 12 ± 3 ( p < 0.05 ) while it was unchanged in the dopexamine group ( from 16 ± 6 to 17 ± 4 ) . Arterial pH increased in the dobutamine group from 7.35 ± 0.05 to 7.38 ± 0.07 ( p < 0.05 ) while it was unchanged in the dopexamine group ( from 7.34 ± 0.01 to 7.35 ± 0.10 ) . The PCO2 gap decreased after 1 and 4 h in both the dobutamine and dopexamine groups ( p < 0.05 with respect to baseline ) . When looking at individual responses , however , patients from both groups exhibited an increased gastric PCO2 gap . No difference was found between dobutamine and dopexamine for renal parameters . Conclusions : In norepinephrine-treated septic shock , low doses of neither dobutamine nor dopexamine caused significant effects on systemic hemodynamics and renal function and both dobutamine and dopexamine inconsistently improved the PCO2 gap . The present results support the need for individual measurement of the effects of catecholamine on the PCO2 gap BACKGROUND Both dopamine and norepinephrine are recommended as first-line vasopressor agents in the treatment of shock . There is a continuing controversy about whether one agent is superior to the other . METHODS In this multicenter , r and omized trial , we assigned patients with shock to receive either dopamine or norepinephrine as first-line vasopressor therapy to restore and maintain blood pressure . When blood pressure could not be maintained with a dose of 20 microg per kilogram of body weight per minute for dopamine or a dose of 0.19 microg per kilogram per minute for norepinephrine , open-label norepinephrine , epinephrine , or vasopressin could be added . The primary outcome was the rate of death at 28 days after r and omization ; secondary end points included the number of days without need for organ support and the occurrence of adverse events . RESULTS The trial included 1679 patients , of whom 858 were assigned to dopamine and 821 to norepinephrine . The baseline characteristics of the groups were similar . There was no significant between-group difference in the rate of death at 28 days ( 52.5 % in the dopamine group and 48.5 % in the norepinephrine group ; odds ratio with dopamine , 1.17 ; 95 % confidence interval , 0.97 to 1.42 ; P=0.10 ) . However , there were more arrhythmic events among the patients treated with dopamine than among those treated with norepinephrine ( 207 events [ 24.1 % ] vs. 102 events [ 12.4 % ] , P<0.001 ) . A subgroup analysis showed that dopamine , as compared with norepinephrine , was associated with an increased rate of death at 28 days among the 280 patients with cardiogenic shock but not among the 1044 patients with septic shock or the 263 with hypovolemic shock ( P=0.03 for cardiogenic shock , P=0.19 for septic shock , and P=0.84 for hypovolemic shock , in Kaplan-Meier analyses ) . CONCLUSIONS Although there was no significant difference in the rate of death between patients with shock who were treated with dopamine as the first-line vasopressor agent and those who were treated with norepinephrine , the use of dopamine was associated with a greater number of adverse events . ( Clinical Trials.gov number , NCT00314704 . RATIONALE Sustained arrhythmias are common in postoperative and cardiac intensive care units ( ICUs ) , but their incidence and prognosis in general ICUs have never been reported . OBJECTIVES To estimate the incidence and prognosis of sustained arrhythmias in a general ICU population . METHODS Prospect i ve , multicenter , 1-month inception cohort study . MEASUREMENTS AND MAIN RESULTS A total of 1,341 patients were included : 12 % ( 163/1,341 ) had sustained arrhythmias , including 8 % ( 113/1,341 ) and 2 % ( 30/1,341 ) with supraventricular and ventricular arrhythmias , respectively , and 2 % ( 30/1,341 ) with conduction abnormalities . In-hospital death rates were 17 % ( 205/1,178 ) in patients without arrhythmia and 29 % ( 33/113 ) in patients with supraventricular arrhythmias ( odds ratio [ OR ] , 1.95 ; 95 % confidence interval [ CI ] , 1.27 - 3.01 ) , 7 
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These findings were consistent among the few large studies and among studies with different levels of within- study bias risk .
We found no evidence of substantial differences in total mortality between several vasopressors .
Dopamine increases the risk of arrhythmia compared with norepinephrine and might increase mortality .
Otherwise , evidence of any other differences between any of the six vasopressors examined is insufficient .
We identified low risk of bias and high- quality evidence for the comparison of norepinephrine versus dopamine and moderate to very low- quality evidence for all other comparisons , mainly because single comparisons occasionally were based on only a few participants .
Increasing evidence indicates that the treatment goals most often employed are of limited clinical value .