***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: BACKGROUND Optimal fluid management in patients with acute lung injury is unknown . Diuresis or fluid restriction may improve lung function but could jeopardize extrapulmonary-organ perfusion . METHODS In a r and omized study , we compared a conservative and a liberal strategy of fluid management using explicit protocol s applied for seven days in 1000 patients with acute lung injury . The primary end point was death at 60 days . Secondary end points included the number of ventilator-free days and organ-failure-free days and measures of lung physiology . RESULTS The rate of death at 60 days was 25.5 percent in the conservative- strategy group and 28.4 percent in the liberal- strategy group ( P=0.30 ; 95 percent confidence interval for the difference , -2.6 to 8.4 percent ) . The mean ( + /-SE ) cumulative fluid balance during the first seven days was -136+/-491 ml in the conservative- strategy group and 6992+/-502 ml in the liberal- strategy group ( P<0.001 ) . As compared with the liberal strategy , the conservative strategy improved the oxygenation index ( [ mean airway pressure x the ratio of the fraction of inspired oxygen to the partial pressure of arterial oxygen]x100 ) and the lung injury score and increased the number of ventilator-free days ( 14.6+/-0.5 vs. 12.1+/-0.5 , P<0.001 ) and days not spent in the intensive care unit ( 13.4+/-0.4 vs. 11.2+/-0.4 , P<0.001 ) during the first 28 days but did not increase the incidence or prevalence of shock during the study or the use of dialysis during the first 60 days ( 10 percent vs. 14 percent , P=0.06 ) . CONCLUSIONS Although there was no significant difference in the primary outcome of 60-day mortality , the conservative strategy of fluid management improved lung function and shortened the duration of mechanical ventilation and intensive care without increasing nonpulmonary-organ failures . These results support the use of a conservative strategy of fluid management in patients with acute lung injury . ( Clinical Trials.gov number , NCT00281268 [ Clinical Trials.gov ] . ) BACKGROUND Some observational studies suggest that the use of pulmonary-artery catheters to guide therapy is associated with increased mortality . METHODS We performed a r and omized trial comparing goal -directed therapy guided by a pulmonary-artery catheter with st and ard care without the use of a pulmonary-artery catheter . The subjects were high-risk patients 60 years of age or older , with American Society of Anesthesiologists ( ASA ) class III or IV risk , who were scheduled for urgent or elective major surgery , followed by a stay in an intensive care unit . Outcomes were adjudicated by observers who were unaware of the treatment-group assignments . The primary outcome was in-hospital mortality from any cause . RESULTS Of 3803 eligible patients , 1994 ( 52.4 percent ) underwent r and omization . The base-line characteristics of the two treatment groups were similar . A total of 77 of 997 patients who underwent surgery without the use of a  pulmonary-artery catheter ( 7.7 percent ) died in the hospital , as compared with 78 of 997 patients in whom a pulmonary-artery catheter was used ( 7.8 percent)--a difference of 0.1 percentage point ( 95 percent confidence interval , -2.3 to 2.5 ) . There was a higher rate of pulmonary embolism in the catheter group than in the st and ard-care group ( 8 events vs. 0 events , P=0.004 ) . The survival rates at 6 months among patients in the st and ard-care and catheter groups were 88.1 and 87.4 percent , respectively ( difference , -0.7 percentage point [ 95 percent confidence interval , -3.6 to 2.2 ] ; negative survival differences favor st and ard care ) ; at 12 months , the rates were 83.9 and 83.0 percent , respectively ( difference , -0.9 percentage point [ 95 percent confidence interval , -4.3 to 2.4 ] ) . The median hospital stay was 10 days in each group . CONCLUSIONS We found no benefit to therapy directed by pulmonary-artery catheter over st and ard care in elderly , high-risk surgical patients requiring intensive care Introduction Several studies have shown that goal -directed hemodynamic and fluid optimization may result in improved outcome . However , the methods used were either invasive or had other limitations . The aim of this study was to perform intraoperative goal -directed therapy with a minimally invasive , easy to use device ( FloTrac/Vigileo ) , and to evaluate possible improvements in patient outcome determined by the duration of hospital stay and the incidence of complications compared to a st and ard management protocol . Methods In this r and omized , controlled trial 60 high-risk patients scheduled for major abdominal surgery were included . Patients were allocated into either an enhanced hemodynamic monitoring group using a cardiac index based intraoperative optimization protocol ( FloTrac/Vigileo device , GDT-group , n = 30 ) or a st and ard management group ( Control-group , n = 30 ) , based on st and ard monitoring data . Results The median duration of hospital stay was significantly reduced in the GDT-group with 15 ( 12 - 17.75 ) days versus 19 ( 14 - 23.5 ) days ( P = 0.006 ) and fewer patients developed complications than in the Control-group [ 6 patients ( 20 % ) versus 15 patients ( 50 % ) , P = 0.03 ] . The total number of complications was reduced in the GDT-group ( 17 versus 49 complications , P = 0.001 ) . Conclusions In high-risk patients undergoing major abdominal surgery , implementation of an intraoperative goal -directed hemodynamic optimization protocol using the FloTrac/Vigileo device was associated with a reduced length of hospital stay and a lower incidence of complications compared to a st and ard management protocol .Trial Registration Clinical trial registration information : Unique identifier : Background : An individualized fluid optimization strategy , based on maximization of cardiac stroke volume ( SV ) with colloid boluses ( goal ‐directed therapy ) , improves outcome after surgery .  Oesophageal Doppler ( OD ) is used for SV maximization in most r and omized studies , but evidence ‐based guidelines for the SV maximization procedure are lacking and variation in SV may influence the indication for fluid administration . We measured beat‐to‐beat OD SV before and after  fluid optimization  in order to estimate the number of heartbeats for which SV needs to be averaged to provide an acceptable accuracy for goal ‐directed therapy with this technology Objective To test whether fluid responsiveness can be predicted by the respiratory variation in aortic blood flow and /or the flow time corrected for heart rate monitored with esophageal Doppler . Design and setting Prospect i ve study in a 24-bed medical intensive care unit of a university hospital . Patients 38 mechanically ventilated patients with sinus rhythm and without spontaneous breathing activity in whom volume expansion was planned . Interventions The aortic blood flow was measured using an esophageal Doppler monitoring device before and after fluid infusion ( 500 ml NaCl 0.9 % over 10 min ) . The variation in aortic blood flow over a respiratory cycle between its minimal and maximal values was calculated . The flow time was also measured . Measurements and results Aortic blood flow increased by at least 15 % after volume expansion in 20 patients ( defined as responders ) . Before fluid infusion the respiratory variation in aortic flow was higher in responders than in nonresponders ( 28±12 % vs. 12±5 % ) . It significantly decreased after volume expansion ( 18±11 % ) in responders only . A respiratory variation in aortic flow before volume expansion of at least 18 % predicted fluid responsiveness with a sensitivity of 90 % and a specificity of 94 % . Flow time increased with fluid infusion in responders and nonresponders . A flow time corrected for heart rate below 277 ms predicted fluid responsiveness with a sensitivity of 55 % and a specificity of 94 % . The area under the ROC curve generated for variation in aortic blood flow ABF was greater than that generated for flow time . Conclusions The respiratory variation in aortic blood flow reliably predicts fluid responsiveness in patients with sinus rhythm and without breathing activity Introduction Total hip replacement is one of the most commonly performed major orthopaedic operations . Goal -directed therapy ( GDT ) using haemodynamic monitoring has previously demonstrated outcome benefits in high-risk surgical patients under general anaesthesia .  GDT has never been formally assessed during regional anaesthesia . Methods Patients undergoing total hip replacement while under regional anaesthesia were r and omised to either the control group ( CTRL ) or the protocol group ( GDT ) . Patients in the GDT group , in addition to st and ard monitoring , were connected to the FloTrac sensor/Vigileo monitor haemodynamic monitoring system , and a GDT protocol was used to maximise the stroke volume and target the oxygen delivery index to > 600 mL/minute/m2 . Results Patients r and omised to the GDT group were given a greater volume of intravenous fluids during the intraoperative period ( means ± st and ard deviation ( SD ) : 6,032 ± 1,388 mL vs. 2,635 ± 346 mL ; P < 0.0001 ) , and more of the GDT patients received dobutamine ( 0 of 20 CTRL patients vs. 11 of 20 GDT patients ; P < 0.0003 ) . The GDT patients also received more blood transfused during the intraoperative period ( means ± SD : 595 ± 316 mL vs. 0 ± 0 mL ; P < 0.0001 ) , although the CTRL group received greater volumes of blood replacement postoperatively ( CTRL patients 658 ± 68 mL vs. GDT patients 198 ± 292 mL ; P < 0.001 ) . Overall blood consumption ( intraoperatively and postoperatively ) was not different between the two groups . There were an increased number of complications in the CTRL group ( 20 of 20 CTRL patients ( 100 % ) vs. 16 of 20 GDT patients ( 80 % ) ; P = 0.05 ) . These outcomes were predominantly due to a difference in minor complications ( 20 of 20 CTRL patients ( 100 % ) vs. 15 of 20 GDT patients ( 75 % ) ; P = 0.047 ) . Conclusions GDT applied during regional anaesthesia in patients undergoing elective total hip replacement changes intraoperative fluid management and may improve patient outcomes by decreasing postoperative complications . Larger trials are required to confirm our findings .Trial registration S RCT Objective To test the hypothesis that , in resuscitated septic shock patients , central venous-to-arterial carbon dioxide difference [ P(cv-a)CO2 ] may serve as a global index of tissue perfusion when the central venous oxygen saturation ( ScvO2 ) goal value has already been reached . Design Prospect i ve observational study . Setting A 22-bed intensive care unit ( ICU ) . Patients After early resuscitation in the emergency unit , 50 consecutive septic shock patients with ScvO2 > 70 % were included immediately after their admission into the ICU ( T0 ) . Patients were separated in Low P(cv-a)CO2 group ( Low gap ; n = 26 ) and High P(cv-a)CO2 group ( High gap ; n = 24 ) according to a threshold of 6 mmHg at T0 . Measurements Measurements were performed every 6 h over 12 h ( T0 , T6 , T12 ) . Results At T0 , there was a significant difference between Low gap patients and High gap patients for cardiac index ( CI ) ( 4.3 ± 1.6 vs. 2.7 ± 0.8 l/min/m² , P < 0.0001 ) but not for ScvO2 values ( 78 ± 5 vs. 75 ± 5 % , P = 0.07 ) . From T0 to T12 , the clearance of lactate was significantly larger for the Low gap group than for the High gap group ( P < 0.05 ) as well as the decrease of SOFA score at T24 ( P < 0.01 ) . At T0 , T6 and T12 , CI and P(cv-a)CO2 values were inversely correlated ( P < 0.0001 ) . Conclusion In ICU-resuscitated patients , targeting only ScvO2 may not be sufficient to guide therapy . When the 70 % ScvO2 goal -value is reached , the presence of a P(cv-a)CO2 larger than 6 mmHg might be a useful tool to identify patients who still remain inadequately resuscitated Organ dysfunction and multiple organ failure are the main causes of prolonged hospital stay after cardiac surgery , which increases re source use and health care costs . Increased levels of oxygen delivery and consumption are associated with improved outcome in different groups of postoperative patients . Cardiac surgical patients are at risk of inadequate perioperative oxygen delivery caused by extracorporeal circulation and limited cardiovascular reserves . The purpose of our study was to test whether increasing oxygen delivery immediately after cardiac surgery would shorten hospital and intensive care unit ( ICU ) stay . Four hundred three elective cardiac surgical patients were enrolled in the study and r and omly assigned to either the control or the protocol group . Goals of the protocol group were to maintain Svo2 > 
    Output:
    
Goals with moderate quality evidence were sublingual microcirculation flow , the oxygen extraction ratio , cardiac index , cardiac output , and SVC collapsibility index .