***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 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 Abstract Objectives To evaluate postoperative medical complications and the association between these complications and mortality at 30 days and one year after surgery for hip fracture and to examine the association between preoperative comorbidity and the risk of postoperative complications and mortality . Design Prospect i ve observational cohort study . Setting University teaching hospital . Participants 2448 consecutive patients admitted with an acute hip fracture over a four year period . We excluded 358 patients : all those aged < 60 ; those with periprosthetic fractures , pathological fractures , and fractures treated without surgery ; and patients who died before surgery . Interventions Routine care for hip fractures . Main outcome measures Postoperative complications and mortality at 30 days and one year . Results Mortality was 9.6 % at 30 days and 33 % at one year . The most common postoperative complications were chest infection ( 9 % ) and heart failure ( 5 % ) . In patients who developed postoperative heart failure mortality was 65 % at 30 days ( hazard ratio 16.1 , 95 % confidence interval 12.2 to 21.3 ) . Of these patients , 92 % were dead by one year ( 11.3 , 9.1 to 14.0 ) . In patients who developed a postoperative chest infection mortality at 30 days was 43 % ( 8.5 , 6.6 to 11.1 ) . Significant preoperative variables for increased mortality at 30 days included the presence of three or more comorbidities ( 2.5 , 1.6 to 3.9 ) , respiratory disease ( 1.8 , 1.3 to 2.5 ) , and malignancy ( 1.5 , 1.01 to 2.3 ) . Conclusions In elderly people with hip fracture , the presence of three or more comorbidities is the strongest preoperative risk factor . Chest infection and heart failure are the most common postoperative complications and lead to increased mortality . These groups offer a clear target for specialist medical assessment BACKGROUND Patients with proximal femoral fracture ( PFF ) are at high risk of postoperative complications . Goal -directed haemodynamic treatment ( GDHT ) in other high-risk surgical patients reduces postoperative complications . We aim ed to compare effects of GDHT and routine fluid treatment ( RFT ) on postoperative outcomes after PFF surgery . METHODS PFF patients ( ≥70 yr ) were enrolled in this single-centre , open , r and omized , controlled , parallel-group superiority trial with concealed allocation using computer-generated r and omization . TREATMENTS ( i ) GDHT to attain oxygen delivery index > 600 ml min(-1 ) m(-2 ) using fluids and dobutamine and ( ii ) a protocol -guided RFT .  After 150 enrolled patients , the trial was stopped due to slow recruitment . The short-term primary outcome measure was the relative risk ( RR ) of postoperative complications ; secondary measures were ( i ) administered fluid levels , ( ii ) vasopressor requirements , and ( iii ) haemodynamic responses . RESULTS For the GDHT group , 74 and for the RFT group 75 patients were design ated . The RR of postoperative complications ( GDHT vs RFT ) was 0.79 ( 95 % confidence interval 0.54 - 1.16 ) ; the volumes of i.v . fluids decreased ( 1078 vs 1440 ml , P=0.01 ) ; fewer patients required treatment of hypotension ( 18.5 % vs 75 % , P<0.005 ) ; there were more patients with increased oxygen delivery at the end of operation ( 28 % vs 8 % , P=0.04 ) , but the haemodynamic goal was achieved in only 27 % of patients in the GDHT group . CONCLUSIONS The magnitude of risk reduction of postoperative complications is clinical ly relevant , but the trial was underpowered and the null hypothesis can not be rejected BACKGROUND A prospect i ve , r and omized controlled trial comparing conventional intraoperative fluid management with two differing methods of invasive haemodynamic monitoring to optimize intraoperative fluid therapy , in patients undergoing proximal femoral fracture repair under general anaesthesia . METHODS Ninety patients r and omized to three groups ; conventional intraoperative fluid management ( Gp CON  , n=29 ) , and two groups receiving additional repeated colloid fluid challenges guided by central venous pressure ( Gp CVP , n=31 ) or oesophageal Doppler ultrasonography ( Gp DOP , n=30 ) . Primary outcome measures were time to medical fitness to discharge , hospital stay and postoperative morbidity . RESULTS The fluid challenge result ed in significantly greater perioperative changes in central venous pressure between Gp CVP and Gp CON ( mean 5 ( 95 % confidence interval 3 - 7 ) mm Hg ) ( P<0.0001 ) . Important perioperative changes were also shown in Gp DOP with increases of 49.4 ms ( 19.7 - 79.1 ms ) in the corrected flow time , 13.5 ml ( 7.4 - 19.6 ml ) in stroke volume , and 0.9 ( 0.49 - 1.39 ) litre min(-1 ) in cardiac output . As a result , fewer patients in Gp CVP and Gp DOP experienced severe intraoperative hypotension ( Gp CON 28 % ( 8/29 ) , Gp CVP 9 % ( 3/31 ) , Gp DOP 7 % ( 2/30 ) , P=0.048 ( chi-squared , 2 degrees of freedom ( df ) . No differences were seen between the three groups when major morbidity and mortality were combined , P=0.24 ( chi-squared , 2 df ) . Postoperative recovery for survivors , as defined by time to be deemed medically fit for discharge , was significantly faster , in comparison with Gp CON , in both the Gp CVP ( 10 vs 14 ( 95 % confidence interval 8 - 12 vs 12 - 17 ) days , P=0.008 ( t-test ) ) , and Gp DOP ( 8 vs 14 ( 95 % confidence interval 6 - 12 vs 12 - 17 ) days , P=0.023 ( t-test ) . There were no significant differences between groups , for survivors , with respect to acute orthopaedic hospital and total hospital stay . CONCLUSIONS Invasive intraoperative haemodynamic monitoring with fluid challenges during repair of femoral fracture under general anaesthetic shortens time to being medically fit for discharge Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Background Approximately 70,000 patients /year undergo surgery for repair of a fractured hip in the United Kingdom . This is associated with 30-day mortality of 9 % and survivors have a considerable length of acute hospital stay postoperatively ( median 26 days ) . Use of oesophageal Doppler monitoring to guide intra-operative fluid administration in hip fracture repair has previously been associated with a reduction in hospital stay of 4 - 5 days . Most hip fracture surgery is now performed under spinal anaesthesia . Oesophageal Doppler monitoring may be unreliable in the presence of spinal anaesthesia and most patients would not tolerate the probes . An alternative method of guiding fluid administration ( minimally-invasive arterial pulse contour analysis ) has been shown to reduce length of stay in high-risk surgical patients but has never been studied in hip fracture surgery . Methods Single-centre r and omised controlled parallel group trial . R and omisation by website using computer generated concealed tables . Setting : University hospital in UK . Participants : 128 patients with acute primary hip fracture listed for operative repair under spinal anaesthesia and aged > 65 years . Intervention : Stroke volume guided intra-operative fluid management . Continuous measurement of SV recorded by a calibrated cardiac output monitor ( LiDCOplus ) . Maintenance fluid and 250 ml colloid boluses given to achieve sustained 10 % increases in stroke volume . Control group : fluid administration at the responsible ( blinded ) anaesthetist 's discretion . The intervention terminates at the end of the surgical procedure and post-operative fluid management is at the responsible anaesthetist 's discretion . Primary outcome : length of acute hospital stay is determined by a blinded team of clinicians . Secondary outcomes include number of complications and total cost of care . Funding NIHR/RfPB : PB-PG-0407 - 13073.Trial registration numberTrial registration : Current Controlled Trials IS RCT N88284896 Background Intraoperative hypovolemia is common and is a potential cause of organ dysfunction , increased postoperative morbidity , length of hospital stay , and death . The objective of this prospect i ve , r and omized study was to assess the effect of goal -directed intraoperative fluid administration on length of postoperative hospital stay . Methods One hundred patients who were to undergo major elective surgery with an anticipated blood loss greater than 500 ml were r and omly assigned to a control group ( n = 50 ) that received st and ard intraoperative care or to a protocol group ( n = 50 ) that , in addition , received intraoperative plasma volume expansion guided by the esophageal Doppler monitor to maintain maximal stroke volume . Length of postoperative hospital stay and postoperative surgical morbidity were assessed . Results Groups were similar with respect to demographics , surgical procedures , and baseline hemodynamic variables . The protocol group had a significantly higher stroke volume and cardiac output at the end of surgery compared with the control group . Patients in the protocol group had a shorter duration of hospital stay compared with the control group : 5 ± 3 versus 7 ± 3 days ( mean ± SD ) , with a median of 6 versus 7 days , respectively ( P = 0.03 ) . These patients also tolerated oral intake of solid food earlier than the control group : 3 ± 0.5 versus 4.7 ± 0.5 days ( mean ± SD ) , with a median of 3 versus 5 days , respectively ( P = 0.01 ) . Conclusions Goal -directed intraoperative fluid administration results in earlier return to bowel function , lower incidence of postoperative nausea and vomiting , and decrease in length of postoperative hospital stay Background A r and omized , controlled trial , intended to include 460 patients , is currently study ing peroperative goal -directed hemodynamic treatment ( GDHT ) of aged hip-fracture patients . Interim efficacy analysis performed on the first 100 patients was statistically uncertain ; thus , the trial is continuing in accordance with the trial protocol . This raised the present investigation ’s main question : Is it reasonable to continue to fund the trial to decrease uncertainty ? To answer this question , a previously developed probabilistic cost-effectiveness model was used . That model depicts ( 1 ) a choice between routine fluid treatment and GDHT , given uncertainty of current evidence and ( 2 ) the monetary value of further data collection to decrease uncertainty . This monetary value , that is , the expected value of perfect information ( EVPI ) , could be used to compare future research costs . Thus , the primary aim of the present investigation was to analyze EVPI of an ongoing trial with interim efficacy observed . Methods A previously developed probabilistic decision analyt 
    Output:
    
Five studies including a total of 403 participants provided no evidence that fluid optimization strategies improve outcomes for participants undergoing surgery for PFF .