***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: Introduction Acute hemodynamic instability increases morbidity and mortality . We investigated whether early non-invasive cardiac output monitoring enhances hemodynamic stabilization and improves outcome . Methods A multicenter , r and omized controlled trial was conducted in three European university hospital intensive care units in 2006 and 2007 . A total of 388 hemodynamically unstable patients identified during their first six hours in the intensive care unit ( ICU ) were r and omized to receive either non-invasive cardiac output monitoring for 24 hrs ( minimally invasive cardiac output/MICO group ; n = 201 ) or usual care ( control group ; n = 187 ) . The main outcome measure was the proportion of patients achieving hemodynamic stability within six hours of starting the study . Results The number of hemodynamic instability criteria at baseline ( MICO group mean 2.0 ( SD 1.0 ) , control group 1.8 ( 1.0 ) ; P = .06 ) and severity of illness ( SAPS II score ; MICO group 48 ( 18 ) , control group 48 ( 15 ) ; P = .86 ) ) were similar . At 6 hrs , 45 patients ( 22 % ) in the MICO group and 52 patients ( 28 % ) in the control group were hemodynamically stable ( mean difference 5 % ; 95 % confidence interval of the difference -3 to 14 % ; P = .24 ) . Hemodynamic support with fluids and vasoactive drugs , and pulmonary artery catheter use ( MICO group : 19 % , control group : 26 % ; P = .11 ) were similar in the two groups . The median length of ICU stay was 2.0 ( interquartile range 1.2 to 4.6 ) days in the MICO group and 2.5 ( 1.1 to 5.0 ) days in the control group ( P = .38 ) . The hospital mortality was 26 % in the MICO group and 21 % in the control group ( P = .34 ) . Conclusions Minimally-invasive cardiac output monitoring added to usual care does not facilitate early hemodynamic stabilization in the ICU , nor does it alter the hemodynamic support or outcome . Our results emphasize the need to evaluate technologies used to measure stroke volume and cardiac output -- especially their impact on the process of care -- before any large-scale outcome studies are attempted . Trial Registration The study was registered at Clinical Trials.gov ( Clinical Trials identifier NCT00354211 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 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 Background Major colorectal surgery usually requires a hospital stay of more than 12 days . Inadequate pain management , intestinal dysfunction and immobilisation are the main factors associated with delay in recovery . The present work assesses the short and medium term results achieved by an enhanced recovery program based on previously published protocol s. Methods This prospect i ve study , performed at 12 Spanish hospitals in 2008 and 2009 , involved 300 patients . All patients underwent elective colorectal resection for cancer following an enhanced recovery program .  The main elements of this program were : preoperative advice , no colon preparation , provision of carbohydrate-rich drinks one day prior and on the morning of surgery , goal directed fluid administration , body temperature control during surgery , avoiding drainages and nasogastric tubes , early mobilisation , and the taking of oral fluids in the early postoperative period . Perioperative morbidity and mortality data were collected and the length of hospital stay and protocol compliance recorded . Results The median age of the patients was 68 years . Fifty-two % of the patients were women . The distribution of patients by ASA class was : I 10 % , II 50 % and III 40 % . Sixty-four % of interventions were laparoscopic ; 15 % required conversion to laparotomy . The majority of patients underwent sigmoidectomy or right hemicolectomy .  The overall compliance to protocol was approximately 65 % , but varied widely in its different components . The median length of postoperative hospital stay was 6 days . Some 3 % of patients were readmitted to hospital after discharge ; some 7 % required repeat surgery during their initial hospitalisation or after readmission . The most common complications were surgical ( 24 % ) , followed by septic ( 11 % ) or other medical complications ( 10 % ) . Three patients ( 1 % ) died during follow-up . Some 31 % of patients suffered symptoms that delayed their discharge , the most common being vomiting or nausea ( 12 % ) , dyspnoea ( 7 % ) and fever ( 5 % ) . Conclusion The following of this enhanced recovery program posed no risk to patients in terms of morbidity , mortality and shortened the length of their hospital stay . Overall compliance to protocol was 65 % . The following of this program was of benefit to patients and reduces costs by shortening the length of hospital stay . The implantation of such programmes is therefore highly recommended Introduction Perioperative hypovolemia arises frequently and contributes to intestinal hypoperfusion and subsequent postoperative complications . Goal -directed fluid therapy might reduce these complications . The aim of this study was to compare the effects of goal -directed administration of crystalloids and colloids on the distribution of systemic , hepatosplanchnic , and microcirculatory ( small intestine ) blood flow after major abdominal surgery in a clinical ly relevant pig model . Methods Twenty-seven pigs were anesthetized and mechanically ventilated and underwent open laparotomy .  They were r and omly assigned to one of three treatment groups : the restricted Ringer lactate ( R-RL ) group ( n = 9 ) received 3 mL/kg per hour of RL , the goal -directed RL ( GD-RL ) group ( n = 9 ) received 3 mL/kg per hour of RL and intermittent boluses of 250 mL of RL , and the goal -directed colloid ( GD-C ) group ( n = 9 ) received 3 mL/kg per hour of RL and boluses of 250 mL of 6 % hydroxyethyl starch ( 130/0.4 ) . The latter two groups received a bolus infusion when mixed venous oxygen saturation was below 60 % ( ' lockout ' time of 30 minutes ) . Regional blood flow was measured in the superior mesenteric artery and the celiac trunk . In the small bowel , microcirculatory blood flow was measured using laser Doppler flowmetry . Intestinal tissue oxygen tension was measured with intramural Clark-type electrodes . Results After 4 hours of treatment , arterial blood pressure , cardiac output , mesenteric artery flow , and mixed oxygen saturation were significantly higher in the GD-C and GD-RL groups than in the R-RL group . Microcirculatory flow in the intestinal mucosa increased by 50 % in the GD-C group but remained unchanged in the other two groups . Likewise , tissue oxygen tension in the intestine increased by 30 % in the GD-C group but remained unchanged in the GD-RL group and decreased by 18 % in the R-RL group . Mesenteric venous glucose concentrations were higher and lactate levels were lower in the GD-C group compared with the two crystalloid groups . Conclusions Goal -directed colloid administration markedly increased microcirculatory blood flow in the small intestine and intestinal tissue oxygen tension after abdominal surgery . In contrast , goal -directed crystalloid and restricted crystalloid administrations had no such effects . Additionally , mesenteric venous glucose and lactate concentrations suggest that intestinal cellular substrate levels were higher in the colloid-treated than in the crystalloid-treated animals . These results support the notion that perioperative goal -directed therapy with colloids might be beneficial during major abdominal surgery Introduction Little is known about mortality rates following  general surgical procedures  in the United Kingdom . Deaths are most common in the ' high-risk ' surgical population consisting mainly of older patients , with coexisting medical disease , who undergo major surgery . Only limited data are presently available to describe this population . The aim of the present study was to estimate the size of the high-risk general surgical population and to describe the outcome and intensive care unit ( ICU ) re source use . Methods Data on inpatient general surgical procedures and ICU admissions in 94 National Health Service hospitals between January 1999 and October 2004 were extracted from the Intensive Care National Audit & Research Centre data base and the CHKS data base . High-risk surgical procedures were defined prospect ively as those for which the mortality rate was 5 % or greater . Results There were 4,117,727 surgical procedures ; 2,893,432 were elective ( 12,704 deaths ; 0.44 % ) and 1,224,295 were emergencies ( 65,674 deaths ; 5.4 % ) . A high-risk population of 513,924 patients was identified ( 63,340 deaths ; 12.3 % ) , which accounted for 83.8 % of deaths but for only 12.5 % of procedures . This population had a prolonged hospital stay ( median , 16 days ; interquartile range , 9–29 days ) . There were 59,424 ICU admissions ( 11,398 deaths ; 19 % ) . Among admissions directly to the ICU following surgery , there were 31,633 elective admissions with 3,199 deaths ( 10.1 % ) and 24,764 emergency admissions with 7,084 deaths ( 28.6 % ) . The ICU stays were short ( median , 1.6 days ; interquartile range , 0.8–3.7 days ) but hospital admissions for those admitted to the ICU were prolonged ( median , 16 days ; interquartile range , 10–30 days ) . Among the ICU population , 40.8 % of deaths occurred after the initial discharge from the ICU . The highest mortality rate ( 39 % ) occurred in the population admitted to the ICU following initial postoperative care on a st and ard ward . Conclusion A large high-risk surgical population accounts for 12.5 % of surgical procedures but for more than 80 % of deaths . Despite high mortality rates , fewer than 15 % of these patients are admitted to the ICU OBJECTIVE To determine the effect of a community hospital-wide program enabling nurses and prehospital personnel to mobilize institutional re sources for the treatment of patients with nontraumatic shock . DESIGN Historically controlled single-center study . SETTING A 180-bed community hospital . PATIENTS Patients in shock who were c and i date s for aggressive therapy . INTERVENTIONS From January 1998 to May 31 , 2000 , patients in shock received st and ard therapy ( control group ) . During the month of June 2000 , intensive education of all health-care providers ( ie , pre 
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Despite heterogeneity in trial quality and design , we found GDT to be beneficial in all high-risk patients undergoing major surgery .
The mortality benefit of GDT was confined to the subgroup of patients at extremely high risk of death .
The reduction of complication rates was seen across all subgroups of GDT patients