***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: BACKGROUND Comparative clinical effects of balanced crystalloids and saline are uncertain , particularly in noncritically ill patients cared for outside an intensive care unit ( ICU ) . METHODS We conducted a single‐center , pragmatic , multiple‐crossover trial comparing balanced crystalloids ( lactated Ringer 's solution or Plasma‐Lyte A ) with saline among adults who were treated with intravenous crystalloids in the emergency department and were subsequently hospitalized outside an ICU . The type of crystalloid that was administered in the emergency department was assigned to each patient on the basis of calendar month , with the entire emergency department crossing over between balanced crystalloids and saline monthly during the 16‐month trial . The primary outcome was hospital‐free days ( days alive after discharge before day 28 ) . Secondary outcomes included major adverse kidney events within 30 days — a composite of death from any cause , new renal‐replacement therapy , or persistent renal dysfunction ( defined as an elevation of the creatinine level to ≥200 % of baseline ) — all censored at hospital discharge or 30 days , whichever occurred first . RESULTS A total of 13,347 patients were enrolled , with a median crystalloid volume administered in the emergency department of 1079 ml and 88.3 % of the patients exclusively receiving the assigned crystalloid . The number of hospital‐free days did not differ between the balanced‐crystalloids and saline groups ( median , 25 days in each group ; adjusted odds ratio with balanced crystalloids , 0.98 ; 95 % confidence interval [ CI ] , 0.92 to 1.04 ; P=0.41 ) . Balanced crystalloids result ed in a lower incidence of major adverse kidney events within 30 days than saline ( 4.7 % vs. 5.6 % ; adjusted odds ratio , 0.82 ; 95 % CI , 0.70 to 0.95 ; P=0.01 ) . CONCLUSIONS Among noncritically ill adults treated with intravenous fluids in the emergency department , there was no difference in hospital‐free days between treatment with balanced crystalloids and treatment with saline . ( Funded by the V and erbilt Institute for Clinical and Translational Research and others ; SALT‐ED Clinical Trials.gov number , NCT02614040 . BACKGROUND Both balanced crystalloids and saline are used for intravenous fluid administration in critically ill adults , but it is not known which results in better clinical outcomes . METHODS In a pragmatic , cluster‐r and omized , multiple‐crossover trial conducted in five intensive care units at an academic center , we assigned 15,802 adults to receive saline ( 0.9 % sodium chloride ) or balanced crystalloids ( lactated Ringer 's solution or Plasma‐Lyte A ) according to the r and omization of the unit to which they were admitted . The primary outcome was a major adverse kidney event within 30 days — a composite of death from any cause , new renal‐replacement therapy , or persistent renal dysfunction ( defined as an elevation of the creatinine level to ≥200 % of baseline ) — all censored at hospital discharge or 30 days , whichever occurred first . RESULTS Among the 7942 patients in the balanced‐crystalloids group , 1139 ( 14.3 % ) had a major adverse kidney event , as compared with 1211 of 7860 patients ( 15.4 % ) in the saline group ( marginal odds ratio , 0.91 ; 95 % confidence interval [ CI ] , 0.84 to 0.99 ; conditional odds ratio , 0.90 ; 95 % CI , 0.82 to 0.99 ; P=0.04 ) . In‐hospital mortality at 30 days was 10.3 % in the balanced‐crystalloids group and 11.1 % in the saline group ( P=0.06 ) . The incidence of new renal‐replacement therapy was 2.5 % and 2.9 % , respectively ( P=0.08 ) , and the incidence of persistent renal dysfunction was 6.4 % and 6.6 % , respectively ( P=0.60 ) . CONCLUSIONS Among critically ill adults , the use of balanced crystalloids for intravenous fluid administration result ed in a lower rate of the composite outcome of death from any cause , new renal‐replacement therapy , or persistent renal dysfunction than the use of saline . ( Funded by the V and erbilt Institute for Clinical and Translational Research and others ; SMART‐MED and SMART‐SURG Clinical Trials.gov numbers , NCT02444988 and NCT02547779 . Background : The aim of this study was to evaluate postoperative complications in patients having major elective surgery using oesophageal Doppler monitor‐guided goal ‐directed haemodynamic therapy ( GDHT )  , in which administration of fluids , inotropes , and vasopressors was guided by stroke volume , mean arterial pressure , and cardiac index . Methods : The FEDORA trial was a prospect i ve , multicentre , r and omised , parallel‐group , controlled patient‐ and observer‐blind trial conducted in adults scheduled for major elective surgery . R and omization and allocation were carried out by a central computer system . In the control group , intraoperative fluids were given based on traditional principles . In the GDHT group , the intraoperative goals were to maintain a maximal stroke volume , with mean arterial pressure > 70 mm Hg , and cardiac index ≥2.5 litres min−1 m−2 . The primary outcome was percentage of patients with moderate or severe postoperative complications during the first 180 days after surgery . Results : In total , 450 patients were r and omized to the GDHT group ( n=224 ) or control group ( n=226 ) . Data from 420 subjects were analysed . There were significantly fewer with complications in the GDHT group ( 8.6 % vs 16.6 % , P=0.018 ) . There were also fewer complications ( acute kidney disease , pulmonary oedema , respiratory distress syndrome , wound infections , etc . ) , and length of hospital stay was shorter in the GDHT group . There was no significant difference in mortality between groups . Conclusions : Oesophageal Doppler monitor‐guided GDHT reduced postoperative complications and hospital length of stay in low – moderate risk patients undergoing intermediate risk surgery , with no difference in mortality at 180 days . Clinical trial registration : IS RCT N93543537 Metabolic acidosis and changes in serum osmolarity are consequences of 0.9 % normal saline ( NS ) solution administration . We sought to determine if these physiologic changes influence patient outcome . Patients undergoing aortic reconstructive surgery were enrolled and were r and omly assigned to receive lactated Ringer ’s ( LR ) solution ( n = 33 ) or NS ( n = 33 ) in a double-blinded fashion . Anesthetic and fluid management were st and ardized . Multiple measures of outcome were monitored . The NS patients developed a hyperchloremic acidosis and received more bicarbonate therapy ( 30 ± 62 mL in the NS group versus 4 ± 16 mL in the LR group ; mean ± sd ) , which was given if the base deficit was greater than −5 mEq/L. The NS patients also received a larger volume of platelet transfusion ( 478 ± 302 mL in the NS group versus 223 ± 24 mL in the LR group ; mean ± sd ) . When all blood products were summed , the NS group received significantly more blood products ( P = 0.02 ) . There were no differences in duration of mechanical ventilation , intensive care unit stay , hospital stay , and incidence of complications . When NS was used as the primary intraoperative solution , significantly more acidosis was seen on completion of surgery . This acidosis result ed in no apparent change in outcome but required larger amounts of bicarbonate to achieve predetermined measurements of base deficit and was associated with the use of larger amounts of blood products . These changes should be considered when choosing fluids for surgical procedures involving extensive blood loss and requiring extensive fluid administration OBJECTIVES To compare the effects of lactated Ringer 's solution ( LR ) , 6 % hetastarch in a balanced-saline vehicle ( HS-BS ) , and 6 % hetastarch in normal saline ( HS-NS ) on coagulation using thromboelastography . DESIGN Prospect i ve , r and omized double-blinded evaluation of previously published clinical trial . SETTING Tertiary-care medical center . PARTICIPANTS Patients undergoing elective noncardiac surgery with an anticipated blood loss > 500 mL. A total of 90 patients were enrolled with 30 patients in each group . INTERVENTIONS Patients received a st and ardized anesthetic . LR , HS-BS , and HS-NS were administered intraoperatively based on a fluid administration algorithm . Hemodynamic targets included maintenance of arterial blood pressure , heart rate , and urine output within a predefined range . MEASUREMENTS AND MAIN RESULTS Thromboelastography variables for r time , k time , maximum amplitude , and alpha angle ( mean + /- SD ) were recorded at induction of anesthesia , at the end of surgery , and 24 hours postoperatively . Patients in the LR group showed a state of hypercoagulation at the end of surgery with reductions ( p < 0.005 ) in r time ( -3.8 + /- 6.7 mm ) and k time ( -1.7 + /- 2.5 mm ) . This state of hypercoagulation continued into the postoperative period . Patients in the HS-NS group showed a state of hypocoagulation with increases ( p < 0.05 ) in r time ( + 6.2 + /- 8.5 mm ) and k time ( + 1.7 + /- 3.9 mm ) and a reduction in maximum amplitude ( -8.0 + /- 9.8 mm ) at the end of surgery . This state of hypocoagulation was reduced in the postoperative period . Patients in the HS-BS group showed no significant changes in coagulation status at end of surgery , with the smallest changes in r time ( -0.3 + /- 4.1 mm ) , k time ( + 0.1 + /- 3.1 mm ) , maximum amplitude ( -5.4 + /- 12.3 mm ) , and alpha angle ( 0.3 + /- 12.5 degrees ) . CONCLUSION LR-treated patients exhibited a hypercoagulative profile that persisted into the postoperative period . HS-BS administration was associated with a lesser change in the coagulation profile compared with HS-NS , which was associated with a hypocoagulative state Normal saline ( NS ; 0.9 % NaCl ) is administered during kidney transplantation to avoid the risk of hyperkalemia associated with potassium-containing fluids . Recent evidence suggests that NS may be associated with adverse effects that are not seen with balanced-salt fluids , e.g. , lactated Ringer ’s solution ( LR ) . We hypothesized that NS is detrimental to renal function in kidney transplant recipients . Adults undergoing kidney transplantation were enrolled in a prospect i ve , r and omized , double-blind clinical trial of NS versus LR for intraoperative IV fluid therapy . The primary outcome measure was creatinine concentration on postoperative Day 3 . The study was terminated for safety reasons after interim analysis of data from 51 patients . Forty-eight patients underwent living donor kidney transplants , and three patients underwent cadaveric donor transplants . Twenty-six patients received  NS , and 25 patients received LR . There was no difference between groups in the primary outcome measure . Five ( 19 % ) patients in the NS group versus zero ( 0 % ) patients in the LR group had potassium concentrations > 6 mEq/L and were treated for hyperkalemia ( P = 0.05 ) . Eight ( 31 % ) patients in the NS group versus zero ( 0 % ) patients in the LR group were treated for metabolic acidosis ( P = 0.004 ) . NS did not adversely affect renal function .  LR was associated with less hyperkalemia and acidosis compared with NS . LR may be a safe choice for IV fluid therapy in patients undergoing kidney transplantation The IV administration of sodium chloride solutions may produce a metabolic acidosis and gastrointestinal dysfunction . We design ed this trial to determine whether , in elderly surgical patients , crystalloid and colloid solutions with a more physiologically balanced electrolyte formulation , such as Hartmann ’s solution and Hextend ® , can provide a superior metabolic environment and improved indices of organ perfusion when compared with saline-based fluids . Forty-seven elderly patients undergoing major surgery were r and omly allocated to one of two study groups . Patients in the Balanced Fluid group received an intraoperative fluid regimen that consisted of Hartmann ’s solution and 6 % hetastarch in balanced electrolyte and glucose injection ( Hextend ) . Patients in the Saline group were given 0.9 % sodium chloride solution and 6 % hetastarch in 0.9 % sodium chloride solution ( Hespan ® ) . Biochemical indices and acid-base balance were determined . Gastric tonometry was used as a reflection of splanchnic perfusion . Postoperative chloride levels demonstrated a larger increase in the Saline group than the Balanced Fluid group ( 9.8 vs 3.3 mmol/L , P = 0.0 
    Output:
    
There was insufficient evidence on the effect of fluid composition on mortality and organ dysfunction .
Conclusions Small effect sizes for biochemical outcomes and lack of correlated clinical follow-up data mean that robust conclusions on major morbidity and mortality associated with buffered versus non-buffered perioperative fluid choices are still lacking .
Buffered fluid may have biochemical benefits , including a significant reduction in postoperative hyperchloraemia and metabolic acidosis