***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 AND PURPOSE The purpose of this study was to prospect ively evaluate a protocol with hypertonic saline hydroxyethyl starch ( HS-HES ) and mannitol in stroke patients with increased intracranial pressure ( ICP ) .  METHODS We studied 30 episodes of ICP crisis in 9 patients . ICP crisis was defined as ( 1 ) a rise of ICP of more than 25 mm Hg ( n = 22 ) , or ( 2 ) pupillary abnormality ( n=3 ) , or ( 3 ) a combination of both ( n=5 ) . Baseline treatment was performed according to a st and ardized protocol . For initial treatment , the patients were r and omly assigned to either infusion of 100 mL HS-HES or 40 g mannitol over 15 minutes . For repeated treatments the 2 substances were alternated . ICP , blood pressure , and cerebral perfusion pressure ( CPP ) were monitored over 4 hours . Blood gases , hematocrit , blood osmolarity , and sodium were measured before and 15 and 60 minutes after the start of infusion . Treatment was regarded as effective if ICP decreased > 10 % below baseline value or if the pupillary reaction had normalized . RESULTS Treatment was effective in all 16 HS-HES-treated and in 10 of 14 mannitol-treated episodes . ICP decreased from baseline values in both groups , P < 0.01 . The maximum ICP decrease was 11.4 mm Hg ( after 25 minutes ) in the HS-HES-treated group and 6.4 mm Hg ( after 45 minutes ) in the mannitol-treated group . There was no constant effect on CPP in the HS-HES-treated group , whereas CPP rose significantly in the mannitol-treated group . Blood osmolarity rose by 6.2 mmol/L in the mannitol-treated group and by 10.5 mmol/L in the HS-HES-treated group ; sodium fell by 3.2 mmol/L in the mannitol and rose by 4.1 mmol/L in the HS-HES-treated group . CONCLUSIONS Infusion of 40 g mannitol and 100 mL HS-HES decreases increased ICP after stroke . The maximum effect occurs after the end of infusion and is visible over 4 hours . HS-HES seems to lower ICP more effectively but does not increase CPP as much as does mannitol In a prospect i ve study , we r and omly allocated 70 patients with acute ischemic stroke to two therapy groups . Up to interim analysis , 33 patients underwent bloodletting , with simultaneous infusion of an identical volume of hydroxyethyl starch ( 10 % , 200/0.5 ) . The target hematocrit was 35 % . A control group of 37 patients did not receive hemodilution . Apart from an unequal sex distribution , the two groups were comparable with regard to age , cardiovascular risk factors , and medical history . In the hemodilution group , the mean hematocrit fell from 44.4 % to 37.7 % . After 14 days , improvement on the neurological score scale was 3.3 points in the hemodilution group compared with 6.5 points in the control group ( p = 0.12 ) . Subgroups with early inclusion ( less than 12 hours ) or pronounced lowering of hematocrit ( greater than 15 % of initial hematocrit ) also did not profit from hemodilution . Clinical deterioration observed in eight hemodilution group patients ( p less than 0.01 ) led to discontinuation of the study for ethical reasons In a multicenter trial , 183 patients with acute ischemic stroke of less than 48 hours ' duration and hematocrits of 38 - 50 % were r and omized to st and ardized hemodilution treatment ( venesection and dextran 40 administration ) and 190 to a control group .  We have previously reported that there were no beneficial effects of hemodilution in the total patient population . In this report , the case fatality rates and neurologic outcome in survivors ( 3 months ' follow-up ) in subsets of patients have been analyzed . The patients were subgrouped by sex , age , medical history , smoking habits , delay from the onset of symptoms to the start of treatment , hematocrit at entry , venesection volume , neurologic score at entry into the study , blood pressure changes in the acute phase , presence of atrial fibrillation , location of brain lesion by computed tomography , type of diagnostic procedures , and hospital setting . No subset in which hemodilution reduced mortality or improved neurologic outcome could be identified . Case fatality rate was apparently higher in hemodiluted patients with infa rct ion affecting deep brain structures than in control patients with such lesions . By simple clinical criteria , we have been unable to define subsets of stroke patients who benefit from the present st and ardized regimen of moderate hemodilution . The sample sizes are , however , too small to refute the possibility that a modest clinical effect of hemodilution may be present in some patients with stroke BACKGROUND AND PURPOSE Experimental studies suggest a beneficial effect of hemodilution on acute ischemic stroke . This was not proven by previous multicenter trials in the clinical setting . Various reasons have been suggested for the failure of these studies , which we attempted to consider in the Multicenter Austrian Hemodilution Stroke Trial ( MAHST ) . METHODS MAHST is a r and omized , double-blind , placebo-controlled study of hypervolemic hemodilution  ( HHD ) within 6 hours of a clinical ly first ischemic stroke localized in the middle cerebral artery territory . The treatment consisted of 10 % hydroxyethyl starch 200/0.5 ( HES ) and was tested against pure rehydration with Ringer 's lactate over a period of 5 days . Our primary outcome measure was clinical improvement within 7 days as measured by the Grade d Neurologic Scale ( GNS ) . We performed an adaptive interim analysis to reevaluate the study goal after entering half of the projected number of patients ( n = 200 ) . At least 600 patients per group would have been required for significant results , and therefore we decided to terminate the trial . RESULTS Ninety-eight patients received HHD and 102 patients placebo .  The baseline characteristics were comparable between both groups . In the HHD group the absolute reduction of the hematocrit was 2.5 % on day 2 with a maximum of 3.7 % on day 5 , which compares with a reduction in the placebo group of 1 % and 1.9 % , respectively . Intention-to-treat analysis showed no significant difference of the change of the GNS scores between HHD-treated ( median , -8.5 ; 95 % confidence interval , -14.2 to -4.0 ) and placebo-treated patients ( median , -6.0 ; 95 % confidence interval , -11.0 to 0.0 ) on day 7 , and GNS scores remained similar in both treatment groups throughout the trial . At 3 months , slightly more HHD patients showed complete independence on the Barthel Index ( 28 versus 24 ) , and fewer HHD than placebo patients had died ( 13 versus 17 ) , but these differences were not statistically significant . HHD treatment was not associated with any specific adverse event . CONCLUSIONS Mild HHD is safe but failed to demonstrate a significant beneficial effect over the pure rehydration regimen in patients with acute ischemic stroke In a r and om manner , 100 patients with acute cerebral infa rct ion due to thromboembolism were assigned to two groups . The patients in one group received continuous intravenous therapy with dextran 40 for three days ; the others received an equivalent volume of fluid without the dextran 40 . In the treated group , levels of dextran 40  remained greater than 1 % for three to five days after the infusion was stopped . The group treated with dextran 40 showed lower mortality and better quality of survival in terms of the neurological status . The improvement in the treated group was significantly better than in the untreated group ( The results of clinical trials investigating various therapies in acute ischemic stroke have been inconsistent . The effect of glycerol therapy and a combination therapy of glycerol and dextran was evaluated in a double-blind , placebo-controlled study . Repeated neurologic examinations ( Day 0 , Weeks 1 , 6 , 12 , and 24 ) according to a modified Mathew score were performed on 62 patients . Statistical analysis showed no superiority of either treatment compared with placebo in acute ischemic stroke . A retrospective estimation of the Type II error of the study yielded approximately p = 0.25 . A major side effect was hemolysis in 98 % of patients treated with glycerol Hemodilution in the acute phase of ischemic stroke is still controversial . Multicenter studies have failed to demonstrate any benefit . The present study focuses attention on analysis of circulation in stroke and on individual restabilization of circulation . Methods The Amsterdam Stroke Study is a prospect i ve , single-center , r and omized clinical trial ( n=300 ) . Normovolemic hemodilution is accomplished in a customized procedure by administration of 20 % albumin plus crystalloids under hemodynamic and rheological monitoring in the acute phase of stroke . All patients receive general intensive care treatment and monitoring with a pulmonary artery catheter  . This custom-tailored fluid therapy is guided on the basis of a target pulmonary capillary wedge pressure ( 12±3 mm Hg ) and hematocrit ( 0.32±0.02 ) . The control group receives only customized rehydration by infusion of crystalloids . Results We obtained significant ( p<0.05 ) reduction in mortality at 3 months ( from 27 % to 16 % ) and an increase in independence at home ( from 35 % to 48 % ) after viscosity reduction by means of hemodilution with albumin in the subgroup with a hematocrit < 0.45 ( n=201 ) ( specific viscosity effect ) . We also obtained a significant ( p<0.005 ) reduction in mortality at 3 months ( from 27 % to 8 % ) and an increase in independence ( from 35 % to 59 % ) after only rehydration with crystalloids in the subgroup with overt dehydration ( hematocrit ≥0.45 ; n=51 ) as compared with the normal-hematocrit group without signs of dehydration ( hematocrit < 0.45 ; n=103 ) ( specific rehydration effect ) . Conclusions This study may provide an explanation for the failures in former hemodilution trials and may re-establish proper hemodilution and rehydration as a valuable therapy in the acute phase of stroke , thus reducing mortality and improving independence after 3 months We prospect ively r and omized 47 patients with acute ischemic stroke of the middle cerebral artery of less than 24 hours ' duration to either adjusted hypervolemic hemodilution or control treatment and followed them up for 90 days . Rapid hemodilution to a target hematocrit of 30 - 35 % as monitored with bedside determinations was achieved by using infusions of dextran 40 , venesections , and infusions of additional crystalloid solution when necessary . There was no difference in the death rate between the two treatment groups . Of these 47 patients , 37 ( 19 in the hemodilution group and 18 in the control group ) could be followed up for the entire study period of 3 months . The relative improvement in neurologic function from day 1 to days 8 , 21 , and 90 was significantly better in the hemodilution group than in the control group . In accordance , special tests for fine motor control of the paretic arm disclosed better performance in the hemodilution group . The frequency of patients with severe disability was significantly lower in the hemodilution group on days 8 and 21 . Plasma viscosity ( measured in 11 patients ) was not affected by infusions of dextran 40 . Vigorous hypervolemic hemodilution in patients with acute ischemic stroke is well tolerated and improves early neurologic outcome with an effect lasting at least 3 months Fifty-nine patients with onset of moderate to severe unimproving paralysis of less than 24 hours ' duration were r and omized into treatment ( Dextran 40 ) and control groups , managed similarly except for the dextran . A strict effort to study a uniform cerebral process by rejecting patients with hypertension , insulin-dependent diabetes , potential emboli , and pulmonary or renal disease result ed in a small sample . Most patients considered for the study had begun to improve before the initial examination . All patients had spinal tap prior to the decision to r and omize . Results were evaluated independently by the three authors over a three-week interval and tabulated after three years . A greater percentage of dextran-treated patients improved with respect to consciousness and strength in upper and lower extremities , but showed less restoration of language than the untreated patients . The differences in the two groups were not significant . One of 30 patients given dextran  may have had a reaction In stroke penumbra perfusion depends passively on hemodynamics . So far hemodynamic effects of low molecular weight hydroxyethylstarch ( HES ) has not been investigated . Ten stroke patients received hypervolemic HES therapy .  Cardiac output and heart rate were monitored using the bioimpedance method , blood pressure by conventional measurement . The Sc and inavian Stroke Scale assessed clinical outcome . Circadian cardiac output changes were measured in 20 controls . Patients ' cardiac output increased after the loading dose ( 5.3 + /- 1.4 l min(-1 ) to 6.5 + /- 1.7 l min(-1 ) , p < 0.01 ) , fluctuating then between 5 
    Output:
    
The results were similar in confounded and unconfounded trials , and in trials of isovolaemic and hypervolaemic haemodilution .
No statistically significant benefits were documented for any particular type of haemodiluting agents , but the statistical power to detect effects of HES and albumin was weak .
REVIEW ER 'S CONCLUSIONS The overall results of this review are compatible both with modest benefit and moderate harm of haemodilution therapy for acute ischaemic stroke .
This therapy has not been proven to improve survival or functional outcome