***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: Background and Purpose Population -based patient material s have not been used earlier in assessing the effects of neurosurgical treatment on survival and functional outcome of subarachnoid hemorrhage . Moreover , the proportion of all subarachnoid hemorrhage patients who might be c and i date s for neurosurgical treatment has not been estimated . Methods We compared the survival and functional outcome of two population -based patient material s from Central Finl and in 1976 through 1978 ( n=146 ) and 1980 through 1987 ( n=351 ) . The most important basic characteristics of both material s were similar . In the 1970s , only patients aged < 60 years with carotid territory aneurysms were operated on after an interval of 2 weeks from the bleeding . In the 1980s , early surgery was attempted , and the other exclusion criteria were ab and oned . Allocation to medical or surgical treatment was not r and omized . Results During the 1970s , only 14 % of the patients had surgical treatment  , with a median delay of 15 days after the bleeding ; in the 1980s , the corresponding figures were 46 % and 4 days . Despite these fundamental changes in the treatment policy , the survival up to 3 years in the 1980s was only marginally improved compared with the 1970s . Conversely , the functional outcome at 4 years after the bleeding was significantly better in the 1980s than the 1970s , with 82 % and 64 % of the survivors , respectively , being independent in the activities of daily living ( P=.002 ) . We estimated that 60 % of all patients with subarachnoid hemorrhage might be c and i date s for neurosurgical treatment , provided that there are no delays in admission or evaluation . Conclusions An active treatment policy of subarachnoid hemorrhage including early surgery only marginally improves survival , but the quality of life of the survivors is significantly better . Only 60 % of all patients in the population with subarachnoid hemorrhage can , at least theoretically , benefit from surgical treatment . ( Stroke . 1993;24:1649 - 1654 . A controlled clinical trial of epsilon-aminocaproic acid ( E.A.C.A. ) , 36 g/day , was undertaken to assess its effectiveness in reducing immediate recurrence in patients with spontaneous subarachnoid haemorrhage ( S.A.H. ) proved by lumbar puncture . Of 83 patients treated with E.A.C.A.  , 3 ( 4 % ) had recurrent haemorrhage , and 1 ( 33 % ) of these died . Of 82 control patients who were not given any antifibrinolytic drug  , 22 ( 26 % ) had recurrent haemorrhage , and 10 ( 45 % ) of these patients died .  E.A.C.A. produced a striking reduction in the early recurrence of S.A.H. No serious side-effect result ed Summary Tranexamic acid as an antifibrinolytic agent has been investigated in a controlled study in patients with recent subarachnoid haemorrhage . It is concluded that tranexamic acid improves neither rebleeding rates , nor mortality . Predominantly thrombotic complications have been noted as a more serious side effect of tranexamic acid OBJECTIVE --To audit the outcome in patients with subarachnoid haemorrhage ( SAH ) after a change in management strategy . METHODS --A retrospective analysis of patients with aneurysmal subarachnoid haemorrhage over a 20 month period ( phase 1 ) was followed by a prospect i ve analysis of patients presenting during the next 20 months ( phase 2 ) in which a protocol driven management regime of immediate intravenous fluid resuscitation and earlier surgery  was pursued . Patients in this phase were grouped into those receiving early ( within four days of subarachnoid haemorrhage ) and late ( after four days of subarachnoid haemorrhage ) surgery . In phase 1 , 75 out of a total of 92 patients underwent surgery on ( median ) day 12 . From phase 2 , 109 patients out of a total of 129 underwent surgery on ( median ) day 4 , 58 of which had their surgery within 4 days of the subarachnoid haemorrhage . Patients in each phase/group were well matched for demographic features , site of aneurysm , and severity of subarachnoid haemorrhage . RESULTS --The surgical morbidity and mortality were no different in the two phases ( P < 0.92 ; chi2 test ) . The management outcomes in the two phases of the study were also no different ( P < 0.52 ) . However , there was a significant reduction in the rebleed rate in patients undergoing surgery within four days of the subarachnoid haemorrhage in phase 2 ( P < 0.0001 ) with an associated trend towards reduced incidence of postoperative ischaemia ( P = 0.06 ) and mortality ( P = 0.11 ) . Operating earlier in phase 2 of the trial result ed in a lower total hospital inpatient stay of 15.8 ( 95 % CI 13.1 - 18.5 ) days for survivors compared with 25.7 ( 95 % CI 21.6 - 29.8 ) days in the late group ( P < 0.00001 ; t test ) . CONCLUSIONS --surgical morbidity and mortality seemed independent of the timing of aneurysm surgery . Early surgery within four days was associated with a highly significant reduction in rebleed rate , and in the duration of total hospital inpatient stay The outcome of treatment with an antifibrinolytic agent ( tranexamic acid ) for six weeks after rupture of an intracranial aneurysm was assessed in a r and omised controlled trial . Twenty-two out of 25 ( 88 % ) treated patients  survived at follow-up of three to 33 months compared with 14 out of 25 ( 56 % ) control patients . Among the patients who did not undergo operation the survival rate was 81 % ( 13 out of 16 ) in treated patients and 42 % ( 8 out of 19 ) in controls . Antifibrinolytic treatment has so far been assumed merely to postpone rebleeding and has been used to enable surgery to be deferred . These findings suggest that tranexamic acid may actually prevent rebleeding without operation . Prolonged antifibrinolysis may therefore prove useful in those patients in good condition whose aneurysms do not lend themselves to surgical obliteration Objective : To investigate whether antifibrinolytics in combination with treatment to prevent cerebral ischemia improve outcome in patients with subarachnoid hemorrhage ( SAH ) in whom occlusion of the aneurysm is delayed . Background : Antifibrinolytic treatment reduces rebleeding , but outcome does not improve because of a concurrent increase in the occurrence of cerebral ischemia . Because treatment of ischemia has improved , antifibrinolytics might now have a beneficial effect . Methods : A prospect i ve , double-blind , placebo-controlled multicenter clinical trial was performed . R and omized were 462 patients ( 229 received tranexamic acid , 233 placebo ) admitted within 96 hours after onset of SAH , in whom treatment of the aneurysm was delayed beyond 48 hours after SAH . All patients were treated with calcium antagonists and hypervolemia . At 3 months , outcome was assessed with the Glasgow Outcome Scale . The occurrence of cerebral ischemia and other complications were recorded , and the effects of treatment were related to the clinical condition on admission . Results : Antifibrinolytic treatment had no beneficial effect on outcome ( relative risk [ RR ] , 1.10 ; 95 % confidence limits [ CL ] , 0.91–1.34 ) . Antifibrinolytics significantly reduced the occurrence of rebleeding ( RR , 0.58 ; 95 % CL , 0.42–0.80 ) ; the occurrence of ischemic and other complications was the same in the two groups . Conclusion : Antifibrinolytic treatment combined with treatment to prevent cerebral ischemia does not improve outcome A prospect i ve , observational clinical trial was conducted by the International Cooperative Study on the Timing of Aneurysm Surgery to determine the best time in relation to the hemorrhage for surgical treatment of ruptured intracranial aneurysms . Sixty-eight centers contributed 3521 patients in a 2 1/2-year period beginning in December , 1980 . Analysis by a prespecified " planned " surgery interval demonstrated that there was no difference in early ( 0 to 3 days after the bleed ) or late surgery ( 11 to 14 days ) . Outcome was worse if surgery was performed in the 7 to 10-day post-bleed interval . Surgical results were better for patients operated on after 10 days . Patients alert on admission fared best ; however , alert patients had a mortality rate of 10 % to 12 % when undergoing surgery prior to Day 11 compared with 3 % to 5 % when surgery was performed after Day 10 . Patients drowsy on admission had a 21 % to 25 % mortality rate when operated on up to Day 11 and 7 % to 10 % with surgery thereafter . Overall , early surgery was neither more hazardous nor beneficial than delayed surgery . The postoperative risk following early surgery is equivalent to the risk of rebleeding and vasospasm in patients waiting for delayed surgery Summary One hundred patients with a verified subarachnoid haemorrhage were studied in a double blind , placebo-controlled trial at a single centre to determine the value and relative risks of tranexamic acid ( TXA ) in the management of ruptured intracranial aneurysms . The incidence of recurrent haemorrhage between active and placebo groups was identical ( 12 % ) and the mortality from recurrent haemorrhage was 7 % and 5 % , respectively . The overall incidence of cerebral infa rct ion before surgery , at discharge and at 6 months follow-up was greater in the TXA group ( 27 % ) than in the control group ( 11 % ) . Post-operative cerebral ischaemia was significantly more frequent in the active , 18 of 29 as compared to 6 of 32 patients , in the placebo group . In a fifth of the patients in whom cerebral blood flow was estimated there was a significant reduction of cerebral blood flow ( CBF ) on the side of the ruptured aneurysm in the TXA treated group . It is suggested that this may be the cause of the increased incidence of cerebral ischaemia in this group . There was no significant difference in the incidence of cerebral vasospasm , hydrocephalus , visual disturbances and gastrointestinal disturbances . More fatalities were encountered from ischaemia and recurrent haemorrhage in the TXA group but these differences did not reach statistical significance at the 5 % level . Given that disability was due to either vasospasm or recurrent haemorrhage then a patient under TXA treatment was significantly more likely to have disability due to vasospasm ( p<0.04 ) ; the reverse was true for the placebo patient ( p<0.05 ) In a series of 176 prospect ively studied patients who survived for at least 24 hours after aneurysmal subarachnoid hemorrhage , 39 had at least one computerized tomography (CT)-proven rebleed within 4 weeks after the first rupture . There were peaks in the incidence of rebleeding at the end of the 2nd and 3rd weeks . Sudden loss of consciousness occurred in 35 patients , preceded in one-third of them by headache . A sudden increase in headache was a symptom of rebleeding in only one patient . Loss of brain-stem reflexes was recorded in 13 patients , respiratory arrest in six , and both symptoms in eight patients . Apnea was temporary in 11 patients . Rebleeding occurred as gross intraventricular hemorrhage in 20 patients , as a space-occupying hematoma in four , as both types of hemorrhage in three , and as a purely subarachnoid hemorrhage in 12 . The location of the rebleed could not be inferred from the clinical features . Rebleeding was fatal in 51 % of cases ( two of 12 patients with a purely subarachnoid hemorrhage , and 18 of the other 27 patients ( p less than 0.005 ) ) . The risk of rebleeding could not be predicted from the patients ' clinical condition on admission or from the amount of subarachnoid blood identified on the initial CT scan . The risk of further rebleeding was significantly increased in survivors of a first rebleed ( 47 % : p less than 0.01 ) . Only seven ( 18 % ) of the 39 patients with rebleeding had survived at 3 months after the initial hemorrhage A r and omized controlled clinical trial was carried out to study the effect of tranexamic acid ( AMCA , Cyklokapron ; AB Kabi , Stockholm , Sweden ) in the prevention of early rebleeding after the rupture of an intracranial aneurysm . The incidence of vasospasm , hydrocephalus , cerebral ischemic and thromboembolic complications , morbidity , and mortality was also evaluated . The series comprises 59 patients , 30 treated with tranexamic acid and 29 controls .  The treatment was stopped if there was rebleeding , operation , or discharge from the hospital . There were 6 recurrent hemorrhages in 6 patients in the tranexamic acid-treated group and 11 recurrences in 7 patients in the control group . Recurrent hemorrhages occurred later in tranexamic acid-treated patients than in controls . Five patients in each group died from rebleeding 
    Output:
    
Short-term use of AF ( 72 h or less ) associated with medical prevention of ischemic deficit seems to yield better results on functional outcome than long-term use of AF , especially if not associated with a medical prevention of ischemic deficit .
The risk of cerebral infa rct ion is not increased by the short-term use of AF and the risk of rebleeding is decreased independently of the length of AF use .
Conclusions The use of AF should be reconsidered in the setting of modern-era treatment strategies , as the short-term use associated with medical prevention of ischemic deficit decreases the rate of rebleeding and does not increase the risk of cerebral infa rct ion , thus potentially yielding better protection against poor functional outcome