***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: 54 patients with venographically verified deep venous thrombosis ( DVT ) were r and omized to treatment with either intravenous infusions of 240 anti-Xa U/kg/12 h unfractionated heparin ( UFH ) or 240 or 120 anti-Xa U/kg/12 h of the low molecular weight heparin Fragmin . Repeated venographies showed improvement in 48 % of the UFH-treated patients and 50 and 77 % , respectively , in the Fragmin-treated patients . Progression was seen only in the UFH-treated patients and was observed in 11 % . Two bleeding complications were seen in the Fragmin group in 2 patients receiving the very high dose of 240 anti-Xa U/kg/12 h. Anti-Xa activity in plasma and activated partial thromboplastin time ( APTT ) does not correlate in the Fragmin-treated patients . Fragmin was as effective as UFH in preventing the progress of thrombosis in DVT . In another study 120 anti-Xa U/kg Fragmin given subcutaneously 2 times daily to 13 patients with DVT result ed in adequate anti-Xa activity but with a tendency for accumulation of the Fragmin-induced activity . Subcutaneous injections of Fragmin 2 times daily also appears to prevent the progression of thrombosis effectively INTRODUCTION Trials comparing the use of full dose unfractionated heparin ( UFH ) or low molecular weight heparins ( LMWHs ) in very elderly patients with impaired renal function are lacking . IRIS aim ed to assess whether LMWH is at least as safe as UFH in this population . MATERIAL S AND METHODS The study included renally impaired patients ≥70 years with acute symptomatic lower limb deep vein thrombosis ( DVT ) . Patients were r and omized to initial treatment with either tinzaparin 175 IU/kg once daily ( n=269 ) or activated partial thromboplastin time-adjusted UFH twice daily ( n=270 ) . After acute management both groups received vitamin K antagonist to day 90 . RESULTS The trial was stopped prematurely due to a difference in mortality favoring the UFH group ( 11.5 vs. 6.3 % ; p=0.035 ) . Rates of clinical ly relevant bleedings by day 90 were similar in the tinzaparin ( 11.9 % ) and UFH ( 11.9 % ) groups , as were rates of confirmed recurrent venous thromboembolism ( VTE ) ( 2.6 vs. 1.1 % ; p=0.34 ) . As the mortality difference could not be explained by bleedings or recurrent VTE , a post-hoc analysis was performed . This identified six baseline characteristics significantly correlated with mortality , of which five were over-represented in the tinzaparin group . CONCLUSION The IRIS study was a challenging study involving patients ( mean age 83 years ) usually excluded from clinical studies , but its early termination has left questions unanswered . The mortality difference observed with tinzaparin vs. UFH in elderly , renally-impaired patients with DVT can not be explained on the basis of bleedings or recurrent VTE , and may reflect an imbalance of mortality risk factors at baseline Intravenous heparin followed by oral anticoagulant therapy ( e. g. with coumarin ) is still the most widely used treatment for  deep venous thromboembolism .  Self-administered subcutaneous injections of heparin have been thought of as a promising alternative to coumarin , but the high doses required for ongoing prophylaxis have raised concerns about the possible development of bone disease . Certainly , long-term heparin therapy has been reported to cause osteoporosis in both laboratory animals and humans . This study aim ed to compare the efficacy and safety of unfractionated ( UF ) heparin with that of a low molecular weight heparin ( Fragmin , Kabi Pharmacia ) in the prevention of recurrent deep venous thrombosis ( DVT ) and pulmonary embolism ( PE ) in a consecutive series of patients with contraindications to coumarin therapy . The patients comprised 40 men and 40 women , aged between 19 and 92 years ( mean age , 68 years ) . They had all previously been diagnosed as having acute DVT and had been treated with conventional doses of heparin while in hospital . All patients had at least one of the following conditions : recent blood loss ( either spontaneous or during admission while receiving heparin therapy ) ; active gastroduodenal ulcer disease ; psychological or physical inability or unwillingness to underst and and accept the need for regular laboratory monitoring during coumarin treatment ; chronic alcoholism ; dementia ; pregnancy ; recent neurosurgery , and pericardial effusion ; or were over 80 years of age . They were r and omly allocated to receive either UF heparin , 10,000 IU s.c . b.d . , or Fragmin , 5000 IU anti-Factor Xa s.c . b.d . , for a period of 3 - 6 months . ( ABSTRACT TRUNCATED AT 250 WORDS Low molecular weight heparin fractions have been demonstrated as efficient as low doses of st and ard heparin in preventing post-operative deep-vein thrombosis . Several clinical studies are , now , carrying out in patients with acute deep-vein thrombosis in order to assess efficacy and safety of low molecular weight heparin fractions as compared to st and ard heparin . In a r and omised study including patients with deep-vein thrombosis treated either with low molecular weight heparin or with subcutaneously st and ard heparin  , we demonstrated an effectiveness , in terms of thrombus reduction , of low molecular weight heparin as well as st and ard heparin . However , low molecular weight heparin seemed to be safer than st and ard heparin STUDY OBJECTIVE To determine the efficacy and safety of adjusted subcutaneous calcium heparin compared with continuous intravenous calcium heparin as the initial treatment for acute deep vein thrombosis . DESIGN R and omized control trial . SETTING University-affiliated general hospital . PATIENTS Of 111 consecutive patients considered , 103 had acute proximal or calf vein thrombosis confirmed by ascending venography and met all other eligibility criteria . INTERVENTIONS PATIENTS were r and omly assigned to receive subcutaneous or intravenous heparin . The subcutaneous regimen consisted of an initial dose of 15,000 U , adjusted thereafter to prolong the activated partial thromboplastin time to 50 to 70 seconds . The continuous intravenous regimen was begun as a bolus injection of 5000 U , followed by an infusion of 1250 U/h , adjusted to maintain the activated partial thromboplastin time at 50 to 70 seconds . MEASUREMENTS AND MAIN RESULTS There was no significant difference in the rate of new pulmonary embolism between the two groups , as defined by new high-probability defect on repeat ventilation-perfusion scintigrams of the lung in 96 ( 93 % ) of the patients after 7 to 10 days of treatment . Five of forty-seven patients in the subcutaneous group and 5 of 49 in the intravenous group developed pulmonary embolism ( 95 % confidence interval [ CI ] for the difference , -13.1 % to 12.2 % ) . Similarly , there was no significant difference in the frequency of hemorrhagic complications . Five of fifty-one patients in the subcutaneous group and 5 of 52 in the intravenous group had hemorrhagic complications ( 95 % CI for the difference , -11.2 % to 11.6 % ) . CONCLUSION Adjusted subcutaneous calcium heparin may be an effective and safe alternative to continuous intravenous calcium heparin in the initial treatment of acute proximal deep vein thrombosis Summary Two studies have been done to establish recommendations for dosage and dose adjustment in the treatment of deep vein thrombosis ( DVT ) with low molecular weight heparin ( LMWH ) . In the first , 56 patients were r and omized in a double blind study to be treated either with unfractionated heparin ( UFH ) or LMWH s. c. every 12 h. Initial doses were given according to age and sex , disregarding bodyweight , and the dose was then adjusted when the peak plasma heparin concentration fell outside the desired range of 0.5–0.8 anti-FXa U/ml . There were fewer dose adjustments in the LMWH group . The correlation between injected dose ( U/kg bodyweight ) and the heparin concentration was higher in the LMWH group ( r=0.59 ) than in the UFH group ( r=0.38 ) . The results suggest that , in order to obtain the desired heparin concentration , the initial dose of LMWH should be about 100 U/kg bodyweight every 12 h . In the second , open study , this dosage plan was followed in 15 patients . The peak heparin concentration on Day 2 ranged from 0.40 to 0.75 anti-FXa U/ml and adjustment was only required in 3 patients . Day to day variation in peak heparin activity in the individual patient varied little ( CV 11–22 % ) , and there was no accumulation . The results indicate that plasma heparin concentration is more predictable using LMWH than UFH , and they point to definite advantages in the use of LMWH in a bodyweight adjusted dosage Ninety-four patients with deep vein thrombosis of inferior limbs were r and omly allocated to receive sodium heparin either by subcutaneous injections or by continuous intravenous infusion for six days . No significant difference was observed in the therapeutic efficiency as judged by phlebographic examinations and in rate of symptomatic pulmonary embolism between the two groups . There was one instance of major bleeding in the subcutaneous group . Minor bleedings occurred in 10 of the 48 patients treated with subcutaneous heparin and in 13 of the 46 patients receiving intravenous heparin . The results showed that subcutaneous injections of sodium heparin are as effective and safe as continuous intravenous infusion of this drug in the treatment of deep vein thrombosis BACKGROUND Few reports have addressed the value of unfractionated heparin ( UFH ) or low-molecular-weight heparin in treating the full spectrum of patients with venous thromboembolism ( VTE ) , including recurrent VTE and pulmonary embolism . METHODS In an open , multicenter clinical trial , 720 consecutive patients with acute symptomatic VTE , including 119 noncritically ill patients ( 16.5 % ) with pulmonary embolism and 102 ( 14.2 % ) with recurrent VTE , were r and omly assigned to treatment with subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm ( preceded by an intravenous loading dose ) , or fixed-dose ( adjusted only to body weight ) subcutaneous nadroparin calcium . Oral anticoagulant therapy was started concomitantly and continued for at least 3 months . We recorded the incidence of major bleeding during the initial heparin treatment and that of recurrent VTE and death during 3 months of follow-up . RESULTS Fifteen ( 4.2 % ) of the 360 patients assigned to UFH had recurrent thromboembolic events , as compared with 14 ( 3.9 % ) of the 360 patients assigned to nadroparin ( absolute difference between rates , 0.3 % ; 95 % confidence interval , -2.5 % to 3.1 % ) . Four patients assigned to UFH ( 1.1 % ) and 3 patients assigned to nadroparin ( 0.8 % ) had episodes of major bleeding ( absolute difference between rates , 0.3 % ; 95 % confidence interval , -1.2 % to 1.7 % ) . Overall mortality was 3.3 % in each group . CONCLUSIONS Subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm is as effective and safe as fixed-dose nadroparin for the initial treatment of patients with VTE , including those with pulmonary embolism and recurrent VTE One hundred patients with phlebographically proved acute deep vein thrombosis of the legs were prospect ively r and omised into two treatment groups to compare the safety and efficacy of subcutaneous calcium heparin versus intravenous sodium heparin administered by constant infusion pump . The dose of heparin was determined by daily measurement of the kaolin cephalin clotting time . Treatment was maintained for up to 14 days , after which phlebography was repeated . Of 49 patients who received subcutaneous calcium heparin , two showed an increase in thrombus size , while eight showed complete lysis . In the 47 patients who received intravenous sodium heparin  thrombus increased in size in 13 while only one showed evidence of complete lysis . These differences were significant . There were no significant differences between the two groups in the incidence of serious complications , although almost half of those receiving intravenous heparin had some minor problem with the constant infusion pump and just over half of those receiving subcutaneous heparin had some bruising at the injection site . This study showed that subcutaneous calcium heparin was more effective in helping lyse existing thrombus and preventing its propagation than intravenous sodium heparin 48 patients with acute deep venous thrombosis of the lower limbs were treated with sodium he 
    Output:
    
There is no evidence of a difference between subcutaneous versus intravenous UFH for preventing VTE recurrence , VTE-related or all-cause mortality , and major bleeding .
There is also no evidence of a difference between subcutaneous UFH and LMWH for preventing VTE recurrence , VTE-related or all-cause mortality or major bleeding