***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 As the number of patients aged > /=65 years starting haemodialysis ( HD )  continues to increase , more patients are at risk of falls , functional decline and cognitive impairment . In an earlier prospect i ve cohort study , we showed that 44 % of elderly HD patients had more than one fall within a 1-year period . The objective of this study was to assess whether falls remained predictive of increased mortality risk even after controlling for age , comorbidity , dialysis vintage and laboratory variables . METHODS Using a prospect i ve , cohort study design , patients aged > /=65 years and on chronic HD during the period April 2002 - 2003 were recruited . Patients were followed biweekly , and falls occurring within the first year were recorded . Outcome data were collected until death , study end ( 30 December 2006 ) , transplantation or transfer to another dialysis centre . RESULTS A total of 162 patients were followed for a median of 32.7 months ( quartiles 14 - 57 ) . In a univariate Cox model with a time-dependent variable for falls status , survival was worse amongst fallers compared to non-fallers ( HR 2.13 , 95 % CI 1.32 - 3.45 ; P = 0.002 ) . After adjustment for age , dialysis vintage , comorbidity and laboratory variables , falls were a significant predictor of mortality ( HR 1.78 , 95 % CI 1.07 - 2.98 , P = 0.03 ) . Exclusion of falls associated with concurrent illnesses did not alter the results ( HR 1.63 , CI 1.02 - 2.28 P = 0.05 ) . CONCLUSIONS We conclude that the occurrence of more than one accidental fall in a community-dwelling HD patient aged > /=65 years is associated with an independent increased risk of death . As fall interventions are effective , screening HD patients for falls may be a simple measure of clinical importance The goal of the study was to compare effectiveness of regional and local anesthesia in dialysis arterio-venous fistula ( AVF ) operations . It was a prospect i ve , r and omized study . 103 patients with end stage renal disease underwent AVF operations on upper limb . The patients have been r and omly divided in two groups . Group I : 49 patients in whom the operations have been done under the local anesthesia ; and Group II : 54 patients in whom the operation has been performed under  the vertical infraclavicular block . Duplex sonography evaluation of upper arm vessels was performed pre-operatively and at 1 , 3 and 6 months postoperatively . Following parameters were measured on duplex scan : vessel diameter , blood flow rates ( PSV and EDV ) , resistive index ( RI ) and pulsatility index ( PI ) . Significantly less number of patients with regional anesthesia  required additional perioperative analgesics as compared with the local anesthesia group . Time to postoperative pain initiation , need for postoperative pain killers was significantly better in Group II as compared with the Group I. Duration of operation was significantly less in regional as compared with local anesthesia . Postoperative PSV and EDVs were negatively correlated with patient age . The fistula maturation time was positively correlated with age . The vein diameter , postoperative PSV and EDV have been significantly increased in Group I as compared with Group II . The postoperative PI has significantly increased and RI has significantly decreased in Group I as compared with Group II . The total number of dialysis punctures was higher in regional as compared with the local anesthesia . Regional anesthesia provides significantly better analgesia as compared with the local anesthesia in AVF operations . It significantly improves the duplex sonography parameters after AVF formation . It can be a method of choice for some forms of fistulas Purpose Assessment of the effectiveness of Brachial Plexus Block ( BPB ) via axillary approach compared to regional anesthesia for arteriovenous fistula surgery in patients affected by end-stage renal disease . Methods We compared forty patients r and omly divided into two groups . Group A underwent BPB procedure with 15 mL ropivacaine 1 % and 10 mL of saline ( 0.9 % NaCl ) via axillary approach . Group B received local anesthesia with lidocaine 2 % . The forearm blood vessels were assessed by Doppler ultrasonography before and after the intervention . Results BPB performed on Group A was associated with a considerable venous dilation and a significant decrease ( 48.7 % , P<.05 ) in pulsatility index ( PI ) measured by Doppler ultrasound . In Group B , PI and venous dilation remained unaltered in the postoperative phase . No complications such as thrombosis or occlusion were encountered among patients who underwent BPB . Conclusions The axillary-approached BPB was more advantageous than local anesthesia . Its effectiveness was because of venous dilation and the decrease in the PI , consequent to the reduction in peripheral resistances and the increase in local blood flow , thus offering an ideal background for fistula creation and short-term patency BACKGROUND Central venous catheters ( CVC ) are a potential source of bacteraemia and have been associated with increased mortality in haemodialysis patients . We aim ed to investigate the relationships between haemodialysis vascular access , taking into account changes in vascular access type during patients ' lives , and cause specific mortality risk in a national cohort of dialysis patients . METHODS Prospect i ve cohort study including all patients receiving haemodialysis in Scotl and at annual cross sectional surveys in 2009 , 2010 and 2011 . Data were collected through the Scottish Renal Registry and by a structured review of case records following death . Cox proportional hazards regression and multivariable logistic regression were used to model survival and risk of death from septicaemia respectively . RESULTS Of a cohort of 2666 patients , 873 ( 32 % ) died during follow-up . After case-mix adjustment , patients using only tunnelled CVC during follow-up had a higher risk of all cause mortality across all strata of prior renal replacement therapy exposure [ adjusted hazard ratio ( HR ) : 1.83 - 2.08 ] . Case-mix adjusted risks of cardiovascular death ( adjusted HR : 2.20 - 2.95 ) and infection-related death ( adjusted HR : 3.10 - 3.63 ) were also higher in this group . Patients using tunnelled CVCs during follow-up and prior to death had 6.9-fold higher odds of death from septicaemia compared with those using only arteriovenous fistulae or grafts . CONCLUSION Compared with an arteriovenous fistula or graft , sustained use of tunnelled CVCs for vascular access is associated with higher risks of all-cause , cardiovascular and infection-related mortality Background An arteriovenous fistula is the optimal form of vascular access in patients with end-stage renal failure requiring haemodialysis . Unfortunately , approximately one-third of fistulae fail at an early stage . Different anaesthetic techniques can influence factors associated with fistula success , such as intraoperative blood flow and venous diameter . A regional anaesthetic brachial plexus block results in vasodilatation and improved short- and long-term fistula flow compared to the infiltration of local anaesthetic alone . This , however , has not yet been shown in a large trial to influence long-term fistula patency , the ultimate clinical measure of success . The aim of this study is to compare whether a regional anaesthetic block , compared to local anaesthetic infiltration , can improve long-term fistula patency . Methods This study is an observer-blinded , r and omised controlled trial . Patients scheduled to undergo creation of either brachial or radial arteriovenous fistulae will receive a study information sheet , and consent will be obtained in keeping with the Declaration of Helsinki . Patients will be r and omised to receive either : ( i ) an ultrasound guided brachial plexus block using lignocaine with adrenaline and levobupivicaine , or ( ii ) local anaesthetic infiltration with lignocaine and levobupivicaine .  A total of 126 patients will be recruited . The primary outcome is fistula primary patency at three months . Secondary outcomes include primary patency at 1 and 12 months , secondary patency and fistula flow at 1 , 3 and 12 months , flow on first haemodialysis , procedural pain , patient satisfaction , change in cephalic vein diameter pre- and post-anaesthetic , change in radial or brachial artery flow pre- and post-anaesthetic , alteration of the surgical plan after anaesthesia as guided by vascular mapping with ultrasound , and fistula infection requiring antibiotics . Conclusions No large r and omised controlled trial has examined the influence of brachial plexus block compared with local anaesthetic infiltration on the long-term patency of arteriovenous fistulae . If the performance of brachial plexus block increases fistulae patency , this will have significant clinical and financial benefits as the number of patients able to commence haemodialysis when planned should increase , and the number of “ redo ” or revision procedures should be reduced . Trial registration This study has been approved by the West of Scotl and Research Ethics Committee 5 ( reference no. 12/WS/0199 ) and is registered with the Clinical Trials.gov data base ( reference no. NCT01706354 ) The use of ultrasound reduces the onset time , improves the quality of sensory block , and minimizes the risks associated with the supraclavicular approach for brachial plexus and stellate ganglion blockade . The present study was design ed to evaluate whether ultrasound also facilitates the approach for 3-in-1 blocks . Forty patients ( ASA physical status II or III ) undergoing hip surgery after trauma were r and omly assigned to two groups . In the ultrasound ( US ) group , 20 mL bupivacaine 0.5 % was administered under US guidance , whereas in the control group , the same amount and concentration of local anesthetic was administered with the assistance of a nerve stimulator ( NS ) . After US- or NS-based identification of the femoral nerve , the local anesthetic solution was administered , and the distribution of the local anesthetic solution was visualized and recorded on videotape in the US group . The quality and the onset of the sensory block was assessed by using the pinprick test in the central sensory region of each of the three nerves and compared with the same stimulation on the contralateral leg every 10 min for 60 min . The rating was performed using a scale from 100 % ( uncompromised sensibility ) to 0 % ( no sensory sensation ) . Heart rate , noninvasive blood pressure , and oxygen saturation were measured at short intervals for 60 min . The onset of sensory blockade was significantly shorter in Group US compared with Group NS ( US 16 + /- 14 min , NS 27 + /- 16 min , P < 0.05 ) . The quality of the sensory block after injection of the local anesthetic was also significantly better in Group US compared with Group NS ( US 15 % + /- 10 % of initial value , NS 27 % + /- 14 % of initial value , P < 0.05 ) . A good analgesic effect was achieved in 95 % of the patients in the US group and in 85 % of the patients in the NS group . In the US group , visualization of the cannula tip , the femoral nerve , the major vessels , and the local anesthetic spread was possible in 85 % of patients . Incidental arterial puncture ( n = 3 ) was observed only in the NS group . We conclude that an US-guided approach for 3-in-1 block reduces the onset time , improves the quality of the sensory block and minimizes the risks associated with this regional anesthetic technique . Implication s : The onset time and the quality of a regional anesthetic technique for the lower extremity is improved by ultrasonographic nerve identification compared with older techniques . ( Anesth Analg 1997;85:854 - 7 OBJECTIVE To reduce the onset of 0.5 % bupivacaine by adding 2 % lidocaine with 0.5 % bupivacaine for ultrasound-guided and double stimulation technique at musculocutaneous and radial nerve for infraclavicular brachial plexus block . DESIGN Prospect i ve r and omized double-blinded , controlled trial study . MATERIAL AND METHOD 90 patients undergoing creation of arteriovenous fistula under ultrasound-guided infraclavicular brachial plexus block were r and omized into 2 groups . Gr B ( 46 patients ) received 0.5 % bupivacaine 30 mL and Gr BL ( 44 patients ) received mixture of 0.5 % bupivacaine 20 mL and 2 % lidocaine 10 mL. The onset of sensory block were assessed by response to pinprick ( grading : 0 = no sensation , 1 = hypoesthesia , and 2 = normal sensation ) . Rescue analgesia during the operation , duration of sensory and motor blockade were recorded . Surgeon and patient satisfactions are also evaluated using 6-point scale ( 0 = dissatisfied to 5 = very satisfied ) . RESULTS There were no significant difference in the onset time of either group . Duration of sensory and motor block was not different . Surgeons ' and patients ' satisfaction were also not significantly different between the groups . CONCLUSION Mixing 2 % lidocaine with 0.5 % bupivacaine to the final concentration of 0.67%for lid 
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In conclusion , RA was associated with higher primary patency rates of AVF and improved local blood flow in comparison to LA ; however , both procedures were comparable in terms of primary failure rates and postoperative complications .