***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: We carried out a double-blind prospect i ve study of the effect of a filter on the incidence of  phlebitis associated with intravenous infusion in 541 patients . A total of 277 patients received infusions through intravenous sets with 0.22-micron IVEX-HP filters , and 264 received infusions without filters . Each infusion was evaluated daily for a maximum of three days . The incidence of phlebitis on Days 1 , 2 , and 3 of the study was 14.3 , 31.1 , and 27 per cent for patients receiving infusions without filters and 6.8 , 9.7 , and 11.3 per cent for those receiving infusions through the filters ( P less than 0.001 ) . Thus , the incidence was reduced by approximately two thirds in the patients who received infusions through the IVEX-HP filters . We conclude that infusion-related phlebitis is a pervasive problem in hospitalized patients , and that it is usually caused by microparticulate components that are present in the infusion fluids and can be removed by in-line filtration Four techniques of administering peripheral parenteral nutrition ( PPN ) were examined prospect ively to investigate the role of mechanical trauma in the development of infusion phlebitis .  Patients in group 1 ( n = 15 ) were fed via a st and ard 18-G Teflon cannula which was removed on completion of the infusion and was rotated to the contralateral arm every day . Group 2 patients ( n = 15 ) had a similar catheter sited in each forearm simultaneously , with rotation of the side of infusion each day . Patients in group 3 ( n = 17 ) had a 15-cm Silastic rubber catheter inserted into a forearm vein and a st and ard cannula sited in the contralateral forearm , with alternation of infusion each day . Those in group 4 ( n = 13 ) had a fine-bore 23-G silicone catheter sited in one arm only . Patients in groups 1 , 2 and 3 were fed over 12-h cycles and those in group 4 for a 24-h continuous cycle . A total of 408 patient-days of PPN were given . Mean duration of PPN in groups 1 - 4 was 7.5 , 9 , 5.5 and 5 days respectively . Infusion phlebitis was not recorded in patients who had a daily change of cannula ( group 1 ) , but occurred in four patients in group 2 , eight in group 3 and eight in group 4 . Phlebitis scores were 0 , 9 , 15 and 12 for groups 1 - 4 respectively . Severe phlebitis and line occlusion occurred more frequently in patients with a 15-cm catheter ( group 3 ) and in those fed continuously over 24 h ( group 4 ) . These results suggest that mechanical trauma is an important factor in the aetiology of infusion phlebitis . This can be minimized by reducing the time for which the vein wall is exposed to nutrient infusion and by reducing the amount of prosthetic material within the vein BACKGROUND Data concerning the effectiveness of strategies implemented to reduce short peripheral vein catheter (PVC)-related adverse events are scarce . METHODS A quasiexperimental study ( 2004 - 2011 ) was conducted to evaluate an intervention to reduce  peripheral vein phlebitis ( PVP ) and PVC-related bloodstream infections ( BSIs ) . Bundle intervention consisted of health care worker education and training , withdrawal of unnecessary catheters , exchange catheter policy , withdrawal of catheters at early stages of PVP , use of scales as a measuring tool , and repeated period-prevalence surveillance of PVC adverse events on wards . A Poisson exponentially weighted moving average control chart was used to assess time series analysis . RESULTS One thous and six hundred thirty-one patients with 2,325 short catheters inserted were prospect ively followed .  PVP decreased by 48 % ( 12.1 % [ 95 % confidence interval ( CI ) : 10.7 - 13.2 ] during the intervention period versus 23.3 % [ 95 % CI : 16.4 - 30.1 ] in preintervention period ; P < .05 ) , and no reduction of PVP measured as 1,000 catheter-days was noted ( 48.6 [ 95 % CI : 46.1 - 51.2 ] vs 37.9 [ 95 % CI : 24.5 - 51.4 ] , P > .05 ) . A significant incidence reduction in PVC-related BSIs and health care-acquired Staphylococcus aureus BSIs was also achieved . CONCLUSION A comprehensive multifaceted hospital approach was successful in reducing PVC-related adverse effects . Poisson exponentially weighted moving average control chart fits well as time series using Poisson data when very few events are present Summary A prospect i ve , r and omised , controlled clinical study was performed to compare the incidence and severity of postoperative peripheral venous thrombophlebitis  associated with a single intravenous cannula used for both intra‐operative and postoperative purpose s , and two cannulae , one used intra‐operatively and the other postoperatively . Sixty American Society of Anaesthesiologists ( ASA ) physical status I or II patients aged 18–65 years undergoing elective surgery were studied . The technique of cannula insertion was st and ardised . After surgery , the cannulation sites were examined daily by a blinded investigator for the presence and severity of thrombophlebitis using the Baxter Scale . The two groups were similar in terms of age , gender , weight , type and duration of surgical procedures , and drugs and fluids administered both intra‐operatively and postoperatively . The proportion of patients that developed phlebitis was significantly less in the two cannulae group ( 26.1 % ) than in the single cannula group ( 63.3 % ) ( p < 0.0001 ) . The severity of phlebitis was greater in the single cannula group than in the two cannulae group . These results indicate that the use of a dedicated cannula for postoperative use decreases the incidence and severity of postoperative , peripheral , cannula‐related phlebitis Phlebitis is the commonest complication of intravenous infusion . It has been suggested that it is initiated by venoconstriction at the infusion site , hence treatment with a vasodilator may reduce its incidence . We carried out a prospect i ve double‐blind controlled study of the effect of transdermal glyceryl trinitrate on the survival of peripheral intravenous infusions in 340 patients . Fifty‐five per cent ( 94 out of 170 ) of the infusions failed in the control group compared with 19 per cent ( 33 out of 170 ) in the treatment group ( χ2 = 45 , P < 0.0005 ) . The commonest cause of infusion failure was superficial phlebitis : 47 per cent in the control group and 17 per cent in the treatment group ( χ2 = 46 , P<0.0005 ) . The estimated median time of infusion survival was 74 h in the control group compared with 127 h in the treatment group ( log rank χ2 = 143 , P < 0.0001 ) . We conclude that infusion phlebitis is a common problem in hospitalized patients and its incidence can be effectively reduced by transdermal glyceryl trinitrate In a non-r and omized controlled study of the effects of an occlusive polymer dressing on the  morbidity associated with intravenous ( iv ) cannulation , it was found that the polymer dressing adversely affected the rate of cannula tip colonization , but that this could not be generally related to an increased risk of thrombophlebitis . A strong association was found between Staphylococcus aureus colonization and thrombophlebitis . It is proposed that the material s , method of manufacture and the use to which the cannula is put are more important in the genesis of the minor complications of iv cannulation than the type of dressing To reduce the likelihood of  thrombophlebitis  during intravenous feeding through a peripheral vein , the osmolality of the solution is usually reduced by disproportionately raising the lipid content and lowering the carbohydrate , electrolyte , and aminoacid concentrations . The possibility that delivery system rather than feed is the main influence on the development of thrombophlebitis was examined in a r and omised comparison of a fine-bore silicone catheter against a short ' Teflon ' cannula . The nutrient solution given through a peripheral vein was a st and ard feed used for infusion into a central vein ( osmolality 1250 mOsmol/kg , 13 g nitrogen , 200 g glucose [ 800 kcal ] , and lipid emulsion [ 1000 kcal ] ) . 27 patients received the infusion through a fine-bore silicone rubber catheter ( diameter 23 G , length 15 cm ) and 23 through a teflon catheter ( diameter 20 G , length 3.2 cm ) . The median duration of feeding was 5 days in each of the two groups . Thrombophlebitis developed in all patients in the teflon group but in only 2 ( 7 % ) of the silicone group . The first silicone catheter for a patient lasted a median of 128.5 h , compared with 40 h for the first teflon cannula ( p less than 0.001 ) . The results show that when a nutrient solution of osmolality 1250 mOsmol/kg is delivered through a peripheral vein with an ultrafine-bore silicone catheter , the risk of thrombophlebitis is low . For many patients intravenous feeding may thus be given through a peripheral instead of a central vein without compromising the nutritional adequacy of the feed The purpose of this prospect i ve multi-site study was to determine the frequency of  intravenous ( IV ) site symptoms and to develop a preliminary model of the factors implicated in the number of these symptoms . In a sample of 514 patients from four institutions , IV  site symptoms including pain , redness , swelling , in duration , and /or a venous cord were present in 205 ( 39.9 % ) of the patients . The IV catheters were in place an average of 48.7 hr . There were no significant differences in symptoms by hospital site . Using multiple regression techniques , a seven-factor model explained 18 % of the variance in number of IV site symptoms . Further research is required to explore other potential causes for the numbers of IV site symptoms Previous studies indicated that the risk of  thrombophlebitis  associated with continuous infusion of intravenous nutrition ( IVN ) via peripheral veins was reduced when fine-bore catheters , inserted to 15 cm , were used in place of st and ard intravenous cannulas . An explanation has not been identified , but may be owing to the greater length of the catheters . A r and omised controlled study was performed in which a st and ard nutritional solution was infused via 22 G polyurethane catheters inserted to a length of either 5 cm or 15 cm . Catheters were review ed twice each day and removed when complications occurred , or when IVN was no longer required . There was no significant difference in median time to thrombophlebitis or extravasation , or in daily risk of thrombophlebitis , between insertion lengths . Survival proportions were similar for each length at all times . Catheters inserted into cephalic veins were more prone to thrombophlebitis or extravasation ( nine episodes , 14 catheters ) than catheters inserted into basilic veins ( five episodes , 24 catheters , P = 0.009 ) . The survival proportion was at all times greater when catheter tips lay in basilic veins . Thus , the risk of thrombophlebitis or extravasation was not influenced by the length of catheter within the vein . However , the vein in which the catheter tip lay appeared to influence the development of morbidity We found clinical phlebitis in 57 of 88 patients with peripheral hyperalimentation ( 65 % ) . To determine if this was a problem common to all intravenous fluid therapy at our hospital , we performed a point-prevalence study . The prevalence of phlebitis in nonhyperalimentation intravenous patients was 18 % ( 84 of 456 patients ) . We then performed a r and omized , prospect i ve , double-blind trial of sham versus st and ard in-line filters to determine if bacteria or filterable particulate matter was responsible for phlebitis in the peripheral hyperalimentation group . The st and ard-filter group had a phlebitis rate of 74 % compared with 64 % in the sham-filter group . We then eliminated in-line filters and replaced the st and ard glucose-based solution with a glycerol-based peripheral hyperalimentation solution . The phlebitis rate decreased from 68 % to 27 % ( p less than 0.001 ) . In conclusion , phlebitis in peripheral hyperalimentation patients was probably due to chemical properties of the peripheral hyperalimentation solution rather than bacteria or particulates Phlebitis is a major obstacle to successful and prolonged  peripheral parenteral nutrition ( PPN ) . This study evaluated the effects of elective changes of the intravenous cannula and cyclic infusion of PPN on the incidence and the severity of phlebitis .  51 consecutive patients requiring PPN were r and omised into three groups . Group 1 received PPN continuously through a line which 
    Output:
    
A lack of consensus on phlebitis measures has likely contributed to disparities in reported phlebitis incidence , precluding meaningful comparison of phlebitis rates