***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: Background Pediatric r and omized controlled trials ( RCTs ) are susceptible to a high risk of bias . We examined the barriers and facilitators that pediatric trialists face in the design and conduct of unbiased trials . Methods We used a mixed methods design , with semi-structured interviews building upon the results of a quantitative survey . We surveyed Canadian ( n=253 ) and international ( n=600 ) pediatric trialists regarding their knowledge and awareness of bias and their perceived barriers and facilitators in conducting clinical trials . We then interviewed 13 participants from different subspecialties and geographic locations to gain a more detailed description of how their experiences and attitudes towards research interacted with trial design and conduct . Results The survey response rate was 23.0 % ( 186/807 ) . 68.1 % of respondents agreed that bias is a problem in pediatric RCTs and 72.0 % felt that there is sufficient evidence to support changing some aspects of how trials are conducted . Knowledge related to bias was variable , with inconsistent awareness of study design features that may introduce bias into a study . Interview participants highlighted a lack of formal training in research methods , a negative research culture , and the pragmatics of trial conduct as barriers . Facilitators included contact with knowledgeable and supportive colleagues and infrastructure for research . Conclusions A lack of awareness of bias and negative attitudes towards research present significant barriers in terms of conducting method ologically rigorous pediatric RCTs . Knowledge translation efforts must focus on these issues to ensure the relevance and validity of trial results Background : Administration of bupivacaine caudally has been used for postoperative analgesia after urogenital , rectal and lower abdominal surgery in children .  Caudal opioids may offer analgesic advantages over bupivacaine alone but have been associated with side effects such as respiratory depression .  Tramadol is an analgesic assumed to lack a respiratory depressant effect and has been shown to provide effective , long‐lasting analgesia after epidural administration in adults and children . The aim of this study was to determine whether the addition of tramadol to bupivacaine caudally prolongs the duration of analgesia compared with bupivacaine alone , with respect to side effects , and whether caudal tramadol alone provides satisfactory analgesia OBJECT Stable hemodynamics , normocapnia , and adequate pain relief are considered important factors in the reduction of neurological complications in pediatric patients undergoing encephaloduroarteriomyosynangiosis ( EDAMS ) operations for the treatment of moyamoya disease . A preoperative skull block may reduce hemodynamic fluctuations and hypo- or hyperventilation due to emergence delirium or oversedation and provide adequate pain relief , thereby reducing postoperative morbidity . METHODS Pediatric patients ( age 3 - 13 years ) undergoing EDAMS surgery for moyamoya disease were r and omly divided into a nerve block ( NB ) group ( 18 cases ) or control group ( 21 cases ) . The treatment group patients received a preoperative NB ( 0.25 % 5 - 8 ml bupivacaine mixed with 20 - 40 mg methylprednisolone ) targeting the supraorbital , supratrochlear , auriculotemporal , and posterior auricular nerves . Patients in the control group did not receive NB . General anesthesia with sevoflurane was induced in both groups . RESULTS In the NB group , stable hemodynamic parameters were obtained with a lower sevoflurane concentration than in the control group . For delirious awakening , the odds ratio in the control group was 4.9 compared with the NB group . Pain and analgesic requirement were higher in the control patients than in the NB-treated patients during the postanesthesia care unit stay . However , the arterial CO(2 ) tension in the postanesthesia care unit did not differ between the 2 groups . The odds ratio in the control group for the rate of morbidity ( cerebral infa rct ion and reversible ischemic neurological deficits ) during the first 24 hours following the operation was 3.2 compared with the NB group . CONCLUSIONS The use of skull block during EDAMS surgery provided easy hemodynamic control , calm awakening , and better pain relief and may be related to the reduced postoperative morbidity BACKGROUND : The classical response to nerve stimulation may be altered in cases of radial club h and . Ultrasound guidance may prove to be a useful tool in such situations . In this study , we compared the success rate of ultrasound-guided infraclavicular brachial plexus block with nerve stimulation for children undergoing radial club h and repair . METHODS : Fifty children , aged 1 - 2 yr , undergoing radial club h and repair were r and omly assigned to  receive infraclavicular brachial plexus block guided by nerve stimulator ( Group NS ) or ultrasound ( Group U ) in combination with light general anesthetic . Bupivacaine 0.5 mL/kg of 0.5 % was injected in both groups . Pain response to surgical stimulus was considered as block failure . The Children ’s Hospital Eastern Ontario Pain Scale pain score was recorded at 1 , 4 , 6 , 8 , and 10 postoperative hours . RESULTS : In Group NS , the blocks were successful in 16 of 25 patients ( 64 % ) , whereas in Group U , 24 of 25 patients had successful blocks ( P = 0.0053 ) . There was no difference in the time to first analgesia or analgesic consumption in the 10-h study period . CONCLUSION : Ultrasound-guided infraclavicular brachial plexus block improves the success rate in patients with radial club h and s when compared with nerve stimulation in patients undergoing radial club h and correction We compared in a r and omized double-blind study , the postoperative analgesia and degree of motor block produced by the new local anaesthetic ropivacaine , with bupivacaine , for caudal anaesthesia in children . Eighty children , 2 - 5-years-old , ASA I , received one of two local anaesthetics ; either ropivacaine 0.25 % ( 1.0 ml x kg(-1 ) ) or bupivacaine 0.25 % ( 1.0 ml x kg(-1 ) ) . They were se date d with a continuous infusion of propofol ( 200 microg x kg(-1 ) min(-1 ) . The lungs were ventilated with a mixture of 50 % nitrous oxide with oxygen . 60 min after local anaesthetic injection , and every 60 min , the extent of the motor block in the recovery room was scored as 1 - 3 , according to a modified Bromage scale . Adverse events and the time to the first analgesic requirement were reported . Patients in the two groups did not differ with respect to age , weight and height . There were no differences in heart rate and arterial pressure between the two groups(P>0.05 ) . No adverse events were observed . The ropivacaine group showed a shorter duration of motor block than the bupivacaine group ( P<0.05 ) . The first postoperative analgesic requirement was a mean ( sd ) of 5 h+/-4.32 after the operation in the ropivacaine group and 5 h+/-3.81 for the bupivacaine group . These findings suggest that caudal anaesthesia with ropivacaine 0.25 % in paediatric patients can be effective , with less motor blockade in the postoperative period OBJECTIVE We set out to compare a eutectic mixture of local anesthetic cream ( lidocaine and prilocaine ) to dorsal penile nerve block with lidocaine for anesthesia during circumcision . STUDY DESIGN In a double-blind study , term newborns were r and omized to local anesthetic cream and sodium chloride solution dorsal penile nerve block ( n = 31 ) or to placebo cream and lidocaine dorsal penile nerve block ( n = 29 ) . Pain was assessed by determination of heart rate , respiratory rate , and behavioral distress scoring . Group differences were evaluated with repeat- measures analyses of variance . RESULTS Distress scores and heart rates were significantly higher in the eutectic mixture group than in the lidocaine group . Respiratory rates were higher in the eutectic mixture group but did not reach statistical significance . CONCLUSIONS Distress scores and heart rates were significantly higher in infants treated with the anesthetic mixture than in infants treated with lidocaine . Dorsal penile nerve block with lidocaine is a more efficacious means of providing anesthesia for neonatal circumcision than the mixture of local anesthetics BACKGROUND We attempted to determine the efficacy of a one plane ilioinguinal and iliohypogastric nerve block with a single shot and double shot techniques . METHODS In a r and omized single blind study , 90 children , aged 2 - 12 years , received a single shot ( SS ) or a double shot ( DS ) technique for ilioinguinal and iliohypogastric ( IG-IH ) nerve block for inguinal hernia repair . In the SS group , 0.25 ml x kg(-1 ) of 0.25 % bupivacaine was given one fingerbreadth medial to the anterior superior iliac spine under the external oblique aponeurosis . In the DS group , one-third of the total dose of bupivacaine was given as for the SS group . The remaining two-thirds was deposited 0.5 cm above and lateral to the mid-inguinal point deep to the external oblique aponeurosis . RESULTS The success rates of both techniques were similar , at 72 % , although the presence of local anaesthetic in the inguinal canal was significantly higher with the DS technique . The incidence of femoral nerve block was 4.5 % with the SS and 9 % with the DS technique ( P > 0.05 ) . Parental satisfaction with postoperative pain relief was high , at 94 % . CONCLUSIONS The DS technique , while technically more difficult , does not improve the success rate of the IG-IH nerve block compared with the SS technique BACKGROUND Dorsal penile nerve block ( DPNB ) is a commonly performed regional anesthetic technique for male circumcision . Traditionally , DPNB is based on an anatomical l and mark technique . Recently , an ultrasound-guided technique for DPNB has been described . OBJECTIVES The aim of our study was to compare the anatomical l and mark technique with this ultrasound-guided technique . The hypothesis to be tested was that ultrasound guidance of DPNB would lead to less administration of opioid when compared to the anatomical l and mark technique . METHODS Boys of ASA status I/II scheduled for day case circumcision were prospect ively recruited and r and omized .  DPNB was performed under general anesthesia using the anatomical l and mark technique or ultrasound guidance . Fentanyl was administered intraoperatively and immediately postoperatively if patients demonstrated signs of pain . Similarly , oral codeine was given prior to discharge if required . The primary outcome measure was the number of patients requiring fentanyl . Secondary outcome measures included initial pain score on emergence from general anesthesia , requirement for codeine predischarge , and time to perform block . RESULTS A total of 32 patients were recruited to the l and mark group and 34 to the ultrasound group . There was no significant difference between the two groups in terms of fentanyl administration . The ultrasound technique took longer to perform but was associated with a reduction in codeine requirement prior to discharge . CONCLUSIONS This study does not support the routine use of ultrasound for the performance of DPNB in male pediatric circumcision . Nonetheless , an associated reduction in codeine administration postoperatively suggests some benefit in terms of postoperative pain We compared the effects of pre- and postsurgical axillary block on  pain after h and and forearm surgery in 55 children in a double-blind r and omized study . The successful blocks are reported here ( n=49 ) . Children aged 1 - 11 years and ASA I or II were allocated r and omly to receive axillary block with 2 mg.kg-1 of 0.25 % bupivacaine , either after induction but before the surgery ( presurgical group , n=25 ) or immediately after surgery , before the end of anaesthesia ( postsurgical , n=24 ) . In all patients , a st and ard general anaesthesia technique was used . The Faces Pain Scale ( FPS ) and analgesic requirements were recorded for 24 h at various times after operation . Eight patients ( 32 % ) in the presurgical group and 20 patients ( 83.33 % ) in the postsurgical group did not require additional analgesic within the first 24 h after operation ( P < 0.05 ) . In patients who had pain during the observation period , the pain started 13.66+/-2.61 h in the presurgical group and 13.14+/-2.34 h in the postsurgical group after performing block ( P > 0.05 ) . The FPS scores were similar in both groups during the first 8 h in the postoperative period ( P > 0.05 ) . There was a significant difference at 10 h after surgery ( P < 0.05 ) . Cumulative FPS score was higher in the presurgical group ( 10.50+/-1.06 ) than in the postsurgical group ( 9.45+/-1.28 ) ( P < 0.05 ) , but both groups had effective analgesia overall , the mean FPS score being less than 2 . Additional analgesic consumption was similar in these patients in both groups . A lower isoflurane concentration was used in the presurgical group ( 0.68 % vs 1.72 % , P < 0.001 ) . We 
    Output:
    
Additional evidence is required to support the use of specific regional anaesthesia techniques to improve postoperative pain for several surgical procedures ( craniectomy , adenotonsillectomy , appendectomy , cardiac surgery , umbilical hernia repair , upper and lower extremity ) in paediatric patients .
Currently , only a very limited number of regional anaesthesia techniques have demonstrated significant improvement on postoperative pain outcomes for a restricted number of surgical procedures .