***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 : Ultrasonographic observation of peripheral nerve blocks enables direct visualization of the spread of local anesthetic around the targeted nerves . Similarly , ultrasonography may be used to determine the site of local anesthetic placement when l and mark-based techniques are used . We performed a study to determine the actual location of local anesthetic when ilioinguinal/iliohypogastric nerve blocks are performed using l and mark-based techniques  in children in an attempt to explain a failed block . METHODS : After induction of general anesthesia ( 1 minimum alveolar anesthetic concentration halothane and laryngeal mask airway ) , 62 children scheduled for inguinal surgery received an  ilioinguinal/iliohypogastric nerve block  based on st and ard anatomical l and marks . Ultrasonography was then used to determine the actual location of local anesthetic placement . The anesthesiologist performing the block was blinded to the ultrasonographic investigation . Successful blocks were recorded either when the local anesthetic surrounded the nerves or were based on clinical signs after skin incision . RESULTS : In 14 % of the blocks , the local anesthetic was administered correctly around the nerves result ing in successful blocks . In the remaining 86 % , the local anesthetic was administered in adjacent anatomical structures ( iliac muscle 18 % , transverse abdominal muscle 26 % , internal oblique abdominal muscle 29 % , external oblique abdominal muscle 9 % , subcutaneous 2 % , and peritoneum 2 % ) , and 45 % of these blocks failed . CONCLUSION : Accurate placement of local anesthetic around the ilioinguinal/iliohypogastric nerves in children is seldom possible when l and mark-based techniques are used . In the majority of patients , the local anesthetic was inaccurately placed in adjacent anatomical structures with unpredictable block results BACKGROUND Ultrasound-guided transversus abdominis plane ( TAP ) block has shown promise for analgesia after pediatric inguinal surgery . This prospect i ve , r and omized study tested the hypothesis that the TAP block would provide comparable analgesia after pediatric inguinal surgery compared with a conventional ultrasound-guided ilioinguinal block . METHODS After induction of general anesthesia , infants and children presenting for elective inguinal surgery were r and omly assigned to receive an ultrasound-guided TAP block ( needle cephalad of the iliac crest at the anterior axillary line ) ( n = 20 ) or ilioinguinal block ( needle immediately anteromedial to the anterior superior iliac spine ) ( n = 21 ) . Supplemental analgesia consisted of as-required intraoperative fentanyl , regular acetaminophen , as-required ibuprofen , and rescue morphine . Patients were assessed in the recovery room , the day-stay unit ( 30 min to 2 h after surgery ) and at 24 h for age appropriate numerical pain score , analgesic consumption , and parental satisfaction . RESULTS In the day-stay unit , pain was more frequent ( 76 % vs 45 % , P = 0.040 ) , and ibuprofen use was higher ( 62 % vs 30 % , P = 0.037 ) in the TAP group . Recovery room pain , morphine consumption and postdischarge ibuprofen use , comfort and satisfaction scores were similar between groups . Ultrasound image quality was poorer , and needle time under the skin was longer ( median [ interquartile range ] 81 [ 66 - 120 ] vs 46 [ 40 - 51 ] , P < 0.001 ) for the ilioinguinal group . CONCLUSIONS Following pediatric inguinal surgery , ilioinguinal block provides more effective analgesia than the TAP block BACKGROUND Transient femoral nerve palsy ( TFNP ) has been reported in patients undergoing inguinal hernia repair involving the use of ilio-inguinal nerve block . Ilio-inguinal nerve blocks can be administered under vision by the surgeon or by the anaesthetist using a st and ard blind technique . There has been no study that has specifically examined the incidence of this complication and whether its development is related to the type of method used to administer the block . PATIENTS AND METHODS Data on patients undergoing surgery in the Royal Infirmary Edinburgh Day Case Unit are collected prospect ively . All patients who undergo inguinal hernia repair are given ilio-inguinal field blocks , either pre-operatively by anaesthetists ( blind technique ) or peri-operatively under direct vision by surgeons . Several cases of TFNP were initially identified during the process of surgical audit and this led to a retrospective analysis over a period of one year . RESULTS During a 12-month period , 194 patients underwent 200 open inguinal hernia repairs ( 188 unilateral and 6 bilateral ) , under general anaesthesia . Ten patients ( 5 % ) developed TFNP result ing in overnight admission . Surgeons administered 101 blocks under direct vision of which 4 ( 4 % ) result ed in TFNP , whereas 6 out of 99 ( 6 % ) blind blocks result ed in TFNP ( p=0.49 , df=1 , Chi2 test ) . DISCUSSION AND CONCLUSION TFNP is a recognised complication following ilioinguinal nerve blockade for inguinal hernia surgery . Our series shows that ilio-inguinal block given under direct vision does not appear to reduce the chance of this complication occurring . This may result from the fact that this complication could be due to local infiltration into the operative field rather than direct infiltration around the femoral nerve . As inguinal hernia repair undertaken as a day case procedure increases , the awareness of this complication is important to avoid The effectiveness of postoperative analgesia was compared in 44 children undergoing inguinal surgery  , 19 of whom received caudal analgesia ( 1 ml 0.2 % bupivacaine/kg ) and 25 ilioinguinal block ( 0.25 ml 0.5 % bupivacaine/kg ) . The requirement for supplementary analgesia ( intramuscular morphine )  was less in the caudal group , although this did not reach statistical significance in the number studied . Ilioinguinal and caudal blockade both provide useful postoperative analgesia for children following ilioinguinal surgery Background : The control of postoperative pain is important in children , and poor pain control leads to organ dysfunction and behavioral problems . Objectives : We compared the analgesic effects of suppository acetaminophen , bupivacaine wound infiltration , and caudal block with bupivacaine on postoperative pain in pediatric inguinal herniorrhaphy . Patients and Methods : In this double-blinded , r and omized controlled clinical trial , 90 children of American Society of Anesthesiologists ( ASA ) grade I-II , aged between 3 months and 7 years , and scheduled for elective unilateral inguinal herniorrhaphy under general anesthesia were assigned to three equal groups . Patients in the first group received 20 mg/kg of suppository acetaminophen . In the second group , 2 mg/kg of 0.5 % bupivacaine was infiltrated in the incisional site , and in the third group , a caudal block was performed with 0.75 mL/kg of 0.25 % bupivacaine . The Face , Legs , Activity , Cry , Consolability ( FLACC ) pain scale was applied 30 minutes after operation . Thereafter , the FLACC score was obtained every hour during the next 6 hours . If the FLACC score was 4 or over , we administered 0.5 mg/kg of intravenous meperidine . The data was transferred to SPSS-10 software and analyzed statistically with chi-square and analysis of variance tests . P < 0.05 was considered significant . Results : The mean analgesic duration in the acetaminophen , bupivacaine infiltration , and caudal block groups was 4.07 , 5.40 , and 5.37 hours , respectively . Significant differences were not observed between the bupivacaine infiltration and caudal block groups ( P = 0.9 ) , but the differences between the bupivacaine infiltration and acetaminophen groups ( P = 0.034 ) and the caudal block and acetaminophen groups ( P = 0.039 ) were significant . With regard to meperidine administration , significant differences were not observed between the bupivacaine infiltration and caudal block groups ( P = 0.848 ) , but significant differences were observed between these two groups and the acetaminophen group ( P < 0.05 ) . Conclusions : Patients in the bupivacaine infiltration and caudal block groups had less postoperative pain than those in the acetaminophen group and received lower amount of meperidine . We concluded that in children , bupivacaine infiltration and caudal block with bupivacaine produce better analgesia than suppository acetaminophen . It seems that bupivacaine infiltration is better than caudal block because of its simplicity , lower incidence of complications , and failure rate BACKGROUND The ilioinguinal/iliohypogastric nerve block is a popular regional anaesthetic technique for children undergoing inguinal surgery . The success rate is only 70 - 80 % and complications may occur . A prospect i ve r and omized double-blinded study was design ed to compare the use of ultrasonography with the conventional ilioinguinal/iliohypogastric nerve block technique . METHODS One hundred children ( age range , 1 month-8 years ) scheduled for inguinal hernia repair , orchidopexy or hydrocele repair were included in the study . Following induction of general anaesthesia , the children received an ilioinguinal/iliohypogastric block performed either under ultrasound guidance using levobupivacaine 0.25 % until both nerves were surrounded by the local anaesthetic or by the conventional ' fascial click ' method using levobupivacaine 0.25 % ( 0.3 ml kg(-1 ) ) . Additional intra- and postoperative analgesic requirements were recorded . RESULTS Ultrasonographic visualization of the ilioinguinal/iliohypogastric nerves was possible in all cases . The amount of local anaesthetic used in the ultrasound group was significantly lower than in the ' fascial click ' group ( 0.19 ( SD 0.05 ) ml kg(-1 ) vs 0.3 ml kg(-1 ) , P<0.0001 ) . During the intraoperative period 4 % of the children in the ultrasound group received additional analgesics compared with 26 % in the fascial click group ( P=0.004 ) . Only three children ( 6 % ) in the ultrasound-guided group needed postoperative rectal acetaminophen compared with 20 children ( 40 % ) in the fascial click group ( P<0.0001 ) . CONCLUSIONS Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks can be achieved with significantly smaller volumes of local anaesthetics . The intra- and postoperative requirements for additional analgesia are significantly lower than with the conventional method This study compared the postoperative pain relief provided by simple instillation of bupivacaine into a hernia wound with that provided by ilioinguinal/iliohypogastric ( IG/IH ) nerve block . Sixty children undergoing inguinal hernia repair under general anesthesia were r and omized to receive 0.25 ml/kg of 0.25 % bupivacaine for either IG/IH nerve block or up to 0.5 ml/kg of the same solution for instillation nerve blocks . In the postanesthesia care unit ( PACU ) , a trained blinded observer evaluated the patient 's level of postoperative pain using a st and ardized 10-point objective pain scale .  Fentanyl 1 - 2 micrograms/kg was administered intravenously to any child scoring 6 or more points on the pain scale . The difference in pain scores among the two groups were compared . The two groups were not significantly different in age , duration of surgery , or anesthesia . There was no significant difference between patients who received the two treatment modalities in their pain scores , analgesic requirements in the PACU , recovery times , and discharge times . These results demonstrate that the simple instillation of local anesthetics into a wound provides postoperative pain relief following hernia repair , which is as effective as that provided by intraoperative IG/IH nerve block The purpose of this study was to compare the effect of local anaesthesia ( LA ) with that of caudal anaesthesia ( CA ) on postoperative care of children undergoing inguinal hernia repair . This was a r and omized , single-blind investigation of 202 children aged 1–13 yr . Anaesthesia was induced with N2O/O2 and halothane or propofol and maintained with N2O/O2/halothane . Local anaesthesia included ilioinguinal and iliohypogastric nerve block plus subcutaneous injection by the surgeon of up to 0.3 ml · kg−1 bupivacaine 0.25 % with 5 μg · kg−1 adrenaline . The dose for caudal anaesthesia was 1 ml · kg−1 up to 20 ml bupivacaine 0.2 % with 5 μg · kg−1  adrenaline . Postoperative pain was assessed with mCHEOPS in the anaesthesia recovery room , with postoperative usage of opioid and ac 
    Output:
    
Caudal analgesia was found to be better in both early ( RR = 0.81 [ 0.66 , 0.99 ] , P = 0.04 ) and late ( RR = 0.81 [ 0.69 , 0.96 ] , P = 0.01 ) periods , but with a significant risk of motor block and urinary retention .
Although potentially superior , caudal analgesia increases the chance of motor block and urinary retention .
There are limited studies to demonstrate that the technical superiority using ultrasound translates into better clinical success with the inguinal nerve blocks