***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 and Objectives Opioids have been shown to possess antinociceptive effects after peripheral administration in experimental and clinical studies . The results of clinical studies on intra-articularly administered morphine are , however , conflicting . The objective of this study was to examine a possible analgesic effect of incisionally administered morphine on postoperative pain in patients undergoing inguinal herniotomy . Methods Forty out patients were included in a double-blind , r and omized , placebo-controlled study . The patients had spinal anesthesia with 1.5 - 2.0 mL hyperbaric 5 % lidocaine . At conclusion of herniotomy morphine 5 mg was injected incisionally in 10 patients , intravenously in 10 , and subcutaneously in 10 . The placebo group of 10 patients had saline injected in the incision .  Postoperative pain was assessed with a visual analog scale at rest and during mobilization . Assessment s were made immediately before and at 0 , 2 , 4 , and 6 hours after herniotomy and on the second and seventh postoperative days . At the same times morphine and acetaminophen consumptions were recorded . Results There were no significant differences in postoperative visual analog scores between the groups . Except for the cumulative morphine requirement from the second to the seventh postoperative day , which was significantly higher in the placebo group than in other groups , no significant differences in cumulative morphine and acetaminophen requirements were found between the groups . Conclusions A single 5-mg dose of morphine injected in the herniotomy wound did not affect pain scores or supplementary analgesic requirements , which argues against a role of peripheral opioid receptors in mediating analgesia STUDY OBJECTIVE To determine whether the addition of morphine to the axillary block local anesthetic solution provides improved or prolonged postoperative analgesia . DESIGN Prospect i ve , r and omized , double-blind clinical trial with 24-hour follow-up . SETTING Ambulatory unit of a large academic referral center . PATIENTS Consecutive healthy volunteers scheduled for elective upper extremity surgery . INTERVENTIONS Patients in the treatment group ( AX ) were given intravenous ( IV ) saline and had morphine 0.1 mg/kg added to their axillary block solution .  Control subjects ( CT ) received morphine 0.1 mg/kg IV and had saline added to their axillary block solution . All axillary blocks were performed using 0.55 ml/kg of 1.5 % lidocaine with epinephrine 1:200,000 . MEASUREMENTS AND MAIN RESULTS During the first 24 hours after surgery , visual analog scale ( VAS ) scores , supplementary analgesic ( oxycodone 5 mg with acetaminophen 500 mg ) use , and complications were recorded . Both groups had similar VAS scores throughout the study . In the 24-hour postoperative study period , AX patients required approximately half as many doses ( median , 2 doses ; range , 0 to 7 doses of supplemental analgesic as CT patients ( median , 4 doses ; range , 0 to 12 doses ) . There were no major complications in either group . CONCLUSIONS The addition of morphine 0.1 mg/kg to the local anesthetic axillary block solution provided improved postoperative analgesia without an increased frequency of side effects or major complications Objective . To determine whether 1 mg morphine injected intravenously in conjunction with prilocaine has any effect on postoperative pain and analgesic requirement during intravenous regional anesthesia . Methods . This was a r and omized , double-blind study that included 37 patients undergoing carpal tunnel operations of the h and under intravenous regional anesthesia . Either 1 ml of morphine or 1 ml of physiologic saline diluted to 5 ml with 5 % glucose was injected into the isolated exsanguinated arm . This was followed by 3 mg/kg of 0.5 % prilocaine ( total volume , 30 - 50 ml ) . Pain was assessed at 30 , 60 , 90 , and 120 minutes , and 8 , 24 , and 48 hours after the end of the operation using a linear visual analog scale ( VAS ) . The total number of analgesic tablets consumed in the first 48 hours were also counted . Results . No difference was found in the VAS pain scores between the groups at any of the time periods studied . The postoperative analgesic requirement was similar in both groups . Conclusion . The authors conclude that 1 mg morphine showed no effect on postoperative pain or analgesic requirements when given in conjunction with prilocaine during intravenous regional anesthesia We have reported recently that continuous administration of butorphanol into the brachial plexus sheath provided analgesia of a quality superior to that of continuous i.v . administration . In the present study , we have compared postoperative pain relief produced by continuous infusion of one of three types of solution into the axillary sheath : opioid alone , local anaesthetic alone or a mixture of local anaesthetic and opioid . In patients undergoing upper extremity surgery with continuous axillary brachial plexus block , we injected one of the three solutions into the axillary neurovascular sheath : butorphanol 2 mg ( group B ) , 0.5 % mepivacaine alone ( group M ) and 0.5 % mepivacaine-butorphanol ( group MB ) ; the volume of each solution was 50 ml , administered at a rate of 50 ml per 24 h. At 3 h after operation , visual analogue scale ( VAS ) scores were significantly higher in group M than in group MB ( P < 0.01 ) , and higher in group B than in group MB ( P < 0.05 ) The effect of the addition of 0.1 mg or 0.2 mgfentanyl to 40 ml 0.5 % prilocaine in intravenous regional anaesthesia of the arm was investigated in 37 patients in a r and omised , double‐blind study . The characteristics of the sensory and motor block were studied . There was no difference in the speed of onset of analgesia in the groups ( mean latency approximately 4 min in each group ) . However , significantly more patients in thefentanylO.2 mg group ( 7/12 ) had complete anaesthesia at 15 min than in the fentanyl 0.1 mg group ( 1/13 ) and the control group ( 2/12 ) ( p < 0.05 ) . There were no differences in the incidence of tourniquet pain immediately before cuff deflation ( tourniquet time 45–87 min ) . After cuff deflation , in those patients who complained of wound pain within 30 min , on average the pain appeared later in the fentanyl 0.2 mg group ( six patients , mean 14.3 min ) than in the control group ( eight patients , mean 9.4 min ) ( ns ) . In the fentanyl groups , the incidence of central nervous system side effects was greater than in the control group ( fentanyl 0.1 mg 7/13 patients , fentanyl 0.2 mg 6/12 patients , control 1/12 patients ) ( p < 0.05 ) . The plasma concentrations of prilocaine  after cuff deflation were higher , in a dose‐dependent fashion , in the fentanyl groups than in the control group , but the concentrations of prilocaine and fentanyl did not correlate with the symptoms . Postoperative nausea occurred only in the patients who had received fentanyl BACKGROUND Traditional and largely qualitative review s of evidence are now giving way to much more structured systematic overviews that use a quantitative method to calculate the overall effect of treatment . The latter approach is dependent on the quality of primary studies , which may introduce bias if they are of poor method ologic quality . OBJECTIVE To test the hypothesis that the inclusion of poor- quality trials in meta-analyses would bias the conclusions and produce incorrect estimates of treatment effect . METHODS An overview of r and omized trials of antiestrogen therapy in subfertile men with oligospermia was performed to test the hypothesis . Data sources included online search ing of MEDLINE and Science Citation Index data bases between 1966 and 1994 , scanning the bibliography of known primary studies and review articles , and contacting experts in the field . After independent , blind assessment , nine of 149 originally identified studies met the inclusion criteria and were selected . We assessed study quality independently . Outcome data from each study were pooled and statistically summarized . RESULTS There was a marginal improvement in pregnancy rate with antiestrogen treatment ( odds ratio , 1.6 ; 95 % confidence interval , 0.9 to 2.6 ) . Sensitivity analyses on the basis of method ologic quality demonstrated that poor- quality studies produced a positive effect with treatment , whereas no benefit was observed with high- quality studies . CONCLUSION The results of a meta- analysis are influenced by the quality of the primary studies included . Method ologically , poor studies tend to exaggerate the overall estimate of treatment effect and may lead to incorrect inferences The effectiveness of buprenorphine and morphine , administered into the brachial plexus sheath , was evaluated in 40 patients , aged 18 - 90 years . All patients received 40 ml of 0.5 % bupivacaine , injected into the brachial plexus sheath using the supraclavicular technique . In addition , the 20 patients in Group I received morphine hydrochloride ( 50 μg/kg ) , while the 20 patients in Group II received buprenorphine hydrochloride ( 3 μg/kg ) . Using a three-point pain scale , the quality of analgesia was evaluated every hour for six hours , every two hours for the next six hours , and then at 12 , 24 , 36 and 48 hours . A significant difference in the quality of analgesia was found ; and was consistently superior with buprenorphine as compared with morphine . The duration of analgesia was nearly twice as long in the buprenorphine group as in the morphine group ( 35.05 ± 1.95 hour versus 18.25 ± 1.15 hour ) . We conclude that buprenorphine injection into the brachial plexus sheath is an efficient way to assure control of postoperative pain after upper limb surgery We have studied 40 patients undergoing elective shoulder surgery for chronically painful conditions . Patients were allocated r and omly to two groups and received interscalene brachial plexus block with 0.5 % bupivacaine and adrenaline 1/200,000 40 ml either alone or with the addition of morphine 5 mg . All patients also received a general anaesthetic . The quality of the block , analgesic requirements and any complications or side effects were noted in the intraoperative period and during the 48 h after operation . No significant difference was seen in quality of analgesia or patient satisfaction between the two groups In a double – blind study , 2 mg of morphine in saline , or saline only , was given subcutaneously into a seconddegree bilateral leg – burn injury in 12 volunteers .  Heat – pain thresholds and pressure – pain thresholds were significantly increased by local morphine administration . These results confirm experimental data demonstrating a peripheral antinociceptive effects of opioids in inflamed tissue Background and Objectives . Continuous interscalene brachial plexus block with 0.25 % bupivacaine decreases diaphragmatic motility and ventilatory function . The author studied the effects of 0.125 % bupivacaine with and without fentanyl . Methods . Forty patients who were to undergo shoulder surgery were given an interscalene brachial plexus block using 20 - 28 ml 0.75 % bupivacaine plus epinephrine . In r and om order , 10 patients then had a 24-hour continuous block with 0.125 % bupivacaine ( BUPI ) ( 5 - 9 ml/h ) . Nine patients had an additional s.c . infusion of fentanyl ( F-SC ) ( 15 - 27 μg/h ) and 10 the same dose of fentanyl with the bupivacaine infusion ( F-PLX ) . Ten patients had a single block ( PLX ) for minor surgery . Spirometry , double-exposure chest radiography , pulse oximetric hemoglobin saturation and maximal airway pressures were measured . Results . Postoperatively , BUPI patients were given , on average , 1.2 , F-SC patients 0.7 , and F-PLX patients 0.4 doses of oxycodone in 24 hours ( not significant ) . Average ipsilateral diaphragmatic motility was reduced to 8 % in F-PLX group ( p < 0.01 ) and to 19 - 30 % in the other groups ( p < 0.05 ) . At 24 hours , average motility in BUPI , F-SC , F-PLX and PLX groups was 54 , 48 , 31 and 91 % , respectively . In all groups FVC , FEV1 and PEF were reduced by 20 - 40 % at 3 hours ( p < 0.001 ) . At 8 and 24 hours , FVC and FEV1 were in F-SC and F-PLX groups significantly lower ( p < 0.05 ) than in PLX group . Conclusions . Use of 0.125 % bupivacaine for continuous interscalene block did not prevent a deterioration of diaphragmatic motility and ventilatory function . Coinfusion of fentanyl did not significantly potentiate the block Peripheral administration of opioids has been suggested as a means of improving regional block . We studied 60 patients receiving ax 
    Output:
    
Trials of lower quality were more likely to report increased efficacy with opioids .
Adverse events related to the route of administration were not reported .
These trials provide no evidence for a clinical ly relevant peripheral analgesic efficacy of opioids in acute pain