***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 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 BACKGROUND : Surgical site infiltration and transversus abdominis plane ( TAP ) blocks are commonly used to improve pain relief after lower abdominal surgery . This r and omized , observer-blinded study was design ed to compare the analgesic efficacy of TAP blocks with surgical site infiltration in patients undergoing open total abdominal hysterectomy via a Pfannenstiel incision . METHODS : Patients were r and omized to receive either  bilateral ultrasound-guided TAP blocks using bupivacaine 0.5 % 20 mL on each side ( n = 30 ) or surgical site infiltration with liposomal bupivacaine 266 mg diluted to 60 mL injected in the preperitoneal , subfascial , and subcutaneous planes ( n = 30 ) . The remaining aspects of the perioperative care were st and ardized . An investigator blinded to the group allocation documented pain scores at rest and with coughing , opioid requirements , nausea , vomiting , and rescue antiemetics in the postanesthesia care unit and at 2 , 6 , 12 , 24 , and 48 hours postoperatively . The primary outcome measure was pain scores on coughing at 6 hours postoperatively . RESULTS : One patient in each group was excluded from the analysis because of reoperation within 24 hours in the TAP block group and change of incision type in the infiltration group . The pain scores at rest and with coughing were significantly lower in the surgical site infiltration group at all postoperative time points ( P < 0.0001 ) except at rest in the postanesthesia care unit . The opioid requirements between 24 and 48 hours were significantly lower in the infiltration group ( P = 0.009 ) . The nausea scores , occurrence of vomiting , and need for rescue antiemetics were similar . CONCLUSIONS : Surgical site infiltration provided superior pain relief at rest and on coughing , as well as reduced opioid consumption for up to 48 hours . Future studies need to compare TAP blocks with liposomal bupivacaine with surgical site infiltration with liposomal bupivacaine Background Liposome bupivacaine ( Exparel ) is a multivesicular liposomal formulation of bupivacaine currently approved in the United States for single-dose administration into the surgical site to provide postsurgical analgesia . This retrospective analysis examined safety data from clinical trials involving the off-label use of this formulation in peripheral nerve blocks . Methods Data from 6 controlled ( phases I-III ) studies were compiled involving single-injection ankle , femoral nerve , and intercostal nerve blocks ( 2 each ) . Adverse events ( AEs ) were monitored for 1 to 30 days after study drug administration . Results Of 575 subjects , 335 received liposome bupivacaine ( 2–310 mg ) , 33 received bupivacaine HCl ( 75–125 mg ) , and 207 received normal saline ( placebo ) . Overall , 76 % of subjects receiving liposome bupivacaine experienced 1 or more AEs compared with 61 % receiving bupivacaine HCl and 76 % receiving placebo . The most frequently reported AEs among subjects receiving liposome bupivacaine  were nausea , pyrexia , pruritus , constipation , and vomiting . The most common treatment-related AE was hypesthesia among subjects treated with liposome bupivacaine or bupivacaine HCl  . Incidence of nervous system AEs for liposome bupivacaine , bupivacaine HCl , and placebo was 21 % , 27 % , and 21 % , respectively . Similarly , incidence of cardiac AEs was 9 % , 0 % , and 12 % , respectively . At least 1 serious AE occurred in 8 % of subjects receiving liposome bupivacaine compared with 10 % of those receiving placebo ( none assessed by investigators as related to study medication ) . Conclusions Liposome bupivacaine has a similar safety and side effect profile to bupivacaine HCl and normal saline , suggesting that most of the more common AEs are related to either opioid rescue or the surgical procedure itself STUDY OBJECTIVES To explore the influence of liposomes on the pharmacodynamic action of bupivacaine and to determine whether postsurgical analgesic advantages can be obtained from epidural delivery of liposomal bupivacaine compared with the current formulation . DESIGN Open , nonr and omized study . SETTING Physiopathology laboratory , general operating theaters , and intensive care units of Reine Fabiola Hospital and Institut Médical de Traumatologie et Revalidation . PATIENTS 26 ASA physical status II and III patients who had undergone major surgery ( abdominal , vascular , urologic , thoracic , orthopedic ) . INTERVENTIONS After completion of the operation , the patients were divided into 2 groups to receive 1 of 2 bupivacaine preparations epidurally for postsurgical pain : Group 1 ( n = 12 ) received plain 0.5 % bupivacaine with 1:200,000 epinephrine ; Group 2 ( n = 14 ) received liposomal 0.5 % bupivacaine . MEASUREMENTS AND MAIN RESULTS The following observations were made : onset and quality of analgesia , quality of motor block according to the Bromage scale , and sympathetic block . Onset time of sensory block averaged 15 minutes in both groups . Pain relief duration s were 3.2 + /- 0.4 hours with plain bupivacaine and 6.25 + /- 1.13 hours with the liposomal preparation ( p < 0.05 ) . In the liposomal bupivacaine group , no motor block was recorded . Low sympathetic block occurred in all patients . Analgesia in a subset of patients following abdominal aortic surgery increased from 2.4 + /- 0.35 hours to 10.6 + /- 1.4 hours by encapsulation of bupivacaine ( p < 0.01 ) . There was no neurotoxicity or cardiotoxicity . CONCLUSIONS The liposomal formulation of bupivacaine increased duration of analgesia without motor block or adverse side effects INTRODUCTION Optimal pain control after major surgery contributes to a patient 's recovery and satisfaction . The use of liposomal bupivacaine in subcostal transversus abdominis plane ( TAP ) blocks for postoperative pain control after  robot assisted abdominal surgery  has yet to be studied . METHODS We conducted a prospect i ve r and omized controlled observer-blinded study comparing bilateral subcostal TAP blocks with bupivacaine to bilateral subcostal TAP blocks with liposomal bupivacaine . These were performed prior to the patient undergoing robot assisted hysterectomy .  The patients ' pain scores , opioid use , side effects , and satisfaction were followed for 72h after injection . RESULTS Total opioid use in the first 72h after injection was significantly decreased in the group that received liposomal bupivacaine compared to bupivacaine . Patients in the liposomal bupivacaine group had significantly lower maximal pain scores at all time periods studied as well as decreased incidence of nausea/vomiting . There was a trend toward decreased length of stay in the liposomal bupivacaine group . CONCLUSION Subcostal TAP blocks with liposomal bupivacaine decreased the total opioid requirement for the first 72h after robot assisted hysterectomy when compared to subcostal TAP blocks with bupivacaine 
    Output:
    
A lack of evidence has prevented an assessment of the efficacy of liposomal bupivacaine administered as a peripheral nerve block .
At present there is a lack of data to support or refute the use of liposomal bupivacaine administered as a peripheral nerve block for the management of postoperative pain .