***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Pain control after thoracotomy prevents postsurgical complications and improves respiratory function . The gold st and ard for post-thoracotomy analgesia is the epidural catheter . The aim of this study was to compare it with a new technique that involves placement of a catheter in the paravertebral space at the end of surgery under a surgeon 's direct vision . METHODS From November 2011 to June 2012 , 52 patients were r and omized into 2 groups depending on catheter placement : an epidural catheter for group A and a paravertebral catheter for group B. At 12 , 24 , 48 , and 72 hours after surgery , the following parameters were recorded : ( 1 ) pain control using the patient 's completion of a visual analog scale module , ( 2 ) respiratory function using forced expiratory volume in 1 second and ambient air saturation , and ( 3 ) blood cortisol values as an index of systemic reaction to pain . RESULTS Statistically significant differences ( P < .05 ) were found in favor of group B for both cough and rest pain control ( P = .002 and .002 , respectively ) and respiratory function in terms of forced expiratory volume in 1 second and ambient air saturation levels ( P = .023 and .001 , respectively ) . No statistically significant differences were found in blood cortisol trends between the 2 groups ( P > .05 ) . Collateral effects such as vomiting , nausea , low pressure , or urinary retention were observed only in group A. No collateral effects were recorded in the paravertebral group . CONCLUSIONS According to our data , drugs administered through a paravertebral catheter are very effective . Moreover , it does not present contraindications to its positioning or collateral effects . More studies are necessary to confirm data we collected AIM Epidural analgesia is considered to be the best method of pain relief after major surgery despite its side-effects , which include hypotension , respiratory depression , urinary retention , incomplete or failed block , and , in rare cases , paraplegia . Paravertebral block is an alternative technique that may offer a comparable analgesic effect and a better side-effect profile . This study measured postoperative pain and respiratory function in patients r and omized to receive either paravertebral block or epidural analgesia for pain control after thoracic surgery . METHODS Twenty-four adult patients undergoing thoracic surgery were enrolled in a prospect i ve and r and omized clinical study . Patients were r and omly allocated to receive either postoperative continuous paravertebral analgesia ( N=12 ) or epidural analgesia ( N=12 ) starting at pleura closure . Postoperative use of morphine , visual analogue scores , and spirometer data were collected for 72 hours after surgery as markers of pain relief . RESULTS There was a statistically significant ( P=0.003 ) increase in median ( 25th-75th percentiles ) patient-controlled use of morphine , with values of 36 ( 22 - 42 ) mg in the paravertebral group vs. 9 ( 2 - 22 ) mg in the epidural group . This increase in morphine usage in the paravertebral group was statistically significant at 6 , 24 , 48 , and 72 hours after surgery . Postoperative pain measured with the visual analogue score was not significantly different in the two groups . Spirometer values at 72 h were better in the epidural group than in the paravertebral group ( P=0.03 ) . CONCLUSIONS Epidural analgesia is more efficient than paravertebral continuous block at reducing pain after thoracic surgery DESIGN A prospect i ve , r and omized , open study . The regional technique used was not blinded . SETTING A university teaching hospital . PARTICIPANTS Forty-eight patients undergoing video-assisted thoracoscopic surgery ( VATS ) for tumor resection . INTERVENTIONS Patients received either continuous extrapleural block or continuous epidural block using ropivacaine for a period of 60 hours after surgery . MEASUREMENTS AND MAIN RESULTS To evaluate postoperative pain control , the primary and secondary endpoints were the visual analog scale ( VAS ) on movement and the amount of rescue analgesia , respectively . There were no significant differences between the extrapleural and epidural block groups with regard to VAS at rest and during movement assessed at 4 , 12 , 24 , 36 , and 48 hours after surgery , dosage of intravenous morphine ( extrapleural : 12.9 ± 11.3 , epidural : 10.2 ± 6.9 mg ) ,  supplemental nonsteroidal anti-inflammatory drugs , incidence of postoperative nausea and vomiting ( extrapleural : 12/20 , epidural : 11/20 ) , postoperative ambulation ( extrapleural : 18 at postoperative day [ POD ] 1 and 20 at POD 2 , epidural : 19 at POD 1 and 20 at POD 2 ) and hospital stay after surgery ( extrapleural : 12.7 ± 6.3 , epidural : 12.6 ± 4.7 days ) . CONCLUSIONS Although this study did not show the superiority of continuous extrapleural block relative to continuous epidural in VATS patients , the results suggest that both methods provided effective analgesia with a relatively small dose of rescue morphine . Although the analgesic effects of these techniques were comparable , extrapleural block has the advantage of safety and precise placement of the catheter and can be considered an alternative to epidural block in VATS patients Background : Relevant discharge information about the use of analgesic medication and other strategies may help patients to manage their pain more effectively and prevent postoperative persistent pain . Aims : To examine patients ’ pain characteristics , analgesic intake and the impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery . Concerns about pain and pain medication prior to surgery will also be described . Methods : From March 2012 to September 2013 , 416 participants ( 23 % women ) were consecutively enrolled in a r and omized controlled trial . The intervention group received usual care plus an educational booklet at discharge with supportive telephone follow-up on postoperative day 10 , and the control group received only usual care . The primary outcome was worst pain intensity ( The Brief Pain Inventory – Short Form ) . Data about pain characteristics and analgesic use were collected at 2 weeks and at 1 , 3 , 6 and 12 months post-surgery . General linear mixed models were used to determine between-group differences over time . Results : Twenty-nine percent of participants reported surgically related pain at rest and 9 % reported moderate to severe pain at 12 months post-surgery . Many participants had concerns about pain and pain medication , and analgesic intake was insufficient post-discharge . No statistically significant differences between the groups were observed in terms of the outcome measures following surgery . Conclusion : Postoperative pain and inadequate analgesic use were problems for many participants regardless of group allocation , and the current intervention did not reduce worst pain intensity compared with control . Further examination of supportive follow-up monitoring and /or self-management strategies post-discharge is required OBJECTIVE To compare the results of continuous epidural bupivacaine analgesia with and without hydromorphone to continuous paravertebral analgesia with bupivcaine in patients with post-thoracotomy pain . DESIGN A prospect i ve , r and omized , double-blinded trial . SETTING A teaching hospital . PARTICIPANTS Patients at a tertiary care teaching hospital undergoing throracotomy for lung cancer . INTERVENTIONS Subjects were assigned r and omly to receive a continuous thoracic epidural or paravertebral infusion . Patients in the epidural group were r and omized to receive either bupivacaine alone or in combination with hydromorphone .  Visual analog scores as well as incentive spirometery results were obtained before and after thoracotomy . METHODS AND MAIN RESULTS Seventy-five consecutive patients presenting for thoracotomy were enrolled in this institutional review board-approved study . On the morning of surgery , subjects were r and omized to either an epidural group receiving bupvicaine with and without hydromorphone or a paravertebral catheter-infused bupvicaine .  Postoperative visual analog scores and incentive spirometry data were measured in the postanesthesia care unit , the evening of the first operative day , and daily thereafter until postoperative day 4 . Analgesia on all postoperative days was superior in the thoracic epidural group receiving bupivacaine plus hydromorphone .  Analgesia was similar in the epidural and continuous paravertebral groups receiving bupivacaine alone . No significant improvement was noted by combining the continuous infusion of bupivacaine via the paravertebral and epidural routes . Incentive spirometry goals were best achieved in the epidural bupivacaine and hydromorphone group and equal in the group receiving bupivacaine alone either via epidural or continuous paravertebral infusion . CONCLUSIONS The current study provided data that fill gaps in the current literature in 3 important areas . First , this study found that thoracic epidural analgesia ( TEA ) with bupivacaine and a hydrophilic opioid , hydromorphone , may provide enhanced analgesia over TEA or continuous paravertebral infusion ( CPI ) with bupivacaine alone . Second , in the bupivacaine-alone group , the increased basal rates required to achieve analgesia result ed in hypotension more frequently than in the bupivacaine/hydromorphone combination group , underscoring the benefit of the synergistic activity . Finally , in agreement with previous retrospective studies , the current data suggest that CPI of local anesthetic appears to provide acceptable analgesia for post-thoracotomy pain Background : The aim of this prospect i ve , r and omized , blinded study was to compare analgesic efficacy of continuous paravertebral and epidural analgesia for  post‐thoracotomy pain . Methods : Forty‐two ASA physical status II – III patients undergoing lung resection surgery were r and omly allocated to receive post‐thoracotomy analgesia with either a thoracic epidural ( group EPI , n = 21 ) or paravertebral ( group PVB , n = 21 ) infusion of 0.2 % ropivacaine ( infusion rate : 5–10 mL h−1 ) . The degree of pain at rest and during coughing , haemodynamic variables and blood gas analysis were recorded every 12 h for the first 48 h. Results : The area under the curve of the visual analogue pain score during coughing over time was 192 ( 60–444 ) cm h−1 in group EPI and 228 ( 72–456 ) cm h−1 in group PVB ( P = 0.29 ) . Rescue morphine analgesia was required in four patients of group EPI ( 19 % ) and five patients of group PVB ( 23 % ) ( P = 0.99 ) . The PaO2/FiO2 ratio reduced significantly from baseline values in both groups without between‐group differences . The median ( range ) percentage reduction of systolic arterial pressure from baseline was −9 ( 0 to −9)% in group PVB and −17 ( 0 to −38)% in group EPI ( P = 0.02 ) ; while clinical ly relevant hypotension ( systolic arterial pressure decrease > 30 % of baseline ) was observed in four patients of group EPI only ( 19 % ) ( P = 0.04 ) . Patient satisfaction with the analgesia technique was 8.5 ( 8–9.8 ) cm in group EPI and 9 ( 7.5–10 ) cm in group PVB ( P = 0.65 ) . Conclusions : Continuous thoracic paravertebral analgesia is as effective as epidural blockade in controlling post‐thoracotomy pain , but is associated with less haemodynamic effects OBJECTIVES Paravertebral block is an effective alternative to epidural analgesia in the management of post-thoracotomy pain , however , there are no established guidelines regarding what is the most suitable strategy when varying drugs and dosages between different groups . Our objective was to evaluate the effectiveness of paravertebral block comparing the most frequently employed drugs in this procedure ( bupivacaine vs ropivacaine ) . METHODS Prospect i ve r and omized study of 70 patients su bmi tted to thoracotomy . Patients were divided in two independent groups ( anterior thoracotomy ( AT ) and posterolateral thoracotomy ( PT ) ) . At the end of surgery a catheter was inserted under direct vision in the thoracic paravertebral space at the level of incision . In each group ( AT or PT ) patients were r and omized to receive a bolus of 15 ml of bupivacaine 0.5 % or 20 ml of ropivacaine 0.2 % before closing the thoracotomy . They postoperatively received 10 ml of bupivacaine or 15 ml of ropivacaine every 6h combined with methamizol ( every 6h ) . Subcutaneous meperidine was employed as rescue drug . The level of pain was measured with the visual analogic scale ( VAS ) at 1 , 6 , 24 , 48 and 72 h after surgery . The need of meperidine as rescue drug and secondary effects was also recorded . RESULTS We did not register secondary effects in relation to the paravertebral catheter ( paravertebral or cutaneous bleeding or hematoma , respiratory depression ( respiratory rate < 8 breaths per minute ) , cardiotoxicity , confusion , sedation , urinary retention , nausea , vomiting and pruritus ) . Eleven patients ( 1 
    Output:
    
No statistically significant difference in pain relief was reported .
The continuous paravertebral block has equivalent analgesic effects to epidural analgesia , wound infiltration and st and ard care , but is associated with a lower incidence of nausea and vomiting , hypotension and urinary retention than epidural analgesia