***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 Persistent pain is a challenging clinical problem after breast cancer treatment . After surgery , inflammatory pain and nociceptive input from nerve injury induce central sensitization which may play a role in the genesis of persistent pain . Using quantitative sensory testing , we tested the hypothesis that adding COX-2 inhibition to st and ard treatment reduces hyperalgesia after breast cancer surgery . A secondary hypothesis was that patients developing persistent pain would exhibit more postoperative hyperalgesia . Methods 138 women scheduled for lumpectomy/mastectomy under general anesthesia with paravertebral block were r and omized to COX-2 inhibition ( 2x40 mg parecoxib on day of surgery , thereafter 2x200 mg celecoxib/day until day five ) or placebo . Preoperatively and 1 , 5 , 15 days and 1 , 3 , 6 , 12 months postoperatively , we determined electric and pressure pain tolerance thresholds in dermatomes C6/T4/L1 and a 100 mm VAS score for pain . We calculated the sum of pain tolerance thresholds and analyzed change in these versus preoperatively using mixed models analysis with factor medication . To assess hyperalgesia in persistent pain patients we performed an additional analysis on patients reporting VAS>30 at 12 months . Results 48  COX-2 inhibition  and 46 placebo  patients were analyzed in a modified intention to treat analysis . Contrary to our primary hypothesis , change in the sum of tolerance thresholds in the COX-2 inhibition group was not different versus placebo . COX-2 inhibition had an effect on pain on movement at postoperative day 5 ( p<0.01 ) . Consistent with our secondary hypothesis , change in sum of pressure pain tolerance thresholds in 11 patients that developed persistent pain was negative versus patients without pain ( p<0.01 ) from day 5 to 1 year postoperatively . Conclusions Perioperative COX-2 inhibition has limited value in preventing sensitization and persistent pain after breast cancer surgery . Central sensitization may play a role in the genesis of persistent postsurgical pain Background : Regional anesthesia improves postoperative analgesia and enhances quality of recovery ( QoR ) after ambulatory surgery . This r and omized , double-blinded , parallel-group , placebo-controlled trial examines the effects of multilevel ultrasound-guided paravertebral blocks ( PVBs ) and total intravenous anesthesia on QoR after ambulatory breast tumor resection . Methods : Sixty-six women were r and omized to st and ardized general anesthesia ( control group ) or PVBs and propofol-based total intravenous anesthesia ( PVB group ) . The PVB group received T1–T5 PVBs with 5 ml of 0.5 % ropivacaine per level , whereas the control group received sham subcutaneous injections .  Postoperative QoR was design ated as the primary outcome . The 29-item ambulatory QoR tool was administered in the preadmission clinic , before discharge , and on postoperative days 2 , 4 , and 7 . Secondary outcomes included block success , pain scores , intra- and postoperative morphine consumption , time to rescue analgesia , incidence of nausea and vomiting , and hospital discharge time . Results : Data from sixty-four patients were analyzed . The PVB group had higher QoR scores than control group upon discharge ( 146 vs. 131 ; P < 0.0001 ) and on postoperative day 2 ( 145 vs. 135 ; P = 0.013 ) ; improvements beyond postoperative day 2 lacked statistical significance . None of the PVB group patients required conversion to inhalation gas – based general anesthesia or experienced block-related complications . PVB group patients had improved pain scores on postanesthesia care unit admission and discharge , hospital discharge , and postoperative day 2 ; their intraoperative morphine consumption , incidence of nausea and vomiting , and discharge time were also reduced . Conclusion : Combining multilevel PVBs with total intravenous anesthesia provides reliable anesthesia , improves postoperative analgesia , enhances QoR , and expedites discharge compared with inhalational gas- and opioid-based general anesthesia for ambulatory breast tumor resection BACKGROUND : The efficacy of continuous wound infiltration with local anesthetic has not been compared with that of thoracic paravertebral block ( PVB ) after breast surgery . In this study , we evaluated the analgesic efficacy and morphine consumption of the two techniques after mastectomy . METHODS : Forty-eight patients undergoing modified radical mastectomy with axillary dissection were r and omly assigned to either a preoperative PVB with 20 mL of ropivacaine 0.5 % ( group PVB ) or a continuous ropivacaine 0.5 % infusion ( CRI ) at a 2 mL/h rate for each of two multilumen catheters placed subcutaneously at the end of the procedure ( group CRI ) . The catheters were left in place for 24 h postoperatively . A st and ardized general anesthetic was administered to all patients . Postoperative morphine consumption , pain scores and painful restricted movement of the shoulder for 24 h postoperatively as well as incidence of adverse events , including postoperative nausea and vomiting , were recorded . RESULTS : Morphine consumption was similar between groups ( PVB : 42.6 ± 11 vs CRI : 38.7 ± 11 mg in 24 h , P = 0.225 ) . Absolute pain scores were low in both groups . Four hours after surgery , group PVB showed a significant reduction in postoperative pain ( PVB : 0 [ 0–10 ] vs CRI : 0 [ 0–30 ] , P = 0.002 ) and reduced painful restricted movement ( P = 0.004 ) , whereas the CRI group had lower pain scores ( PVB : 10 [ 0–30 ] vs CRI : 0 [ 0–20 ] , P = 0.034 ) and painful restricted movement ( P = 0.043 ) 16 and 24 h ( PVB : 10 [ 0–30 ] vs CRI : 0 [ 0–30 ] , P = 0.012 ) after surgery . Postoperative nausea and vomiting was significantly more frequent in the CRI group ( P = 0.017 ) . CONCLUSIONS : Continuous wound infiltration of local anesthetics is an effective alternative to paravertebral analgesia after mastectomy with axillary dissection Background The pectoral nerves ( PECS ) block can not block the most internal mammary region , whereas a transversus thoracic muscle plane ( TTP ) block can . The combination of PECS and TTP blocks may be suitable for anterior chest surgery . We studied patients undergoing mastectomy to assess whether the combination of PECS and TTP blocks provides better analgesia than PECS block alone . Methods Seventy adult female patients undergoing unilateral mastectomy under general anaesthesia were r and omly allocated to receive either the combination of PECS and TTP blocks ( PT group , n=35 ) or the PECS block only ( C group , n=35 ) . The primary outcome measure was visual analog scale pain score . Secondary outcomes were the sensory level loss confirmed by cold tests and additional analgesic drugs within 24 h after the operation . Results The visual analog scale pain scores were lower in the PT group than the C group . The use of postoperative additional analgesic drugs was also lower lower in the PT group than that in the C group . In the majority of patients in the PT group , sensory loss was confirmed in both the anterior and the lateral branches of thoracic nerves ( Th2–6 ) . Conclusion Compared with PECS block , the combination of PECS and TTP blocks provides effective perioperative pain relief for breast cancer surgery . Clinical trial registration University Hospital Medical Information Network ( UMIN ) ID number 000018299 Avoidance of general anaesthesia for breast surgery may be because of clinical reasons or patient choice . There is emerging evidence that the use of regional anaesthesia and the avoidance of volatile anaesthetics and opioid analgesia may have beneficial effects on oncological outcomes . We conducted a prospect i ve observational case series of 16 breast cancer surgeries performed under thoracic paravertebral plus pectoral nerve block with propofol sedation  to demonstrate feasibility of technique , patient acceptability and surgeon satisfaction . Fifteen out of 16 cases were successfully completed under sedation and regional anaesthesia , with one conversion to general anaesthesia . Eleven out of 16 cases required low‐dose intra‐operative opioid analgesia . Out of the 15 surgical procedures completed under regional anaesthesia with sedation , all patients experienced either no or minimal intra‐operative pain , and all would choose this anaesthetic technique again . Surgeon‐reported operating conditions were ‘ indistinguishable from general anaesthesia ’ in most cases , and surgeons were ‘ extremely satisfied ’ or ‘ satisfied ’ with the technique after every procedure . Combined thoracic paravertebral plus pectoral nerve block with intra‐operative sedation is a feasible technique for breast surgery Background and Objectives Serratus plane block is performed for analgesia of the anterior chest wall . However , there has been no study concerning the appropriate volume for this block . This prospect i ve r and omized controlled study assesses the dermatomal spread and analgesic effects of serratus plane block . Methods Ultrasound-guided serratus plane block was performed for breast cancer surgery . The patients were r and omly assigned to receive 20 or 40 mL of 0.375 % ropivacaine . The primary end point was the number of affected dermatomes as assessed by cold test  and  pinprick test 20 minutes after the block procedure . Secondary end points were the time until the first postoperative analgesic rescue , adverse effects , and complications . Results The number of affected dermatomes assessed by the cold test for patients receiving 40 mL of 0.375 % ropivacaine was significantly larger than that for patients receiving 20 mL ( P = 0.002 ; 6 [ 5–7 ] vs 4 [ 3–4 ] dermatomes ) . Similarly , with the pinprick test , the affected area was larger for the 40 mL group than for the 20 mL group ( P = 0.009 ; 4 [ 2–6 ] vs 2 [ 1–3 ] dermatomes ) . There were no differences between the 2 groups in secondary end points . Conclusions Ultrasound-guided serratus plane block spread in the craniocaudal direction is more widespread with 40 mL than with 20 mL of 0.375 % ropivacaine . The time until the first postoperative analgesic rescue dose was not extended by a larger volume of injection . Clinical Trials Registration UMIN Clinical Trials Registry ( identifier UMIN000016549 ) BACKGROUND Breast surgery is an exceedingly common procedure with an increased incidence of acute and chronic pain . Pectoral nerve block is a novel peripheral nerve block alternative to neuro-axial and paravertebral blocks for ambulatory breast surgeries . OBJECTIVES This study aims to compare the analgesic efficacy and safety of modified Pecs block with ketamine plus bupivacaine versus bupivacaine in patients undergoing breast cancer surgery . STUDY DESIGN A r and omized , double-blind , prospect i ve study . SETTING Academic medical center . METHODS This study is registered at www . clinical trials.gov under number : ( NCT02620371 ) after approval by the ethics committee of South Egypt Cancer Institute , Assuit University , Assuit , Egypt . Sixty patients aged 18 - 60 years scheduled for modified radical mastectomy were enrolled and r and omly assigned into 2 groups ( 30 patients each ) : Control group patients were given ultrasound-guided , Pecs block with 30 mL of 0.25 % bupivacaine only . Ketamine group patients were given ultrasound-guided , Pecs block with 30 mL of 0.25 % bupivacaine plus ketamine hydrochloride ( 1 mg/kg ) . Patients were followed up for 48 hours postoperatively for vital signs , VAS score , first request of rescue analgesia and total morphine consumption , sedation score , and side effects . RESULTS Ketamine plus bupivacaine in Pecs block compared to bupivacaine alone prolonged the mean time of first request of analgesia ( 18.25 ± 1.98 ) , ( 12.56 ± 2.64 ) , respectively ( P < 0.001 ) , reduced total morphine consumption ( 12.50 ± 4.63 ) , ( 18.86 ± 6.28 ) , respectively ( P = 0.016 ) . With no significant difference in hemodynamics , respiratory rate , oxygen saturation , VAS and sedation scores , and side effects observed between the 2 groups ( P > 0.05 ) . LIMITATIONS This study is limited by its sample size . CONCLUSION The addition of ketamine to modified Pecs block prolonged the time to first request of analgesia and reduced total opioid consumption without serious side effects in patients who underwent a modified radical mastectomy . KEY WORDS Ketamine , bupivacaine , pecs block , postoperative , pain , breast cancer Background and Objectives General anesthesia for breast surgery may be supplemented by using a regional anesthetic technique . We evaluated the efficacy of the first pectoral nerve block ( Pecs I 
    Output:
    
Quantitative analysis suggests that dexamethasone and gabapentin reduced postoperative pain .
The use of paravertebral blocks also reduced postoperative pain scores , analgesia consumption and the incidence of postoperative nausea and vomiting .
Intra-operative opioid requirements were documented to be lower when a pectoral nerves block was performed , which also reduced postoperative pain scores and opioid consumption .