***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 Attenuation of central sensitization with NMDA-active drugs such as S-Ketamine may play a role in postoperative analgesia and prevention of neuropathic pain . However , during cesarean section with neuraxial block , S-Ketamine might have adverse effects on the interaction between mothers and infants , including breastfeeding . METHODS Women undergoing elective repeat cesarean section with subarachnoid anesthesia ( 0.5 % hyperbaric bupivacaine 8 - 10 mg and sufentanil 5 μg ) were enrolled in a double-blind , r and omized study . Patients in the S-Ketamine group ( N.=28 ) received i.v . midazolam 0.02 mg/kg and S-Ketamine 0.5 mg/kg i.m . bolus 10 minutes after birth followed by a 2 μg/kg/min i.v . continuous infusion for 12 h. The  control group ( N.=28 )  received placebo . Paracetamol and patient controlled analgesia with intravenous morphine were given postoperatively . Von Frey filaments were used to assess pain threshold on the inner forearm and T10-T11 dermatomes ( supposed hyperalgesic area ) . RESULTS S-Ketamine  reduced morphine consumption at 4 - 8 , 8 - 12 , and 12 - 24 hours after surgery ( total 31 % ) , even after its effect has ceased , suggesting an anti-hyperalgesic action . Mild side effects were observed in the S-Ketamine group one hour after delivery . All side effects were rated as light and there were no serious adverse events . Pain threshold was not significantly different between groups . S-Ketamine patients showed a trend towards reduced pain sensitivity at the T10 dermatome , which is involved by surgical damage . After three years , patients reported no differences in residual pain , dysesthetic symptoms , or duration of breast-feeding . CONCLUSION Preventive administration of S-Ketamine via 12-hour infusion was safe and may have anti-hyperalgesic action after cesarean section OBJECTIVES Low-dose ketamine has been considered a good substitute for opioids for controlling  postoperative pain . The purpose of this study was to determine the effect of low-dose intravenous ketamine following cesarean section with spinal anesthesia on postoperative pain and its potential complications . METHODS One hundred and sixty pregnant women volunteered to participate in this r and omized controlled trial . Participants were r and omly divided into two groups ( n=80 for each group ) . Five minutes after delivery , the experimental group received 0.25mg/kg ketamine while the control group received the same amount of normal saline . RESULTS There was a significant difference between the two groups in the severity of pain at one , two , six , and 12 hours following surgery . Postoperative pain was significantly less severe in the experimental group . Compared to the control group , the experimental group felt pain less frequently and therefore asked for analgesics less often . On average , the number of doses of analgesics used for the participants in the experimental group was significantly less than the number of doses used for the control group . Analgesic side effects ( including nausea , itching , and headache ) were not significantly different between the two groups . However , vomiting was significantly more prevalent in the control group and hallucination was more common in the experimental group . CONCLUSION We conclude that administration of low doses of ketamine after spinal anesthesia reduces the need for analgesics and has fewer side effects than using opioids . Further studies are required to determine the proper dose of ketamine which offers maximum analgesic effect . Furthermore , administration of low-dose ketamine in combination with other medications in order to minimize its side effects warrants further investigation BACKGROUND AND OBJECTIVES Analgesia after caesarean section is important because postpartum women with pain have difficulty in mobility , which undermines breastfeeding . Intrathecal morphine provides adequate and prolonged analgesia after cesarean . The aim of this study was to compare the quality of analgesia provided by two doses of intrathecal morphine and its side effects in patients undergoing cesarean section . METHOD The study included 123 pregnant women with gestational age over 38 weeks and scheduled for cesarean section . The women were r and omly allocated into two groups to receive either 50 or 100 μg of intrathecal morphine ( Group 50/Group 100 ) . All patients were intrathecally anesthetized with 12 mg of 0.5 % hyperbaric bupivacaine . Patients were assessed between the 9(th ) and 11(th ) hour and the 22(nd ) and 24(th ) hour after blockade for quality of analgesia , analgesic consumption , side effects , and main cause of discomfort in the first 24 hours after surgery . RESULTS There was similarity between groups regarding anthropometric data and obstetric history . There was no statistical difference in pain intensity between groups . In both groups , pain was more intense in the first 12 hours after anesthesia ( p < 0.001 ) . Tramadol hydrochloride consumption and time to first dose were similar in both groups . Pruritus was the most common side effect , with statistically higher incidence in Group 100 ( p = 0.026 ) . CONCLUSIONS Intrathecal morphine 50 μg provides the same quality of analgesia as 100 μg , with a lower incidence of side effects Background and Objectives The transversus abdominis plane ( TAP ) block is an established technique to manage post – cesarean delivery pain .  Transversus abdominis plane blocks with a local anesthetic only offer no analgesic benefits compared with intrathecal morphine . Adjuvants to extend TAP block duration and possibly reduce wound hyperalgesia , known to be a risk factor for chronic pain , have not been studied . We hypothesized that a TAP block with clonidine will affect postsurgical wound hyperalgesia and improve pain outcomes . Methods Ninety women were r and omly assigned to receive 1 of 3 TAP blocks after cesarean delivery  : saline ( placebo ) , bupivacaine ( BupTAP ) , or bupivacaine + clonidine ( CloTAP ) . The primary outcome was wound hyperalgesia index at 48 hours . Secondary outcomes included pain scores , analgesic consumption , and pain descriptors up to 12 months . Results Wound hyperalgesia index at 48 hours ( median [ 25th–75th percentiles ] ) was 1.07 ( 0.48–3.26 ) in the placebo group , 1.27 ( 0.59–2.95 ) in the BupTAP group , and 0.74 ( 0.09–2.25 ) in the CloTAP group ( P = 0.48 ) . Morphine request in the postanesthesia care unit was significantly higher in the placebo group compared with the other TAP groups ( P = 0.01 ) . Postoperative pain scores and requests for breakthrough medication at 48 hours ( 30 % in the placebo group , 24 % in the BupTAP group , and 12 % in the CloTAP group , P = 0.25 ) or chronic pain descriptors reported up to 12 months did not differ significantly among groups . Conclusions Adding clonidine to a TAP block with bupivacaine did not affect wound hyperalgesia index and it did not improve short-term or long-term pain scores in women undergoing elective cesarean delivery . Further studies are warranted to determine the benefits of antihyperalgesic adjuvants in TAP solutions for specific individuals at risk for chronic pain Background : Cesarean section is one of the common surgeries of women . Acute post-operative pain is one of the recognized post-operative complications . Aims : This study was planned to compare the effects of suppositories , indomethacin , diclofenac and acetaminophen , on post-operative pain and opioid usage after cesarean section . Material s and Methods : In this double-blind clinical trial study , 120 c and i date s of cesarean with spinal anesthesia and American Society of Anesthesiologists ( ASA ) I-II were r and omly divided into four groups . Acetaminophen , indomethacin , diclofenac , and placebo suppositories were used in groups , respectively , after operation and the dosage was repeated every 6 h and pain score and opioid usage were compared 24 h after the surgery . The severity of pain was recorded on the basis of Visual Analog Scale ( VAS ) and if severe pain ( VAS > 5 ) was observed , 0.5 mg/kg intramuscular pethidine had been used . Statistical Analysis Used : The data were analyzed in SPSS software version 15 and analytical statistics such as ANOVA , Chi-square , and Tukey 's honestly significant difference ( HSD ) post-hoc . Results : Pain score was significantly higher in control group than other groups , and also pain score in acetaminophen group was higher than indomethacin and diclofenac . The three intervention groups received the first dose of pethidine far more than control group and the distance for diclofenac and indomethacin were significantly longer ( P < 0.001 ) . The use of indomethacin , diclofenac , and acetaminophen significantly reduces the amount of pethidine usage in 24 h after the surgery relation to control group . Conclusions : Considering the significant decreasing pain score and opioid usage especially in indomethacin and diclofenac groups rather than control group , it is suggested using of indomethacin and diclofenac suppositories for post-cesarean section analgesia Background : Epidural analgesia with opioid provides good control of postoperative pain in cesarean section , thereby improving the mother 's ability to mobilize and interact with her newborn infant . Aim : The aim of this study is to evaluate and compare the analgesic actions and side effects of epidural analgesia with sufentanil , morphine or combination of the two after cesarean section . Material s and Methods : 60 women undergoing elective cesarean section were allocated into three groups of 20 each in a r and omized blinded fashion . Epidural analgesia was administered with sufentanil 50 mcg in Group S ; morphine 4 mg in Group M ; and , a combination of sufentanil 25 mcg and morphine 2 mg was used in Group SM . Analgesic efficacy in terms of onset of action and duration of analgesia was assessed by using the Visual Analog Scale ( 0 to 10 cm ) for 24 hours . Number of opioid doses needed in 24 hours was noted . Side effects like respiratory depression /excessive sedation , pruritus and nausea were recorded . Results : Onset of action were at 7.6 ± 1.5 minutes in group S , 67.6 ± 1.5 minutes in group M and 12.2 ± 2.6 minutes in group SM . Duration of analgesia was longer in group M 17.5 ± 1.9 hours and SM 13.8 ± 1.6 hours than in group S 5.2 ± 1.2 hours . More doses of analgesia were required in group S compared to group M and SM . Side effects were comparable in the three groups . Conclusion : Epidural administration of a combination of sufentanil and morphine offered the advantage of faster onset of action and longer duration of analgesia as compared to the two drugs administered alone BACKGROUND : A single dose of epidural morphine is effective in reducing pain after cesarean delivery but is associated with adverse effects . In this study , we sought to establish whether half the traditional dose of epidural morphine , when administered as part of a multimodal analgesia regimen after cesarean delivery , was associated with noninferior analgesia and fewer adverse effects . METHODS : Ninety term parturients undergoing cesarean delivery under epidural anesthesia were enrolled in this r and omized , double-blinded , noninferiority study . Patients were r and omly allocated to receive either 3 mg epidural morphine or , half this dose , 1.5 mg epidural morphine . In addition , subjects received regular systemic ketorolac and acetaminophen . Rescue analgesia ( oral oxycodone ) was administered for breakthrough pain . The primary outcome was the difference between groups in total opioid consumption ( measured in median IV morphine equivalents ) within the first 24 hours . A prespecified noninferiority margin of 3.33 mg was used . Secondary outcomes included total opioid consumption from 24 to 48 hours , numerical rating scale pain scores , time to first request for analgesics , overall pain relief , maternal satisfaction , quality of recovery , and adverse effects . RESULTS : Data were analyzed for 87 participants . Noninferiority was demonstrated as the difference in median 24-hour opioid consumption between the 1.5 mg epidural morphine ( EM ) and 3 mg EM groups was 0 mg ( 1-sided 95 % confidence interval [ CI ] , 2.5 mg ) , which was less than the prespecified noninferiority margin of 3.33 mg . No significant differences were found between groups in the median 24- to 48-hour opioid consumption or the median total opioid consumption within 48 hours . Pain scores , overall pain relief , and satisfaction at 24 and 48 hours were not significantly different between groups . The 1.5 mg EM group had a lower incidence of moderate and severe pruritus at 6 and 12 hours ( relative risk [ RR ] 0.44 , 95 % CI , 0.2–0.9 and RR 0.41 , 95 
    Output:
    
The analgesic efficacy of TAP block as a part of multimodal analgesia is established in post-CS cases where intrathecal morphine is not employed and in CS under general anaesthesia .
Among non-steroidal anti-inflammatory drugs , COX-I inhibitors and intravenous paracetamol are found to be useful in post-operative analgesic regimen .
The perioperative use of ketamine is found useful only in CS done under spinal anaesthesia ; no benefit is seen where general anaesthesia is employed .