***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 There has been concern about rising rates of caesarean section worldwide . This Article reports the third phase of the WHO global survey , which aim ed to estimate the rate of different methods of delivery and to examine the relation between method of delivery and maternal and perinatal outcomes in selected facilities in Africa and Latin America in 2004 - 05 , and in Asia in 2007 - 08 . METHODS Nine countries participated in the Asia global survey : Cambodia , China , India , Japan , Nepal , Philippines , Sri Lanka , Thail and , and Vietnam . In each country , the capital city and two other regions or provinces were r and omly selected . We studied all women admitted for delivery during 3 months in institutions with 6000 or fewer expected deliveries per year and during 2 months in those with more than 6000 deliveries . We gathered data for institutions to obtain a detailed description of the health facility and its re sources for obstetric care . We obtained data from  women 's medical records to summarise obstetric and perinatal events . FINDINGS We obtained data for 109 101 of 112 152 deliveries reported in 122 recruited facilities ( 97 % coverage ) , and analysed 107 950 deliveries . The overall rate of caesarean section was 27.3 % ( n=29 428 ) and of operative vaginal delivery was 3.2 % ( n=3465 ) . Risk of maternal mortality and morbidity index ( at least one of : maternal mortality , admission to intensive care unit [ ICU ] , blood transfusion , hysterectomy , or internal iliac artery ligation ) was increased for operative vaginal delivery ( adjusted odds ratio 2.1 , 95 % CI 1.7 - 2.6 ) and all types of caesarean section ( antepartum without indication 2.7 , 1.4 - 5.5 ; antepartum with indication 10.6 , 9.3 - 12.0 ; intrapartum without indication 14.2 , 9.8 - 20.7 ; intrapartum with indication 14.5 , 13.2 - 16.0 ) . For breech presentation , caesarean section , either antepartum ( 0.2 , 0.1 - 0.3 ) or intrapartum ( 0.3 , 0.2 - 0.4 ) , was associated with improved perinatal outcomes , but also with increased risk of stay in neonatal ICU ( 2.0 , 1.1 - 3.6 ; and 2.1 , 1.2 - 3.7 , respectively ) . INTERPRETATION To improve maternal and perinatal outcomes , caesarean section should be done only when there is a medical indication . FUNDING US Agency for International Development ( USAID ) ; UNDP/UNFPA/WHO/World Bank Special Programme of Research , Development and Research Training in Human Reproduction ( HRP ) , WHO , Switzerl and ; Ministry of Health , Labour and Welfare of Japan ; Ministry of Public Health , China ; and Indian Council of Medical Research BACKGROUND : Difficulties in inserting an epidural catheter while performing combined spinal-epidural anesthesia for cesarean delivery may lead to undue delays between the spinal injection of the local anesthetic mixture and the adoption of the supine position with lateral tilt . We hypothesized that this delay may affect the intrathecal distribution of local anesthetic of different baricities such that hypobaric local anesthetic would lead to a higher sensory block level . METHODS : Healthy parturients with uncomplicated pregnancies undergoing elective cesarean delivery under combined spinal-epidural anesthesia were enrolled in this prospect i ve double-blind r and omized controlled trial . The subjects were allocated to receive hyperbaric ( hyperbaric group ) , isobaric ( isobaric group ) , or hypobaric ( hypobaric group ) spinal bupivacaine 10 mg . After the spinal injection , the subjects remained in the sitting position for 5 minutes ( to simulate difficulty in inserting the epidural catheter ) before being helped into the supine lateral tilt position . The primary outcome was the sensory block level during the 25 minutes after the spinal injection . Other end points included motor block score , maternal hypotension , and vasopressor requirements . RESULTS : Data from 89 patients were analyzed . Patient characteristics were similar in all groups . The median [ interquartile range ] ( 95 % confidence interval ) sensory levels after spinal injection were significantly higher with decreasing baricity : hyperbaric T10 [ T11 - 8 ] ( T10 - 9 ) , isobaric T9 [ T10 - 7 ] ( T9 - 7 ) , and hypobaric T6 [ T8 - 4 ] ( T8 - 5 ) ( P < 0.001 , Cuzick trend ) . All patients in the hypobaric group reached a sensory block level of T4 at 25 minutes after spinal injection compared with 80 % of the patients in both the isobaric and hyperbaric groups ( P = 0.04 ; difference 20 % , 95 % confidence interval of difference 4%–33 % ) . Significantly more patients in the hypobaric group had complete lower limb motor block ( Bromage score = 4 ) ( hyperbaric 43 % , isobaric 63 % , and hypobaric 90 % ; P < 0.001 ) . The incidences of maternal hypotension and nausea and vomiting were similar among groups , although the ephedrine requirements were significantly increased in the isobaric and hypobaric groups by factors of 1.83 and 3.0 , respectively , compared with the hyperbaric group ( P < 0.001 , Cuzick trend ) . CONCLUSIONS : We demonstrated that when parturients undergoing cesarean delivery were maintained in the sitting position for 5 minutes after spinal injection of the local anesthetic , hypobaric bupivacaine result ed in sensory block levels that were higher compared with isobaric and hyperbaric bupivacaine , respectively , during the study period Though hyperbaric solution of bupivacaine following intrathecal injection had satisfactory spread of analgesia , it regressed rapidly with more side effects .  Isobaric bupivacaine seemed to provide a slow regression of analgesia with fewer undesirable effects except for its inadequate spread of analgesia . As a result , if the dosages as well as the time of administration of isobaric solution are well adjusted , we believe that it is safe and reliable with an excellent level of analgesia for caesarean section Introduction The aim of our study was to compare the effects of isobaric and hyperbaric bupivacaine combined with morphine or fentanyl in patients undergoing caesarean section . We assessed quality and spread of analgesia and anaesthesia , postoperative analgesic requirement and side effects . Material and methods Hundred patients with American Society of Anesthesiologists physical status ( ASA ) I-II , age 18 to 40 years , were r and omized to 4 groups . The intrathecal solutions were isobaric bupivacaine + morphine ( group A ) , isobaric bupivacaine + fentanyl ( group B ) , heavy bupivacaine + + morphine ( group C ) and heavy bupivacaine + fentanyl ( group D ) . Mean arterial pressure , heart rate , oxygen saturation , ephedrine consumption , analgesic requirement time and additional analgesic needs were recorded . Results The 1st min value of mean arterial pressure was the lowest one in all groups . Heart rate decreased significantly in group A at the 10th min but not in the other groups . The decrease of visual analogue scale ( VAS ) pain scores began in the groups after the 4th postoperative h ( p < 0.05 ) and the VAS value of group B at the 8th h was significantly higher than the other groups . The first analgesic requirement time in the postoperative period was longer in patients who had intrathecal morphine than those who had fentanyl . The duration of analgesia with isobaric bupivacaine and morphine was the longest one . Conclusions We concluded that intrathecal morphine provides a long duration of postoperative analgesia but the duration gets longer when it is combined with plain bupivacaine instead of heavy bupivacaine UNLABELLED Anesthesia and surgery induce macrophage aggregation and neutrophil influx , responses that characterize an inflammatory reaction in the distal airway . We thus evaluated the time-dependent expression of genes for proinflammatory cytokines during propofol and isoflurane anesthesia . We studied patients anesthetized with propofol ( n = 20 ) or isoflurane ( n = 20 ) . Alveolar macrophages were harvested by bronchoalveolar lavage immediately , 2 , 4 , and 6 h after induction of anesthesia , and at the end of surgery . RNA was extracted from harvested cells and cDNA was synthesized by reverse transcription . Expression of interleukin-1beta ( IL-1beta ) , IL-6 , IL-8 , interferon gamma , and tumor necrosis factor-alpha was measured by semiquantitative polymerase chain reaction using beta-actin as an internal st and ard . We observed two 10-fold increases in gene expression of all proinflammatory cytokines except IL-6 . The increases in IL-8 and interferon gamma were 1.5 - 3 times greater during isoflurane than propofol anesthesia . Expression of the genes for IL-1beta and tumor necrosis factor-alpha was similar with each anesthetic . Our data thus indicate that the pulmonary inflammatory response accompanying anesthesia and surgery is accompanied by the expression of proinflammatory cytokines , and that this expression was in some cases greater during isoflurane than propofol anesthesia . IMPLICATION S Gene expression of proinflammatory cytokines in alveolar macrophages increased significantly over time . The increases were greater during isoflurane than propofol anesthesia , suggesting that inflammatory responses at transcriptional levels in alveolar macrophages are modulated by the type and duration of anesthesia An extensive and growing number of review s of the published literature demonstrate that health research publications have frequent deficiencies . Of particular concern are poor reports of r and omised trials , which make it difficult or impossible for readers to assess how the research was conducted , to evaluate the reliability of the findings , or to place them in the context of existing research evidence . As a result , published reports of trials often can not be used by clinicians to inform patient care or to inform public health policy , and the data can not be included in systematic review s. Reporting guidelines are design ed to identify the key information that research ers should include in a report of their research . We describe the history of reporting guidelines for r and omised trials culminating in the CONSORT Statement in 1996 . We detail the subsequent development and extension of CONSORT and consider related initiatives aim ed at improving the reliability of the medical research literature Both hyper- and hypobaric solutions of bupivacaine are often combined with morphine to provide subarachnoid anesthesia for cesarean section . Differences in the baricity of subarachnoid solutions influence the intrathecal distribution of anesthetic drugs and would be expected to influence measurable clinical variables . We compared the effects of hyper- and hypobaric subarachnoid bupivacaine with morphine to determine whether one has significant advantages with regard to intraoperative anesthesia and postoperative analgesia in term parturients undergoing elective cesarean section . Thirty parturients were r and omized to receive either hyper- or hypobaric bupivacaine ( 15 mg ) with morphine sulfate ( 0.2 mg ) . Intraoperative outcomes compared included extent of sensory block , quality of anesthesia , and side effects . Postoperative outcomes , including pain visual analog scale scores , systemic analgesic requirements , and side effects , were monitored for 48 h. Sedation effects were quantified and compared using Trieger and digit-symbol substitution tests . We detected no differences in sensory or motor block , quality of anesthesia , quality of postoperative analgesia , incidence of side effects , or psychometric scores . Both preparations provide highly satisfactory anesthesia for cesarean section and effective postoperative analgesia . Implication s : Dextrose alters the density of intrathecal bupivacaine solutions and is thought to influence subarachnoid distribution of the drug . We r and omized parturients undergoing cesarean section to one of two often used spinal bupivacaine preparations , hypobaric and hyperbaric . We detected no differences in clinical outcomes between groups . ( Anesth Analg 1998;87:336 - 40 Epidural volume extension ( EVE ) via a combined spinal-epidural ( CSE ) technique is the enhancement of a small-dose intrathecal block by epidural saline boluses . In this prospect i ve , r and omized , double-blind study , we compared the EVE technique with single-shot spinal anesthesia with respect to its sensory and motor block profile and hemodynamic stability . Sixty-two parturients ( n = 31 in each group ) undergoing elective cesarean deliveries were administered either spinal anesthesia with hyperbaric 0.5 % bupivacaine 9 mg and fentanyl 10 & mgr;g or CSE comprising intrathecal hyperbaric 0.5 % bupivacaine 5 mg with fentanyl 10 & mgr;g , followed by 0.9 % saline 6.0 mL through the epidural catheter 5 min thereafter . In each group , the lowest systolic blood pressure ( SBP ) , sensory block level to loss of pain from pinprick , and modified Bromage scores were recorded at 2.5-min intervals . The visual analog pain score ( VAS ) , peak sensory block height , highest modified Bromage motor score , time for sensory 
    Output:
    
This review found that intrathecal hyperbaric bupivacaine had a more rapid onset of sensory blockade at the 4th thoracic vertebra ( T4 ) level than isobaric bupivacaine .
Hower , despite incorporating more data in the analysis , we found little evidence that the need for conversion to general anaesthesia and supplemental analgesia differed between the hyperbaric or isobaric bupivacaine groups .
There were no differences in the adverse effects studied .