***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: Forty patients undergoing elective and emergency Caesarean section ( excluding severe fetal distress ) were divided into four groups to receive 50 % oxygen , 50 % nitrous oxide , and 0.5 % halothane ( group 1 , controls ) or 100 % oxygen supplemented by 1.5 x MAC of halothane , enflurane or isoflurane ( groups 2,3,4 , respectively ) reducing to 1.0 x MAC 5 min after induction . The umbilical venous PO2 in the oxygen-only groups was higher than in the oxygen-nitrous oxide groups , this difference reaching statistical significance when the patients in the oxygen-only groups were combined . Blood loss and uterine contractility were unaffected by the increased concentrations of volatile agents , and awareness did not occur . Improved cardiovascular stability was demonstrated in the elective high-oxygen groups . The technique is safe and warrants further study , since there are no important ethical objections To comprehend the results of a r and omised controlled trial ( RCT ) , readers must underst and its design , conduct , analysis , and interpretation . That goal can be achieved only through total transparency from authors . Despite several decades of educational efforts , the reporting of RCTs needs improvement . Investigators and editors developed the original CONSORT ( Consoli date d St and ards of Reporting Trials ) statement to help authors improve reporting by use of a checklist and flow diagram . The revised CONSORT statement presented here incorporates new evidence and addresses some criticisms of the original statement . The checklist items pertain to the content of the Title , Abstract , Introduction , Methods , Results , and Discussion . The revised checklist includes 22 items selected because empirical evidence indicates that not reporting this information is associated with biased estimates of treatment effect , or because the information is essential to judge the reliability or relevance of the findings . We intended the flow diagram to depict the passage of participants through an RCT . The revised flow diagram depicts information from four stages of a trial ( enrolment , intervention allocation , follow- up , and analysis ) . The diagram explicitly shows the number of participants , for each intervention group , included in the primary data analysis . Inclusion of these numbers allows the reader to judge whether the authors have done an intention- to-treat analysis . In sum , the CONSORT statement is intended to improve the reporting of an RCT , enabling readers to underst and a trial 's conduct and to assess the validity of its results The use of supplemental oxygen in uncomplicated cesarean deliveries under spinal anesthesia has been thoroughly investigated during recent decades . The aim of this study was to determine the benefits for both mother and infant of administering supplemental , low-dose oxygen via a nasal cannula versus having no supplement ( i.e. , room air only ) . Healthy parturients at term undergoing elective cesarean section under spinal anesthesia were r and omly allocated into two groups : an oxygen group ( n = 170 ) , who received 3 LPM oxygen via a nasal cannula ; and a room-air group ( n = 170 ) , who were assigned to breathe room air .  Maternal oxygen saturation was measured continuously by using pulse oximeter . The desaturation was determined by oxygen saturation < 94 % over 30 seconds . Umbilical cord gases and Apgar scores were collected followed delivery of the infant . All maternal desaturation events occurred in 12 parturients assigned to the room-air group . Most events were concurrent with hypotension . The umbilical venous partial pressure of oxygen was significantly higher in the oxygen group . The other blood gas measurements and Apgar scores were not significantly different between the two groups . Based on our findings , the use of supplemental oxygen could prevent maternal desaturation result ing from receiving sedation and intraoperative hypotension BACKGROUND Newborns exposed to oxygen  suffer from an oxidative stress with significant alterations in the concentrations of superoxide dismutase ( SOD ) and glutathione ( GSSG ) . OBJECTIVE To investigate the biological and clinical effects of oxygen administration to delivering mothers . METHODS We conducted a r and omized , double-blinded , controlled trial on a cohort of delivering women ( n=56 ) with an uncomplicated term pregnancy . Women were r and omly assigned to one of two groups : Oxygen group or Room Air group . The Oxygen group received 100 % oxygen ( 2l/min ) via nasal cannula for at least 30 min before delivery . Subjects in the Room Air group were connected to a nasal cannula while on room air . Concentrations of SOD ( μg/g of Hb ) and GSSG ( μM/ml ) were measured in maternal and umbilical cord blood . Bivariate and multivariate analyses were used to compare the two groups using the SAS system . RESULTS Maternal SOD and GSSG did not differ between the two groups at baseline or after delivery . Concentrations of SOD and GSSG in umbilical cord blood did not differ between groups . More infants in Oxygen Group required delivery room resuscitation ( 20 % vs. 0 % , P=0.03 ) . This difference could not be explained by mode of delivery , infant sex , or other confounders . CONCLUSIONS Maternal exposure to oxygen during delivery is not associated with changes in umbilical cord SOD or GSSG . Further studies are needed to explore mechanisms responsible for the need of resuscitation in the oxygen group Spinal anesthesia recently has gained popularity for elective cesarean section . Our anesthesia service changed from epidural to spinal anesthesia for elective cesarean section in 1991 . To evaluate the significance of this change in terms of time management , costs , charges , and complication rates , we retrospectively review ed the charts of patients who had received epidural ( n = 47 ) or spinal ( n = 47 ) anesthesia for nonemergent cesarean section . Patients who received epidural anesthesia had significantly longer total operating room ( OR ) times than those who received spinal anesthesia ( 101 + /- 20 vs 83 + /- 16 min , [ mean + /- SD ] P < 0.001 ) ; this was caused by longer times spent in the OR until surgical incision ( 46 + /- 11 vs 29 + /- 6 min , P < 0.001 ) . Length of time spent in the postanesthesia recovery unit was similar in both groups . Supplemental intraoperative intravenous ( IV ) analgesics and anxiolytics were required more often in the epidural group ( 38 % ) than in the spinal group ( 17 % ) ( P < 0.05 ) . Complications were noted in six patients with epidural anesthesia and none with spinal anesthesia ( P < 0.05 ) . Average per-patient charges were more for the epidural group than for the spinal group . Although direct cost differences between the groups were negligible , there were more substantial indirect costs differences . We conclude that spinal block may provide better and more cost effective anesthesia for uncomplicated , elective cesarean sections . ( Anesth Analg 1995;80:709 - 12 Objective : To compare general , epidural and combined spinal-epidural anesthesia with respect to short-term outcome of newborns delivered by elective Cesarean section of healthy parturients with normal pregnancies . Study design : A total of 238 eight pregnant women admitted to our institution between January 1998 and July 2002 , for whom elective Cesarean section was planned after 38 weeks ' gestation , were grouped according to the kind of anesthesia used for the procedure . Maternal characteristics , birth weight , Apgar scores , and maternal and umbilical artery ( UA ) acid-base parameters were analyzed . Results : Maternal pH was significantly lower and pCO2 and pO2 were significantly higher in the general anesthetic group , compared to the other two groups ( 7.38 ± 0.03 vs. 7.43 ± 0.02 and 7.43 ± 0.05 , respectively ; 35.03 ± 3.88 mmHg vs. 29.25 ± 5.05 mmHg and 29.64 ± 4.16 mmHg , respectively ; and 224.56 ± 86.77 mmHg vs. 151.28 ± 38 mmHg and 157.36 ± 53.51 mmHg , respectively , p < 0.05 ) . The pH of the UA was higher in the general anesthetic group , compared to the spinal-epidural group ( 7.29 ± 0.02 vs. 7.26 ± 0.06 , p < 0.05 ) . The pO2 as well as O2 saturation of the UA were higher when general anesthetic was administered , compared to the two regional modalities ( 15.60 ± 5.48 mmHg vs. 9.29 ± 4.41 mmHg and 9.20 ± 4.06 mmHg , respectively ; and 17.37 ± 9.79 % vs. 7.87 ± 4.98 % and 6.90 ± 5.22 % , respectively , p < 0.05 ) . UA O2 saturation fell to zero in some cases in the combined spinal-epidural group , without an evident effect on fetal well-being . No fetal acidemia was noted in any group . Neonatal outcomes were similar in the three groups studied . Conclusions : Type of anesthesia does not influence short-term outcomes in infants born via elective Cesarean section , although differences in acid-base status of both the mother and especially the newborn recommend careful use of spinal anesthesia We investigated the necessity for administration of supplementary oxygen to mothers undergoing elective Caesarean section under spinal anaesthesia . Sixty‐nine women undergoing elective Caesarean section were r and omly allocated to one of three groups to be given either oxygen ( 40 % ) by facemask , air by facemask or oxygen at 2 l.min−1 by nasal cannulae .  Umbilical arterial and venous blood sample s were taken and analysed immediately after delivery . The results showed that there were no significant differences in the umbilical arterial or venous pH , partial pressure of oxygen and partial pressure of carbon dioxide between any of the three groups . We also assessed the patient acceptability of oxygen administered by facemask vs. nasal cannulae should the need for supplementary oxygen arise . It was found that use of the facemask impeded communication BACKGROUND Oxygen supplementation is given routinely to parturients undergoing Caesarean section under regional anaesthesia . While the aim is to improve fetal oxygenation , inspiring a high oxygen fraction ( FIO2 ) can also increase free radical activity and lipid peroxidation in both the mother and baby . In this prospect i ve , r and omized , double-blind study , we investigated the effect of high inspired oxygen fraction ( FIO2 ) on maternal and fetal oxygenation and oxygen free radical activity in parturients having Caesarean section under spinal anaesthesia . METHODS Forty-four healthy parturients were r and omized to breathe either 21 % ( air group ) or 60 % oxygen ( oxygen group ) intraoperatively via a ventimask .  Maternal arterial blood was collected at 5-min intervals from baseline until delivery , and umbilical arterial and venous blood was collected at delivery . We measured blood gases and the products of lipid peroxidation ( 8-isoprostane , malondialdehyde ( MDA ) , hydroperoxide ( OHP ) ) and purine metabolites . RESULTS At delivery , the oxygen group had greater maternal arterial PO2 [ mean 30.0 ( SD 6.3 ) vs 14.2 ( 1.9 ) kPa ; mean difference 15.8 kPa , 95 % confidence interval 12.9 - 18.7 kPa , P<0.001 ] and greater umbilical venous PO2 [ 4.8 ( 1.0 ) vs 4.0 ( 1.4 ) kPa ; mean difference 0.8 kPa , 95 % confidence interval 0.0 - 1.5 kPa , P=0.04 ] compared with the air group . Maternal and umbilical plasma concentrations of lipid peroxides ( 8-isoprostane , MDA , OHP ) were greater in the oxygen group than in the air group ( P<0.05 ) . CONCLUSIONS We conclude that breathing high FIO2 modestly increased fetal oxygenation but caused a concomitant increase in oxygen free radical activity in both mother and fetus We report the changes observed in a number of pulmonary function tests performed on 36 patients undergoing Caesarean section under spinal anaesthesia .  The tests comprised peak expiratory flow , forced expiratory volume in one second , forced vital capacity , forced expiratory volume in one second to forced vital capacity ratio and the maximal mid‐expiratory flow . Significant changes occurred that are consistent with a restrictive ventilatory defect . These changes persisted for four hours after the induction of spinal anaesthesia . Administration of 35 % oxygen by facemask failed to change significantly fetal umbilical vein pH or partial pressure of oxygen Purpose The aim of this investigation was to determine whether supplementary oxygen provided by either nasal cannula or face mask versus room air might affect fetal oxygenation during elective cesarean section under spinal anesthesia by assessing maternal and neonatal regional cerebral oxygenation ( rSO2 ) with a cerebral oximeter . Methods Ninety parturients were r and omly allocated into three groups : two groups received 5 L/min oxygen by either nasal cannula ( Group NC , n = 30 ) or face mask ( 
    Output:
    
Overall , we found no convincing evidence that giving supplementary oxygen to healthy term pregnant women during elective caesarean section under regional anaesthesia is either beneficial or harmful for either the mother or the foetus ' short-term clinical outcome as assessed by Apgar scores .