***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: UNLABELLED We studied the in vitro effects of sevoflurane , isoflurane , and propofol anesthesia on platelet function .  Thirty patients undergoing minor surgical procedures were divided into three groups ( n = 10 each ) . Induction of anesthesia was achieved by using 5 mg/kg thiopental i.v . , and 0.1 mg/kg vecuronium i.v . was used for muscle relaxation . Anesthesia maintenance was provided by sevoflurane in the first , isoflurane in the second , and propofol infusion in the third group with 70 % N2O in O2 .  Hemoglobin , hematocrit , thrombocyte count , prothrombin time , activated partial thromboplastin time , international normalized ratio , arterial pH , von Willebr and factor , viscosity , platelet aggregation , and bleeding time were measured 1 h pre- , intra- , and postanesthesia . There was no difference among the platelet aggregation ratios of the pre- , intra- , and postoperative periods in the isoflurane group . The aggregation ratios in the sevoflurane and propofol groups were significantly reduced at intraoperative periods compared with preoperative values . Diminished aggregation values were also found 1 h postoperatively compared with the control values in the sevoflurane and propofol groups . We conclude that , in patients with a bleeding tendency during the intra- and early postoperative period , isoflurane may be preferred as a general anesthetic . IMPLICATION S In our study , using vacuum-operated tubes , we demonstrated that sevoflurane and propofol had a significant inhibitory effect on intraoperative and early postoperative platelet aggregation , whereas isoflurane had no effect . Therefore , isoflurane may be preferred as a general anesthetic in patients with a clinical ly relevant bleeding tendency SUMMARY The addition of 0.5 per cent of halothane vapour to a basic thiopentone , nitrous oxide , muscle relaxant anaesthetic technique does not increase blood loss at Caesarean section , does not affect the incidence of hypotension , and is likely to ensure unconsciousness . By permitting the administration of 50 per cent of oxygen with nitrous oxide , the condition of the newborn infant is likely to be improved . The use of 0.8 per cent of halothane vapour does not increase blood loss but is associated with a high incidence of hypotension and for this reason is not advisable Objective To determine the surgical and anaesthetic benefits and problems associated with the practice of routine exteriorisation of the uterus to facilitate repair at caesarean section Background There are no r and omized studies on neonatal outcome after spinal versus general anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace . This study examined both markers of neonatal hypoxia and maternal hemodynamics . Methods Seventy patients were r and omized to general ( n = 35 ) or spinal anesthesia ( n = 35 ) . The general anesthesia group received thiopentone , magnesium sulfate , and suxamethonium intravenously before intubation , followed by 50 % nitrous oxide in oxygen , 0.75–1.5 % isoflurane , and morphine after delivery . The target end-tidal partial pressure of carbon dioxide ( Pco2 ) was 30–34 mmHg . The spinal anesthesia group received 1.8 ml hyperbaric bupivacaine plus 10 & mgr;g fentanyl at the L3–L4 interspace . Heart rate and blood pressure were measured at specific time points . Hypotension was treated with ephedrine .  Maternal arterial and neonatal umbilical arterial blood gas sample s were taken at delivery . Resuscitation requirements were recorded . Results In both groups , hemodynamic measures remained within acceptable limits . Spinal anesthesia patients required more ephedrine ( 13.7 vs. 2.7 mg ) . Maternal Paco2 was lower in the spinal group ( 28.9 vs. 32.4 mmHg ) . One-minute Apgar scores were lower after general anesthesia . Base deficit was greater ( 7.13 vs. 4.68 mEq/l ) and neonatal umbilical arterial pH was lower ( 7.20 vs. 7.23 ) after spinal anesthesia . Post hoc analysis showed that if maternal diastolic blood pressure on admission was greater than 110 mmHg , neonatal umbilical arterial base deficit was greater after spinal anesthesia . There was no difference in the number of patients with Apgar scores less than 7 at 1 or 5 min or umbilical arterial pH less than 7.2 or in the requirements for resuscitation . Conclusions In preeclamptic patients with a nonreassuring fetal heart trace , spinal anesthesia for cesarean delivery was associated with a greater mean neonatal umbilical arterial base deficit and a lower median umbilical arterial pH. The clinical significance remains to be established . Maternal hemodynamics were similar and acceptable with either anesthetic technique Objective To evaluate the maternal and fetal effects of three anesthetic methods used r and omly in women with severe preeclampsia who required cesarean delivery . Methods Eighty women with severe preeclampsia , who were to be delivered by cesarean , were r and omized to general ( 26 women ) , epidural ( 27 ) , or combined spinalepidural ( 27 ) anesthesia .  The mean preoperative blood pressure ( BP ) was approximately 170/110 mmHg , and all women had proteinuria . Anesthetic and obstetric management included antihypertensive drug therapy and limited intravenous ( IV ) fluid and drug therapy . Results The mean  gestational age  at delivery was 34.8 weeks . All infants were born in good condition  as assessed by Apgar scores and umbilical arterial blood gas determinations . Maternal hypotension result ing from regional anesthesia was managed without excessive IV fluid administration . Similarly , maternal BP was managed without severe hypertensive effects in women undergoing general anesthesia . There were no serious maternal or fetal complications attributable to any of the three anesthetic methods . Conclusion General as well as regional anesthetic methods are equally acceptable for cesarean delivery in pregnancies complicated by severe preeclampsia if steps are taken to ensure a careful approach to either method There are few consistent guidelines in choosing anesthesia for cesarean section for a parturient with placenta previa . This prospect i ve r and omized trial was organized to compare the maternal hemodynamics , blood loss and neonatal outcome of general versus epidural anesthesia  for cesarean section with the diagnosis of grade 4 placenta previa . After giving informed consent , 12 patients received general anesthesia and 13 received epidural .  Intraoperative blood pressures demonstrated a more stable course in the epidural group than in the general group . Blood loss did not differ significantly between the groups ( 1622 + /- 775 mL vs. 1418 + /- 996 mL ) . General anesthesia result ed in lower immediate postoperative hematocrit level ( 28.1 + /- 3.5 % vs. 32.5 + /- 5.0 % , P < 0.05 ) . The patients in the general group received a significantly larger transfusion than the epidural group ( 1.08 + /- 1.6 vs. 0.38 + /- 0.9 units , P < 0.05 ) . The Apgar scores at 1 and 5 min were similar in the two groups ( 8 [ 4 - 9 ] vs. 8 [ 7 - 9 ] and 10 [ 6 - 10 ] vs. 9 [ 9 - 10 ] , respectively ) . We concluded that epidural anesthesia is superior to general anesthesia in elective cesarean section for grade 4 placenta previa with regard to maternal hemodynamics and blood loss . There was no difference in neonatal outcome BACKGROUND The risks associated with allogeneic blood transfusion are increasingly recognized . More blood is cross-matched for moderate blood loss surgery than any other indication . The role of acute normovolemic hemodilution ( ANH ) as a blood transfusion strategy was evaluated in a prospect i ve r and omized controlled trial . STUDY DESIGN AND METHODS A total of 155 patients undergoing elective hip surgery were r and omly assigned to either " ANH " ( n = 78 ) or " st and ard transfusion " ( n = 77 ) . ANH on induction of anesthesia was to a target hemoglobin ( Hb ) level of 110 g per L with return of autologous blood on wound closure . Allogeneic blood was prescribed by an objective transfusion trigger based on an Hb level of less than 80 g per L. Transfusion requirements and postoperative complications were recorded . RESULTS  Allogeneic transfusion  was necessary in 22 ( 29 % ) st and ard transfusion patients and 15 ( 19 % ) ANH ( odds ratio [ OR ] , 0.6 ; 95 % CI , 0.28 - 1.3 ; p = 0.23 ) with 63 and 33 units transfused , respectively ( p = 0.1 ) . Significant postoperative complications occurred in 30 ( 38 % ) st and ard transfusion patients compared with 14 ( 18 % ) of those r and omly assigned to ANH ( OR , 0.3 ; 95 % CI , 0.14 - 0.65 ; p = 0.009 ) . The major difference between the groups was the frequency of infective complications . CONCLUSION Despite modest allogeneic transfusion requirements in hip surgery , ANH reduced postoperative complications OBJECTIVE A prospect i ve r and omized trial was organized to compare the effectiveness of general and regional anesthesia for cesarean section ( C/S ) . METHOD Three hundred and forty-one patients were r and omized into the general anesthesia group ( GA ) , epidural anesthesia group ( EA ) and spinal anesthesia group ( SA ) . The effectiveness of interest was success rate , blood loss and patient satisfaction . RESULT We found that the success rates of EA and SA were lower than GA . Success in EA should be improved by using an epidural catheter to add more local anesthetic drug instead of a single shot ; and the surgeon should allow more time for the block to work adequately . Success in SA should be improved by using bupivacaine instead of lidocaine . GA result ed in significantly more blood loss , lower postoperative hematocrit , and higher proportion of patients who had postoperative hematocrit < 30 per cent than EA and SA . The patients ' satisfaction scores were not different among the 3 techniques . This meant that , given adequate explanation and perioperative care , Thai women were satisfied with regional anesthesia . CONCLUSION Regional anesthesia is a better choice of anesthesia for C/S than general anesthesia . However , the availability of different techniques and ability to change the technique when needed were very useful and important . If GA is chosen , all safety procedures must be followed . Oxygen supplement and endotracheal intubation facilities must be available in all techniques . Guidelines of anesthesia for C/S at a national level should be agreed upon , including the type of personnel , monitoring equipment and postoperative care Summary : A prospect i ve study was conducted to compare the accuracy of visual estimation of blood loss ( EBL )  at delivery with laboratory determination of measured blood loss ( MBL ) . It showed that EBL tends to be clouded by the conventional teaching that blood loss at delivery is usually between 200 to 300 mL. Women with MBL up to 150 mL were overestimated and the best correlation was in women with MBL between 150 to 300 mL. There was a tendency to underestimate blood loss when the MBL was between 301 to 500 mL. Of the 9 women with a primary postpartum haemorrhage , only one was correctly diagnosed as such and 3 women were estimated to have blood losses of at least 500 mL but the measured blood losses were all lower . It was concluded that  visual estimation of blood loss is inaccurate , especially at the extremes of MBL and that primary postpartum haemorrhage is not detected by visual estimation of blood loss , unless there are associated signs of haemodynamic instability 
    Output:
    
Based on RCTs , there was no significantly increased risk of blood transfusions with general anaesthesia .
The incidence of hypotension and the amount of fluid given were higher in the neuraxial anaesthesia groups .
General anaesthesia is associated with a higher blood loss than neuraxial anaesthesia .
However , based on high- quality studies , the need for blood transfusion was not greater .
The higher blood loss with general anaesthesia is therefore of uncertain clinical relevance