許蘭蘭 陸紅明 劉景菁 鄒昌騮
[摘要] 目的 探討程序性簡(jiǎn)短硬膜外給藥技術(shù)聯(lián)合硬膜刺破硬膜外麻醉優(yōu)化技術(shù)在產(chǎn)婦分娩鎮(zhèn)痛中的安全性和有效性。 方法 選取2019年12月至2020年12月在深圳市羅湖人民醫(yī)院和西林縣人民醫(yī)院進(jìn)行分娩鎮(zhèn)痛的產(chǎn)婦110例,采用隨機(jī)數(shù)字表法分為程序性間斷硬膜外給藥組(P組,n=55)和對(duì)照組(C組,n=55),記錄鎮(zhèn)痛前,鎮(zhèn)痛后10、30、60、90 min,第二產(chǎn)程VAS評(píng)分,產(chǎn)婦的心率及MAP、PCEA次數(shù)及產(chǎn)婦剖宮產(chǎn)率、器械助產(chǎn)率、Bromage 評(píng)分、不良反應(yīng)(胎心減速率、低血壓、惡心嘔吐、瘙癢、神經(jīng)功能障礙)、新生兒1 min及5 min Apgar評(píng)分。 結(jié)果 P組在分娩鎮(zhèn)痛后60 min、第二產(chǎn)程的MAP[(74.71±6.84)mmHg,(80.38±6.59)mmHg],第二產(chǎn)程VAS為(1.49±1.12)分、PECA為(3.76±2.21)次,均低于C組鎮(zhèn)痛后60 min的第二產(chǎn)程MAP[(79.31±7.10)mmHg,82.84±5.81)mmHg],第二產(chǎn)程VAS(1.49±1.12)分及PECA次數(shù)(5.29±3.20)次,兩組比較,差異有統(tǒng)計(jì)學(xué)意義(P<0.05);兩組分娩方式、不良反應(yīng)及新生兒Apgar評(píng)分等比較,差異均無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。 結(jié)論 PIEB聯(lián)合DPE技術(shù)對(duì)產(chǎn)婦MAP的影響更大,并且能夠提供更好的第二產(chǎn)程鎮(zhèn)痛效果及更少的藥物使用量,對(duì)產(chǎn)科結(jié)局、運(yùn)動(dòng)神經(jīng)阻滯情況、不良反應(yīng)及新生兒結(jié)局都未產(chǎn)生不良影響。
[關(guān)鍵詞] 硬膜外麻醉;分娩鎮(zhèn)痛;程序性間斷硬膜外給藥;硬脊膜穿破硬膜外麻醉
[中圖分類號(hào)] R715.7? ? ? ? ? [文獻(xiàn)標(biāo)識(shí)碼] B? ? ? ? ? [文章編號(hào)] 1673-9701(2021)30-0128-04
[Abstract] Objective To explore the safety and effectiveness of programmed intermittent epidural bolus (PIEB) combined with optimized dural puncture epidural (DPE) anesthesia in maternal labor analgesia. Methods A total of 110 puerperae who underwent labor analgesia in Shenzhen Luohu People′s Hospital and Xilin People′s Hospital from December 2019 to December 2020 were selected. They were divided into the programmed intermittent epidural bolus group (group P,n=55) and the control group (group C,n=55) by using the random number table method. The scores of Visual Analogue Scale/Score(VAS),heart rate,mean arterial pressure (MAP), number of patient controlled epidural analgesia (PCEA) of puerperae before analgesia, and at 10 min,30 min,60 min and 90 min after analgesia as well as the second stage of labor were recorded.The cesarean section rate, instrument midwifery rate and Bromage score of puerperae, adverse reactions [ARs (the deceleration rate of fetal heart, hypotension, nausea and vomiting, pruritus, neurological dysfunction)], and the Apgar score of the neonates at 1 min and 5 min after birth were also recorded. Results The MAP at 60 min after analgesia and the second stage of labor [(76.29±6.25)mmHg, 80.32±6.59) mmHg], VAS score at the second stage of labor (1.49±1.12)points, and number of PECA (3.76±2.21)times in group P were all lower than those of group C[(79.31±7.10)mmHg,(82.84±5.81)mmHg], (1.49±1.12) points and (5.29±3.20)times, respectively], with statistically significant differences(P<0.05).There were no statistically significant differences between the two groups in mode of delivery, ARs and Apgar scores of the neonates(all P>0.05). Conclusion PIEB combined with DPE technique has a greater effect on MAP of puerperae and can provide better analgesia in the second stage of labor with less drug use. It has no adverse effects on obstetric outcomes, motor nerve block conditions, ARs and neonatal outcomes.
[Key words] Epidural anesthesia; Labor analgesia; Programmed intermittent epidural bolus; Dural puncture epidural anesthesia
生產(chǎn)痛機(jī)制多種多樣,受到心理和生理等方面的多重因素影響,椎管內(nèi)鎮(zhèn)痛被認(rèn)為是分娩鎮(zhèn)痛中最為有效的方法。硬脊膜穿破硬膜外阻滯術(shù)(Dural puncture epidural,DPE)是對(duì)椎管內(nèi)神經(jīng)阻滯的一種技術(shù)改進(jìn),即用脊髓針在硬膜上穿孔,但不用于直接向蛛網(wǎng)膜下腔內(nèi)給藥。近年研究[1-2]發(fā)現(xiàn),硬膜外穿刺術(shù)與傳統(tǒng)硬膜外神經(jīng)阻滯相比較有更快的起效時(shí)間和穩(wěn)定的鎮(zhèn)痛效果,并且對(duì)產(chǎn)婦和新生兒的副作用更小。如何優(yōu)化硬膜外麻醉從而更好的進(jìn)行分娩鎮(zhèn)痛,提高產(chǎn)婦的整體滿意率,減少產(chǎn)程的時(shí)間,降低中轉(zhuǎn)剖宮產(chǎn)率和器械助產(chǎn)率,依然是一個(gè)值得探究的問(wèn)題。程序性間斷硬膜外給藥(Programed intermittent epidural bolus,PIEB)被認(rèn)為可以改善分娩鎮(zhèn)痛效果,提高產(chǎn)婦滿意度[3],將兩種技術(shù)相結(jié)合是否有更多的益處未見(jiàn)相關(guān)的報(bào)道。本文將討論P(yáng)IEB用于DPE對(duì)產(chǎn)婦及新生兒的效果和安全性,現(xiàn)報(bào)道如下。
1 資料與方法
1.1 一般資料
本研究通過(guò)深圳大學(xué)附屬第三醫(yī)院醫(yī)學(xué)倫理委員會(huì)批準(zhǔn),并與患者簽署知情同意書。納入標(biāo)準(zhǔn):選取2019年12月至2020年12月在深圳大學(xué)附屬第三醫(yī)院和西林人民醫(yī)院自愿進(jìn)行分娩鎮(zhèn)痛的產(chǎn)婦110例,美國(guó)麻醉醫(yī)師協(xié)會(huì)(American society of anesthesiologists,ASA)Ⅱ級(jí),孕齡37~45周,胎兒胎心、胎動(dòng)正常。采用隨機(jī)數(shù)字表法分為優(yōu)PIEB組(P組,n=55)和對(duì)照組(C組,n=55)。兩組穿刺成功后予DPE硬膜外分娩鎮(zhèn)痛,維持疼痛視覺(jué)模擬評(píng)分(Visual simulation score,VAS;0 cm為無(wú)痛,10 cm為最大疼痛)VAS<3分。排除標(biāo)準(zhǔn):合并妊娠期高血壓、妊娠期糖尿病者;局麻藥物過(guò)敏;椎管內(nèi)麻醉禁忌證者;剖宮產(chǎn)后陰道分娩者。
1.2 方法
分娩鎮(zhèn)痛前開(kāi)放靜脈通路,備搶救藥品備于床旁。待產(chǎn)科宮口開(kāi)至2~3指時(shí)實(shí)施硬膜外穿刺,穿刺點(diǎn)選擇L2~L3或L3~L4,硬膜外腔穿刺成功后先用27號(hào)腰麻穿刺針刺破硬脊膜到達(dá)蛛網(wǎng)膜下腔,有腦脊液流出后拔掉穿刺針頭向硬膜外腔置管4 cm。兩組均給予1%鹽酸利多卡因注射液(遂成藥業(yè)股份有限公司,國(guó)藥準(zhǔn)字H41023668,批號(hào):1B2007311102,5 mL:0.1 g)3 mL實(shí)驗(yàn)量,無(wú)不良反應(yīng)后給首劑8 mL,藥物配置0.1%鹽酸羅哌卡因注射液(宜昌人福藥業(yè),國(guó)藥準(zhǔn)字H20103636,批號(hào):03B05191,10 mL:100 mg)+0.25 μg/mL枸櫞酸舒芬太尼注射液(宜昌人福藥業(yè),國(guó)藥準(zhǔn)字H20054171,批號(hào):01A07121,50 μg:1 mL),P組接PIEB鎮(zhèn)痛泵,速率設(shè)置為8 mL/45 min,單次8 mL,鎖定時(shí)間15 min,胎兒娩出后停藥。C組接連續(xù)輸注泵,同樣設(shè)置硬膜外藥物注入后,8 mL/45 min,單次8 mL,鎖定時(shí)間15 min。記錄鎮(zhèn)痛前,10 min,30 min,60 min,90 min及第二產(chǎn)程VAS評(píng)分,產(chǎn)婦的心率及血壓,VAS>3分則增加PCEA一次。用改良Bromage法評(píng)定鎮(zhèn)痛前,記錄用藥后10、30、60、90 min及第二產(chǎn)程下肢運(yùn)動(dòng)神經(jīng)阻滯程度。4分為無(wú)運(yùn)動(dòng)阻滯(髖、膝、踝關(guān)節(jié)可充分屈曲);3分為部分阻滯(只能曲膝、踝關(guān)節(jié));2分為大部分阻滯(僅能移動(dòng)踝關(guān)節(jié));1分為完全阻滯(不能移動(dòng)膝關(guān)節(jié)和踝關(guān)節(jié))[4]。完成分娩后,記錄產(chǎn)婦剖宮產(chǎn)率、器械助產(chǎn)率、不良反應(yīng)的發(fā)生率(胎心減速率、低血壓、惡心嘔吐、瘙癢、神經(jīng)功能障礙)及新生兒Aprar評(píng)分(1 min、5 min)。
1.3 觀察指標(biāo)及評(píng)價(jià)標(biāo)準(zhǔn)
①觀察P組和C組鎮(zhèn)痛前、鎮(zhèn)痛后10、30、60、90 min及第二產(chǎn)程VAS評(píng)分,產(chǎn)婦心率和血壓,PCEA次數(shù)。②剖宮產(chǎn)率、器械助產(chǎn)率、Bromage評(píng)分、胎心減速率、低血壓、惡心、瘙癢、神經(jīng)功能障礙、新生兒1 min及5 min Apgar評(píng)分。兩種方法對(duì)產(chǎn)婦產(chǎn)程中疼痛評(píng)分、血流動(dòng)力學(xué)影響為主要研究終點(diǎn),對(duì)不良反應(yīng)、分娩方式等的影響為次要研究終點(diǎn)。
1.4 統(tǒng)計(jì)學(xué)方法
采用SPSS 26.0統(tǒng)計(jì)學(xué)軟件進(jìn)行數(shù)據(jù)分析。正態(tài)分布的計(jì)量資料以均數(shù)±標(biāo)準(zhǔn)差(x±s)表示,采用t檢驗(yàn);偏態(tài)分布的計(jì)量資料以中位數(shù)(四分位間距)[M(Q1,Q3)]表示,采用Mann Whitney U檢驗(yàn);計(jì)數(shù)資料以[n(%)]表示,采用χ2檢驗(yàn);P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
樣本量估計(jì)是基于PIEB和PCEA時(shí)發(fā)生突破性疼痛的發(fā)生率分別為5%、25%[8-9],80%的功效雙向統(tǒng)計(jì)顯著性設(shè)為0.05,每組需要55例產(chǎn)婦。
2 結(jié)果
2.1 兩組產(chǎn)婦一般情況各指標(biāo)比較
兩組產(chǎn)婦一般情況各指標(biāo)比較,差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。見(jiàn)表1。
2.2 兩組產(chǎn)婦鎮(zhèn)痛前、鎮(zhèn)痛后10 min、30 min、60 min、90 min及第二產(chǎn)程VAS評(píng)分、HR、MAP及PCEA次數(shù)比較
P組在分娩鎮(zhèn)痛后60 min,第二產(chǎn)程的MAP為(76.29±6.25)mmHg,(80.38±6.59)mmHg,第二產(chǎn)程VAS(1.49±1.12)分,PECA次數(shù)(3.76±2.21)次,均低于C組鎮(zhèn)痛后60 min,第二產(chǎn)程MAP(79.31±7.10)mmHg,(82.84±5.81)mmHg,第二產(chǎn)程VAS為(1.49±1.12)分及PECA次數(shù)(5.29±3.20)次,兩組比較,差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。見(jiàn)表2。
2.3兩組產(chǎn)婦剖宮產(chǎn)率,器械助產(chǎn)率,不良反應(yīng)和新生兒Apgar評(píng)分比較
兩組產(chǎn)婦剖宮產(chǎn)率、器械助產(chǎn)率、Bromage 評(píng)分、不良反應(yīng)和新生兒Apgar評(píng)分比較,差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。見(jiàn)表3。
3 討論
分娩鎮(zhèn)痛在我國(guó)的需求越來(lái)越廣泛,椎管內(nèi)阻滯依然是最好的選擇。由于第一產(chǎn)程產(chǎn)痛主要是由于子宮壓迫T10~L1的傳導(dǎo)的內(nèi)臟痛。第二產(chǎn)程是由S2~S4介導(dǎo)的軀體痛,而硬膜外麻醉鎮(zhèn)痛效果受局麻藥擴(kuò)散,穿刺位置,硬脊膜粘連情況等因素影響,在單點(diǎn)穿刺置管的情況下鎮(zhèn)痛效果很難覆蓋整個(gè)產(chǎn)程。而腰硬聯(lián)合麻醉(Combined spinal epidural anesthesia,CSEA)麻醉平面不易掌控,對(duì)產(chǎn)婦心血管系統(tǒng)及新生兒副作用較大[5],在1996年suzuki等提出了DPE技術(shù)可以很好的結(jié)合兩者的優(yōu)點(diǎn),而如何在分娩鎮(zhèn)痛中優(yōu)化硬膜外麻醉,提高安全性和鎮(zhèn)痛效果,減少并發(fā)癥,而如何優(yōu)化DPE一直是國(guó)內(nèi)外麻醉醫(yī)生不斷探討的內(nèi)容。無(wú)論在分娩鎮(zhèn)痛中使用CSEA或硬膜外鎮(zhèn)痛,聯(lián)合PIEB、持續(xù)輸注、患者控制硬膜外鎮(zhèn)痛(Patient controlled epidural analgesia,PCEA)技術(shù)在臨床中都得到廣泛應(yīng)用[7]。Delgado等[8]認(rèn)為與連續(xù)硬膜外相比較,PIEB能夠使局麻藥在硬膜外更好的擴(kuò)散,并且45 min的間隔時(shí)間比60 min更加合適。而藥物到達(dá)蛛網(wǎng)膜下腔的阻滯效果取決于硬膜穿刺點(diǎn)的大小、穿刺位置、硬膜外給藥點(diǎn)離穿刺點(diǎn)的距離及兩個(gè)腔室之間的壓力梯度。此外,局麻藥物的的體積和濃度也有一定的影響[9]。
本研究中選取產(chǎn)婦ASAⅡ級(jí)即臨產(chǎn)無(wú)產(chǎn)科相關(guān)并發(fā)癥,無(wú)肥胖、無(wú)煙酒等不良嗜好,自愿要求分娩鎮(zhèn)痛并能配合[10]。結(jié)果表明,PIEB聯(lián)合DPE技術(shù)在第二產(chǎn)程中影響較大,在鎮(zhèn)痛后60 min和第二產(chǎn)程中MAP低于連續(xù)硬膜外輸注,可能是因?yàn)镻IEB在硬膜外造成的腔隙壓力較大,導(dǎo)致更多的局麻藥物進(jìn)入蛛網(wǎng)膜下腔,造成了更廣泛的阻滯。產(chǎn)婦在第二產(chǎn)程由于屏氣用力造成血壓大幅波動(dòng)易導(dǎo)致子癇的發(fā)生,因而控制血壓穩(wěn)定是第二產(chǎn)程重要的策略,特別是合并妊娠期高血壓的患者中尤其重要,而過(guò)去的研究表明,第二產(chǎn)程應(yīng)用PIEB可以降低第二產(chǎn)程產(chǎn)科的血壓[11]。本研究中使用VAS作為疼痛的評(píng)估標(biāo)準(zhǔn),VAS評(píng)分在小樣本研究,正態(tài)分布和極端分布的樣本都被認(rèn)為有良好的統(tǒng)計(jì)學(xué)效力[12]。P組在第二產(chǎn)程MAP和VAS均低于C組,顯然在鎮(zhèn)痛和控制血壓方面,PIEB聯(lián)合DPE更有優(yōu)勢(shì)。同時(shí)在PIEB組中產(chǎn)婦每隔45 min就會(huì)泵入8 mL的局麻藥,大劑量局麻藥物產(chǎn)生的壓力保證了更多的藥物進(jìn)入蛛網(wǎng)膜下,而C組在背景劑量上產(chǎn)生宮縮痛以后追加了PECA,實(shí)際上等于PIEB組的產(chǎn)婦進(jìn)行了超量的鎮(zhèn)痛,從而在第二產(chǎn)程的時(shí)候產(chǎn)生更好的鎮(zhèn)痛效果。實(shí)施分娩鎮(zhèn)痛時(shí),硬膜外導(dǎo)管位置固定,持續(xù)輸注的情況下,反而更容易產(chǎn)生運(yùn)動(dòng)阻滯,相比較下,PIEB技術(shù)在神經(jīng)根處的麻醉藥大劑量包裹后藥物濃度逐漸降低,能夠更好地阻滯感覺(jué)神經(jīng)而不是運(yùn)動(dòng)神經(jīng),降低交感神經(jīng)興奮性[13-14]。
DPE技術(shù)中將硬膜刺破是否會(huì)引起潛在并發(fā)癥等尚存在爭(zhēng)議,近期產(chǎn)科麻醉研究認(rèn)為DPE并沒(méi)有增加胎心減速率、低血壓、惡心嘔吐、硬膜穿破后頭疼的發(fā)病率[15]。本研究中也表明兩組剖宮產(chǎn)率器械助產(chǎn)率、Bromage評(píng)分、不良反應(yīng)及新生兒的Apgar評(píng)分方面比較,差異無(wú)統(tǒng)計(jì)學(xué)意義,并且P組PECA次數(shù)明顯少于C組,減少舒芬太尼和羅哌卡因的用量。Apgar評(píng)分較低的嬰兒,特別是在5 min和小于5 min時(shí),新生兒死亡率、新生兒感染、窒息相關(guān)并發(fā)癥、呼吸窘迫和新生兒低血糖的比值比較高[16]。最近的一個(gè)Meta分析中表明低濃度局麻藥方案(Low concentration local anesthetics,LCLA)(布比卡因濃度≤0.1%或羅哌卡因濃度≤0.17%)和持續(xù)的使用硬膜外鎮(zhèn)痛并不會(huì)延長(zhǎng)第二產(chǎn)程的時(shí)間也不會(huì)增加剖宮產(chǎn)率和器械助產(chǎn)率,對(duì)產(chǎn)婦和新生兒未造成不良影響[17-18]。Willfurth等[19]認(rèn)為產(chǎn)科麻醉對(duì)于新生兒的SpO2和HR是有一定影響的,但是并不影響腦氧和Apgar評(píng)分。
綜上所述,PIEB聯(lián)合DPE技術(shù)對(duì)產(chǎn)婦MAP的影響更大,并且能夠提供更好的第二產(chǎn)程鎮(zhèn)痛效果及更少的藥物使用量,對(duì)產(chǎn)科結(jié)局、運(yùn)動(dòng)神經(jīng)阻滯情況、不良反應(yīng)及新生兒結(jié)局都未產(chǎn)生不良影響。本研究樣本量有限,分娩鎮(zhèn)痛的鎮(zhèn)痛時(shí)間長(zhǎng),影響因素復(fù)雜,PIEB和DPE技術(shù)的安全性和在分娩鎮(zhèn)痛中如何優(yōu)化仍然是繼續(xù)值得探討的話題。
[參考文獻(xiàn)]
[1] Chau A,Bibbo C,Huang CC,et al. Dural puncture epidural technique improves labor analgesia quality with fewer side effects compared with epidural and combined spinal epidural techniques:A randomized clinical trial[J].Anesth Analg,2017,124:560-569.
[2] Wilson SH,Wolf BJ,Bingham KN,et al. Labor analgesia onset with dural puncture epidural versus traditional epidural using a 26-gauge Whitacre needle and 0.125% bupivacaine bolus:A randomized clinical trial[J]. Anesth Analg,2018, 126:545-551.
[3] Sng BL,Zeng Y,de Souza NNA,et al. Automated mandatory bolus versus basal infusion for maintenance of epidural analgesia in labour[J].Cochrane Database Syst Rev,2018,17(5):CD011 344.
[4] Craig D,Carli F. Bromage motor blockade score-a score that has lasted more than a lifetime[J].Can J Anesth/J Can Anesth,2018,65(7):837-838.
[5] 盧園園,蔡嘉靖,李軍,等.硬脊膜穿破硬膜外阻滯在產(chǎn)婦分娩鎮(zhèn)痛中的應(yīng)用[J].中華醫(yī)學(xué)雜志,2020,100(5):363-366.
[6] 晏明,張玉鳳,孫劍,等.硬脊膜穿破硬膜外阻滯在分娩鎮(zhèn)痛中的應(yīng)用[J].國(guó)際麻醉學(xué)與復(fù)蘇雜志,2020,41(8):763-768.
[7] Lim Y,Ocampo CE,Supandji M,et al. A randomized controlled trial of three patient-controlled epidural analgesia regimens for labor[J]. Anesthesia and Analgesia,2008, 107:1968-1972.
[8] Delgado C,Ciliberto C,Bollag L,et al. Continuous epidural infusion versus programmed intermittent epidural bolus for labor analgesia:Optimal configuration of parameters to reduce physician-administered top-ups[J]. Curr Med Res Opin,2018,34:649-656.
[9] Kocarev M,Khalid F,Khatoon F,et al. Neuraxial labor analgesia:A focused narrative review of the 2017 literature[J]. Current Opinion in Anaesthesiology,2018,31(3):251-257.
[10] Erin E,Hurwitz MD,Michelle Simon,et al. Adding examples to the ASA-physical status classification improves correct assignment to patients[J]. Anesthesiology,2017, 126(4):614-622.
[11] Wang X,Xu S,Qin X,et al. Comparison between the use of ropivacaine alone and ropivacaine with sufentanil in epidural labor analgesia[J].Medicine (Baltimore),2015, 94(43):1882.
[12] Gillian Z. Heller,Maurizio Manuguerra,Roberta Chow,et al. How to analyze the visual analogue scale: Myths, truths and clinical relevance[J].Scandinavian Journal of Pain,2016,13(1):67-75.
[13] Zakus P,Arzola C,Bittencourt R,et al. Determination of the optimal programmed intermittent epidural bolus volume of bupivacaine 0.0625% with fentanyl 2 μg/mL at a fixed interval of forty minutes:A biased coin upand-down sequential allocation trial[J].Anaesthesia,2018,73:459-465.
[14] Roofthooft E,Barbé A,Schildermans J,et al. Programmed intermittent epidural bolus vs.patient-controlled epidural analgesia for maintenance of labour analgesia:A two-centre,double-blind, randomised study[J].Anaesthesia,2020,75(12):1635-1642.
[15] Chau A,Bibbo C,Huang CC,et al.Dural puncture epidural technique improves labor analgesia quality with fewer side effects compared with epidural and combined spinal epidural techniques:A randomized clinical trial[J].Anesth Analg,2017,124(2):560-569.
[16] Razaz N,Cnattingius S,Joseph KS.Association between Apgar scores of 7 to 9 and neonatal mortality and morbidity: population based cohort study of term infants in Sweden[J].BMJ (Clinical Research ed.),2019,365:11 656.
[17] Wang TT,Sun S,Huang SQ.Effects of epidural labor analgesia with low concentrations of local anesthetics on obstetric outcomes:A systematic review and meta-analysis of randomized controlled trials[J].Anesth Analg,2017, 124:1571-1580.
[18] Shen X,Li Y,Xu S,et al. Epidural analgesia during the second stage of labor:A randomized controlled trial[J].Obstet Gynecol,2017,130:1097-1103.
[19] Willfurth I,Baik-Schneditz N,Schwaberger B,et al. Cerebral oxygenation in neonates immediately after cesarean section and mode of maternal anesthesia[J].Neonatology,2019,116(2):132-139.
(收稿日期:2021-02-19)