分娩镇痛进展课件

分娩镇痛进展,天津医科大学总医院 王国林 2006-4 合肥,1847年苏格兰产科医生Simpson J给分娩产妇吸入乙醚以缓解疼痛，得出的印象是药物可以缓解分娩痛，但同时要关注其副作用，包括对子宫收缩、腹部肌张力以及对胎儿的影响,Epidural analgesia in labour is used by about 100 000 women in Britain each year,BMJ 2002;325:357,分娩痛产生的机制,理想的分娩镇痛,dramatically reduce the pain of labour, while allowing the parturient to actively participate in the birthing experience. In addition, it should have minimal effect on the fetus or the progress of labour,Regional analgesia for labour,spinal opiates and combined spinal-epidural (CSE) analgesia patient controlled epidural analgesia continuous spinal analgesia,neuraxial blockade (epidural, spinal, CSE, continuous spinal) provides the most effective and least depressant analgesia Epidural analgesia via a catheter technique provides excellent pain relief and the ability to extend the duration of the block to match the duration of labour, but it is not “instant“ in onset and may be associated with motor block.,One-shot spinal analgesia using a lipid soluble opioid is rapid and simple, but is associated with a limited duration of action The combination of epidural and spinal anesthesia into one technique, termed “CSE“ provides the advantages of a spinal (speed of onset, lack of motor block) with the additional flexibility of renewal with an epidural catheter.,CSE can be safely used to provide labour analgesia in parturients who are to receive an epidural for labour specific patients who will greatly benefit from this technique. These include patients in early or late labour,early labour can be made comfortable with spinal narcotics (such as sufentanil or fentanyl) which will last for approximately two to three hours, during which time the patient will not have a motor block and will be able to ambulate. advantage of CSE for patients in late labour is the almost immediate pain relief,CSE allows for ambulation of the parturient, it has been called the “walking epidural.“ A recent study has evaluated CSE and “mobile epidurals“ and has concluded that CSE provides better pain relief in the early stages after insertion,Anesthesiology 2002; 97: 156775,CSE analgesia for labour is usually achieved using a short-acting lipid soluble narcotic such as fentanyl or sufentanil morphine has been described as an intrathecal opiate for labour, it has several disadvantages including slow onset, incomplete analgesia, prolonged nausea and pruritus, and delayed respiratory depression,pruritus is associated with lipid soluble opioids, it is usually mild and short lived and does not generally need to be treated A review of the complications associated with CSE has concluded that CSE is as safe a technique as a conventional epidural technique and is associated with greater patient satisfaction,Norris MC et al. Anesth Analg 1995; 79: 52937,opioids are most often used to produce analgesia in the labouring patient: sufentanil 2.5 to 10 g; fentanyl 10 to 25 g.,In cases where the second stage of labour is imminent, the subarachnoid administration of a combination of local anesthetic plus opioid should be considered combination of sufentanil 2.5 to 5 g plus bupivacaine 2.5 mg provides rapid analgesia without motor block, alleviates the pain of the second stage of labour, and lasts longer than sufentanil alone.,Anesth Analg 1995; 81: 3059,Effects of Epidural Analgesia on Labor and Maternal and Infant Outcomes,Am J Obstet Gynecol 2002;186(Suppl 5):S31-68. Am J Obstet Gynecol 2002;186(Suppl 5):S69-77.,TABLE 1 Effects of Epidural Analgesia on Labor and Maternal and Infant Outcomes,Labor factors,Outcome*,P value,Possible complications and side effects of intrathecal opioids for labour,CSE has been reported to be as safe as conventional epidural techniques pruritus; nausea/vomiting; hypotension; urinary retention; uterine hyperstimulation and fetal bradycardia; maternal respiratory depression.,Uterine hyperstimulation/fetal bradycardia spinal opioids, perhaps due to their associated decrease in maternal catecholamines, may precipitate uterine hypertonicity and fetal bradycardia,Postdural puncture headache (PDPH) use of small bore “atraumatic“ spinal needles will reduce the incidence of PDPH in patients receiving CSE to approximately 1% or less. incidence of unintentional dural puncture is less in CSE patients than in patients receiving conventional epidurals possible explanation for this finding is that, as part of the CSE technique, the spinal needle may be used for verification of correct placement of the epidural needle when there is inconclusive loss of resistance.,Subarachnoid migration of the epidural catheter almost impossible to pass an epidural catheter through a single dural hole made by a 25 g spinal needle Special epidural needles with a separate port for the spinal needle are now available and should totally prevent the unintentional subarachnoid threading of the epidural catheter Regardless of needle used, all epidural doses should be incremental.,Respiratory depression Sufentanil and fentanyl-induced central respiratory depression have been reported but are extremely rare This respiratory depression occurs acutely and therefore any patient receiving CSE must be appropriately monitored for signs of respiratory depression for a period of at least 20 min following administration of the subarachnoid opioid.,Anesthesiology 1994; 81: 5112,硬膜外阻滞应用的时机,多数研究显示，过早采用硬膜外阻滞可以增加剖宫产率和器械助产的机率。 美国妇产科医师协会推荐：如果情况允许，应该等宫口开至45cm再采用硬膜外阻滞行分娩镇痛，其他的镇痛措施也应该在这一时机应用，目的是减少剖宫产及器械助产率 这一观点也在改变,Timing of Epidural Analgesia during Labor,Most observational studies show higher rates of cesarean delivery with early administration of epidural analgesia three randomized studies specifically comparing the initiation of epidural analgesia at different degrees of cervical dilatation in nulliparous(初产妇) women found no difference in the rate of cesarean delivery or instrument-assisted vaginal delivery between women in whom analgesia was initiated early and those in whom it was initiated late,Effect of Epidural Analgesia on Maternal Temperature and the Newborn,Epidural anesthesia in nonobstetrical patients is generally associated with a decrease in body temperature. Epidural anesthesia causes vasodilatation in the anesthetized dermatomes, which leads to a redistribution of heat from the core to the periphery, resulting in a net decrease in body temperature,In contrast, observational and randomized studies demonstrate that epidural analgesia during labor is often associated with an increase in maternal body temperature to over 100.4F (38.0C),a randomized trial in which fever was reported, an additional 11 percent of women receiving epidural analgesia became febrile during labor (15 percent, vs. 4 percent of women who received no epidural analgesia), and the proportion of the population affected was even greater among nulliparous women (24 percent vs. 5 percent),Many investigators believe the association of epidural analgesia with fever is probably attributable to noninfectious causes, such as an alteration in the production and dissipation of heat resulting from epidural analgesia,Fasting during Labor and Delivery,recent data from the United States indicate that for every 10 million births, seven women die from aspiration. Advances in analgesia permit the liberalization of requirements for fasting during labor,Anesthesiology 1997;86:277-284,practice guidelines of the American Society of Anesthesiologists recommend limited amounts of clear fluid during labor recent study demonstrating that the use of isotonic sport drinks during labor has the potential to decrease the risk of maternal ketosis associated with starving without increasing gastric volume or the risk of nausea and vomiting,Anesth Analg 2002;94:404-408,其他方法,人工辅助(Continuous labor support provided by a doula) 温水浴法 注射无菌水： 体位、按摩,Intradermal injections of 0.1 mL of sterile water in the treatment of women with back pain during labor. Sterile water is injected into four locations on the lower back, two over each posterior superior iliac spine (PSIS) and two 3 cm below and 1 cm medial to the PSIS. The injections should raise a bleb below the skin. Simultaneous injections administered by two clinicians will decrease the pain of the injections.,Other advances in labour analgesia,Continuous infusion of dilute local anesthetic plus opioid,routine use of continuous infusion of dilute local anesthetics plus lipid soluble opioids by continuous infusion provided better pain relief while producing less motor block drug concentrations have been tested and continuous infusions have been demonstrated to be safe for both mother and neonate,Int J Obstet Anesth 1993; 2: 634.,0.0625% bupivacaine with 2 g mL1 fe