Presentation on theme: "Patient-Controlled Epidural Analgesia for Labor"— Presentation transcript:
1 Patient-Controlled Epidural Analgesia for Labor Obstetric Anesthesiology(Anesth Analg 2009;108:921–8)R2 한 진 희
2 PCEA vs continuous epidural infusion (CEI) patient-controlled epidural analgesia(PCEA) for labor: Gambling et al.1 in 1988PCEA vs continuous epidural infusion (CEI)1. analgesia : similar2. PCEA reduces the incidence of unscheduled clinician interventions3. total dose of local anesthetic 감소4. reduces the incidence of lower extremity motor block5. no clinically significant impact on obstetric or neonatal outcomes
3 Clinical research has focused on refining PCEA techniques 1. further improve analgesia2. reduce motor block3. increase maternal satisfaction4. reducing the frequency of unscheduled clinician interventions1) Should a background infusion be used?2) Is ropivacaine superior to bupivacaine when used for PCEA in labor?3) Can the volume of the PCEA bolus dose and lockout interval be manipulated to optimize analgesia?4) What is the impact of new techniques and technologies on current PCEA practice?
4 THE USE OF BACKGROUND INFUSION seven studies : PCEA with and without background infusionsthe infusion rates : quite low, with most <5 mL/h.one study found a difference in analgesia:: without a background infusion a higher incidence of intense pain (>4/10)all of these studies : Significant motor block was uncommonTwo studies : more clinician interventions in the no infusion group.One study : more local anesthetic in the no infusion groupmaternal satisfaction : no differences
6 summary background infusion 1. reduces the incidence of unscheduled clinician interventions2. improve patient analgesia3. no increase in motor block associated with the background infusion.
7 ROPIVACAINE VS BUPIVACAINE 11 studieswide range of PCEA settings.Bupivacaine : 0.05% ~ 0.125%.Ropivacaine : 0.05% ~ 0.20%.Two studies : used different concentrations reflect differences in potencyfive studies : bupivacaine increased incidence of motor block: However, most studies did not account for relative differences in potency between ropivacaine and bupivacaineHalpern et al : Maternal satisfaction: mobility - ropivacaine group: analgesia at delivery - bupivacaine groupFischer et al.: relief of contraction and delivery pain in bupivacaine
10 Summary both ropivacaine and bupivacaine : well suited for PCEA in labor.an increased incidence of motor block in bupivacainebut this difference may not be clinically significant,particularly for short labors.Flexibility in the PCEA settings may offset any advantage that drug selection may have.
11 BOLUS DOSE VOLUME AND LOCKOUT INTERVAL Six studies : compared various PCEA settings : try to determine the ideal bolus dose and corresponding lockout time intervalAnalgesia, maternal satisfaction, motor block, and clinician rescue boluses were reported in all of the studies.bupivacaine (0.0625%–0.125%) and ropivacaine (0.1%–0.2%) with fentanyl or sufentanil.Bolus volumes ( 2 ~ 20 mL ) , lockout intervals (5 ~ 30 min)
12 Three studies used a background infusion Bernardet al:Group 1: bolus 4 mL, lockout 8 minGroup 2: bolus 12 mL, lockout 25 min: Significantly better analgesia in Group 2All study: no significant difference in unscheduled clinician interventions: Significant motor block was uncommon: no reports of toxicity or increased side effects with the larger bolus volumes
14 Summary no ideal bolus dose or lockout interval setting for labor PCEA Large bolus doses of dilute local anesthetic superior analgesia and maternal satisfaction
15 DRUG CONCENTRATION Six studies three studies : The more concentrated solution groups significantly greater motor blockTwo studies : less pruritus with local anesthetic without opioidsuse of dilute local anesthetic solutions with opioids for labor PCEA less local anesthetic consumption less motor block without compromising labor analgesiamore dilute solutions also used larger volumes improve analgesia more uniform anesthetic spread in the epidural spaceaddition of lipophilic opioids to local anestheticsreduction in the minimum local analgesic concentration of bupivacaineimproves the quality of analgesiabut, lipophilic opioids dose dependent pruritus
17 summary labor PCEA : dilute local anesthetic solutions should be used. The use of 0.25% bupivacaine and 0.2% ropivacaine: increased incidence of motor blockade without concomitantincreases maternal analgesia or satisfaction.avoid excessive pruritus The lowest, clinically effective, concentration of lipophilicopioid should be added
18 FUTURE DEVELOPMENTS Computer-Integrated PCEA automatically adjusts the background infusion rate based on the number of PCEA demandsadjusts the background infusion to 5, 10, or 15 mL/h If the patient require one, two, or three demand bolusesdecreases the background infusion by increments of 5 mL/h if there are no bolus demands in the previous hourimprove efficacy while minimizing increases in local anesthetic use-associated background infusionshad similar local anesthetic consumption compared with demand-only PCEA but was associated with increased maternal satisfactionnot currently commercially available
19 Programmed Intermittent Mandatory Epidural Boluses (PIEB) Same total hourly amount of local anesthetic is administered as intermittent boluses(e.g., two boluses of 6mL every 30 min vs 12 mL/h CEI)more effective for labor analgesia-similar analgesia-higher maternal satisfaction-less need for unscheduled clinician rescue bolusesthe local anesthetic-sparing effect of PIEB more uniform epidural spread of local anesthetics when large volumes of local anestheticreduced consumption of ropivacaine and less PCEA demand boluses while maintaining similar analgesic efficacycurrently not available
20 Disposable Epidural PCEA simple disposable PCEA vs standard electronic PCEA deviceno significant differences in analgesic efficacy, maternal satisfaction, local anesthetic use, or side effectsless bulky, may facilitate ambulation during labordisadvantages : the lack of programmability and potentially increased costs.
21 SUMMARY PCEA-reliable and effective method Low concentrations of bupivacaine or ropivacaine with opioids excellent analgesiausing dilute local anesthetic solutions (up to 0.125% bupivacaine or 0.2% ropivacaine) Motor block can be minimizedBackground infusion reduces the need for unscheduled clinician interventions better analgesiaBackground infusion rates ( 2 ~ 10 mL/h) : effectivelyno ideal bolus dose or lockout interval setting for labor PCEALarger bolus doses (more than 5 mL) of dilute local anesthetic: superior analgesia