Table 1.
Characteristic of included studies.
| Author | No. of patients (PIEB/CEI) | Country | PIEB group | CEI group | Outcomes | Jadad score |
| A. Ojo 2020 | 61/59 | USA | 6-mL programmed intermittent epidural boluses every 45 min | Continuous epidural infusion at 8 mL/h | Patient-controlled epidural analgesia consumption per hour, a need for physician interventions, patterns of patient-controlled epidural analgesia use, motor blockade, number of patients who developed hypotension, pain scores, duration of second stage of labor, mode of delivery, and maternal satisfaction | 4 |
| Capogna 2011 | 75/70 | Italy | Levobupivacaine 0.0625% with sufentanil 0.5 g/mL, after an initial epidural loading dose of 20 mL, 10 mL every hour beginning 60 min after the initial dose | Levobupivacaine 0.0625% with sufentanil 0.5 g/mL, 10 mL/h, beginning immediately after the initial dose | Total dose of levobupivacaine/total dose of sufentanil/patients requiring PCEA boluses/PCEA boluses for each patient/motor block occurred at least once/motor block occurred/instrumental delivery/cesarean delivery | 4 |
| Chua 2004 | 21/21 | Singapore | 0.1% ropivacaine and fentanyl 2 μg/mL, 5 mL boluses were given hourly, with the first bolus 30 min postinduction | 0.1% ropivacaine and fentanyl 2 μg/mL, at the rate of 5 mL/h was initiated in the minute after CSE | Duration of analgesia/need for supplemental analgesia/hourly consumption of epidural bupivacaine + fentanyl solution/sensory block/motor block | 4 |
| Fan 2019 | 1454/1411 | China | Hourly PIEB dose of 10 mL was given starting 75 min post the loading dose | Maintained at a constant speed of 10 mL/h for CEI group | Baseline demographic characteristics of epidural labor analgesia patients; incidence of maternal fever; visual analog scale pain scores over time; epidural sensory levels over time; epidural, obstetric, and neonatal outcomes | 4 |
| Fang 2016 | 100/100 | China | In the PIEB group, the background infusion dose was 8mL/h, the administration rate was 6mL/min, and the dose was once an hour | The CEI group was continuously administered at a rate of 8 mL/h | Baseline characteristics; pain VAS Score at various time points; the duration and interval of uterine contractions, fetal heart rate, labor analgesia time, delivery method, and ratio of oxytocin use in the 2 groups | 2 |
| Feng 2014 | 66/66 | China | A bolus dose (10 mL of 0.08% ropivacaine + 0.4 μg/mL sufentanil) was manually administrated once an hour | A bolus dose (10 mL of 0.08% ropivacaine + 0.4 μg/mL sufentanil) was manually administrated at a constant rate of 10 mL/h | Cervical dilatation/sensory block levels/apgar score/number of epidural boluses/consumption of ropivacaine, sufentanil/neonatal weight/instrumental delivery/duration of analgesia, labor/artificial rupture of membranes/rupture of the membranes to delivery/number of vaginal examinations | 4 |
| Fettes 2006 | 20/20 | UK | An infusion of ropivacaine 2 mg/mL with fentanyl 2 mg/mL at hourly boluses of 10 mL | An infusion of ropivacaine 2 mg/mL with fentanyl 2 mg/mL at 10 mL/h | Caesarean section/first stage of labour second stage of labour/duration of epidural/ VAS pre-epidural/ropivacaine dose/epidural bolus given/2 epidural boluses or more/cervical dilatation | 3 |
| Fidkowski 2019 | 41/34 | USA | Epidural analgesia regimen of bupivacaine 0.125% with fentanyl 2 μg/mL at PIEB 10 mL every 60 min | Epidural analgesia regimen of bupivacaine 0.125% with fentanyl 2 μg/mL at 10 mL/h continuous infusion | Average pain scores; demographic data; vaginal delivery; cesarean delivery; duration epidural analgesia; maximum bromage score; lowest dermatomal sensory level; physician administered epidural bolus; patient satisfaction | 4 |
| Haidl 2020 | 75/75 | Norway | PIEB + PCEA (5 mL bolus every hour, 5 mL PCEA bolus lockout 20 min) using a solution of bupivacaine 1mg/mL, fentanyl 2 mcg/mL, and adrenaline 2 mcg/mL | CEI + PCEA (5 mL/h, 5 mL PCEA bolus, lockout 20 min) using a solution of bupivacaine 1mg/mL, fentanyl 2 mcg/mL, and adrenaline 2 mcg/mL | Baseline characteristics; total epidural solution consumption; No. of completed PCEA boluses;/rejected PCEA boluses/participants needing any further physician intervention/physician administered manual boluses of the study epidural solution/rescue bupivacaine boluses/supplemental spinal injections/unilateral epidural effect/new epidural catheter; time from epidural placement to birth (min); modified bromage score at 60 min; modified bromage score at delivery; mode of delivery; hypotension; nausea; pruritus; satisfaction with treatment | 4 |
| Ji 2016 | 25/25 | China | Epidural boluses of LA 8 mL each 60 min | Maintained at a constant speed of 8 mL/h | Baseline characteristics, gestational age, uterine orifice size before analgesia, and artificial membrane rupture rate between the 2 groups; comparison of the time for maternal block level to reach T10, PCEA usage and breakthrough pain; pain VAS score at various time points; maternal delivery and newborn Apgar score | 2 |
| Leo 2010 | 31/31 | Singapore | 0.1% ropivacaine + fentanyl 2 μg/mL, automated mandatory boluses of 5 mL/h | 0.1% ropivacaine + fentanyl 2 μg/mL, basal continuous infusion of 5 mL/h | Hourly consumption of ropivacaine/sensory block/pain scores/duration of labor, 2nd stage/mode of delivery/apgar scores/satisfaction/shivering/pruritus/nausea/vomiting/breakthrough pain/cervical dilation/VAS/oxytocin infusion/sensory level/time to 1st breakthrough pain | 4 |
| Lim 2005 | 30/30 | Singapore | Levobupivacaine 0.1% with fentanyl 2 μg/mL, 5 mL epidural boluses every half hour | Levobupivacaine 0.1% with fentanyl 2 μg/mL at a rate of 10 mL/h | Breakthrough pain/ pruritus/nausea/vomiting/shivering/ hypotension/satisfaction score/pain scores/mode of delivery/Apgar scores at 5 min/cervical dilatation/use of oxytocin/motor block | 4 |
| Lim 2010 | 25/26 | Singapore | 2.5 mL automated intermittent epidural boluses of ropivacaine 0.1% plus fentanyl 2 μg/mL delivered over a 2-min period every 15 min | Continuous epidural infusion of ropivacaine 0.1% plus fentanyl 2 μg/mL at 10 mL/h | Breakthrough pain/pruritus/nausea/vomiting/shivering/hypotension/foetal bradycardia, birth weight/urinary catheter inserted/mode of delivery/duration of labour, second stage of labour/total ropivacaine dose/Apgar score/satisfaction score/mean time to first breakthrough pain/pain score/sensory level/oxytocin being administered/crvical dilation | 3 |
| Lin 2016 | 102/98 | China | 0.1% ropivacaine mixed with sufentanil 0.3 μg/mL; an hourly IEB of 5 mL and mixed with a PCEA bolus of 5 mL | 0.1% ropivacaine mixed with sufentanil 0.3 μg/mL; CEI at a rate of 5 mL/h and mixed with a PCEA bolus of 5 mL | Demographic properties/cervical dilation/and VAS scores/delivery mode/duration of first stage of labor/duration of second stage of labor/Apgar score at 1 min, Apgar score at 5 min, dosage consumption of ropivacaine, rescue medication dose by PCEA, Time to reach maximum block height (T10) | 4 |
| Morau 2019 | 124/125 | France | Received an hourly bolus of 8 mL (injection rate of 250 mL/h) beginning 60 min after the loading dose. | A continuous infusion rate of 8 mL/h was immediately commenced in the PCEA group | Maternal characteristics; reasons for instrumental vaginal delivery; primary outcome and detailed analysis of events included in the composite endpoint; presence of a motor block; data recorded during labour | 3 |
| Nunes 2016 | 33/60 | Portugal | Deliver 10 mL of ropivacaine 0.15% plus sufentanil 0.2g/mL solution every hour beginning 60 min after the administration of the initial epidural loading dose | Deliver the ropivacaine 0.15% plus sufentanil 0.2g/mL solution at a rate of 5 mL/h, with PCEA boluses of 5 mL with a lockout interval of 20 min, and a per hour maximum volume of 15 mL | Subject and labor characteristics, Apgar scores at 1st and 5th minutes | 3 |
| Riazanova 2019 | 42/38 | Russia | Programmed intermittent epidural boluses of LA 8.0 mL each 30 min with patient controlled epidural analgesia, LA bolus 8.0 mL, lockout interval 30 min | Patient-controlled epidural analgesia was conducted (8.0 mL LA lockoutinterval 30 min) with continuous background infusion of ropivacaine hydrochloride 0.08% with an infusion rate of 8.0 mL/h | General characteristics of examined patients; indices of blood pressure (BP) and heart rate (HR) during labour pain relief; assessment of pain level using VAS and assessment of motor block using the Bromage scale in different study stages; Apgar score; duration of delivery with epidural analgesia and local anaesthetic consumption | 3 |
| Rodríguez–Campoó 2018 | 100/95 | Spain | A 2 mL/h continuous infusion plus a 7 mL/30 min PIEB bolus | A continuous infusion of 5 mL/h plus 6 mL/20 min PCEA | Total levobupivacaine dose; pain control; subject satisfaction; type of delivery; vaginal tears; episiotomy | 4 |
| Sia 2007 | 21/21 | Singapore | 0.1% ropivacaine + fentanyl 2 μg/mL, lockout 10 min, automated mandatory boluses of 5 mL/h | 0.1% ropivacaine + fentanyl 2 μg/mL, lockout 10 min, basal continuous infusion of 5 mL/h | Epidural ropivacaine consumed per hour/number of self-bolus/time to the first self-bolus/number of breakthrough pain requiring an anesthesiologist's intervention/nausea/vomiting/ pruritus/duration of labor/duration of second stage/mode of delivery/fetal birthweight/Apgar score/satisfaction score/use of oxytocin at time/cervical dilatation/ pain score/lowest systolic blood/maximum dermatomal block to cold/lower limb motor block | 4 |
| Sia 2013 | 51/51 | Singapore | 0.1% ropivacaine + fentanyl 2 μg/mL, automated boluses of 5 mL in addition to the patient-controlled boluses | 0.1% ropivacaine + fentanyl 2 μg/mL, PCEA with basal infusion 5 mL/h | Baseline characteristics/breakthrough pain/side-effects/obstetric and neonatal outcomes | 4 |
| Song 2020 | 38/40 | China | The pump was programmed to administer the first bolus of 8 mL 1 h after initiation and every hour afterward | The epidural pump was programmed to deliver at a constant rate of 8 mL/h | Demographic and baseline characteristics; analgesia characteristics and labor outcomes; pain VAS score at various time points | 4 |
| Wang 2016 | 100/100 | China | Programmed intermittent epidural boluses of LA 10 mL each 30 min with patient controlled epidural analgesia, lockout interval 30 min | Maintained at a constant speed of 10 mL/h for CEI group. | Baseline characteristics; pain VAS score at various time points; thoracic sensory block level; PCA frequency and total medication; maternal delivery, blood loss, satisfaction scores and newborn Apgar scores; hypotension, nausea, vomiting, itching and others. | 2 |
| Wang 2017 | 62/62 | China | 10 mL/60 min, pulse dosing starts 60 min after the first dose is injected | Maintained at a constant speed of 10 mL/h for CEI group. | Baseline characteristics; pain VAS score at various time points; time to add medication for the first time, the number of PCEA compressions and the total amount of epidural analgesia used by the parturient; satisfaction and newborn situation; the duration and interval of uterine contractions, labor analgesia time, delivery method, and ratio of oxytocin use in the 2 groups | 2 |
| Wong 2006 | 63/63 | USA | 6 mL bolus every 30 min beginning 45 min after the intrathecal injection | 12 mL/h infusion beginning 15 min the after the intrathecal injection | Labor pain/epidural bupivacaine dose/epidural fentanyl dose/time to first PCEA request/PCEA bupivacaine dose/manual bolus (number of subjects, number per subject)/manual bupivacaine dose (mg/h)/total bupivacaine dose | 4 |
| Zhao 2013 | 29/28 | China | Delevered a 3 mL bolus at a rate of 60mL/h per 30 min | maintained at a constant speed of 6 mL/h for CEI group | Baseline characteristics; maternal labor, mode of delivery; oxytocin use, postpartum hemorrhage, and newborn Apgar score | 3 |
CEI = continuous epidural infusion, PCEA = patient-controlled epidural analgesia, PIEB = programmed intermittent epidural bolus, VAS = visual analogue scale.