Clinical trial NCT03236298: Programmed Intermittent Epidural Bolus for Labor Analgesia During First Stage of Labor: Comparing 125 mL/h Versus 250 mL/h Bolus Delivery Flow
Official title: Programmed Intermittent Epidural Bolus for Labor Analgesia During First Stage of Labor: a RCT Comparing 125 mL/h Versus 250 mL/h Bolus Delivery Flow
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Labor Pain
Keywords: Epidural
Labor analgesia
Programmed intermittent epidural bolus
Lead sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Sponsor class: OTHER
First posted: 2017-08-01
Enrollment: 90
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: At Mount Sinai Hospital, epidural analgesia for labor pain is delivered by programmed intermittent epidural bolus (PIEB), in combination with pushes of medication activated by the patient, a technique called patient controlled epidural analgesia (PCEA). Studies have shown that delivering analgesia in this manner can prolong the duration of analgesia, diminish motor block, lower the incidence of breakthrough pain, improve maternal satisfaction and decrease local anesthetic consumption comparing to a conventional continuous infusion. The use of this PIEB technique in routine practice has reduced the total consumption of local anesthetic and the percentage of patients requesting additional boluses (PCEA or manual rescues).

However, at the same time, sensory blocks above those targeted for labor pain relief have been reported in our institution, suggesting that the spread of the freezing medication is wider than necessary. Based on the information already available in the literature, the investigators will conduct this study to determine the best regimen of PIEB achievable with a slower delivery speed.

The hypothesis of this study is that PIEB boluses with 125 mL/h will decrease by 50% the incidence of women presenting sensory block to ice equal or higher than T6 as compared to a delivery rate of 250 mL/h.

Detailed description: PIEB is a novel technique, which provides better analgesia and less motor block; however, the ideal regimen has not been established. To optimize the PIEB regimen, the investigators have conducted several clinical trials using bupivacaine with fentanyl. Although PIEB provides the excellent analgesia to laboring parturients, studies completed by the instigators have shown that the incidence of sensory block to ice ≥T6 was 66%. For labor analgesia during the first stage of labor, effective sensory block requires T10 to L1; therefore, a sensory block ≥T6 seems unnecessarily high, and the investigators seek to confine epidural spread within a proper range.

Our previous studies showed that the effective volume 90% using 0.0625% bupivacaine was 10.7 mL, and incidence of epidural blockade ≥T6 was similar even using a 5-mL bolus with 0.125% bupivacaine. The investigators concluded that it is not possible to reduce volume of the PIEB, or use a higher concentration of local anesthetic without compromising the quality of analgesia. There is some evidence in the literature that supports the idea that higher injection pressures result in a wider spread of local anesthetic administered into the epidural space, therefore a slower epidural delivery flow rate may result in less spread.

Eligibility criteria: Inclusion Criteria:

* ASA II or III
* Term pregnancy (gestational age ≥ 37 weeks)
* Nulliparous
* Singleton pregnancy with vertex presentation
* Active labour defined as occurring regular uterine contractions at least every 5 minutes with progressive cervical dilatation
* Verbal Numerical Rating Score (VNRS) greater than 5 at requiring epidural analgesia (VNRS 0-10)
* Cervical dilation between 2 and 5 cm

Exclusion Criteria:

* Any contraindication to epidural analgesia
* Accidental dural puncture
* Drug allergy to lidocaine, bupivacaine or fentanyl
* Use of pharmacological analgesics within the last 4 hours
* Patient refusal to participate in the trial

Primary outcomes:
measure: Sensory block level to ice equal to or higher than T6 within the study period (6 hours)
timeFrame: 6 hours
Secondary outcomes:
measure: Sensory block level to ice
timeFrame: 6 hours
measure: Sensory block level to pin prick
timeFrame: 6 hours
measure: Motor block level assessed using Bromage score
timeFrame: 6 hours
measure: Pain score
timeFrame: 6 hours
measure: Total number of PCEA demands
timeFrame: 6 hours
measure: Total number of rescue boluses administered
timeFrame: 6 hours
measure: Total amount of local anesthetic (ml)
timeFrame: 6 hours
measure: Maternal satisfaction rating
timeFrame: 6 hours
measure: Hypotension
timeFrame: 6 hours
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Mount Sinai Hospital
state: Ontario
Study officials:
affiliation: MOUNT SINAI HOSPITAL
name: Jose CA Carvalho, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Mazda Y, Arzola C, Downey K, Ye XY, Carvalho JCA. Programmed intermittent epidural bolus for labour analgesia: a randomized controlled trial comparing bolus delivery speeds of 125 mL.hr-1 versus 250 mL.hr-1. Can J Anaesth. 2022 Jan;69(1):86-96. doi: 10.1007/s12630-021-02132-w. Epub 2021 Nov 1.