Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT03044392 |
| Other study ID # |
1021552 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
June 5, 2017 |
| Est. completion date |
July 1, 2024 |
Study information
| Verified date |
March 2024 |
| Source |
IWK Health Centre |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The current standard of practice for the maintenance of epidural analgesia is through use of
a continuous infusion pump. Enhanced technology now supports the use of programmed
intermittent bolus (PIEB) administration. This novel drug delivery system provides small
boluses of local anesthetic and opioid at programmed intervals. Several studies suggest that
administration of PIEB allows a more extensive spread of local anesthetic in the epidural
space and provides superior labour analgesia compared to traditional continuous epidural
infusions. PIEB is associated with lower anesthetic consumption, a shorter second stage of
labour and greater patient satisfaction.
The authors are focusing on a PIEB setting known as the "Next Bolus". "Next Bolus" (NB)
determines when the first PIEB bolus is given after the initiation of the epidural and
starting the PIEB pump. Currently we set this to be 15-45 minutes. In an attempt to optimize
resources, authors hope to determine the optimal NB interval that will provide adequate
analgesia but limit overall drug consumption. An optimally timed next bolus should minimize
drug costs and limit nurse and physician intervention by decreasing the need for manual
boluses.Increased local anesthetic consumption can cause undesirable side effects such as
itchiness, decreased blood pressure and motor blockade. By assigning patients to receive the
NB at 15, 30 or 45 minutes the authors hope to find the interval that provides analgesia
while minimizing side effects, improving patient safety. If the bolus is given too late then
there may be increased pain, less patient satisfaction, and the need for more analgesia in
the form of Patient Controlled Epidural Anesthesia or a manual bolus.The authors hope that
determining the NB will result in an institutional change to improve patient outcomes and
facilitate knowledge transfer. This information will be the first available research to help
guide other obstetrical centres using PIEB technology in determining the optimal NB interval.
Description:
Background
Enhanced epidural pump technology now supports the use of automated or programmed
intermittent bolus (PIB) administration. Anesthesiologists can now program pumps to deliver
small, regularly timed intermittent boluses for maintenance of labour analgesia and specify
"lockout" intervals to ensure patient safety.
Several studies suggest that administration of PIB may result in a more extensive spread of
local anesthetic in the epidural space and provide superior labour analgesia compared to CEI.
In a recently published systematic review by George et al. (1), PIB was associated with lower
anesthetic consumption, a shorter second stage of labour and greater patient satisfaction
compared to CEI (1).
The optimal PIB volume and dosing interval for programmed intermittent bolus has not been
determined. A small volume with a short bolus interval may be associated with similar
drawbacks as continuous infusion, while a large volume bolus interval may be associated with
increased breakthrough pain and reduced patient satisfaction. Wong et al. showed that
extending the PIB interval from 15 min to 60 min with a larger PIB volume (10 mL vs. 2.5 mL)
results in decreased anesthetic consumption without affecting patient satisfaction (3). Until
recently, there was not a pump that could provide PIB along with PCEA. Smith Medical now
produces the CADD pump with this feature. It ensures that that there are specific limits set
to not allow "stacking" of boluses and potentially unsafe administration of local
anesthetics. This pump now has more variables to program and determine the quality of labour
analgesia.
A variable that has not received any research attention is the "Next Bolus" (Figure 5). "Next
Bolus" (NB) determines when the first PIB bolus is given after the initiation of the epidural
and starting of the pump. Currently we set this to be 15-45 minutes depending on the
clinician. Determining the optimal timing of the NB is important because if the bolus is
given too late there may be increased pain and less patient satisfaction. This could lead to
earlier initiation of PCEA, more frequent PCEA attempts and possibly the need for physician
intervention for a manual bolus. As more local anesthetic is delivered, the patient may have
a decrease in blood pressure or greater motor blockade (i.e. leg weakness) than desired.
Design & Procedure Potential participants will be identified by research personnel by
communicating with the attending anesthesiologist on the Birth Unit and the Clinical Leader
of Operations for the Birth Unit at the IWK Health Centre. Birth Unit nurses will receive an
educational session and training provided by the research coordinator prior to study
commencement. Birth unit nurses will be notified by the Clinical Leader of Operations if
their patient meets study inclusion criteria. The patient's nurse will review options for
labour pain relief with the patient. These options include non-pharmacological measures
(baths, massage, hypnosis etc.), inhaled nitrous oxide, opioid injections, or an epidural.
When labour pain management options are introduced, the nurse will provide the patient with a
brochure that includes basic study information. If an epidural is requested for labour
analgesia, nurses who have received education regarding the study, will ask the patient if
they would be willing to speak with research staff. With their consent, participants will be
approached by study personnel and informed, written consent will be obtained. As standard
care in the birth unit, upon request of labour analgesia, the cervix will be measured and a
baseline pain score and blood pressure will be determined.
A staff anesthesiologist will use a combined spinal-epidural (CSE) technique to initiate
labour analgesia. As per standard practice at the IWK, an IV catheter will be in place before
initiation of the technique. With the patient in the sitting position, the epidural space
will be identified at the L3-4 or L2-3 interspace with a 17G, 9 cm Tuohy epidural needle
using a loss of resistance to air or saline (< 1 mL) technique. A 27G, 12 cm Whitacre spinal
needle will be placed into the shaft of the epidural needle and the presence of cerebrospinal
fluid in the hub of the spinal needle will confirm dural puncture. Bupivicaine 0.25% 0.8 mL
(2 mg) + Fentanyl 10 mcg (total 1 mL) will be injected into the intrathecal space.
Each participant will be randomly allocated (using a computer generated randomization table)
to one of three groups. Group assignments will be sealed in sequentially numbered envelopes
that will be opened by study personnel following the consent process. The pump will be
programmed by an unblinded member of the anesthesia team (anesthesiologist or anaesthesia
assistant) and maintenance epidural analgesia will be initiated in accordance with IWK
policies when the epidural procedure is complete. The individual programming the pump will
not be collecting data. The start time of the pump will be recorded on the envelope and the
sealed envelope will be given to the study personnel. The pump will be connected and
initiated once the epidural procedure is complete and will start the infusion exactly 5
minutes after the intrathecal injection. Each participant will have the same PIB settings
(PIB bolus 8 mL, PIB interval 45 minutes). Group A will be assigned a NB of 15 minutes, group
B 30 minutes and group C 45 minutes.
The data collection will take place in the patient's assigned labour room in the IWK Birth
Unit. The CADD Solis Ambulatory Infusion System (Smiths Medical ASD, Inc., St Paul MN) will
be used to administer the programmed intermittent epidural bolus doses and patient-controlled
epidural analgesia (PCEA). The current IWK labour analgesia standard ensures each labour room
is equipped with a Smith Medical CADD pump, epidural infusion tubing and an epidural
procedure tray. No new or additional supplies or personnel will be required for the study.
Prior to study commencement, the research assistant will be trained by one of the
investigators (anesthesiologist) on how to complete a dermatome sensory evaluation and
Bromage score. In addition, the research assistant will receive training from the
anesthesiologist regarding how to instruct patients to use the PCEA device. For all groups
the PCEA will remain standardized. If after two confirmed PCEA doses that participant's pain
is not suitably controlled the anesthesiologist will be consulted to provide a manual bolus
(0.1% ropivacaine 10 mL). The patient and research personnel recording data will be blinded
to the group assignment.
Data to be collected Demographic data and health history Medical record number, maternal age,
height, weight, BMI.
Labour Information Gestational age, cervical dilation at initiation of CSE analgesia,
duration of labour (initiation of analgesia to delivery), maximum oxytocin infusion rate
during labour, mode of delivery, time from initiation of analgesia to delivery.
Analgesia Data Maintenance epidural solution volume administered from programmed intermittent
bolus pump, time of first administered PCEA bolus request, number of PCEA bolus requests and
delivered doses, PCEA ropivacaine dose, time to first request for manual bolus, number of
manual bolus doses, manual bolus ropivacaine dose, total ropivacaine dose, highest thoracic
dermatome sensory level to pin prick at 0, 15, 30, 45, 60, 120, 180, 240, 300, and 360
minutes, along with a modified Bromage score, hypotension, need for vasopressors.
Satisfaction Scores Overall maternal satisfaction scores (NRS) will be sought within one day
of delivery. Patients will be asked "On a scale from 0 to 100, how satisfied were you with
the pain control provided by the epidural during your labour?"
Data Collection In keeping with CONSORT guidelines all participants enrolled will be included
in an intention to treat analysis. Descriptive statistics will be expressed as mean +/-
standard deviation. The Student's t-test will be used for comparison of the means of
continuous, normally distributed data. Two-way ANOVA or Friedman test will be used for
variable differences in groups, and Bonferroni or Tukey HSD test will be used for multiple
comparisons. Categorical data are to be analyzed using χ2 test or Fisher's exact test, as
appropriate. The investigators will perform the statistical analysis, with the assistance of
collaborating statistician. An interim analysis will not be conducted and α set at 0.05 for
significance. A sample size of 26 per group will have an 80 % power to detect a reduction in
the time to first administered PCEA request by 20 minutes at alpha=0.05. To account for any
dropouts, we will aim to recruit 35 patients per group.
