Programmed Intermittent Bolus Versus Continuous Infusion for Epidural Analgesia in Abdominal Surgery

Programmed Intermittent Bolus Versus Continuous Infusion for Epidural Analgesia in Major Abdominal Surgery: a Randomized Clinical Trial

Epidural analgesia is an efficient way to relieve pain after major abdominal surgery. Two different protocols are used to provide analgesia: continuous epidural infusion (CEI) and programmed intermittent boluses (PIEB). CEI consists in the delivery of a continuous administration of the intended hourly dose. PIEB consists in the administration of sequential high pressure boluses of the intended dose. Although some studies in the postoperative setting have observed that PIEB reduces the total dose needed to ensure adequate pain control, the clinical value of this finding is still uncertain. Moreover, nursing and medical interventions to the epidural infusion rates are frequently needed in the first 48 postoperative hours to optimize the provision of analgesia. These interventions add to the already important nursing workload associated with major abdominal surgery, and are correlated with suboptimal analgesia for the patient. This randomized controlled trial aims to compare the effect of epidural PIEB on the workload as a reflection of adequate analgesia compared to the standard CEI protocol in use. The investigators hypothesize that the use of PIEB decreases the number of interventions needed to obtain adequate analgesia.

A continuous epidural infusion of bupivacaine 0,1% is administered at a prescribed rate in milliliters per hour.

Programmed intermittent epidural boluses of bupivacaine 0,1% are administered every hour. Protocolized adjustments of the dose are performed in order to obtain adequate analgesia. Standardized patient-controlled epidural boluses are available as top-ups.

A continuous epidural infusion of bupivacaine 0,1% is administered at a prescribed rate. Protocolized adjustments of the dose are performed in order to obtain adequate analgesia. Standardized patient-controlled epidural boluses are available as top-ups.

A morphine infusion (0,1mg/ml) is administered in both groups at a prescribed rate. Protocolized adjustments of the dose are performed in order to obtain adequate analgesia.

Number of epidural infusion adjustments by the nursing team (based on the usual protocol of our institution) will be recorded.

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

Prescribed additional analgesia (IV/PO/S/C opioids or other) administered to the patient while epidural analgesia is still provided.

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

Documented by medical records review (vitals, medication received, temporary interruption of the local anesthetic epidural infusion, IV fluids, etc.).

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

Total epidural dose of local anesthetic administered (including additional boluses ordered by the anesthesiologist and PCEA).

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

From the admission to the ICU until the end of the ICU stay (or until the patient has met ICU discharge criteria).

Time to postoperative mobilization as defined as a patient who can tolerate standing without symptoms that limit the mobilization.

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

48 hours after reaching the discharge criteria from the post-anesthesia care unit (or until the beginning of the epidural weaning period, if started in less than 48 hours)

Inclusion Criteria: Adult patients (18 years and older) Major abdominal surgery in an elective setting Thoracic epidural (between T7 and T12) Exclusion Criteria: Contraindication to bupivacaine Contraindication to morphine Decision to keep the patient intubated and sedated at the end of the surgery Chronic opioid use (> 3 months) Pregnancy