Postoperative Analgesia in Neonates and Infants Using Epidural Chloroprocaine and Clonidine

Continuous epidural chloroprocaine after abdominal surgery is associated with lower postoperative opioid exposure in NICU infants

BACKGROUND

Epidural anesthesia in infants undergoing open abdominal surgery has the potential to reduce opioid consumption, lower pain scores, and expedite tracheal extubation. We evaluated associations between use of continuous epidural chloroprocaine and improved intra- and post-operative outcomes.

METHODS

This matched retrospective cohort study first identified 24 patients who between April 2018 through December 2019 were treated with a caudal catheter and epidural chloroprocaine infusion for a laparotomy at postnatal age of 6 months or less. A matched comparator group of 24 patients was derived based on age and type of surgery. Exclusion criteria were the presence of a preoperative opioid infusion, comorbidities that would preclude appropriate pain assessment, or a recent surgical procedure. Primary outcomes included opioid consumption and pain scores; we secondarily analyzed intraoperative anesthetic requirements, other systemic analgesic use, vital signs, tracheal extubation time, and procedural times.

RESULTS

Treatment with epidural anesthesia was associated with lower 5-day total postoperative opioid consumption (3.2 mg/kg vs. 19.7 mg/kg in the respective epidural vs. systemic groups, p = 0.001) and time to tracheal extubation (1.3 days vs. 3.2 days, p = 0.005). Any statistically significant differences in pain scores were not clinically meaningful. There were no differences in mean arterial pressure or intraoperative inhaled anesthetic doses.

CONCLUSION

Continuous infusion of epidural chloroprocaine in infants following open abdominal surgery may limit exposure to systemic opioid medications while providing adequate postoperative analgesia and shortening time to tracheal extubation.

Postoperative Apnea in a Neonate Following an Epidural Bolus Dose Through a High Thoracic Epidural Catheter

Regional anesthesia is being used more frequently in the practice of pediatric anesthesia including neonates and infants. While generally safe and effective, adverse effects may occur related to catheter placement or its subsequent use. We present the rare occurrence of high motor blockade with apnea following the administration of a bolus dose of the local anesthetic agent, 2-chloroprocaine, into the thoracic epidural catheter of a 4-week-old, 2.2-kg former premature neonate. The patient had an epidural catheter that had been threaded from the caudal space to the thoracic level to provide analgesia following an abdominal surgical procedure. Subsequent investigation with a standard chest radiograph revealed a higher than intended placement of the epidural catheter (T4 instead of T8-10) which resulted in a transient high motor blockade with apnea. The epidural infusion was discontinued and assisted ventilation was provided by bag-valve-mask ventilation. Immediately, the heart rate and oxygen saturation returned to baseline values, and within 5 min the patient became more active, spontaneous ventilation resumed, and a strong cry was noted. The epidural catheter was removed and the remainder of the postoperative course was unremarkable. Adverse effects of epidural anesthesia in neonates are discussed and options for identifying the correct placement of a thoracic epidural catheter are reviewed.

Evaluation of neurotoxicity and long-term function and behavior following intrathecal 1 % 2-chloroprocaine in juvenile rats

Spinally-administered local anesthetics provide effective perioperative anesthesia and/or analgesia for children of all ages. New preparations and drugs require preclinical safety testing in developmental models. We evaluated age-dependent efficacy and safety following 1 % preservative-free 2-chloroprocaine (2-CP) in juvenile Sprague-Dawley rats. Percutaneous lumbar intrathecal 2-CP was administered at postnatal day (P)7, 14 or 21. Mechanical withdrawal threshold pre- and post-injection evaluated the degree and duration of sensory block, compared to intrathecal saline and naive controls. Tissue analyses one- or seven-days following injection included histopathology of spinal cord, cauda equina and brain sections, and quantification of neuronal apoptosis and glial reactivity in lumbar spinal cord. Following intrathecal 2-CP or saline at P7, outcomes assessed between P30 and P72 included: spinal reflex sensitivity (hindlimb thermal latency, mechanical threshold); social approach (novel rat versus object); locomotor activity and anxiety (open field with brightly-lit center); exploratory behavior (rearings, holepoking); sensorimotor gating (acoustic startle, prepulse inhibition); and learning (Morris Water Maze). Maximum tolerated doses of intrathecal 2-CP varied with age (1.0 μL/g at P7, 0.75 μL/g at P14, 0.5 μL/g at P21) and produced motor and sensory block for 10-15 min. Tissue analyses found no significant differences across intrathecal 2-CP, saline or naïve groups. Adult behavioral measures showed expected sex-dependent differences, that did not differ between 2-CP and saline groups. Single maximum tolerated in vivo doses of intrathecal 2-CP produced reversible spinal anesthesia in juvenile rodents without detectable evidence of developmental neurotoxicity. Current results cannot be extrapolated to repeated dosing or prolonged infusion.