Background

Pain management after thoracotomy is challenging in premature neonates. Regional anaesthesia can be a useful adjunct to reduce opioid-related respiratory depression, but many of these patients present with contraindications to the traditional standard epidural analgesia. The erector spinae plane (ESP) block has emerged as a potential analgesic option in this patient population. The ESP block provides analgesia by indirectly targeting both the dorsal and the ventral rami of multiple levels of spinal nerves through deposition of local anaesthetic deep to the erector spinae muscle.1 The potential advantage of this indirect approach is that bleeding complications associated with this block are likely to be less consequential compared with epidural blockade due to the relatively superficial and readily compressible location of needle placement. Though little data is available to compare the analgesia from ESP blocks with epidurals, there is growing evidence of analgesic effectiveness of the ESP block for acute and chronic thoracic pain. Continuous ESP blocks have been used as an analgesic adjunct in adult and older paediatric thoracotomy patients.2–4

Only single injection ESP blocks, which provide analgesia of limited duration, have been reported in preterm neonates that presented for thoracic surgery.5–8 A continuous block is desirable for these patients to allow the provision of several days of opioid-sparing analgesia. However, continuous ESP blocks may require large volume local anaesthetic infusions to be efficacious, which presents an additional challenge in this population due to immature hepatic metabolism and increased susceptibility to the cardiotoxic and neurotoxic effect of aminoamide local anaesthetics.9

We present the novel management of a coagulopathic premature neonate undergoing thoracotomy for tracheoesophageal fistula (TEF) repair with a preoperatively placed ESP catheter with continuous intraoperative and postoperative chloroprocaine infusion.

Case presentation

Informed consent was given by the patient’s parent to publish this report.

A 2-day-old, 2.25 kg female infant, born at 35 weeks 6 days, presented for TEF repair via right thoracotomy. Workup for associated anomalies found a bifid S4 vertebral segment, aberrant right subclavian artery and possible anorectal anomaly. Laboratory tests were notable for unexplained coagulopathy with international normalised ratio (INR) 2.6, despite routine vitamin K administration intramuscularly 1 hour after birth. The patient’s INR remained elevated at 1.6 on the morning of surgery despite fresh frozen plasma administration.

Treatment

We viewed the patients elevated INR as a contraindication to epidural placement, as per The American Society of Regional Anesthesia and Pain Medicine (ASRA) guidelines.10 Therefore, a continuous ESP block was planned. Following uneventful anaesthesia induction and rigid bronchoscopy, the trachea was intubated and the patient was turned to the left lateral decubitus position. At the level of the marked planned T7-8 chest tube site, we identified a parasagittal view of the right erector spinae muscle group and thoracic transverse processes with ultrasound. Following sterile preparation, we advanced a 20-gauge Tuohy needle in plane from caudal to cephalad deep to the erector spinae muscle at T7-8 (figure 1A). We aimed to place the catheter tip at the midpoint (T5-6) between the planned T4-T5 incision and T7-8 chest tube sites to achieve sufficient cephalad and caudal spread of the local anaesthetic solution to provide analgesia at both sites of source of postoperative pain.11 We injected 1.5 mL normal saline to open the ESP and threaded a 24-gauge epidural catheter into the plane. Catheter location was confirmed with 0.5 mL normal saline and 2 mL 3% chloroprocaine. The catheter was tunnelled away from the planned surgical site (figure 1B–D) and secured with a sterile dressing. A posterolateral thoracotomy incision was made and the chest wall was opened between the fourth and fifth ribs. We chose 1.5% chloroprocaine for local anaesthetic solution; however, it was not readily available from our pharmacy to administer a loading bolus dose. While awaiting chloroprocaine infusion preparation, 1 mL 0.1% (0.44 mg/kg) ropivacaine bolus was administered prior to incision. One hour later, an infusion of 1.5% chloroprocaine was initiated at 0.25 mL/kg/hour (3.75 mg/kg/hour). We took care to ensure that the administered doses were significantly lower than the maximum allowed doses for each local anaesthetics individually and in their current combination. The patient received remifentanil 0.1 mcg/kg/min during the first half of the case, but no other intraoperative opioids. Following chest tube placement between the seventh and the eighth ribs and completion of the surgery, the patient was extubated and transferred to the neonatal intensive care unit.

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Figure 1

(A) Ultrasound image of the needle in the erector spinae muscle plane. (B–D) Tunnelling the catheter away from the surgical field by using the 20-gauge Tuohy needle and stylet to create a subcutaneous conduit for the catheter. ESM, erector spinae muscle; T6TP, thoracic 6 transversus process; T5TP, thoracic 5 transversus process.

Outcome and follow-up

Postoperative analgesia was supplied via chloroprocaine infusion and scheduled rectal acetaminophen. The Neonatal Pain, Agitation and Sedation Scale (N-PASS) was recorded every 2 hours to assess postoperative pain. Our patient received two doses of morphine (0.05 mg/kg per dose) on each of the postoperative days (POD) 1 and 2 for N-PASS scores of 5–7. The remainder of N-PASS scores was recorded as 0–2. Oxygen supplementation via nasal cannula was titrated off POD 2. The erector spinae catheter was removed without complication on POD 5. A repeat INR was 1.17 prior to catheter removal, and there were no signs of impaired haemostasis. The patient was discharged home on POD 8. No short-term or long-term complications related to the ESP block were observed.