Bilateral single shot erector spinae plane block for pectus excavatum and pectus carinatum surgery in 2 pediatric patients

Abstract

Numerous publications have emerged on the application of erector spinae plane block in adult population. There are few reports of the use of this block in pediatric patients. The objective is to report 2 cases of adolescents, one diagnosed with pectus excavatum and the other one with pectus carinatum undergoing reconstructive surgery in which a bilateral single-shot erector spinae plane block was performed as an analgesic technique. The block was performed before surgery under general anesthesia in lateral decubitus position, guided by ultrasound using 20 ml of 0.25% bupivacaine per side. After the surgery they were extubated and transferred to the Intensive Care Unit. During their postoperative period they had visual analogic scale values less than 4 and no long term narcotics were used during the intraoperative and postoperative period. Bilateral single shot erector spinae plane block was effective as an analgesic technique for the intraoperative and postoperative period in pectus excavatum and pectus carinatum surgery in adolescents.

Resumen

Recientemente han surgido numerosas publicaciones sobre la aplicación del bloqueo del plano del músculo erector de la columna espinal en población adulta. Existen escasos reportes del uso de este bloqueo en cirugía pediátrica. Nuestro objetivo es reportar 2 casos de adolescentes, uno con diagnóstico de pectus excavatum y otro de pectus carinatum, sometidos a cirugía reconstructiva esternal a los que se realizó bloqueo del plano del músculo erector de la columna espinal bilateral en inyección única como técnica analgésica. El bloqueo se realizó antes de la cirugía con los pacientes sometidos a anestesia general en posición de decúbito lateral, guiado por ecografía utilizando 20 ml de bupivacaína al 0,25% por lado. Luego de la cirugía fueron extubados y trasladados a la Unidad de Cuidados Intensivos. Durante su hospitalización los valores de la escala visual análoga fueron menores de 4 y no fue requerido el uso de opioides de larga duración durante el intraoperatorio ni el postoperatorio de los pacientes. El bloqueo del plano del músculo erector de la columna espinal bilateral en inyección única fue efectivo como técnica analgésica para el intra y el postoperatorio en cirugía de pectus excavatum y pectus carinatum en población adolescente.

Introduction

Since its description in 2016, numerous studies have emerged on the use of erector spinae plane (ESP) block. The technique was first reported for thoracic neuropathic pain and postoperative analgesia following thoracic surgery, but is now used in abdominal and breast surgery and to facilitate extubation in adult patients in intensive care units (ICU).^1,2

The technique consists of an interfascial block in which local anesthetic is injected between the spinae erector muscle and the transverse process, where the dorsal ramus of the spinal nerves emerges, achieving anesthesia of the posterior and anterolateral region of the thorax.¹

The mechanism of action is probably deep penetration of local anesthetic through the intertransverse soft tissue to the ventral ramus, dorsal ramus and ramus communicants.

Recent case studies have reported the use of ESP block for postoperative analgesia in pediatric thoracic and abdominal procedures. The first was a 7-year-old patient undergoing oncological thoracic surgery³; the second was a 3-year-old patient undergoing open thoracotomy⁴; the third was a 3-year-old patient undergoing surgery of the posterior thoracic wall⁵; and the last was a preterm infant undergoing inguinal repair.⁶

We report 2 cases involving 13-year-old adolescents, 1 diagnosed with pectus excavatum, and the other with pectus carinatum, who underwent sternal reconstructive surgery in which bilateral single shot ESP block was performed for intra-operative and post-operative analgesia.

Case report

Case 1

13-Year-old patient, ASA II with a history of asthma in treatment with budesonide twice daily and salbutamol PRN, weight 63 kg, height 174 cm, with diagnosis of pectus excavatum.

Preanesthetic assessment was performed. The parents were informed and gave their consent for the procedure.

In the operating room, we used basic monitoring (ECG, SAO2, NIBP), an intravenous line was placed, and general anesthesia was induced with effect site target controlled infusion (TCI) delivered using a Paedfusor® with the Munoz Tpeak model for propofol and infusion of remifentanyl titrated by BIS. Vecuronium was administered at a dose of 0.1 mg/kg (6 mg). Intubation was uneventful. A urinary catheter, esophageal thermometer and arterial line were placed, and a thermal blanket was used.

With the patient in the right lateral decubitus position (Fig. 1), using aseptic techniques, we visualized the transverse process of T5 on ultrasound using a linear transducer (4.2–13 MHz frequency, NextGen LOGIQ e GE Medical Systems, Wauwatosa, USA). We inserted a 100 mm needle (Stimuplex® Ultra 360, 20Gx4, Braun Co., Melsungen, Germany) in plane in a caudal to cranial direction until the tip contacted the T5 transverse process (Fig. 2). Hydrodissection was performed with 2 ml of 0.9% saline solution, and 20 ml of 0.25% bupivacaine were injected. Adequate spread under the spinae erector muscle was visualized. The same procedure was repeated on the left side, with a total drug volume of 100 mg of bupivacaine (1.6 mg/kg). Anesthesia was maintained with TCI propofol-remifentanil for BIS 50–60, and a dexmedetomidine infusion at 0.2 mcg/kg/h. We administered acetaminophen 1 g, ketoprofen 100 mg and metamizol 1.5 g as a multimodal analgesia scheme. No long-acting intraoperative opioids were used. After the surgery, the patient was extubated without incident and transferred to the pediatric ICU. Upon admission, he rated his pain at 1/10 on a visual analog scale (VAS), after 2 h at 2/10, and after 4 h at 3/10. During the postoperative period, pain was treated with NSAIDS and acetaminophen. He did not require analgesic rescue during his entire stay. The next day he was transferred to an intermediate care unit, and then to a standard pediatric ward on the third day.

Figure 1.

Positioning of the patient and placement of ultrasound probe for ESP block.

Figure 2.

Visualization of needle in contact with the transverse process of T5. TP: transverse process, ESM: erector spinae muscle, RMM: rhomboid major muscle, TZM: trapezius muscle, N: needle.

Case 2

13-Year-old patient, ASA I, weight 55 kg, height 169 cm with diagnosis of right unilateral pectus carinatum.

Preanesthetic assessment was performed and the parents gave their consent for the procedure.

Basic monitoring (ECG, SAO2, NIBP) was used, an intravenous line was placed, and general anesthesia was induced with effect site target controlled infusion (TCI) delivered using a Paedfusor® with the Munoz Tpeak model for propofol and infusion of remifentanyl titrated by BIS. Vecuronium 5 mg (0.1 mg/kg) was administered. Intubation was performed without incident. A urinary catheter and esophageal thermometer were placed and a thermal blanket was used.

With the patient in the right lateral decubitus position (Fig. 1), using aseptic techniques, we visualized the transverse process of T5 on ultrasound using a linear transducer (4.2–13 MHz frequency, NextGen LOGIQ e GE Medical Systems, Wauwatosa, USA). We inserted a 100 mm needle (Stimuplex® Ultra 360, 20Gx4, Braun Co., Melsungen, Germany) in plane in a caudal to cranial direction until the tip contacted the T5 transverse process (Fig. 2). Hydrodissection was performed with 2 ml of 0.9% saline solution, and 20 ml of 0.25% bupivacaine were injected. Adequate spread under the spinae erector muscle was visualized (Fig. 3). Anesthesia was maintained with TCI infusion propofol–remifentanil for BIS 50–60, and dexmedetomidine infusion at 0.2 mcg/kg/h. We administered acetaminophen 1 g, ketoprofen 100 mg and metamizol 1.5 g as a multimodal analgesia regimen. No long-acting intraoperative opioids were used.

Figure 3.

Ultrasound visualization of local anesthetic spread under the spinae erector muscle. AT: transverse process T5, LA: local anesthetic, ESM: erector spinae muscle, N: needle.

After 1 hour of surgery, the surgeon correct an asymmetry on the left side, a situation that had not been programmed, so no analgesic block was performed on that side. The patient developed taquicardia and blood pressure increased by more than 20%, which was managed by increasing the remifentanil dose.

We decided to perform ESP block on the left side at the end of surgery, repeating the previous procedure and administering 100 mg bupivacaine (1.8 mg/kg) in total. The patient was extubated in the operating room and transferred to the intermediate care unit. He rated his pain at 1/10 on a VAS scale after 5 min, at 2/10 after 2 h, and at 2/10 at 4 postoperative hours. The next day, he was transferred to a basic care room. No analgesic rescue was needed during his hospital stay.

The patient's parents signed consent for scientific publication of the clinical cases.

Discussion

Surgery to correct pectus excavatum and pectus carinatum is extremely painful, so techniques such as epidural analgesia, paravertebral block and intravenous morphine infusion are usually used for postoperative analgesia, but there is no consensus on the optimum analgesic regimen.^7,8 Spinal cord injury following thoracic epidural analgesia for pectus excavatum surgery has been reported.⁹ This is considered cosmetic surgery, so several institutions no longer recommend epidural analgesia as an option for pectus excavatum repair.⁸ Unlike other techniques, the ESP block has the advantage of avoiding the neuraxis and the pleura, thus decreasing the risk of neurological damage and pneumothorax. These are the first published cases of ESP block for pectus surgery. The technique provided excellent intraoperative and postoperative analgesia with no need for long term opioids. In a recent case study of a patient managed with epidural plus patient controlled analgesia (PCA), the mean morphine equivalent dose (MED) in the first 24 h was 0.8 mg/kg/day. PCA was continued for a mean (SD) of 3.2 days, and the total MED was 2.2 mg/kg/day.⁸ In 2017, a technique comparable to ESP was described as extrathoracic sub-paraspinal blocks. The authors reported administering 0.13 mg ± 0.08 mg/kg of hydromorphone during the first 24 h.¹⁰ They also used intraoperative long acting opioids. In our cases, no long acting opioids were required either intraoperatively or during hospitalization, and NSAIDs were sufficient to maintain low VAS scores. This reduced the risk of undesirable opioid effects, such as nausea and vomiting, urinary retention, and constipation, and reveals the ESP block as a new and effective alternative for pain management in this type of surgery.

Our 2 patients required shorter ICU stays compared to other patients undergoing pectus surgery in our hospital. This suggests that the ESP block could reduce length of stay in comparison to other techniques, but this hypothesis needs to be confirmed in future studies.

The minimum local anesthetic concentration and the minimum local anesthetic volume in pediatric patients needs to be determined in order to enable clinicians to adjust the volume and concentration of local anesthetic to each patient. Further studies are also needed to evaluate the use of continuous ESP block to prolong postoperative analgesia in pectus surgery in adolescents.

Conclusions

Bilateral single shot ESP block provided effective intraoperative and postoperative analgesia in pectus excavatum and pectus carinatum surgery in adolescents, with no need for long term opioids.

Conflicts of interest

The authors declare no conflicts of interest.

Acknowledgements

The author would like to thank Mario Fajardo MD who taught me this technique with great kindness, and María Paz Olhagaray MD for her advice in the preparation of this manuscript.