Dual epidural catheter technique to provide opioid‐free anaesthesia for an open abdominoperineal resection

Summary

The peri‐operative analgesic management of patients undergoing major elective colorectal surgery has an impact on patient recovery. An approach that favours an opioid‐free strategy has demonstrated improved patient outcomes. Avoiding systemic opioids during and after abdominal surgery promotes early recovery of bowel function and early re‐initiation of oral intake, shortens hospital length of stay, minimises postoperative complications, and may improve long‐term outcomes. In this case report we describe an opioid‐free anaesthetic technique, in line with current Enhanced Recovery After Surgery recommendations, for a patient undergoing an open abdominoperineal resection who reported experiencing severe side‐effects to opioids in the past. Two epidural catheters were sited pre‐operatively at the interspaces between the ninth and tenth thoracic and third and fourth lumbar vertebrae respectively, and used intra‐ and postoperatively. The utilisation of two epidural catheters not only ensured complete peri‐operative analgesia, but also successfully attenuated the neuroendocrine stress response to surgery. The dual epidural catheter technique may be considered for extensive colorectal surgery when conventional opioid‐based anaesthetic techniques are contraindicated.

Introduction

Reviews on the peri‐operative management of elective colorectal surgery have shown improved patient outcomes with the application of Enhanced Recovery After Surgery (ERAS) principles. A core recommendation pertains to the analgesic management plan which favours an opioid‐sparing technique. Epidural analgesia remains the gold standard for open surgery in this regard [1]. Epidural infusions of local anaesthetic agents (+/‐ adjuncts) are used to provide analgesia along the dermatomes of the operative site. However, the caudad and cephalad spread of local anaesthetic solution from a single epidural catheter may be inadequate for surgeries requiring extensive dermatomal coverage. In these cases, employing a dual epidural catheter (DEC) technique to manage intra‐ and postoperative nociception and pain merits consideration. Previous reports on DEC therapy to provide extensive analgesic dermatomal coverage are sparse. Here, we describe a case in which a DEC technique was used successfully intra‐ and postoperatively for an open abdominoperineal resection to provide complete analgesia and attenuation of the neuroendocrine stress response to surgery. Epidural analgesia was maintained throughout the postoperative period with the patient reporting high levels of satisfaction. Both catheters were removed after 24 h, and at the time of discharge from hospital, no complications from DEC therapy were reported.

Report

A 72 kg 29‐year‐old male patient was diagnosed with anorectal carcinoma six months before his scheduled abdominoperineal resection. He was known to be living with human immunodeficiency virus (HIV) and had been compliant with his antiretroviral therapy (ART) for the past 10 years as reflected by his undetectable viral load. He had completed neoadjuvant chemoradiation therapy two months before admission. To treat his chronic pain, he was using multiple oral agents. He reported experiencing severe nausea and vomiting with opioid use and requested the anaesthetic team to avoid opioid administration during his planned anaesthetic.

An opioid‐free anaesthetic technique was performed by inserting two epidural catheters at the level of the interspaces between the ninth and tenth thoracic (T9/T10) and the third and fourth lumbar (L3/L4) vertebrae before induction (Fig. 1). With the patient in the sitting position, the epidural space was located at both levels using a loss‐of‐resistance technique with saline 0.9%, and the epidural catheters were secured 5 cm into the epidural space. The thoracic epidural was bolused with 8 ml bupivacaine 0.5% with 1:200,000 adrenaline, followed by a continuous infusion of bupivacaine 0.25% (4 ml.h^‐1). The lumbar epidural was bolused with 6 ml bupivacaine 0.5% with 1:200,000 adrenaline 3 h into the surgery, 30 m before the perineal dissection commenced, followed by a continuous infusion of bupivacaine 0.25% (5 ml.h^‐1). Additional non‐opioid intravenous analgesia was administered during the surgery and included dexmedetomidine (1 mcg.kg^‐1 over 20 m, followed by an infusion of 0.5 mcg.kg^‐1.h^‐1), ketamine (0.25 mg.kg^‐1 hourly), paracetamol (1 g 6‐hourly) and dexamethasone (0.15 mg.kg^‐1 after induction).

Figure 1.

Patient in sitting position with dual epidural catheters sited preoperatively (T9/T10 and L3/L4 respectively).

An ultrasound‐guided right internal jugular central venous catheter and left radial arterial line were inserted after the induction of general anaesthesia. General anaesthesia was maintained with sevoflurane, targeting a minimal alveolar concentration of 0.8‐1. Rocuronium 70 mg was administered i.v. for muscle relaxation. A pre‐operative mean arterial pressure of 80 mmHg was maintained intra‐operatively with a low‐dose phenylephrine infusion (0.2‐0.4 mcg.kg^‐1.min^‐1 i.v.) which was stopped before emergence from general anaesthesia. Goal‐directed fluid therapy (GDFT) was used during surgery by monitoring static markers of cardiac output (heart rate, blood pressure and urine output) and the patient’s systolic pressure variation (SPV). Urine output averaged 1.6 ml.kg^‐1.h^‐1. The patient’s SPV ranged between 4 and 7 mmHg. Total blood loss was estimated to be 200 ml. The pre‐ and postoperative haemoglobin was 13.2 g.dl^‐1 and 12.8 g.dl^‐1 respectively. A total fluid volume of 1900 ml of lactated Ringer's solution and 1000 ml of hydroxyethyl starch 6% in saline 0.9% (Voluven^®, Fresenius Kabi, Bad Homburg, Germany) was administered intra‐operatively. For the duration of the surgery (6 h 40 m), the patient’s heart rate ranged between 52 and 70 beats.min^‐1, his serum glucose values ranged between 7.7 and 8.8 mmol.l^‐1, his lactate levels remained within the normal range (pre‐operative lactate 1.2 mmol.l^‐1; lactate at extubation 1.3 mmol.l^‐1) and his central venous oxygen saturation remained above 73% on three different intra‐operative measurements (2 h apart). After tracheal extubation, the patient reported a 0/10 verbal pain score and no lower limb weakness. He was transferred to a high dependency unit (HDU), where the thoracic and lumbar epidural infusions were continued (4 ml.h^‐1 of bupivacaine 0.125%) for 24 h. Urinary retention was not assessed at emergence as the urinary catheter was only removed in the HDU the following day. No complications from the epidural catheters were noted at the time of discharge from hospital.

Discussion

The implementation of ERAS principles in colorectal surgery promotes early recovery of bowel function, reduces blood loss, shortens time to discharge, minimises postoperative complications and respiratory events, and may improve long‐term outcomes [1]. The guidelines on postoperative pain management after major colorectal surgery recommend opioid‐sparing analgesia, with epidural analgesia recognised as the gold standard for open surgery [1]. However, epidural analgesia for an open abdominoperineal resection surgery requires extensive dermatomal coverage due to the nature of the surgical procedure. Dissection of colonic tissue requires analgesia at the level of T8–L1, whereas dissection of anorectal tissue requires analgesia at the level of L5–S4 [2]. A single thoracic epidural catheter placed between T8 and T10 may not extend adequate analgesic cover to perineal structures due to the large volume of epidural local anaesthetic required to cover such an extensive surgical field (T8–S4). By inserting a second epidural catheter at a lower vertebral level (L3–L5), analgesia of the large dermatomal area may be achieved with a smaller combined local anaesthetic epidural volume between the two epidural catheters [3].

Dual epidural catheter has been shown to be an effective technique for surgical pain management in spinal and esophageal surgeries. In 2001, 23 patients undergoing spinal deformity surgery were enrolled in a prospective study in which two epidural catheters were placed at the end of surgery, one cranial and one caudal to the site of incision [4]. The DEC technique resulted in adequate analgesia in all participants without motor deficit, sedation or respiratory complications noted. Early mobilisation was achieved in all patients. A retrospective study published in 2009 described the DEC technique being used in 81 patients undergoing an Ivor‐Lewis oesophagectomy [3]. The study compared a single epidural catheter placed at the T7 vertebral level with DEC placement at T5 and T10 vertebral levels. The DEC technique resulted in significantly improved pain scores based on average numeric rating scales, and reduced major postoperative complications and re‐admissions within 28 days.

Apart from providing excellent analgesia for up to 72 h after surgery, epidural infusion of local anaesthetic agents has been shown to reduce the neuroendocrine stress response to surgery and enhance recovery of organ function [5]. Surgery is known to activate metabolic, hormonal and neural pathways that lead to catabolic, inflammatory and immunosuppressive derangements. Attenuating this response to surgical injury should lead to improved patient outcomes. Opioids have been shown to suppress the stress response to surgery, especially at high doses (e.g. at a dose of fentanyl more than 50 mcg.kg^‐1) [6]. However, at these doses, recovery of respiratory control, host immunity and gut motility may be significantly delayed. Epidural analgesia has been shown to attenuate the stress response due to the blockade of somatic and autonomic afferent neural pathways, thereby preventing the activation of the acute phase response. By continuing the epidural infusion after the completion of surgery, the suppression of the surgical stress response may be extended into the postoperative period [7]. This results in earlier recovery of bowel function and oral intake, improved pulmonary function, and a shortened hospital length of stay [1, 7]. In our case, no physiological response to surgical stimulation was noted intra‐operatively. The DEC technique appeared to have successfully suppressed the patient’s neuroendocrine stress response, with no development of insulin resistance, no increase in lactate production, and central venous oxygen saturation remaining above 73% [7]. The patient’s attenuated stress response to surgery likely contributed to his early discharge home after major surgery.

One concern with the use of DEC therapy may be the potential administration of large volumes of local anaesthetic to provide extensive dermatomal coverage. However, in our case, the total dose of bupivacaine administered within 24 h was 347.5 mg, which remains below the maximum recommended daily epidural dose of 400 mg in an adult patient [8]. The combined hourly infusion rate between both epidural catheters (9 ml.h^‐1) was less than the rate described with a single thoracic epidural catheter (14 ml.h^‐1) used in extensive abdominal surgery [9].

The use of epidural analgesia in major surgery is decreasing, potentially due to the perceived lower risks of regional nerve block strategies and multimodal systemic analgesic techniques [10]. However, an epidural analgesic approach to major open colorectal surgery remains the primary recommendation despite the potential for significant complications [1, 5]. Although the DEC technique has been described in several studies with reference to postoperative analgesia, we believe that our report is the first to describe its use for intra‐operative analgesia as part of an opioid‐free anaesthetic technique in a patient undergoing an open abdominoperineal resection. The DEC technique provided opioid‐free analgesia consistent with current ERAS recommendations [1]. However, with limited data on this approach for major colorectal surgery, further studies are warranted to assess this practice for its efficacy, benefits and side‐effects.