Case Report of Opioid Free Anesthesia Combined with Errector Spinae Plane Block for Lumbar Spinal Fusion Surgery

A novel regional anesthesia technique when local anesthetic is injected into the fascial plane between the transverse process of the vertebra and the erector spinae muscles has been demonstrated in lumbar spinal surgery patients with controversial results. Here, we report a case of an 83 year old female, physical status class (ASA) II class, with moderate depression and chronic back pain scheduled for transpedicular fusion surgery at 4 to 5 lumbar level and lumbar spine fusion surgery proved to be an effective and safe method in terms of analgesia, activation, level of depression and disability.


InTRODuCTIOn
While opioids are first-line agents for postoperative pain, those are associated with significant adverse effects, including tolerance and induced hyperalgesia as well as systemic reactions and potentially abuse, particularly for chronic back pain patients. It is well known, that opioid anesthesia does not reduce postoperative pain, which is the main reason for unwilling activization, significantly affecting recovery [1]. A novel regional anesthesia technique when local anesthetic is injected into the fascial plane situated between the transverse process of the vertebra and the erector spinae muscles is defined as Errector Spinae Plane Block (ESPB). The local anesthetic is assumed to penetrate the superior costotransverse ligament and reach the paravertebral space providing analgetic effect [2,3]. The first time ESPB has been demonstrated successfully whilst treating thoracic neuropathic pain and postoperative pain in thoracic surgery in 2016 by Forero M, et al. [4].
Recently, ESPB increasingly has been used in lumbar spine surgery patients due to its effect on dorsal ramus of spinal nerve which gives the sensory innervation to components of dorsal column of spine providing painless back area after spinal surgery [3]. However, in a systematic review published by Qiu Y, et al. [5], was concluded the effectiveness and safety of this block is still controversial in lumbar spine surgery.
We hypothesized, that ketamine instead of phentanyl in combination with ESPB might reduce the rates of opioid consumption and their associated side effects during and after surgery as well as to have a positive effect on incidence of chronic pain, levels of depression and disability. The aim of this case report is to demonstrate effectiveness and safety of ESPB in combination with opioid free anesthesia for lumbar spinal fusion surgery. This case highlights the benefit of this approach on postoperative pain level, levels of depression and disability following spine surgery.

CASE REPORT
An 83-year-old female was admitted for transpedicular fusionsurgery and laminectomy at lumbar 4-5 level.
Magnetic resonance imaging (MRI) revealed a lumbo-sacral spondylolisthesis and L4-L5 stenosis as seen in figure 1.  She presented slightly confused in the first 20 minutes after the surgery but was able to communicate properly and convincingly controlling her airways. The effect on early postoperative period in terms of incidence of chronic pain, level of depression Patient Health Questionnaire-9(PHQ-9)and Oswestry Disability index (ODI) was observed [8,9]. Preoperative assessment showed moderate depression (PHQ-9, 13 points of 27) and severe disability (ODI 30/50 or 60%). At discharge patient showed improved scores, her depression and disability level were minimal (PHQ-9, 4 points of 27 and ODI 10/50 or 20%).

DISCuSSIOn
Standard opioid anesthesia with patient-controlled analgesia is still widely used after a major spinal fusion surgery. Moreover, epidural injection analgesia is applied in some clinics also. In addition, perioperative opioid use in patients undergoing spine surgery is linked to increased length of stay as well as to worse outcomes as demonstrated by decreased ODI [10,11]. pain patients with signs of depression [14].
ESPB is an interfacial plane block where a local anesthetic is injected in a plane preferably below the erector spinae muscle. It has been demonstrated as an effective and safe regional analgesic technique, with numerous applications in thoracic, breast, abdominal, spinal and even orthopedic surgeries, particularly when compared to paravertebral block and epidural analgesia due their well-known risks and side effects [4,5,15]. ESPB is supposed to work at the origin of spinal nerves spreading cranio-caudally for up to 7 dermatomal levels depending on local anesthetic volume [15]. Wide spreading of local anesthetic was confirmed also in our case report providing sensory block up to 4 levels and down to 3 levels from lumbar level 4 where the bilateral injection was performed with 20 ml of 0.25 % Bupivacaine combined with 100 mcg Epinephrine. Singh found that injection of 0.5%-20 ml Bupivacaine bilaterally at the Th8 level last for 6-8 hours after surgery [16]. Epinephrine as an adjuvant might prolong the block [15]. Despite the fact, that vasoactive agent additive to long acting local anesthetic doesn't improve block for longer than one hour, we used 100 mcg of Epinephrin or 2.5 mcg per one ml of local anesthetic when performing this block as suggested by other authors [15,17].  [5,19,16]. In our case we assume that larger volume or concentration of local anesthetic unlikely would prolong the duration of block.
Besides, opioid free anesthesia with Ketamine allowed to avoid opioid administration during the operation and to reduce its requirement in postoperative period, therefore we did not observe any opioid caused side effect. Perioperative analgesia with sub-anesthetic Ketamine dose is effective and safe for acute pain in variety of contexts. American Society of Anaesthesiologist also stated that ketamine can be used as a stand-alone drug or adjunct to opioids in postoperative analgesia plan [20].
In postoperative period the patient had low pain score (NRS 2-3) when moving and no pain when resting and was able to move independently once her rehabilitation period started Hua and co-authors [5] where the analgetic effect of ESPB was controversial based on an analysis of four case reports, four case studies, one retrospective cohort study and two randomized controlled trials, including 171 participants.
Importantly, that conclusion was mainly based on case series, one more time certifying that more randomized controlled studies in this field are needed.
Based on this case report, opioid free anesthesia with Ketamine combined with ESP block may be considered as an option or adjunct for pain management in this very particular group of patients.

COnCLuSIOn
Opioid free anesthesia with Ketamin supplemented with ESPB seems to be safe enough, innovative strategy that ensures good postoperative analgesia following the lumbar spine surgery and contributes to a faster patient recovery, reduced opioid requirement, improved levels of depression and disability and an earlier activation. We further aim to increase the number of participating patients to increase the significance of demonstrated results.

ACKnOWLEDGMEnTS
All authors have contributed equally drafting or revising the manuscript. We thank Orto Clinic, the major Orthopedic and Vertebral Surgery private center in Riga, Latvia, for kind collaboration.

COnFLICT OF InTEREST
There are no existing financial interests or any conflict of interest regarding this manuscript.