INTRODUCTION

Lumbar spine surgery is a prevalent cause of low back pain. L4/5 and L5/S1 are the most common lumbar segments susceptible to Lumbar spine surgery. The incidence of Lumbar spine surgery is highest in middle-aged women [1-2]. Spinal decompression therapy has demonstrated a propensity to create a substantial reduction in pain and an increase in the functional result. It demonstrates a high association between mobility and activities of daily living in the group with chronic low back pain [3].

Perioperative analgesia appears to be one of the most important modifiable factors that can reduce the morbidity associated with these complex spine procedures and hasten recovery [2]. Local infiltration analgesia is a commonly utilized approach [3-4]. In 1979 [5], the first description of intrathecal morphine (ITM) injections was made. Several studies have since documented and popularized the use of ITM, particularly in the setting of gastrointestinal and gynaecological surgery [6]. As a result of the problems that have been recorded (respiratory depression, pruritis, and nausea/vomiting), as well as doubts regarding the ideal dose and duration of analgesia, ITM is still surrounded by a number of uncertainties. The efficacy of ITM in the setting of orthopaedic and spine surgery has been contested [7-9]. ITM for spine surgery is a desirable approach due to the ease of access to the thecal sac and its reliability [10–12]. It is currently believed that multimodal postoperative analgesia is one of the determinants of accelerated recovery after surgery (ERAS) [13]. Knee, hip, and shoulder procedures appear prominently in the media coverage of this technique.

In spinal procedures, the management of post-operative pain has been a concern. The typical analgesic strategy is predicated on the use of opioids; hence, the adverse effects associated with opioids cannot be avoided [14]. Patients may experience nausea, vomiting, pruritis, urine retention, and vertigo as a result of these adverse effects [14]. Multimodal analgesic (MMA) regimen is one of the strategies to reduce post-operative pain and opioid-related side effects [15]. It requires the use of numerous medications and delivery methods.

Regional anaesthesia is an essential aspect of MMA [16-17]. Recently, the erector spinae plane block (ESPB), a novel technique for regional anaesthetic, has attracted considerable interest. ESPB was initially proved to alleviate pain associated with shingles [18]. The anaesthetic is administered between the transverse processes of the vertebrae and the erector spinae muscle [19-20]. After injection, the anaesthetic diffuses cranially and caudally and acts on the ventral and dorsal rami of the spinal nerves [17-19]. As the local anaesthetic is administered at a greater distance from the spinal cord, the danger of causing damage to the cord and resulting complications is reduced. In addition, the block is relatively simple to accomplish and is guided by ultrasonography. Due to all of its qualities, ESPB is commonly used in abdominal, breast, and thoracic surgery [20-22]. Examples include laparoscopic cholecystectomy. Recent randomized controlled trials (RCTs) are investigating the effect of ESPB in spinal procedures; nevertheless, the results are inconsistent.

In 2016, [23] the ESP block was first explained. Local anaesthetic is injected beneath the erector spinae muscle group using ultrasonography [23, 24]. By obstructing the ventral and dorsal rami of the spinal neurons, a sensory blockade is produced over the anterior and dorsolateral thorax. Recent case studies reveal that an ESP block has a good effect on pain for numerous purposes, including vertebral metastases, lumbar transverse process fractures, or after lumbar spine fusion and scoliosis surgery [25-28]. Sonoanatomy is readily identifiable, and there are no structures in close proximity that are at risk of needle injury [23, 29]. The transverse process functions as an anatomical barrier that prevents needle insertion into the pleura or veins, hence avoiding pneumothorax or hematoma. In addition, the needle is quite distant from the vertebral canal, so the danger of spinal cord injury is extremely minimal [30]. A block of the ESP preserves bladder and motor neuron function, allowing for early mobilization. Since motor function is unaffected, it is possible to evaluate the spinal cord’s neurological function immediately after surgery. Thus, the aim of this study is to compare the intrathecal morphine and erector spine plane block efficacy for perioperative analgesia in patient undergoing lumbar spine surgery.

AIM AND OBJECTIVES

·         Comparison of intrathecal morphine vs erector spine plane block for perioperative analgesia in patient undergoing lumbar spine surgery.

·        Primary Objective:

o   To compare the analgesia using numeric rating scale (NRS) in intrathecal morphine vs erector spine plane block for perioperative analgesiain patient undergoing lumbar spine surgery.

·        Secondary Objective:

o   To compare the sedation score

o   To compare the patient satisfaction score

o   To compare the consumption of rescue analgesic

o   To compare the hemodynamic (HR, SBP, DBP, MAP, RR, SpO2)

o   To study the complications (PONV, Respiratory depression, Bradycardia, Pruritus)

MATERIAL AND METHODS

•      Subject:Lumbar spine surgery patients of either sex and age group of 20-65 years, ASA I or II,posted for neurosurgery at Shatabdi Phase I Neurosurgery Operation Theatre, KGMU, U.P., Lucknow will be enrolled for the study.

•      Study Design:  Prospective, Single Blind, Randomized ControlledTrial

•      Sample Size: 74 (37 in each group)

The sample size formulae used are as follows: (Bernard, 5th edition) [31]

n=

n= Sample size

σ = Standard Deviation

∆ = Difference of means

κ= Ratio

Z_1-α/2= Two-sided Z value

Z_1-β= Power

·        Study Groups:

Group A: Intrathecal morphine for perioperative analgesia

Group B: Erector Spine Plane Block(ESPB) for perioperative analgesia

·        Statistical Plan

Descriptive statistics like frequency, percentage, mean, SD and CI to summarize data. Independent t-test to compare mean values between two groups.

·        Inclusion Criteria:

o   Patient of either sex, Age group of20-65years

o   ASA I or II

o   Lumbar spine surgery

·        Exclusion Criteria:

o   Patient Refusal

o   Coagulation disorders

o   Allergies to morphine or study drugs

o   Revision lumbar surgeries

o   Severe respiratory illness (COPD, OSA)

o   Psychiatric illness

o   Pregnancy or Lactation

o   Chronic opioid or analgesic use/abuse

METHODOLOGY:

§  After taking approval from the Institutional Ethics Committee and Informed Consent for the procedure from the patients, patients will be randomized into either of the Groups A or B using a randomization table.

§  For perioperative analgesia in Group A patients will be givenintrathecal morphine while in Group B patients will be given USG guided Erector Spine Plane Block.

§  Demographic data, important present and past history, history of repeat surgery, presence of other systemic and pulmonary disease, detailed of medications, drug allergy, history of ICU admissions, History of seizures, relevant family history, and ASA status will be included.

§  Along with history a detailed general physical, cardiovascular system, respiratory system, neurological system, airway examination,will be done and information will be recorded. Reports of any abnormal findings related to hematological, biochemical investigations, ECG, X ray any special investigation will be recorded.

§  Radiological information regardinglumbar spine surgery will be noted.

§  Using a standard proformainformation pertinent to the preoperative history, examination, reports of investigations, premedication, induction, airway management, anesthesia technique, intraoperative events.

Procedure:

§  At the review preanesthetic checkup night before surgery patients will be taught about the numeric rating scale (NRS) for pain scoring. Patients will be kept fasting for 6–8 hours and premedicated with tablet ranitidine 150 mg and tablet alprazolam 0.25 mg orally to be taken nightbefore surgery with a sip of water.

§  On arrival in the operative room, standard monitoring equipment will be attached (electrocardiogram lead II and lead V5, pulse oximeter, and noninvasive blood pressure) and baseline vital parameters such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), respiratory rate (RR), and oxygen saturation (SpO2) will be recorded just before induction of anesthesia. Peripheral venous access with 18G/20G IV cannula will be secured.

§  Anesthesia will be induced with propofol 2-2.5 mg/kg, midazolam 0.07-0.015 mg/kg and fentanyl 1-2 mcg/kg intravenously. Endotracheal intubation will be facilitated with vecuronium bromide 0.1 mg/kg intravenously. Anesthesia will be maintained with air and oxygen in ratio of 2:1 with sevoflurane 2% with MAC 0.8 to 1.0.Neuromuscular relaxation will be maintained with continuous infusion of vecuronium bromide at the dose of .03mg/kg/hour.

§  The lungs will be mechanically ventilated to keep end‑tidal CO2 within normal range. Temperature probe will be inserted and temperature will be recorded. The patient will be catheterized and urine output will be recorded. The patient will be made prone for surgery. Thirty minutes before completion of surgery, all patients will be given injection ondansetron 0.15 mg/kg

§  In the postoperative period, following parameter will be noted at 1, 2, 3, 6, 12, and 24 hours after the end of surgery: Pain Score using NRS, Rescue analgesic, Patient Satisfaction Scale, RSS, Noninvasive Blood Pressure, HR, RR, SpO2, and side effects like Bradycardia (<50 beats/min), PONV, respiratory depression (RR <10), sedation, pruritus will be recorded and optimally treated.

§  Rescue analgesics will be administered to patients at NRS >3, Paracetamol 10-15 mg/kg intravenous as first rescue drug, Diclofenac Sodium 1-2 mg/kg intramuscular or intravenous as second rescue drug and third rescue drug to be Tramadol 1 mg/kg.

§  Bradycardia will be treated with Atropine 0.05 mg/kg

§  PONV will be treated with Ondansetron 0.15 mg/kg intravenously.

§  Respiratory depression will be managed with oxygenation, naloxone 0.4 mg intravenous, repeating up to maximum dose of 8 mg at interval of 2 minutes.

NRS

RamseySedation Score:

Patient Satisfaction Scale:

In the postoperative period at the end of 24 hours, patients will be assessed for the quality of pain relief on a four‑point pain satisfaction scale with 1 ‑ excellent, 2 ‑ very good, 3 ‑ satisfactory, and 4 ‑ poor.

Intrathecal Morphine:

[Drug preparation: 0.3 mg Morphine in 2 ml 0.9% NS]

The index anesthesiologist prepared the aforementioned injection taking all aseptic precautions and delivered it to the operating room to ensure all parties were blinded.

Patients will be placed in sitting position, and the spinal puncture will be performed at L3–L4 interspace using a 25‑gauge whitacre pencil‑point spinal needle. Once free flow of cerebrospinal fluid will be confirmed, the Intrathecal Morphine 0.3 mg in 2 ml normal saline 0.9% will be given. The patient will be placed supine after the procedure.

Erector Spine Plane Block:

[Drug preparation: 30 mL of 0.5% ropivacaine (Total maximum dose 3mg/kg)]

Patients will be placed in the prone position and the spine palpated upwards from L4-L2; the position of L3 will be marked on the skin. After ensuring skin asepsis in a standard manner, a high frequency linear USG probe in a sterile sheath will be placed longitudinally 3 cm lateral to the L3 spinous process. The quadratus lumborum and erector spinae muscles will be identified from outwards to inwards. The skin will be then infiltrated with local anesthetic, and a 20-G Quincke needle will be inserted using an in-plane cephalad to caudal direction approach, so that the tip will be placed into the fascial plane on the deep (anterior) aspect of the erector spinae muscle. The correct location of the needle tip will be confirmed by visible fluid spread below the erector spinae muscle off the bony shadow of the transverse process. A total volume of 15 ml of 0.5% ropivacainewill be injected through the needle. The procedure will be then repeated on the opposite side. Electrocardiography and oxygen saturation will be monitored continuously, and heart rate and noninvasive blood pressure recorded at baseline, after performing the block, and every 5 minutes for 30 minutes. Any block-related complications, such as hypotension or vascular puncture, will be recorded.

Postoperative period, following parameter will be noted at 1, 2, 3, 6, 12, and 24 hours after the end of surgery: Pain Score using NRS, Rescue analgesic, Patient Satisfaction Scale, RSS, Noninvasive Blood Pressure, HR, RR, SpO2, and side effects like Bradycardia (<50 beats/min), PONV, respiratory depression (RR <10), sedation, pruritus will be recorded and optimally treated.

Follow-Up

Group B (n=37) Erector Spine Plane Block (ESPB) for perioperative analgesia

Enrollment

Group A: (n=37) Intrathecal morphine for perioperative analgesia

Allocation

CONSORT 2010

Follow Up

Assessed for eligibility (n=74  )

Exclusion criteria: o    Patient Refusal o    Coagulation disorders o    Allergies to morphine or study drugs o    Revision lumbar surgeries o    Severe respiratory illness (COPD, OSA) o    Psychiatric illness o    Pregnancy or Lactation o    Chronic opioid or analgesic use/abuse

Randomized (n= 74 )

Inclusion criteria: o    Patient of either sex, Age group of20-65years o    ASA I or II o    Lumbar spine surgery

Follow up

 

REVIEW OF LITERATURE

Yayik, A. M et al., 2019 [32]studied the Postoperative Analgesic Efficacy of the Ultrasound-Guided Erector Spinae Plane Block in Patients Undergoing Lumbar Spinal Decompression Surgery. They included sixty patients undergoing open lumbar decompression surgery were randomly assigned to 2 groups. The ESP Group (n = 30) underwent bilateral ultrasound-guided ESP block with 0.25 percent bupivacaine in 20 ml. Twenty-four-hour tramadol consumption in the Control Group was significantly higher compared with the ESP Group (370.33 ± 73.27 mg and 268.33 ± 71.44 mg; P < 0.001, respectively) and the difference was 28%, and time to first analgesic requirement was significantly longer in the ESP Group than in the Control Group. They conclude that the patients undergoing open lumbar decompression surgery, ESP block can be utilised in multimodal analgesia to decrease opioid usage and alleviate immediate postoperative pain.

Wang, Y et al., 2020 [33] studied the Preemptive analgesia with a single low dose of intrathecal morphine in multilevel posterior lumbar interbody fusion surgery. They randomly allocated the patients to either the ITM group that received 0.2 mg of ITM or the control (CON) group that received 2 ml of 0.9% saline as a skin infiltration 30 minutes prior to anesthesia induction.The ITM group reported a greater degree of satisfaction with the whole hospitalization experience than the CON group (2.4±0.6 vs. 1.9±0.6, p=.000). The two groups did not significantly differ regarding adverse effects, length of hospital stay, and time taken to regain the ability to walk without support.  Thus, they concluded that preemptive analgesia with ITM considerably improves early postoperative pain control and decreases postoperative patient-controlled intravenous analgesic intake without increasing adverse effects.

Singh S et al., 2020 [34]studied the Bilateral Ultrasound-guided Erector Spinae Plane Block for Postoperative Analgesia in Lumbar Spine Surgery. They scheduled the adults for elective lumbar spine surgery under general anesthesia and randomly assigned to the following: Control group-no preoperative ESP block, or ESP block group-preoperative bilateral US-guided ESP block. Postoperative morphine consumption was significantly lower in patients in the ESP group compared with those in the control group (1.4 ± 1.5 vs. 7.2 ± 2.0 mg, respectively; P<0.001). All patients in the control group required supplemental morphine compared with only 9 (45%) in the ESP block group (P=0.002). Pain scores immediately after surgery (P=0.002) and at 6 hours after surgery (P=0.040) were lower in the ESP block group compared with the control group. Patient satisfaction scores were more favorable in the block group. They conclude that the ESP block group reported much less pain than the control group. In the block group, patient satisfaction levels were significantly higher (P <0.0001). In patients after lumbar spine surgery, US-guided ESP block decreases postoperative opioid demand and increases patient satisfaction compared to conventional analgesia.

Çelik, E. C et al., 2020 [35] studied the Modified thoracolumbar interfascial plane block versus epidural analgesia at closure for lumbar discectomy conducted a randomized, prospective study involving sixty adult patients undergoing single-level lumbar discectomy. There was statistically no difference in terms of opioid consumption from zero to 4th hr and VAS scores in the 1-2 hrs postoperatively (p > 0.05) between groups. At 4-12 hrs and 12-24 postoperatively hrs intervals, total opioid consumption was significantly lower in Group mTLIP compared to Group EAC (p < 0.05). At the 4th, 8th, 12th, and 24th hrs VAS scores were lower in Group mTLIP compared to Group EAC (p < 0.05). Rescue analgesia usage was significantly higher in the Group EAC than in the Group mTLIP They concluded that preoperative bilateral ultrasound-guided modified thoracolumbar interfacial plane block provides more effective postoperative analgesia than epidural analgesia at closure after lumbar discectomy surgery, hence lowering tramadol intake.

Van den Broek et al., 2021 [36] study the evaluation of adding the Erector spinae plane block to standard anesthetic care in patients undergoing posterior lumbar interbody fusion surgery. Twenty patients who received an erector spinae plane block were compared with 20 controls. The Postoperative pain scores in the PACU were lower in patients who received an erector spinae plane block (p = 0.041). Opioid consumption during surgery and in the PACU was not significantly different. Need for patient-controlled analgesia postoperatively was significantly lower in the group receiving an ESP block (p = 0.010). Length of stay in hospital was reduced from 3.23 days (IQR 1.1) in the control group to 2.74 days (IQR 1.6) in the study groupTwenty patients who received an erector spinae plane block were compared with 20 controls. They concluded that the addition of an erector spinae plane block to the analgesic regimen for posterior lumbar interbody fusion surgery seems to decrease postoperative pain and hospitalization duration.

Trivedi, R et al., 2022 [37]- “Intrathecal morphine in combination with bupivacaine as pre-emptive analgesia in posterior lumbar fusion surgery”. They taken two groups the first (ITM group) included patients who had general anaesthesia (GA) with low-dose spinal anaesthesia prior to induction using 1–4 ml of 0.25% bupivacaine and 0.2 mg ITM.1 ml of 0.25% bupivacaine was administered per hour of predicted surgery time, up to a maximum of 4 ml. The median total amount morphine equivalent, administered over the first 48 h following discharge from PACU was 20 mg versus 80 mg. Both are in comparison with the control group. The median length of stay was over 1 day less and the median VAS for pain in recovery was 6 points lower. No evidence was found for a difference in the worst VAS for pain at day two postoperatively. They concluded that the usage of perioperative opioids is greatly reduced when ITM is combined with bupivacaine. In addition, both the time of hospitalisation and the patient’s pain perception are diminished.

Beltrame, S. A., et al., 2022 [38]- “Bilateral Radioscopically Guided Erector Spinae Plane Block for Postoperative Analgesia in Spine Surgery”. Theyperformed a randomized, double-blind clinical trial, in which adults undergoing lumbosacral surgery without fixation were randomly assigned to receive either the standard wound infiltration technique, employing long-term anesthetics, or a radioscopically guided ESP block. Over the first 7 postoperative hours, pain relief was superior in the ESP block group among patients who underwent diskectomies or one-level decompression (p< 0.0001). Using an ESP block also was statistically superior at decreasing all postoperative variables recorded in patients scheduled for multilevel decompression. They conclude that the ESP block is a safe approach that appears to be more effective than the infiltration wound treatment for postoperative pain control in individuals after open spine surgery.

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