Comparison of intrathecal morphine vs erector spine plane block for perioperative analgesia in patients undergoing lumbar spine surgery: A prospective single blind randomized controlled trial

INTRODUCTION

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

Perioperative analgesia appears to beone of the most important modifiable factors that can reduce the morbidityassociated with these complex spine procedures and hasten recovery [2]. Localinfiltration analgesia is a commonly utilized approach [3-4]. In 1979 [5], thefirst description of intrathecal morphine (ITM) injections was made. Severalstudies have since documented and popularized the use of ITM, particularly inthe setting of gastrointestinal and gynaecological surgery [6]. As a result ofthe problems that have been recorded (respiratory depression, pruritis, andnausea/vomiting), as well as doubts regarding the ideal dose and duration ofanalgesia, ITM is still surrounded by a number of uncertainties. The efficacyof 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 thethecal sac and its reliability [10–12]. It is currently believed thatmultimodal postoperative analgesia is one of the determinants of acceleratedrecovery after surgery (ERAS) [13]. Knee, hip, and shoulder procedures appearprominently in the media coverage of this technique.

In spinal procedures, the managementof post-operative pain has been a concern. The typical analgesic strategy ispredicated on the use of opioids; hence, the adverse effects associated withopioids 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 reducepost-operative pain and opioid-related side effects [15]. It requires the useof numerous medications and delivery methods.

Regional anaesthesia is an essential aspectof MMA [16-17]. Recently, the erector spinae plane block (ESPB), a noveltechnique for regional anaesthetic, has attracted considerable interest. ESPBwas initially proved to alleviate pain associated with shingles [18]. Theanaesthetic is administered between the transverse processes of the vertebraeand the erector spinae muscle [19-20]. After injection, the anaestheticdiffuses cranially and caudally and acts on the ventral and dorsal rami of thespinal nerves [17-19]. As the local anaesthetic is administered at a greaterdistance from the spinal cord, the danger of causing damage to the cord andresulting complications is reduced. In addition, the block is relatively simpleto 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 controlledtrials (RCTs) are investigating the effect of ESPB in spinal procedures;nevertheless, the results are inconsistent.

In 2016, [23] the ESP block was firstexplained. Local anaesthetic is injected beneath the erector spinae musclegroup using ultrasonography [23, 24]. By obstructing the ventral and dorsalrami of the spinal neurons, a sensory blockade is produced over the anteriorand dorsolateral thorax. Recent case studies reveal that an ESP block has agood effect on pain for numerous purposes, including vertebral metastases,lumbar transverse process fractures, or after lumbar spine fusion and scoliosissurgery [25-28]. Sonoanatomy is readily identifiable, and there are nostructures in close proximity that are at risk of needle injury [23, 29]. Thetransverse process functions as an anatomical barrier that prevents needleinsertion into the pleura or veins, hence avoiding pneumothorax or hematoma. Inaddition, the needle is quite distant from the vertebral canal, so the dangerof spinal cord injury is extremely minimal [30]. A block of the ESP preservesbladder and motor neuron function, allowing for early mobilization. Since motorfunction is unaffected, it is possible to evaluate the spinal cord’sneurological function immediately after surgery. Thus, the aim of this study isto compare the intrathecal morphine and erector spine plane block efficacy forperioperative analgesia in patient undergoing lumbar spine surgery.

A****IM AND OBJECTIVES

·        Comparison of intrathecal morphine vserector spine plane block for perioperative analgesiainpatient undergoing lumbar spine surgery.

 Â·       PrimaryObjective:

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

·       SecondaryObjective:

o  Tocompare the sedation score

o  Tocompare the patient satisfaction score

o  Tocompare the consumption of rescue analgesic

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

o  Tostudy the complications (PONV, Respiratory depression, Bradycardia, Pruritus)

                MATERIALAND METHODS

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

•      Study Design: Prospective, Single Blind, Randomized ControlledTrial

•      Sample Size: 74 (37 in eachgroup)

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

n=

 n= Sample size

σ = Standard Deviation

∆ = Difference of means

κ= Ratio

Z1-α/2= Two-sided Zvalue

Z1-β= Power

 

Confidence Interval (2-sided)

95%

|Power

80%

| |Pain on VAS at H24

(De Bie A et al., 2020) [32]

CONTROL

GROUP

ITM

GROUP

Difference*

|Mean

5.4

 4.2

 1.2

|Standard deviation

1.8

 1.7

  |Variance

3.24

 2.89

  |

---

|Sample size

68

|

---

|Attrition bias (10%)                                                      6

|Total Sample size                                         74 (37 in each group)

·       Study Groups:

Group A: Intrathecalmorphine for perioperative analgesia

Group B: Erector Spine Plane Block(ESPB) for perioperativeanalgesia

·       Statistical Plan

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

 Â·       Inclusion Criteria:

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

o  ASA I or II

o   Lumbarspine surgery

·       Exclusion Criteria:

o   PatientRefusal

o   Coagulationdisorders

o   Allergiesto morphine or study drugs

o   Revisionlumbar surgeries

o   Severerespiratory illness (COPD, OSA)

o   Psychiatricillness

o   Pregnancyor Lactation

o   Chronicopioid or analgesic use/abuse

  METHODOLOGY:

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

§  Forperioperative analgesia in Group A patients will be givenintrathecal morphinewhile in Group B patients will be given USG guided Erector Spine Plane Block.

§  Demographic data, important presentand past history, history of repeat surgery, presence of other systemic andpulmonary disease, detailed of medications, drug allergy, history of ICUadmissions, History of seizures, relevant family history, and ASA status willbe included.

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

§  Radiological information regardinglumbarspine surgery will be noted.

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

Rescue Analgesics

Paracetamol 10-15 mg/kg IV

|Diclofenac Sodium 1-2 mg/kg IM/IV

|Tramadol 1-2 mg/kg IV

|Bradycardia

Atropine 0.05mg/Kg

|PONV

Ondansetron 0.15 mg/kg IV

|Respiratory depression

Oxygenation

|Naloxone 0.4 mg IV repeated to max. dose of 8 mg

 Procedure:

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

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

§  Anesthesiawill be induced with propofol 2-2.5 mg/kg, midazolam 0.07-0.015 mg/kg and fentanyl1-2 mcg/kg intravenously. Endotracheal intubation will be facilitated withvecuronium bromide 0.1 mg/kg intravenously. Anesthesia will be maintained with airand oxygen in ratio of 2:1 with sevoflurane 2% with MAC 0.8 to 1.0.Neuromuscularrelaxation will be maintained with continuous infusion of vecuronium bromide atthe dose of .03mg/kg/hour.

§  Thelungs will be mechanically ventilated to keep end‑tidal CO2 within normalrange. Temperature probe will be inserted and temperature will be recorded. Thepatient will be catheterized and urine output will be recorded. The patient willbe made prone for surgery. Thirty minutes before completion of surgery, allpatients 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 endof surgery: Pain Score using NRS, Rescue analgesic, Patient Satisfaction Scale,RSS, Noninvasive Blood Pressure, HR, RR, SpO2, and side effects likeBradycardia (<50 beats/min), PONV, respiratory depression(RR <10), sedation, pruritus will be recorded and optimally treated.

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

§  Bradycardiawill be treated with Atropine 0.05 mg/kg

§  PONVwill be treated with Ondansetron 0.15 mg/kg intravenously.

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

NRS

RamseySedationScore:

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 painsatisfaction scale with 1 ‑ excellent, 2 ‑ very good, 3 ‑ satisfactory, and 4 ‑poor.

GRADE

LEVELS OF SATISFACTION

|Excellent (1)

|Very good (2)

|Satisfactory (3)

|Poor (4)

IntrathecalMorphine:

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

The index anesthesiologist prepared theaforementioned injection taking all aseptic precautions and delivered it to theoperating room to ensure all parties were blinded.

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

ErectorSpine Plane Block:

[Drugpreparation: 30 mL of 0.5% ropivacaine (Totalmaximum dose 3mg/kg)]

Patients will be placed in the prone position andthe spine palpated upwards from L4-L2; the position of L3 will be marked on theskin. After ensuring skin asepsis in a standard manner, a high frequency linearUSG probe in a sterile sheath will be placed longitudinally 3 cm lateral to theL3 spinous process. The quadratus lumborum and erector spinae muscles will beidentified from outwards to inwards. The skin will be then infiltrated withlocal anesthetic, and a 20-G Quincke needle will be inserted using an in-plane cephalad to caudal directionapproach, 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 theneedle tip will be confirmed by visible fluid spread below the erector spinaemuscle off the bony shadow of the transverse process. A total volume of 15 mlof 0.5% ropivacainewill be injected through the needle. The procedure will bethen repeated on the opposite side. Electrocardiography and oxygen saturationwill be monitored continuously, and heart rate and noninvasive blood pressurerecorded at baseline, after performing the block, and every 5 minutes for 30minutes. Any block-related complications, such as hypotension or vascularpuncture, 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 theUltrasound-Guided Erector Spinae Plane Block in Patients Undergoing LumbarSpinal Decompression Surgery. They included sixty patients undergoing openlumbar decompression surgery were randomly assigned to 2 groups. TheESP Group (n = 30) underwent bilateral ultrasound-guided ESP block with 0.25percent bupivacaine in 20 ml. Twenty-four-hour tramadol consumption in the Control Groupwas significantly higher compared with the ESP Group (370.33 ± 73.27 mg and268.33 ± 71.44 mg; P < 0.001, respectively) and the difference was 28%, andtime to first analgesic requirement was significantly longer in the ESP Groupthan in the Control Group. They conclude that the patients undergoing openlumbar decompression surgery, ESP block can be utilised in multimodal analgesiato decrease opioid usage and alleviate immediate postoperative pain.

Wang, Y et al., 2020 [33] studiedthe Preemptive analgesia with a single low doseof intrathecal morphine in multilevel posterior lumbar interbody fusionsurgery. They randomly allocated thepatients 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 minutesprior to anesthesia induction.The ITM group reported a greater degree ofsatisfaction 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 differregarding adverse effects, length of hospital stay, and time taken to regainthe ability to walk without support. Thus, they concluded that preemptive analgesia with ITM considerablyimproves early postoperative pain control and decreases postoperativepatient-controlled intravenous analgesic intake without increasing adverseeffects.

Singh S et al., 2020 [34]studied the Bilateral Ultrasound-guided Erector SpinaePlane Block for Postoperative Analgesia in Lumbar Spine Surgery. They scheduledthe adults for elective lumbar spine surgery under general anesthesia andrandomly assigned to the following: Control group-no preoperative ESP block, orESP block group-preoperative bilateral US-guided ESP block. Postoperativemorphine consumption was significantly lower in patients in the ESP groupcompared 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 requiredsupplemental 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 aftersurgery (P=0.040) were lower in the ESP block group compared with the controlgroup. Patient satisfaction scores were more favorable in the block group. Theyconclude that the ESP block group reported much less pain than the controlgroup. In the block group, patient satisfaction levels were significantlyhigher (P <0.0001). In patients after lumbar spine surgery, US-guided ESPblock decreases postoperative opioid demand and increases patient satisfactioncompared to conventional analgesia.

Çelik, E. C et al., 2020 [35] studied the Modified thoracolumbar interfascial plane block versusepidural analgesia at closure for lumbar discectomy conducted a randomized,prospective study involving sixty adult patients undergoing single-level lumbardiscectomy. There was statistically no difference in terms of opioidconsumption 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 hrsintervals, total opioid consumption was significantly lower in Group mTLIPcompared to Group EAC (p < 0.05). At the 4th, 8th, 12th, and 24th hrs VASscores were lower in Group mTLIP compared to Group EAC (p < 0.05). Rescueanalgesia usage was significantly higher in the Group EAC than in the GroupmTLIP They concluded that preoperative bilateral ultrasound-guided modifiedthoracolumbar interfacial plane block provides more effective postoperativeanalgesia than epidural analgesia at closure after lumbar discectomy surgery,hence lowering tramadol intake.

Van den Broek et al., 2021 [36] study the evaluationof adding the Erector spinae plane block to standard anesthetic care inpatients undergoing posterior lumbar interbody fusion surgery. Twentypatients who received an erector spinae plane block were compared with 20controls. The Postoperativepain scores in the PACU were lower in patients who received an erector spinaeplane block (p = 0.041). Opioid consumption during surgery and in the PACU wasnot significantly different. Need for patient-controlled analgesiapostoperatively 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) inthe control group to 2.74 days (IQR 1.6) in the study groupTwentypatients who received an erector spinae plane block were compared with 20controls. They concluded that the addition of an erector spinae plane block tothe analgesic regimen for posterior lumbar interbody fusion surgery seems todecrease postoperative pain and hospitalization duration.

Trivedi, R et al., 2022 [37]- “Intrathecal morphine in combination with bupivacaine as pre-emptiveanalgesia in posterior lumbar fusion surgeryâ€. They taken two groups the first (ITM group) includedpatients who had general anaesthesia (GA) with low-dose spinal anaesthesiaprior to induction using 1–4 ml of 0.25% bupivacaine and 0.2 mg ITM.1 ml of0.25% bupivacaine was administered per hour of predicted surgery time, up to amaximum of 4 ml. The median total amount morphine equivalent, administered overthe first 48 h following discharge from PACU was 20 mg versus 80 mg. Both arein comparison with the control group. The median length of stay was over 1 dayless and the median VAS for pain in recovery was 6 points lower. No evidencewas found for a difference in the worst VAS for pain at day twopostoperatively. They concluded that the usage of perioperative opioids isgreatly reduced when ITM is combined with bupivacaine. In addition, both thetime 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 PostoperativeAnalgesia in Spine Surgeryâ€. Theyperformed a randomized, double-blind clinical trial, in which adultsundergoing lumbosacral surgery without fixation were randomly assigned toreceive either the standard wound infiltration technique, employing long-termanesthetics, or a radioscopically guided ESP block. Over the first 7postoperative hours, pain relief was superior in the ESP block group amongpatients who underwent diskectomies or one-level decompression (p< 0.0001).Using an ESP block also was statistically superior at decreasing all postoperativevariables recorded in patients scheduled for multilevel decompression. Theyconclude that the ESP block is a safe approach that appears to be moreeffective than the infiltration wound treatment for postoperative pain controlin individuals after open spine surgery.

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