INTRODUCTION

Spinal anaesthesia is a commonly used and effective technique which provides rapid and reliable anaesthesia with muscle relaxation for patients undergoing lower abdominal and lower limb surgeries.[1]

In the recent days, Ropivacaine is gaining increasing popularity because of reduced risk of central nervous system and cardiotoxicity, early ambulation and discharge with good quality of post-operative analgesia.[2]

Ropivacaine is a pure S(-) enantiomer of propyl derivative of pipecoloxylidide and a new long- acting amino amide with lower lipid solubility and cardiotoxicity than Bupivacaine. [3,4]

Buprenorphine is an opioid of the phenanthrene morphine class with extremely high binding affinity and a partial agonist activity at the μ- and κ-receptors and partial or full agonist activity at the opioid receptor like I/nociception and λ- receptor and competitive antagonist activity at the κ- receptor. [5]

 Clonidine adrenergic alpha2 agonist. Clonidine apparently produces its sedative and anaesthetic-sparing effects by stimulation of centrally located alpha2 adrenoceptors. Analgesia seems to be mediated mainly by activation of alpha2 adrenoceptors in the dorsal horn of the spinal cord. Administration of clonidine in combination with a local anaesthetic prolongs analgesia and motor blockade. [6]

AIMS &OBJECTIVES

AIM

To compare the efficacy of intrathecal Isobaric Ropivacaine (0.75%)-3.5ml with Buprenorphine 0.2ml (60μg) and Isobaric Ropivacaine (0.75%)- 3.5ml with clonidine 0.2ml (30 μg) in patients undergoing lower limb orthopaedics and lower abdominal surgeries under Subarachnoid block.

OBJECTIVES

PRIMARY OBJECTIVES

To compare onset and duration of sensory and motor blockade.

To assess and compare the haemodynamic parameters between both groups.

SECONDARY OBJECTIVES

To assess two segment regression time.

To assess post operative pain using Visual Analogue Score(VAS).

Side effects if any.

STUDY DESIGN:

 A prospective randomized double-blind study.

SAMPLE SIZE:

The sample size is calculated for the two independent study group for continuous variables for randomised control trial using the formula for Continuous variable- Non- Inferiority design.

N- size per group

Z- Standard normal deviate

δ0- Clinically acceptable margin

s2- polled standard deviation of comparison groups

α- Type 1 error

β- Type 2 error

The sample size is based on the previous study in which the Mean (± SD) duration of sensory blockade was higher in patients receiving Ropivacaine (0.75%) with Buprenorphine (215.8± 24.36) than in patients receiving Ropivacaine (0.75%) with isotonic sodium chloride (161.80± 19.34), study by Singh et al.

Sample size: 66 Patients

Group 1= 33 Patients ; Group 2= 33 Patients

Where

Significance level α=0.05

Power (1-β)=0.20

Ratio of sample size, Treat/control=1

SD=0.2; Drop out (%)=10%

Allowable difference= 0.3 (Comparative study of intrathecal isobaric Ropivacaine (0.75%) with Buprenorphine 0.2ml (60μg) and Isobaric Ropivacaine (0.75%) with Clonidine 0.2ml (30 μg) patients undergoing lower limb and abdominal procedures under Subarachnoid block)

The sample size calculated per group

   Group A = 33 patients

   Group B = 33 patients

Patients in each group will receive anaesthesia as follows:

Group A (n= 33) Patients will receive 3.5 ml of Isobaric Ropivacaine (0.75%) + 0.2 ml Buprenorphine (60mcg)

Group B (n= 33) Patients will receive 3.5 ml of Isobaric Ropivacaine (0.75%) + 0.2ml clonidine (30mcg)

MATERIALS AND METHODS

Inclusion criteria:

1. American Society of Anesthesiologists (ASA) grade I-III

2. Age group between 18-60 years of both sexes.

3. Scheduled for Elective and emergency lower limb orthopedic surgeries under Spinal Anaesthesia.

Exclusion criteria:

1. Patient refusal

2. History of allergy to study drugs

3. Post spinal surgeries, Spinal Deformities, skin sepsis in lumbar region, patients with pre-existing neurological disorders.

4. Coagulopathy, Dysrhythmia

5. Major Hepatic, Renal and Cardiovascular Dysfunction

6. BMI >35, Height <140cm

7. Surgeries involving major blood loss

The enrolled subjects will be randomized into the 2 study groups using computer generated randomization code.

All the patients will receive Tab Alprazolam 0.5mg HS and Tab Ranitidine 150mg HS and 6am in the morning of surgery.

On arrival in Pre-op area an IV access with 18G IV cannula will be secured and RL will be started.

Establishment of proper standard monitoring systems (pulse oximetry, continuous electrocardiography and non-invasive blood pressure monitoring and SpO2).

Sitting position is recommended for all patients included in this study. Under all aseptic precautions L3-L4 inter-space will be infiltrated with 2ml of 2% Inj. Lignocaine.

Study drug will be prepared by the person not involved in the study. The subarachnoid space will be entered at L3-L4 intervertebral-space via the midline approach using 26-Gauge Quincke spinal needle. The correct needle placement will be identified by free flow of cerebrospinal fluid and 3.7 ml of study drug will be injected by the anesthesiologist.

The patient will be placed in supine position to carry over the initial assessment. The onset of sensory and motor blockade will be assessed at baseline and 3 min interval up to 15 min.

The onset of sensory blockade will be considered as loss of cold sensations at T10 level and the highest level of sensory blockade will also be noted.

The onset of motor blockade will be evaluated using Modified Bromage score 2.

Two segment sensory blockade and the regression of Motor Blockade which is score 0 will be noted.

Continuous Vital monitoring includes patient’s HR, NIBP, RR and SPO2 will be monitored at 3 min interval up to 15 minutes then every 5 minutes up to 60 minutes then every 10 minutes till end of the procedure.

Throughout the procedure, patient will receive 6 liters of oxygen per minute through facemask.

Reference:

O’Connor PJ, Hanson J, Finucane BT. Induced hypotension with epidural/general anesthesia reduces transfusion in radical prostate surgery. Can J Anaesth 2006;53:873�’80.

Sultan MA, Ali Shams TM, Mageed NA, El�’ebidy MG. Intrathecal hyperbaric ropivacaine versus hyperbaric bupivacaine in geriatric hypertensive patients. Benha M. J. 2005;22:479.

Rattenberry W, Hertling A, Erskine R. Spinal anaesthesia for ambulatory surgery. BJA Educ. 2019 Oct;19(10):321-328. doi: 10.1016/j.bjae.2019.06.001. Epub 2019 Aug 13. PMID: 33456853; PMCID: PMC7807930.

Latwal BS, Singam A, Shrey S, et al. A comparative study of intrathecal 0.5% hyperbaric bupivacaine & intrathecal 0.75% isobaric ropivacaine in lower abdominal surgeries. J. Evolution Med. Dent. Sci. 2020;9(05):256-261, DOI: 10.14260/jemds/2020/58

Gupta R, Bogra J, Singh PK, Saxena S, Chandra G, Kushwaha JK. Comparative study of intrathecal hyperbaric versus isobaric ropivacaine: A randomized control trial. Saudi J Anaesth 2013;7:249-53.

Singh AP, Kaur R, Gupta R, Kumari A. Intrathecal buprenorphine versus fentanyl as adjuvant to 0.75% ropivacaine in lower limb surgeries. J Anaesthesiol Clin Pharmacol 2016;32:229-33.