Efficacy of Magnesium Vs Dexamethasone as an adjuvant to Ropivacaine in Ultrasound guided Adductor Canal Block for postoperative analgesia in patients undergoing Total Knee Replacement surgery- A Prospective Double Blinded Randomized Controlled Study

My study is "Efficacy of Magnesium Vs Dexamethasone as an adjuvant to Ropivacaine in Ultrasound guided Adductor Canal Block for postoperative analgesia in patients undergoing Total Knee Replacement surgery: A Prospective, Double Blinded Randomized Controlled Study**"**

Type of study: Prospective Randomized controlled observational double blind study

Patient age-group : 18 year to 85year

diagnosis:    osteoarthritis

Procedure of study:

1. After clearance from institutional ethical committee, Patients undergoing unilateral TKR surgery will be recruited for our study.

2.They will be randomly allocated by computer generated randomization number into two groups.

Group D (Ropivacaine + Dexamethasone & Group M (Ropivacaine + MgSO4)

3. During Pre-Anesthesia Checkup (PAC) patients will be introduced to pain NRS (Numerical Rating Scale), CADD PCA (Patient Controlled Analgesia) and will be informed about the study.

4. Written informed consent will be obtained from each patient.

5. Choice of anesthesia (GA/SA) for surgery will be as per the attending anesthesiologist.

Pre-incision USG guided ADDUCTOR CANAL BLOCK –

The group allocation list will be discreetly shared with the attending anesthesiologist who will prepare the study drug syringes as per the sequence number and assigned patients to the trial groups.

The study drugs will be prepared in an identical syringes as colorless solutions for administration to ensure blinding.

Patients will be subsequently followed up by a researcher who is unaware of the group allocation.

Thus effectively, the anesthesiologist performing the block will not be blinded to the procedure, but the patient and assessor of pain NRS were blinded to group allocation.

The anesthesiologist perform the block will be registered  under PCPNDT registration.

ADDUCTOR CANAL BLOCK PROCEDIURE

Patient will be in supine position on operating table under anesthesia with all standard monitoring.

The side to be operated is reconfirmed with surgery team as part of safe surgical checklist and positioned with external rotation knee slightly  flex

The block area will be prepared with 5% povidone iodine and cordoned off by surgical drapes

A linear transducer of USG machine (GE VENUE GO) will be cleaned, lubricated with sono jelly and draped in a sterile plastic cover.

The medial aspect of the thigh will be scanned in a transverse axial plane using the linear probe to obtain a short-axis view of the femoral artery at the mid-femoral level.

If the artery is not immediately obvious, several maneuvers can be used to identify it, including color Doppler scanning to trace the femoral artery caudally from the inguinal crease.

Once the femoral artery has been identified, the probe will be moved distally to trace the femoral artery to the point at which it deviates posteriorly into the popliteal fossa indicating its passage through the adductor hiatus to become the popliteal artery. At this point, the saphenous nerve continues its original course just underneath the sartorius muscle.

At a distance of no more than 7cm proximal to the medial condyle, a short-axis view of the sartorius and vastus medialis muscles will be obtained with the saphenous nerve identified between the two muscles.

The operator will use an in-plane approach and will advance the needle from lateral to medial into the adductor canal through sartorius or vastus medialis, aspirated and injected a test dose of 1 ml of the normal saline solution, will observe the spread to ensure the needle tip in the adductor canal.

If  the intravascular placement of the needle is seen or if no spread of saline solution is seen then the operator will reposition the needle and will repeat the previous step again.

After confirming the target location of the needle tip, the injection of the 21 mL of study drug solution will be given in aliquots of 2- 3 ml and aspirating every 5 ml to rule out any intravascular injection.

Group D  will receive 20 ml of 0.2% of Ropivacaine with 4 mg of Dexamethasone in 1 ml while Group M will receive 20 ml of 0.2% of Ropivacaine with 500 mg of MgSO4 in 1 ml.

Primary Outcome:  total Opioid Consumption in post operative 24 hour  period in patients undergoing TKR**.**

Secondary Outcome:

VAS score on movement – (knee bend +/-walk )

VAS score at rest

Need of rescue analgesic

Nausea & vomiting

Patient satisfaction

Based on the outcome what type of analysis and data collection:

The duration of study will be from IEC approval date till 18 months and 52 no. of patients will be included in this study.

Data analysis will be done by statistical tests and results obtained may be published in journal.

Patient Information Sheet will be provided to all patients. Patient Information Sheet will contain methodology, risks, and benefits of the study and before enrolling patients in the study, Informed Consent will be taken from them. No active intervention will be done by the Primary Investigator. The study will be done after approval from Institutional Ethics Committee is granted.