"Comparative evaluation of post-operative analgesia produced by injection Levobupivacaine (0.125%) vs injection Ropivacaine (0.25%) with injection dexamethasone as common additive for USG guided combined adductor canal and popliteal block for tibia and fibula surgeries."- A Randomised Double Blinded Clinical Study

-AIM:

·       To compare duration of postoperative analgesia in tibia and fibula fracture surgeries with inj. Levobupivacaine(0.125%)  and inj. Ropivacaine (0.25%) with inj. Dexamethasone(4 mg) as a common additive.

OBJECTIVE:

o  Primary objective:

               To compare the duration of analgesia

o  Secondary objectives:

Haemodynamic stability post-operatively

Comparison of VAS score between two groups

Sample size and sampling method:

        Sample size is calculated as 72 patients, i.e. for each group 36 patients, taking the difference of mean between two groups (11.1) and pooled SD (4.3), to achieve a power of 80% and a level of significance of 5%, for declaring that one drug is comparable to the other with equivalence margin of 8%  and attrition rate of 10% using statulator tool.⁽²⁾

INCLUSION CRITERIA:

·       AGE-18 years to 70 years

·       Weight-40 to 80 kg

·       Gender-Male &Female

·       American society of anaesthesia grading: l, ll

EXCLUSION CRITERIA:

·       Patient refusal

·       Allergy to local anaesthetics

·       Local site infection

·       Bleeding tendency

·       Post-operative oedema at the site of block

·       Duration of surgery is >180 mins

·       Pre-existing neurological deficit

·       Patients with dementia, psychiatric illness, unco-operative patients

·       Patients with severe cardio-vascular & respiratory comorbidity

Group A:

Inj. Levobupivacaine (0.125%) 30 ml+ Inj. Dexamethasone (4 mg) 1ml

(Equally divided in two blocks)

Group B:

         Inj. Ropivacaine (0.25%) 30 ml+ Inj. Dexamethasone (4 mg) 1 ml

         (Equally divided in two blocks)

INTERVENTION:

·       A detailed pre anaesthetic examination will be done comprising of present and past complaints, personal history, medical history, history of previous anaesthesia exposure. General and systemic examination will be done and relevant baseline investigations ordered.After explaining risk and benefit involved in the study and obtaining written informed consent, patient will be taken to operation room.

·       Under all aseptic and antiseptic precautions , sub-arachnoid block(SAB) will be given with Inj. Bupivacaine heavy (0.5%) 3.4 ml+ Inj. Butorphanol (0.2 mg) 0.2 ml, to make total volume of 3.6 ml injected into the sub-arachnoid space in the L3-L4  intervertebral space using 23G Quincke’s spinal needle.

·       After completion of procedure; for adductor canal block (ACB) patient’s   leg will be externally rotated in supine position. Adductor canal is bounded medially by Adductor longus and Magnus muscle and laterally by Vastus Medialis muscle, It’s roof is formed by the Sartorius muscle. High frequency linear ultrasound probe will be placed on the anterior aspect at the mid-thigh level. The femur bone will be  identified and probe moved medially until the boat shaped Sartorius muscle and pulsatile femoral artery is visualised.23 G spinal needle will be  inserted via in plane technique and drug injected lateral to the artery, deep to the sartorius muscle after negative aspiration.

·       For Saphenous popliteal block, patient would be placed in lateral position on the opposite side of limb which has to be blocked. The limb to be blocked is partially flexed at the knee joint. We will use high frequency linear ultrasound probe & placed at popliteal fossa to identify separate tibial and common peroneal nerve lying superficially and posteriorly to popliteal artery. Movement of the probe proximally brings   tibial and common peroneal nerve together to form the sciatic nerve 2-3 cm above the popliteal crease. At this level using in plane technique with 23G spinal needle, drug will be injected after negative aspiration.

·       Any complication during procedure and post-operatively will be noted.

OUTCOME MEASURES:

Primary outcome:

Comparison of duration of analgesia between two drug combination (inj. Levobupivacaine 0.125% + inj. Dexamethasone VS inj. Ropivacaine 0.25% +inj. Dexamethasone) in combined adductor canal and popliteal block for post op analgesia in tibia & fibula surgeries.

Secondary outcome:

-         Assessment of post-operative haemodynamic stability

-        Comparison of VAS score between two groups

STATISTICAL ANALYSIS PLAN

         The statistical analysis for the observed data will be done with two independent means for duration of analgesia and will be compared using student’s ‘t-test’. All data will be entered in Microsoft excel. ‘Chi-square’ will be done for demographic details. Analysis will be done by using graph pad software.