COMPARISON OF ANALGESIC EFFICACY OF LEVOBUPIVACAINE AND LEVOBUPIVACAINE WITH NALBUPHINE IN LOWER ABDOMINAL SURGERIES UNDER SUBARACHNOID BLOCK

Althoughthere are many studies comparing the analgesic efficacy of nalbuphine added tobupivacaine or bupivacaine alone for lower abdominal surgeries, there is nostudy comparing the effect of addition of nalbuphine to levobupivacaine orlevobupivacaine alone. So in the present study, we propose to compare theanalgesic efficacy of levobupivacaine with or without nalbuphine in lowerabdominal surgeries.**Aim:**To compare the analgesic efficacy of levobupivacaine with or without nalbuphinein patients undergoing lower abdominal surgeries under subarachnoid block.

**Objectives:**To compare levobupivacaine with or without nalbuphine in patients undersubarachnoid block in terms of:-

Primary objective:

Analgesic efficacy:

1.      Timeof regression of the level of sensory blockade to T12 dermatome.

2.      Durationof effective analgesia (Time from the subarachnoid block to the time of patient’sfirst complaint of pain (VAS ≥ 3).

Secondary objective:

1.     Quality of sensory block.

2.     Quality of motor block.

3.     Side effects like nausea, vomiting,hypotension, bradycardia, pruritus and any other.

Population/participantsInclusion criteria:

Patients belonging to ASA grade I or II,between 18-65 years of age, and height 150-180 cm, about to undergo lowerabdominal surgeries under subarachnoid block will be included in the study.

Exclusion criteria:

Patients who do not give consent forsubarachnoid block.

Patients with infection at injectionsite.

Patients with coagulopathy.

Patients with space occupying lesion.

Patients with increased intracranialtension.

Patients with seizure disorder,pre-existing neurological deficit, any spine deformity.

Patients with hepatic and renal disease.

Patients who are on antiarrhythmics.

Drug addicts and chronic alcoholic.

 Samplesize: A minimum of 50 patients (25 in each group) will berecruited.

From a previous study, time ofregression of sensory block to T12 dermatome with  2.5 ml of 0.5% isobaric levobupivacaine was139.5±46.9 minutes. Considering the same standard deviation of 46.9 minutes inlevobupivacaine and levobupivacaine with 1 mg nalbuphine  group, to estimate a difference of 40 minutes intime of regression of sensory block to T12 dermatome , at 5% level of significanceand 80% power,  22 cases are required ineach group. Therefore, it was decided to include 25 patients in each group.They will be randomly allocated in one of the two groups using a computer generatedrandom number table.

**Methods:**Patientswill be randomly allocated to one of the two groups:-

Group-LS: 12.5 mg of 0.5% isobaric levobupivacaine (2.5 ml)+ normal saline(0.5ml)

Group-LN:12.5 mg of 0.5% isobaric levobupivacaine (2.5 ml)+ 1 mg nalbuphine(0.1 ml)

• normal saline(0.4 ml)

                  The total volume of intrathecal drugwill be 3 ml in both the groups.

Under continuous monitoring, subarachnoidblock will be performed under all aseptic precautions as per the standardprotocol. Patients will be assessed for characteristics of sensory and motorblock, sedation score, haemodynamic parameters, pain score and side effects.

OUTCOMEMEASURES

Primary:

Analgesic efficacy:

1. Time of regression of the level ofsensory blockade to T12 dermatome.

2. Duration of effective analgesia ( Time from the subarachnoid block tothe time of patient’s first complaint of pain(VAS ³3).

Secondary:

1.     Quality of sensory block.

2.     Quality of motor block.

3.     Side effects like nausea, vomiting,hypotension, bradycardia, pruritus and any other.

 StatisticalAnalysis:

Statistical analysis will be carried outin SPSS, software version 20.0. The quantitative parameters like age, height,weight, time of onset of block(when the sensory block is achieved at level ofT10 dermatome) , maximum height of sensory block achieved, time  to two segment regression of sensory block(from the maximum  height  of block), time of regression of sensory block to the level of T12dermatome, duration of effective analgesia( time from giving subarachnoid blockto patient’s first complaint of pain (VAS ≥ 3) and rescue analgesia given topatient which are measured at one-time point will be compared usingunpaired  t-test. Qualitative data likegender distribution, ASA physical status, quality of muscle relaxation and VASscore will be analysed using Chi –square test. Repeated measure ANOVA will beused to compare the haemodynamic variables and sedation score. A p- value <0.05 will be considered significant.