Predicting the success of ultrasound guided anaesthesia to upper limb using an perfusion index

Not yet recruiting

• Conditions: Measurement and Monitoring,

• Registration Number: CTRI/2019/01/017187
• Lead Sponsor: Kasturba Medical College and Hospital

Brief Summary

*Supraclavicular brachial plexus block is apopular approach for anaesthesia for upper limb surgeries. Traditional methodsto evaluate the adequacy of the block is based on assessment of sensory andmotor response to stimuli. This method is subjective, time consuming anddepends on patient cooperation. Various objective methods for evaluation of asuccessful block have been described and one among them is the quantitativeevaluation of blockade of the autonomic innervation to arm. Physiologicalchanges such as vasodilation and changes in blood flow and skin temperature areused to assess the success of block. However, these signs do not appear fastenough to be used for clinical decision making particularly for confirming theadequacy of block before or during surgery. Perfusion index (PI) is a numericalvalue for the ratio between pulsatile and non-pulsatile blood flow and is ameasure for the level of vascular dilation. It is measured by a special pulse oximeter(Masimo SET pulse oximeter). This PI is automatically calculated by the pulseoximeter and provides an indication for peripheral perfusion at sensor site (finger).Perfusion index monitoring may provide a highly valuable tool to quicklyevaluate the success of supraclavicular brachial plexus block.*

**Aims:** To determine whether the perfusion index(PI) whichis a measure of peripheral perfusion measured using a pulse oximeter,  can be used to predict and provide a cut offvalue for a successful ultrasound guided supraclavicular brachial plexus blockadministered for upper limb surgeries

Objectives:**Primary objective**

To determine the perfusion index (PI) and PI ratioas predictors of successful supraclavicular brachial plexus block

**Secondaryobjectives**

1)To determine the trend of PI once peripheralnerve block has been administered

 2)To determine best cut off value of PI fordetection of block efficacy

 3)To determine the correlation between the PIvalues and the degree of block (assessing the sensory and motor blockade)

Patients will be seen on theday prior to surgery and will be assessed for suitability of inclusion instudy. Written informed consent will be taken. Standard guidelines for

fastingwill be followed. Any medication being taken by the patient will be continuedor discontinued according to the standard guidelines. On the day of surgery,the

patients will be shifted to the preoperative holding area of operationtheatre. After confirming their NPO status, standard monitors with noninvasiveblood pressure, pulse

oximeter (Masimo SET pulse oximetry) and five lead electrocardiogramwill be connected. An intravenous access is obtained in the non-operative upperlimb.

Baselineperfusion index values will be recorded in both hands using Masimo SET pulse oximeter.Under strict aseptic precaution the supraclavicular nerve block will be

performedunder USG guidance using the supraclavicular approach. The block will be givenwith patient in semi recumbent position with head turned away from site to be

blocked. A 22 gauge insulated block needle will be inserted in plane to USG probe.A volume of 30 ml of local anaesthetic (15ml of 0.5% bupivacaine and 15ml of 2%

lignocaine with adrenaline) will be injected under vision around the plexus.The limb will be evaluated for block success every 5mins.Sensory function willbe assessed

using pinprick in dermatomal areas and motor block will be assessedby modified Bromage scale. Block will be considered successful when brachialplexus dermatomes

(C5-T1) are completely blocked. The perfusion index will bemeasured every 5 mins by Masimo SET pulse oximeter applied on index finger fromthe time of injection of

local anaesthetic, in both blocked and contralateralunblocked limb. The perfusion index will be measured for 30mins. The PI ratiois calculated as the ratio between the PI

at 5mins and the base line PI. The average percentage change in PI from baseline at 5mininterval from patients with successful nerve blocks and failed block will be

calculated. After a minimum of 30 min, patients will be transferred to theoperating room. The operating surgeon will assess the operative site for painsensation using a

surgical forceps. If patients report of pain at this time,the block will be described as “failed†and general anesthesia will beadministered according to the decision of the

anesthesiologist.

Outcome measures:

1. Percentage of change in PI valuefrom baseline in blocked arm and unblocked arm in a successful block

2. Percentage of change in PI valuefrom baseline in blocked arm and unblocked arm in a failed block

3. Cut off value of perfusion indexin a successful block

Detailed Description

Not available

Study Timeline

• Last Update Posted: 2019-01-20
• Study Start: 2019-01-22

Recruitment & Eligibility

• Status: Not Yet Recruiting
• Sex: All
• Target Recruitment: 100

Inclusion Criteria

ASA I Age group- 18 to 65 Patients posted for upper limb surgeries.

Exclusion Criteria

Patient refusal Infection over the site of needle insertion History of allergy to local anaesthetics Bleeding disorder ASA physical status 2 and above Patient on beta blockers Active infection at site of injection Diabeties/vascular disease.

Study & Design

• Study Type: Observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To determine the perfusion index (PI) and PI ratio as predictors of successful supraclavicular brachial plexus block	From the time of giving block to 30mins after the block is been given

Secondary Outcome Measures

Name	Time	Method
To determine the trend of PI once peripheral nerve block has been administered	To determine best cut off value of PI for detection of block efficacy

Trial Locations

Locations (1)

KASTURBA MEDICAL COLLEGE AND HOSPITAL; 🇮🇳 Udupi, KARNATAKA, India

KASTURBA MEDICAL COLLEGE AND HOSPITAL

🇮🇳Udupi, KARNATAKA, India

HASHIM RAHMAN A

Principal investigator

9597910578

hashimrahman91@gmail.com