European Journal of Cardiovascular Medicine

Ultrasound-guided supraclavicular (SC) and costoclavicular (CC) approaches have become increasingly common brachial plexus blocks for upper-extremity surgeries, because of the greater safety due to real-time ultrasound guidance and faster onset times [1]

Costoclavicular approach of brachial plexus block pioneered by Karmakar (2) et al.   is a modification of ultrasound-guided infraclavicular brachial plexus block. Its procedure and cadaveric anatomical study have been published by Sala Blanch et al (3) in 2015.      Brachial plexus block would provide effective analgesia, safe surgical anaesthesia without airway manipulation and hemodynamic changes, which is often seen in general anaesthesia.

In the conventional supraclavicular approach, brachial plexus around the subclavian artery is blocked with higher risk of ulnar nerve sparing and vessel rupture. There is low risk of vessel rupture and pleural puncture in costoclavicular variant of infraclavicular brachial plexus block as the nerve cords are first approached before vessel and the pleura when compared with other approaches to costoclavicular brachial plexus block (CCBPB).

Most frequent approach in infraclavicular brachial plexus block is lateral infraclavicular fossa (LICF) performed using a sagittal ultrasound scan.  Costoclavicular brachial plexus block varies from supraclavicular block as all the three cords of the brachial plexus are clustered in the former and the low dose of local anaesthetic and single injection provides effective analgesia and anaesthesia.

However, to date there are very few studies comparing the efficiencies of ultrasound-guided CC-BPB and SC-BPB in regional blockade in upper extremity surgery. The first of these was a randomized non-inferiority trial conducted by Luo et al. (4) using a modified double-injection technique which found ultrasound-guided CC-BPB and SC-BPB could result in similar block dynamics. As this technique improved the efficiencies of both approaches, a comparative study of conventional ultrasound-guided CC-BPB and SC-BPB is needed to determine the efficiencies, advantages, and disadvantages of the two methods.

The present study was performed to compare ultrasound-guided SC-BPB and CC-BPB. To reduce the bias induced by the natural limitations of retrospective study, the data of enrolled patients were matched by propensity score matching models.

After obtaining the Institutions Ethical committee approval, a single blinded (observer) randomized clinical study was carried out on patients aged between 18 to 65 years of ASA grade I, II and III scheduled for forearm and hand surgeries at King George Hospital, Visakhapatnam between September 2022 and February 2023. The purpose, procedure and risks involved with the study were explained to the patient and a written informed consent was obtained before taking up in the study. Patients with neuromuscular disease/nerve injury, prior surgery on the infraclavicular fossa, pregnant patients and with contraindications to peripheral nerve blocks such as coagulopathies were excluded from the study.

All the patients were subjected to routine detailed pre-anaesthetic evaluation. Routine investigations and specific investigations were done as per patient clinical evaluation. Hemodynamic variables (BP, HR, and SPO2) were evaluated. All the patients were kept nil per oral 8 hours prior to surgery.

Patients was randomly divided into two groups of 30 patients each using computer random numbers using opaque sealed envelope method into groups SC (supraclavicular brachial plexus block) and group CC (Costoclavicular brachial plexus block).

On arrival to the operating room, intravenous access (20 G) was established on the contralateral hand or forearm and standard ASA monitors (electrocardiogram, non-invasive blood pressure and SpO2) were connected and intravenous fluids according to their bodyweight and requirements was started. Block was performed by a skilled anaesthesiologist in ultrasound guided block techniques. Outcome measures were observed by an independent observer after the performance of block by the anaesthesiologist.

In Group SC patients, with the patient in the supine position with head end elevation with the patient head turned away from the side. The skin was disinfected and the transducer was positioned in the transverse plane immediately proximal to the clavicle at its midpoint. The transducer was tilted caudally to obtain a cross-sectional view of the subclavian artery.

The brachial plexus was seen as a collection of hypoechoic oval structures superficial to the artery posteriorly.  When the injection displaced the brachial plexus away from the needle, an additional advancement of the needle 1–2 mm closer to the plexus was done accomplish adequate local anaesthetic spread. A total amount of Inj. Levobupivacaine 0.5% 20ml was given around the subclavian artery.

After LA injection through the block needle, measurements of onset of sensory and motor blockade were done by an independent observer who was blinded to the technique.

In Group CC patients, under strict aseptic precautions, parts prepared and ultrasound scan was done using high frequency linear array (5-12 MHz) transducer. Patients were positioned supine, with ipsilateral arm abducted for the scan and the head was turned slightly to the contralateral side for the brachial plexus block. The following anatomic landmarks were then identified and marked on the skin: clavicle, mid-point of the clavicle, and the tip of the coracoid process. The transducer was placed transversely directly over the mid-point of the clavicle in the transverse orientation with its orientation marker directed laterally (outward) and it was gently moved caudally until it reached the inferior border of the clavicle to visualize axillary artery (first part) and vein. The ultrasound image was stabilized until all 3 cords of the brachial plexus were clearly visualized lateral Care was taken to avoid needle insertion to the cephalic vein or the thoracoacromial artery.

After skin was infiltrated with 2-3 ml of Inj. Lignocaine 2%, a 23-gauge spinal needle was inserted in-plane from a lateral to medial direction, cords of the brachial plexus are located and needle tip was placed at the centre of the nerve cluster by advancing the needle through the gap between the lateral and posterior cord and advancing it toward the medial cord. After confirmation of the placement of needle via direct visualisation, a total volume of 20 mL of 0.5% Inj. levobupivacaine was injected in small aliquots and at a single site over 2 to 3 minutes.

Sensory blockade was graded according to a 3-point scale using a cold test using spirit swab as follows: 0, no block; 1, analgesia (patient can feel touch, not cold); and 2, anaesthesia (patient cannot feel touch). Sensory blockade of the musculocutaneous, median, radial, and ulnar nerves was assessed on the lateral aspect of the forearm, the volar aspect of the thumb, the lateral aspect of the dorsum of the hand, and the volar aspect of the fifth finger, respectively.

Motor blockade was also graded on a 3-point scale: 0, no block; 1, paresis; and 2, paralysis. Motor blockade of the musculocutaneous, radial, median, and ulnar nerves were evaluated by elbow flexion, thumb abduction, thumb opposition, and thumb adduction, respectively.

Duration of onset of surgical anaesthesia was noted by sensory assessment at regular intervals in both the groups. Postoperatively VAS score was assessed to elicit duration of post-operative analgesia at predetermined time intervals 0,1,2,4,6,12,24th hour. Once the VAS score was ≥4, patients were started on Inj. Paracetamol 1g i.v 8th hourly.

In cases of brachial plexus block failure in either of the approaches, supplemental analgesia with Inj. Fentanyl in graded doses or conversion into general anaesthesia was planned. Complications, if any were documented and treated accordingly.

STATISTICAL ANALYSIS

Using SPSS version 26, statistical analysis was done. The appropriate use of descriptive statistics, Chi Square test, independent sample t test, and ANOVA was made. It was applied in order to compare the categorical results between two groups. A p value of 0.05 or less is deemed statistically significant

COMPARISON OF DEMOGRAPHIC PARAMETERS IN STUDY GROUPS

In our study there was no significant difference statistically in age in between the two groups.

FIGURE 1: AGE DISTRIBUTION

FIGURE 2; GENDER DISTRIBUTION

GENDER DISTRIBUTION:

In our study there was no significant difference statistically in Gender distribution in between the two groups.

FIGURE 3:  COMPARISON OF ONSET OF SENSORY BLOCKADE

COMPARISON OF ONSET OF SENSORY BLOCKADE IN STUDY GROUPS

In our study, the onset of sensory blockade in two groups were comparable and there is statistically significant difference between the groups with p value of less than 0.05. Group CC has a shorter onset of sensory blockade than Group SC.

FIGURE 4: COMPARISON OF ONSET OF MOTOR BLOCKADE BETWEEN THE TWO GROUPS.

COMPARISON OF ONSET OF MOTOR BLOCKADE

In our study, the onset of motor blockade in two groups were comparable and there is statistically significant difference between the groups with p value of less than 0.05(p value=0.0019). Group CC has a shorter onset of motor blockade than Group SC.

FIGURE 5: COMPARISON OF DURATION OF ANALGESIA BETWEEN THE TWO GROUPS

COMPARISON OF DURATION OF ANALGESIA BETWEEN THE TWO GROUPS

In our study, the duration of analgesia between the two groups were comparable and there is no statistically significant difference between the groups with p value of more than 0.05(p value=0.6380).

FIGURE 6: COMPARISON OF REQUIREMENT OF RESCUE ANALGESIA IN THE EARLY POST-OPERATIVE PERIOD.

COMPARISON OF REQUIREMENT OF RESCUE ANALGESIA IN THE EARLY POST-OPERATIVE PERIOD (UPTO 24 HOURS):

In our study, the duration of rescue analgesia between the two groups were comparable and there is no statistically significant difference between the groups with p value of more than 0.05(p value=0.8699).

In this prospective randomized, observer blinded study, we compared supraclavicular and costoclavicular approach of brachial plexus block using 0.5% levobupivacaine under ultrasound guidance.

The Costoclavicular space was a well-defined intermuscular space lying deep to the mid-point of the clavicle posteriorly. Costoclavicular space can be visualised by infraclavicular approach which allows the visualization of the posterior, medial, and lateral nerve cords of the brachial plexus in a triangular arrangement.  In the costoclavicular space, cords of the brachial plexus lie lateral to the axillary artery. The cords appeared as hypoechoic clusters and exhibited a consistent anatomic arrangement relative to one another and to the axillary artery which are comparable with the study conducted by Demond ion (5) et al. This anatomic arrangement of the brachial plexus may help in the high success rate of this approach.

A study conducted by Li et al. (6) aimed at describing the ultrasound guided costoclavicular brachial plexus block performed using 20ml of 0.5% Inj. Ropivacaine on 30 patients, it produced rapid onset of sensory-motor blockade with a median time to readiness for surgery as 10 (5-20 min) and it was effective as surgical anaesthesia in 97% patients whereas in our study, we used 0.5% levobupivacaine which produces similar onset of motor and sensory blockade which was comparable.

Luo et al (4) were the first to compare the efficiency of ultrasound-guided SC-BPB and CC-BPB in similar block dynamics and found similarity between the two as compared to our study. However, they applied a novel modified double-injection technique, which may have affected the results. We used a conventional single injection technique in the present study and found that SC-BPB and CC-BPB had a similar efficiency of nerve block.

Our study also showed a lower incidence of other side effects or complications, especially Horner’s syndrome, in the CC-BPB group compared with the SC-BPB group. At present, the developmental history of CC-BPB is relatively short, and modifications must be made to further improve its efficiency and safety.

In our study we observed that earlier onset of sensory and motor blockade in group CC than group SC (Figure 3,4).

In a study conducted by Abhinaya et al(7) where infraclavicular block was compared with supraclavicular block, results showed early onset of sensory blockade (6.43 ± 2.61 min) in Group I than Group S (8.45 ± 2.87 min, P = 0.006) which was similar to our study. The onset of motor blockade was early in Group I (7.32 ± 2.90 min) than Group S (8.68 ± 3.50 min, P = 0.121) which was also similar when compared to our study.

Other studies on supraclavicular approach have shown ulnar nerve sparing requiring supplemental analgesia or conversion to general anaesthesia, our study did not show any such results in both the groups.

Even though all the results were in Favor of costoclavicular approach, there were no statistically significant difference in postoperative analgesia in both the approaches in our study.

Since, this is a single blinded small group study which requires further evaluation in larger groups for validation of our results.

In our study, we conclude that ultrasound guided costoclavicular brachial plexus block is easily performed and has rapid onset of sensory-motor blockade when compared to supraclavicular group. It has provided equivalent duration of postoperative analgesia and safety profile like conventional ultrasound guided supraclavicular block for forearm and hand surgeries. Costoclavicular approach to brachial plexus block can be used as an alternative technique to supraclavicular approach for providing surgical anaesthesia for forearm and hand surgeries in routine clinical practice.

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