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Completed

NCT Number: NCT06015204

Assessment of the C8 Dermatomal Block with Photoplethysmographic Amplitude After Interscalene Brachial Plexus Block

The goal of this clinical trial is to investigate the effectiveness of photoplethysmographic amplitude in assessing the extent of anesthesia in the 8th cervical dermatome in patients undergoing interscalene brachial plexus block (ISBPB). The main question it aims to answer is

* Is there any difference in the post-block changes in photoplethysmographic amplitude measured from the ipsilateral 5th finger (supplied by the 8th cervical nerve root) between ISBPBs targeting the C5-to-C6 nerve roots and the C5-to-C8 nerve roots? * Do the changes in photoplethysmographic amplitude represent the extent of anesthesia in the 8th cervical dermatome? Participants will receive either ISBPB targeting the C5-to-C6 nerve roots or the C5-to-C8 nerve roots, and then the changes in photoplethysmographic amplitude will be measured from the 5th finger ipsilateral to ISBPB.

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Key information

Conditions

Brachial Plexus Block Oximetry

Age range

20 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Daegu Catholic University Medical Center

Daegu, 42472, South Korea

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • American Society of Anesthesiologists physical status 1 or 2
  • Schedule to receive interscalene brachial plexus block for arthroscopic shoulder surgery

Exclusion criteria

  • Coagulopathy
  • Peripheral vascular diseases
  • Arrhythmias
  • Cardiac conduction abnormalities
  • A history of medication affecting cardiac conduction
  • Ischemic heart disease
  • Hypertension
  • Diabetes mellitus
  • Thyroid dysfunction
  • Other medical conditions affecting autonomic nervous activity
  • Infection at the skin area for interscalene brachial plexus block
  • Peripheral neuropathy or neurologic sequelae in the upper limb ipsilateral to the surgery
  • Allergy to local anesthetics or a history of allergic shock
  • Contralateral vocal cord palsy, hemidiaphragmatic paresis/paralysis or pneumo/hemo thorax
  • Severe restrictive pulmonary disorder
  • Electrolyte imbalance
  • Difficulty in communicating with medical personnel
  • Patients refusal

Treatment and study plan

Interscalene brachial plexus block targeting the C5-to-C6 nerve roots

Procedure

With the head rotated contralateral to interscalene brachial plexus block (ISBPB), the compactly arranged brachial plexus is visualized lateral to the pulsating subclavian artery under ultrasound guidance. The linear ultrasound transducer is moved cephalad until the C5-to-C8 nerve roots are visualized between the anterior and middle scalene muscles. A block needle is introduced from lateral to medial direction. A nerve root is blocked by placing at least 5 ml of 0.75% ropivacaine around it. The most caudal cervical nerve root (C6 nerve root) is blocked first, and the most cephalad one (C5 nerve root) is blocked last. Then, 3 ml of 0.75% ropivacaine is placed between the scalene and sternocleidomastoid muscles to block the supraclavicular nerves. An equivalent volume of a standard study drug is planned to be used (A total of 25 ml of 0.75% ropivacaine).

Interscalene brachial plexus block targeting the C5-to-C8 nerve roots

Procedure

With the head rotated contralateral to interscalene brachial plexus block (ISBPB), the compactly arranged brachial plexus is visualized lateral to the pulsating subclavian artery under ultrasound guidance. The linear ultrasound transducer is moved cephalad until the C5-to-C8 nerve roots are visualized between the anterior and middle scalene muscles. A block needle is introduced from lateral to medial direction. A nerve root is blocked by placing at least 5 ml of 0.75% ropivacaine around it. The most caudal cervical nerve root (C8 nerve root) is blocked first, and the most cephalad one (C5 nerve root) is blocked last. Then, 3 ml of 0.75% ropivacaine is placed between the scalene and sternocleidomastoid muscles to block the supraclavicular nerves. An equivalent volume of a standard study drug is planned to be used (A total of 25 ml of 0.75% ropivacaine).

Primary outcomes

  1. Time to achieve 50% of maximum photoplethysmographic amplitude measured from the 5th finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 50% of maximum photoplethysmographic amplitude is achieved, can be derived.

Secondary outcomes

  1. Time to achieve 5% of maximum photoplethysmographic amplitude measured from the 5th finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 5% of maximum photoplethysmographic amplitude is achieved, can be derived.

  2. Time to achieve 10% of maximum photoplethysmographic amplitude measured from the 5th finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 10% of maximum photoplethysmographic amplitude is achieved, can be derived.

  3. Time to achieve 90% of maximum photoplethysmographic amplitude measured from the 5th finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 90% of maximum photoplethysmographic amplitude is achieved, can be derived.

  4. Time to achieve 95% of maximum photoplethysmographic amplitude measured from the 5th finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 95% of maximum photoplethysmographic amplitude is achieved, can be derived.

  5. Time to achieve 99% of maximum photoplethysmographic amplitude measured from the 5th finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 99% of maximum photoplethysmographic amplitude is achieved, can be derived.

  6. Time to achieve 5% of maximum photoplethysmographic amplitude measured from the 1st finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 5% of maximum photoplethysmographic amplitude is achieved, can be derived.

  7. Time to achieve 10% of maximum photoplethysmographic amplitude measured from the 1st finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 10% of maximum photoplethysmographic amplitude is achieved, can be derived.

  8. Time to achieve 50% of maximum photoplethysmographic amplitude measured from the 1st finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 50% of maximum photoplethysmographic amplitude is achieved, can be derived.

  9. Time to achieve 90% of maximum photoplethysmographic amplitude measured from the 1st finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 90% of maximum photoplethysmographic amplitude is achieved, can be derived.

  10. Time to achieve 95% of maximum photoplethysmographic amplitude measured from the 1st finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 95% of maximum photoplethysmographic amplitude is achieved, can be derived.

  11. Time to achieve 99% of maximum photoplethysmographic amplitude measured from the 1st finger

    Time frame: 25 minutes after the introduction of a block needle

    During the whole study period, the photoplethysmographic waveform obtained from the 1st and 5th fingers ipsilateral to interscalene brachial plexus block is recorded at 100 Hz. The photoplethysmographic amplitude is calculated by subtracting the valley amplitude from the peak amplitude of one heartbeat in photoplethysmographic waveform. Using all the photoplethysmographic amplitudes between 0 and 25 minutes after the introduction of a block needle, a sigmoid Emax model is built. From the model, the time point, when 99% of maximum photoplethysmographic amplitude is achieved, can be derived.

  12. Baseline blood flow measured from the brachial artery ipsilateral to interscalene brachial plexus block

    Time frame: 15 minutes before the introduction of a block needle

    The linear ultrasound transducer is placed parallel with the brachial artery at the antecubital fossa. Using pulse wave Doppler ultrasound, time velocity integral per heartbeat is calculated. The cross-sectional diameter of the artery is measured with the transducer placed transversely to the artery. The blood flow of the artery (ml/min) is the product of the averaged time velocity integral (cm), cross-sectional area of the artery (cm2), and heart rate (beats/min).

  13. Baseline blood flow measured from the radial artery ipsilateral to interscalene brachial plexus block

    Time frame: 15 minutes before the introduction of a block needle

    The linear ultrasound transducer is placed parallel with the radial artery at the distal forearm area. Using pulse wave Doppler ultrasound, time velocity integral per heartbeat is calculated. The cross-sectional diameter of the artery is measured with the transducer placed transversely to the artery. The blood flow of the artery (ml/min) is the product of the averaged time velocity integral (cm), cross-sectional area of the artery (cm2), and heart rate (beats/min).

  14. Baseline blood flow measured from the ulnar artery ipsilateral to interscalene brachial plexus block

    Time frame: 15 minutes before the introduction of a block needle

    The linear ultrasound transducer is placed parallel with the ulnar artery at the distal forearm area. Using pulse wave Doppler ultrasound, time velocity integral per heartbeat is calculated. The cross-sectional diameter of the artery is measured with the transducer placed transversely to the artery. The blood flow of the artery (ml/min) is the product of the averaged time velocity integral (cm), cross-sectional area of the artery (cm2), and heart rate (beats/min).

  15. Post-block blood flow measured from the brachial artery ipsilateral to interscalene brachial plexus block

    Time frame: 25 minutes after the introduction of a block needle

    The linear ultrasound transducer is placed parallel with the brachial artery at the antecubital fossa. Using pulse wave Doppler ultrasound, time velocity integral per heartbeat is calculated. The cross-sectional diameter of the artery is measured with the transducer placed transversely to the artery. The blood flow of the artery (ml/min) is the product of the averaged time velocity integral (cm), cross-sectional area of the artery (cm2), and heart rate (beats/min).

  16. Post-block blood flow measured from the radial artery ipsilateral to interscalene brachial plexus block

    Time frame: 25 minutes after the introduction of a block needle

    The linear ultrasound transducer is placed parallel with the radial artery at the distal forearm area. Using pulse wave Doppler ultrasound, time velocity integral per heartbeat is calculated. The cross-sectional diameter of the artery is measured with the transducer placed transversely to the artery. The blood flow of the artery (ml/min) is the product of the averaged time velocity integral (cm), cross-sectional area of the artery (cm2), and heart rate (beats/min).

  17. Post-block blood flow measured from the ulnar artery ipsilateral to interscalene brachial plexus block

    Time frame: 25 minutes after the introduction of a block needle

    The linear ultrasound transducer is placed parallel with the ulnar artery at the distal forearm area. Using pulse wave Doppler ultrasound, time velocity integral per heartbeat is calculated. The cross-sectional diameter of the artery is measured with the transducer placed transversely to the artery. The blood flow of the artery (ml/min) is the product of the averaged time velocity integral (cm), cross-sectional area of the artery (cm2), and heart rate (beats/min).

  18. Sensory blockade of the C5 dermatome

    Time frame: 30 minutes after the introduction of a block needle

    Using an alcohol swab, the sensory blockade of each dermatome is graded as 0 (no cold sensation), 1 (reduced cold sensation), 2 (normal cold sensation).

  19. Sensory blockade of the C6 dermatome

    Time frame: 30 minutes after the introduction of a block needle

    Using an alcohol swab, the sensory blockade of each dermatome is graded as 0 (no cold sensation), 1 (reduced cold sensation), 2 (normal cold sensation).

  20. Sensory blockade of the C7 dermatome

    Time frame: 30 minutes after the introduction of a block needle

    Using an alcohol swab, the sensory blockade of each dermatome is graded as 0 (no cold sensation), 1 (reduced cold sensation), 2 (normal cold sensation).

  21. Sensory blockade of the C8 dermatome

    Time frame: 30 minutes after the introduction of a block needle

    Using an alcohol swab, the sensory blockade of each dermatome is graded as 0 (no cold sensation), 1 (reduced cold sensation), 2 (normal cold sensation).

  22. Sensory blockade of the T1 dermatome

    Time frame: 30 minutes after the introduction of a block needle

    Using an alcohol swab, the sensory blockade of each dermatome is graded as 0 (no cold sensation), 1 (reduced cold sensation), 2 (normal cold sensation).

  23. Motor blockade of shoulder abduction

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  24. Motor blockade of elbow flexion

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  25. Motor blockade of forearm supination

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  26. Motor blockade of forearm pronation

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  27. Motor blockade of finger abduction

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  28. Motor blockade of thumb abduction

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  29. Motor blockade of thumb adduction

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  30. Motor blockade of thumb opposition

    Time frame: 30 minutes after the introduction of a block needle

    Motor blockade is assessed by rating the force of movement corresponding to each nerve as 0 (complete block), 1 (partial block), or 2 (no block).

  31. Baseline pupil diameter ipsilateral to interscalene brachial plexus block

    Time frame: 5 minutes before the introduction of a block needle

    Three minutes after the adaptation in low mesopic conditions, the pupil diameter is measured for 2 seconds at 30 Hz using a portable pupillometer. The pupil diameter is obtained by averaging 60 measurement values.

  32. Baseline pupil diameter contralateral to interscalene brachial plexus block

    Time frame: 5 minutes before the introduction of a block needle

    Three minutes after the adaptation in low mesopic conditions, the pupil diameter is measured for 2 seconds at 30 Hz using a portable pupillometer. The pupil diameter is obtained by averaging 60 measurement values.

  33. Post-block pupil diameter ipsilateral to interscalene brachial plexus block

    Time frame: 35 minutes after the introduction of a block needle

    Three minutes after the adaptation in low mesopic conditions, the pupil diameter is measured for 2 seconds at 30 Hz using a portable pupillometer. The pupil diameter is obtained by averaging 60 measurement values.

  34. Post-block pupil diameter contralateral to interscalene brachial plexus block

    Time frame: 35 minutes after the introduction of a block needle

    Three minutes after the adaptation in low mesopic conditions, the pupil diameter is measured for 2 seconds at 30 Hz using a portable pupillometer. The pupil diameter is obtained by averaging 60 measurement values.

  35. Pain upon a pinch at the skin area for posterior portal placement (1.5-3 cm inferior and medial to the posterolateral tip of the acromion)

    Time frame: 1 minute before the surgical incision

    The pain intensity is rated as 0 (no pain), 1 (mild pain), and 2 (severe pain).

  36. Pain upon surgical incision (1.5-3 cm inferior and medial to the posterolateral tip of the acromion)

    Time frame: An average of 1 hour after the introduction of a block needle

    The pain intensity is rated as 0 (no pain), 1 (mild pain), and 2 (severe pain).

  37. Pain upon posterior portal placement (1.5-3 cm inferior and medial to the posterolateral tip of the acromion)

    Time frame: 1 minute after surgical incision

    The pain intensity is rated as 0 (no pain), 1 (mild pain), and 2 (severe pain).

Other outcomes

  1. Complications related to interscalene brachial plexus block

    Time frame: 35 minutes after the introduction of a block needle

    Accidental puncture of the common carotid, subclavian, or vertebral artery, pneumo/hemothorax, epidural or intrathecal injection of local anesthetic, local anesthetic systemic toxicity, and other neurological complications

  2. Baseline systolic blood pressure

    Time frame: 5 minutes before the introduction of a block needle

    Measured with a non-invasive blood pressure cuff

  3. Post-block systolic blood pressure

    Time frame: 35 minutes after the introduction of a block needle

    Measured with a non-invasive blood pressure cuff

  4. Baseline heart rate

    Time frame: 5 minutes before the introduction of a block needle

    Measured from electrocardiogram

  5. Post-block heart rate

    Time frame: 35 minutes after the introduction of a block needle

    Measured from electrocardiogram

Sponsors and collaborators

Lead sponsor

JongHae Kim

Other

Collaborators

  • Research Institute of Medical Science, Daegu Catholic University

Registry information

Official study title

Objective Assessment of Extent of Anesthesia in the 8th Cervical Dermatome Using Photoplethysmographic Amplitude in Patients Undergoing Interscalene Brachial Plexus Block

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Aug 29, 2023
Registry last updated
Feb 6, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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