Dose-Response Relationships for Hemidiaphragmatic Paresis Following Ultrasound-Guided Supraclavicular Block

Study Overview
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Brief Summary
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This clinical trial is for subjects undergoing right upper extremity surgery. The aim of the study is to investigate the dose-response relationship between local anesthetic volume and ipsilateral hemidiaphragmatic paresis (HDP) in patients getting ultrasound-guided supraclavicular brachial plexus blocks in a blinded, prospective trial.

Detailed Description
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With traditional landmark-based or nerve-stimulator techniques, the incidence of HDP following supraclavicular blocks is approximately 50-67%. Ultrasound-guided techniques are thought to enhance precision while reducing the volume of anesthetic used, but even then HDP incidence is nearly 60%. To date, no trials have studied the dose-response relationship between local anesthetic volume and degree of HDP. Patient Selection 30 eligible patients undergoing right upper extremity surgery and eligible for supraclavicular blocks will be recruited at NewYork-Presbyterian/Weill Cornell Medical Center. Evaluation of HDP Baseline M-mode recordings of diaphragm function will be made by an anesthesiologist. Patients will perform voluntary sniff (VS) tests, or forceful nasal inhales, immediately preceding the brachial plexus blockade, and again at 15 minutes and 30 minutes after the block. Diaphragmatic excursion from baseline will be measured in centimeters; three measurements will be made and averaged. Hemidiaphragmatic paresis will be defined as greater than or equal to 60% reduction in diaphragmatic excursion, no movement, or paradoxical movement in the VS test. Evaluation of Pulmonary Function A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block. Evaluation of Supraclavicular Block At the 15- and 30-minute marks, the investigators will assess sensory blockade and motor block in the axial, musculocutaneous, radial, median, and ulnar distributions. Both will be judged on 3-point scales. The investigators will also apply a 0-10 point verbal rating scale to assess dyspnea at 30 minutes. Oxygen saturation will be measured off of supplemental oxygen before the block and 30 minutes after the block. Following the assessments, patients will have surgery using brachial plexus blockade as the primary anesthetic.

Official Title
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Dose-Response Relationships for Hemidiaphragmatic Paresis Following Ultrasound-Guided Supraclavicular Brachial Plexus Blockade

Conditions
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Surgery of Right Upper Extremity

Intervention / Treatment
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* Diagnostic Test: Ultrasound Imaging
* Drug: Supraclavicular Block
* Other: Bedside Negative Inspiratory Force Meter


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Undergoing right upper extremity surgery with supraclavicular block as the primary anesthetic Age greater than or equal to 18 years of age American Society of Anesthesiologists (ASA) physical status 1 to 3 Able to give informed consent Exclusion Criteria: Patient refusal for supraclavicular block Inability to give informed consent Allergy to local anesthetics Hemidiaphragmatic dysfunction, suspected or known pulmonary disease Neuromuscular disease Obstructive or restrictive pulmonary disease Medical or anatomic contraindication to supraclavicular blockade as judged by clinician Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 105 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: A modified 3+3 dose escalation design, modeled after Phase I dose-finding trials, was used to define the dose response curve for local anesthetic volume in the supraclavicular block and resulting hemidiaphragmatic paresis in patients undergoing right upper extremity surgery with supraclavicular block as the primary anesthetic. Possible dosing levels of 5, 10, 15, 20, 25, 30, 35 and 40 mL of local anesthetic were pre-specified with a cohort of three subjects per dose. Diaphragm function was determined by a blinded assessor with M-mode tracings of the right diaphragm before and after supraclavicular block. Secondary objectives included the assessment of respiratory function via negative inspiratory force, oxygen saturation and subjective dyspnea, as well as the extent of sensory and motor blockade.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Dose Cohort 7<br>5 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|
| Other: Dose Cohort 6<br>10 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|
| Other: Dose Cohort 5<br>15 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|
| Other: Dose Cohort 4<br>20 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|
| Other: Dose Cohort 3<br>Supraclavicular Block: 25 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|
| Other: Dose Cohort 2<br>30 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|
| Other: Dose Cohort 1<br>35 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine Ultrasound Imaging Bedside Negative Inspiratory Force Meter | Diagnostic Test: Ultrasound Imaging<br>* M-mode tracings of right diaphragm motion will be made and recorded by a skilled anesthesiologist. Patients will be examined in the supine position and scanned from a low intercostal or subcostal approach using the liver as an acoustic window. Patients will be asked to perform a voluntary sniff (VS) test, for which they will be asked to forcefully inhale through the nose in a sniffing position. The above measurement will be performed immediately preceding the brachial plexus blockade, and then at 15 minute and 30 minutes after block.<br>Drug: Supraclavicular Block<br>* The patient will be positioned supine with the head turned to the contralateral side. The ultrasound will be placed in the supraclavicular fossa, and the skin and subcutaneous tissues will be infiltrated lateral to the probe with 2% lidocaine. The anesthesiologist can redirect the needle and perform additional injections for complete coverage of the brachial plexus. The local anesthetic will be a 2:1 mix of 1.5% mepivacaine and 0.5% bupivacaine.<br>Other: Bedside Negative Inspiratory Force Meter<br>* A bedside negative inspiratory force (NIF) meter will be used to measure negative inspiratory force prior to the block and 30 minutes after the block.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular Block | Diaphragm motion was recorded during voluntary sniffing fifteen minutes after supraclavicular block with the specified volume of local anesthetic. Blinded investigators reviewed the scans and determined whether the scans were indicative of hemidiaphragmatic paresis (HDP) or not (No HDP). This data was fit to a dose response curve. | 15 minutes | 
| Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular Block | Diaphragm motion was recorded during voluntary sniffing 30 minutes after supraclavicular block with the specified volume of local anesthetic. Blinded investigators reviewed the scans and determined whether the scans were indicative of hemidiaphragmatic paresis (HDP) or not (No HDP). This data was fit to a dose response curve. | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Negative Inspiratory Force (NIF) at 30 Minutes | The change of the absolute value of NIF from the baseline measurement to that at 30 minutes after the block | 30 minutes | 
| Dose Response Curve for Motor and Sensory Block 15 Minutes After Block | As described in the protocol, each subject's block was assessed via motor and sensory exam at 15 minutes and given a score (0-20), with 20 being a perfect block and any score less than 10 indicating an ineffective block. A dose response curve was generated for block score with different volumes of local anesthetic administered. | 15 minutes | 
| Dose Response Curve for Motor and Sensory Block Score 30 Minutes After Block | As described in the protocol, each subject's block was assessed via motor and sensory exam at 30 minutes and given a score (0-20), with 20 being a perfect block and any score less than 10 indicating an ineffective block. A dose response curve was generated for block score with different volumes of local anesthetic administered. | 30 minutes | 
| Change in Room Air Oxygen Saturation at 30 Minutes. | The change in room air oxygen saturation from baseline to 30 minutes after the block was calculated. | 30 minutes | 
| Subjective Dyspnea 30 Minutes After Block | 30 minutes after the block, patients were asked to rate any symptoms of dyspnea on a scale of 0 (no trouble breathing) to 10 (extreme trouble breathing). | 30 minutes |