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

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

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03138577
Enrollment
24
Registered
2017-05-03
Start date
2018-02-12
Completion date
2019-07-30
Last updated
2020-05-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Surgery of Right Upper Extremity

Brief summary

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

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.

Interventions

DIAGNOSTIC_TESTUltrasound Imaging

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.

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.

OTHERBedside Negative Inspiratory Force Meter

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.

Sponsors

Weill Medical College of Cornell University
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Masking description

The physician reviewing the ultrasound images and determining the presence/absence of diaphragm paralysis is masked to treatment assignment.

Intervention 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.

Eligibility

Sex/Gender
ALL
Age
18 Years to 105 Years
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular Block15 minutesDiaphragm 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.
Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular Block30 minutesDiaphragm 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.

Secondary

MeasureTime frameDescription
Dose Response Curve for Motor and Sensory Block Score 30 Minutes After Block30 minutesAs 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.
Change in Negative Inspiratory Force (NIF) at 30 Minutes30 minutesThe change of the absolute value of NIF from the baseline measurement to that at 30 minutes after the block
Subjective Dyspnea 30 Minutes After Block30 minutes30 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).
Change in Room Air Oxygen Saturation at 30 Minutes.30 minutesThe change in room air oxygen saturation from baseline to 30 minutes after the block was calculated.
Dose Response Curve for Motor and Sensory Block 15 Minutes After Block15 minutesAs 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.

Countries

United States

Participant flow

Recruitment details

Study subjects were recruited from August 2018 to July 2019. Fifty-nine subjects were assessed for eligibility. Fourteen subjects were excluded or refused to participate, and 21 were eligible but not approached due to the anticipation of insufficient time to complete assessments. Twenty-four patients consented to enrollment.

Pre-assignment details

3 of the 24 enrolled patients were excluded due to baseline abnormal diaphragm motion or inability to visualize the diaphragm on baseline ultrasound scan.

Participants by arm

ArmCount
5 mL
5 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
10 mL
10 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
15 mL
15 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
20 mL
20 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
25 mL
25 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
30 mL
30 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
35 mL
35 mL of 2:1 mixture of 1.5% mepivacaine and 0.5% bupivacaine
3
Total21

Baseline characteristics

Characteristic5 mLTotal35 mL30 mL25 mL20 mL15 mL10 mL
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
2 Participants8 Participants0 Participants1 Participants2 Participants0 Participants1 Participants2 Participants
Age, Categorical
Between 18 and 65 years
1 Participants13 Participants3 Participants2 Participants1 Participants3 Participants2 Participants1 Participants
ASA Classification
ASA Class I
1 Participants5 Participants0 Participants1 Participants0 Participants1 Participants1 Participants1 Participants
ASA Classification
ASA Class II
2 Participants15 Participants2 Participants2 Participants3 Participants2 Participants2 Participants2 Participants
ASA Classification
ASA Class III
0 Participants1 Participants1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race and Ethnicity Not Collected0 Participants
Region of Enrollment
United States
3 participants3 participants3 participants3 participants3 participants3 participants3 participants3 participants
Sex: Female, Male
Female
3 Participants20 Participants2 Participants3 Participants3 Participants3 Participants3 Participants3 Participants
Sex: Female, Male
Male
0 Participants1 Participants1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Upper Extremity Surgery Location
Distal to elbow
0 Participants3 Participants1 Participants1 Participants1 Participants0 Participants0 Participants0 Participants
Upper Extremity Surgery Location
Mid arm (at elbow)
2 Participants9 Participants0 Participants1 Participants2 Participants1 Participants1 Participants2 Participants
Upper Extremity Surgery Location
Proximal to elbow
1 Participants9 Participants2 Participants1 Participants0 Participants2 Participants2 Participants1 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
EG005
affected / at risk
EG006
affected / at risk
deaths
Total, all-cause mortality
0 / 30 / 30 / 30 / 30 / 30 / 30 / 3
other
Total, other adverse events
0 / 30 / 30 / 30 / 30 / 30 / 30 / 3
serious
Total, serious adverse events
0 / 30 / 30 / 30 / 30 / 30 / 30 / 3

Outcome results

Primary

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.

Time frame: 15 minutes

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
Dose Cohort 7 (5 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP1 Participants
Dose Cohort 7 (5 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP2 Participants
Dose Cohort 6 (10 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP1 Participants
Dose Cohort 6 (10 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP2 Participants
Dose Cohort 5 (15 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP1 Participants
Dose Cohort 5 (15 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP2 Participants
Dose Cohort 4 (20 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP2 Participants
Dose Cohort 4 (20 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP1 Participants
Dose Cohort 3 (25 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP2 Participants
Dose Cohort 3 (25 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP1 Participants
Dose Cohort 2 (30 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP3 Participants
Dose Cohort 2 (30 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP0 Participants
Dose Cohort 1 (35 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockHDP3 Participants
Dose Cohort 1 (35 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 15 Minutes After Supraclavicular BlockNo HDP0 Participants
Primary

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.

Time frame: 30 minutes

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
Dose Cohort 7 (5 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP1 Participants
Dose Cohort 7 (5 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP2 Participants
Dose Cohort 6 (10 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP2 Participants
Dose Cohort 6 (10 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP1 Participants
Dose Cohort 5 (15 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP1 Participants
Dose Cohort 5 (15 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP2 Participants
Dose Cohort 4 (20 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP2 Participants
Dose Cohort 4 (20 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP1 Participants
Dose Cohort 3 (25 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP3 Participants
Dose Cohort 3 (25 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP0 Participants
Dose Cohort 2 (30 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP3 Participants
Dose Cohort 2 (30 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP0 Participants
Dose Cohort 1 (35 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockNo HDP0 Participants
Dose Cohort 1 (35 mL)Number of Subjects With Hemidiaphragmatic Paresis at Various Volumes of Local Anesthetic 30 Minutes After Supraclavicular BlockHDP3 Participants
Secondary

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

Time frame: 30 minutes

ArmMeasureValue (MEDIAN)
Dose Cohort 7 (5 mL)Change in Negative Inspiratory Force (NIF) at 30 Minutes-7.5 cm H2O
Dose Cohort 6 (10 mL)Change in Negative Inspiratory Force (NIF) at 30 Minutes0 cm H2O
p-value: 0.01Sign test
p-value: 1Sign test
Secondary

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.

Time frame: 30 minutes

ArmMeasureValue (MEDIAN)
Dose Cohort 7 (5 mL)Change in Room Air Oxygen Saturation at 30 Minutes.-1 percent
Dose Cohort 6 (10 mL)Change in Room Air Oxygen Saturation at 30 Minutes.0 percent
p-value: 0.01Sign test
p-value: 1Sign test
Secondary

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.

Time frame: 15 minutes

ArmMeasureGroupValue (NUMBER)
Dose Cohort 7 (5 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/310 score on a scale
Dose Cohort 7 (5 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/312 score on a scale
Dose Cohort 7 (5 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/31 score on a scale
Dose Cohort 6 (10 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/312 score on a scale
Dose Cohort 6 (10 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/311 score on a scale
Dose Cohort 6 (10 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/30 score on a scale
Dose Cohort 5 (15 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/318 score on a scale
Dose Cohort 5 (15 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/37 score on a scale
Dose Cohort 5 (15 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/30 score on a scale
Dose Cohort 4 (20 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/31 score on a scale
Dose Cohort 4 (20 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/32 score on a scale
Dose Cohort 4 (20 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/30 score on a scale
Dose Cohort 3 (25 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/319 score on a scale
Dose Cohort 3 (25 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/320 score on a scale
Dose Cohort 3 (25 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/35 score on a scale
Dose Cohort 2 (30 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/315 score on a scale
Dose Cohort 2 (30 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/316 score on a scale
Dose Cohort 2 (30 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/315 score on a scale
Dose Cohort 1 (35 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 3/319 score on a scale
Dose Cohort 1 (35 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 2/315 score on a scale
Dose Cohort 1 (35 mL)Dose Response Curve for Motor and Sensory Block 15 Minutes After BlockSubject 1/311 score on a scale
Secondary

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.

Time frame: 30 minutes

ArmMeasureGroupValue (NUMBER)
Dose Cohort 7 (5 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 318 score on a scale
Dose Cohort 7 (5 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 310 score on a scale
Dose Cohort 7 (5 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 32 score on a scale
Dose Cohort 6 (10 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 314 score on a scale
Dose Cohort 6 (10 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 314 score on a scale
Dose Cohort 6 (10 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 312 score on a scale
Dose Cohort 5 (15 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 318 score on a scale
Dose Cohort 5 (15 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 38 score on a scale
Dose Cohort 5 (15 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 32 score on a scale
Dose Cohort 4 (20 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 316 score on a scale
Dose Cohort 4 (20 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 320 score on a scale
Dose Cohort 4 (20 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 310 score on a scale
Dose Cohort 3 (25 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 320 score on a scale
Dose Cohort 3 (25 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 316 score on a scale
Dose Cohort 3 (25 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 320 score on a scale
Dose Cohort 2 (30 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 314 score on a scale
Dose Cohort 2 (30 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 316 score on a scale
Dose Cohort 2 (30 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 316 score on a scale
Dose Cohort 1 (35 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 3 of 319 score on a scale
Dose Cohort 1 (35 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 1 of 315 score on a scale
Dose Cohort 1 (35 mL)Dose Response Curve for Motor and Sensory Block Score 30 Minutes After BlockSubject 2 of 318 score on a scale
Secondary

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).

Time frame: 30 minutes

ArmMeasureValue (MEDIAN)
Dose Cohort 7 (5 mL)Subjective Dyspnea 30 Minutes After Block0 score on a scale
Dose Cohort 6 (10 mL)Subjective Dyspnea 30 Minutes After Block0 score on a scale
p-value: 0.08Wilcoxon (Mann-Whitney)

Source: ClinicalTrials.gov · Data processed: Feb 17, 2026