Trial Outcomes & Findings for Feasibility of an Analgesic Device Enabling Local Anesthetic Delivery and Neuromodulation After Shoulder/Foot Surgery (NCT NCT06818708)

Results Overview

The median of 5 daily "average" pain intensity scores for Days 1-4 and 7 as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

20 participants

Primary outcome timeframe

Days 1-4 and 7

Results posted on

2025-11-18

Participant Flow

Participant milestones

Participant milestones
Measure	Experimental Treatment RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Overall Study STARTED	20
Overall Study COMPLETED	20
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Age, Continuous	57 years STANDARD_DEVIATION 14 • n=20 Participants
Sex: Female, Male Female	9 Participants n=20 Participants
Sex: Female, Male Male	11 Participants n=20 Participants
Region of Enrollment United States	20 participants n=20 Participants
Height	173 cm STANDARD_DEVIATION 9 • n=20 Participants
Weight (kg)	87 kg STANDARD_DEVIATION 20 • n=20 Participants
Body Mass Index	30 kg/m^2 STANDARD_DEVIATION 6 • n=20 Participants

PRIMARY outcome

Timeframe: Days 1-4 and 7

The median of 5 daily "average" pain intensity scores for Days 1-4 and 7 as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Average Daily Pain Intensity 1st Week	2 units on a scale Interval 0.0 to 3.0

SECONDARY outcome

Timeframe: The first 7 days following surgery

The cumulative opioid use measured in oxycodone equivalents during the first 7 days following surgery

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Cumulative Opioid Use 1st Week	43 milligrams Interval 18.0 to 73.0

SECONDARY outcome

Timeframe: Postoperative day 3

The Brief pain Inventory (short form) is an instrument specifically designed to assess pain and its impact on physical and emotional functioning. The brief Inventory is comprised of three domains: (1) pain, with four questions involving "worst", "average" and "current" pain levels using a 0-10 numeric rating scale; (2) percentage of relief provided by pain treatments with one question \[reported score is the percentage divided by 10 and then subtracted from 10: 0=complete relief,10=no relief\] and, (3) interference with 7 questions involving physical and emotional functioning using a 0-10 Likert scale \[0=no interference;10=complete interference\]: general activity, mood, walking ability, normal work, relations with other people, sleep and enjoyment of life. This outcome will include solely the interference subscale with a minimum score of 0 (optimal outcome) and maximum score of 70 (worst possible outcome).

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Brief Pain Inventory (Interference Sub Scale) Day 3	2 units on a scale Interval 0.0 to 4.0

SECONDARY outcome

Timeframe: Postoperative day 7

The Brief pain Inventory (short form) is an instrument specifically designed to assess pain and its impact on physical and emotional functioning. The brief Inventory is comprised of three domains: (1) pain, with four questions involving "worst", "average" and "current" pain levels using a 0-10 numeric rating scale; (2) percentage of relief provided by pain treatments with one question \[reported score is the percentage divided by 10 and then subtracted from 10: 0=complete relief,10=no relief\] and, (3) interference with 7 questions involving physical and emotional functioning using a 0-10 Likert scale \[0=no interference;10=complete interference\]: general activity, mood, walking ability, normal work, relations with other people, sleep and enjoyment of life. This outcome will include solely the interference subscale with a minimum score of 0 (optimal outcome) and maximum score of 70 (worst possible outcome).

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Brief Pain Inventory (Interference Sub Scale) Day 7	0 units on a scale Interval 0.0 to 7.0

SECONDARY outcome

Timeframe: Days 1-4 and 7

The median of 5 daily "worst" (maximum) pain intensity scores for Days 1-4 and 7 as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Worst Daily Pain Intensity 1st Week	4.0 units on a scale Interval 2.6 to 6.0

SECONDARY outcome

Timeframe: Collected on postoperative days 1, 2, 3, 4, and 7

Cumulative number of nightly awakenings due to pain

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Awakenings Due to Pain 1st Week	2 number of awakenings Interval 0.0 to 7.0

SECONDARY outcome

Timeframe: Day 7

The "average" pain intensity score on Day 7 as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Average Daily Pain Intensity Day 7	0 units on a scale Interval 0.0 to 1.1

SECONDARY outcome

Timeframe: Day 7

The "worst" pain intensity score on Day 7 as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Worst (Maximum) Daily Pain Intensity Day 7	1.8 units on a scale Interval 1.0 to 3.5

SECONDARY outcome

Timeframe: Day 7

The cumulative opioid use from the previous 24 hours measured in oxycodone equivalents as recorded on Day 7

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Opioid Consumption Day 7	0 milligrams Interval 0.0 to 0.0

SECONDARY outcome

Timeframe: postoperative Days 1, 2, 3, 4, 7, 8 and 14

The "average" pain intensity score on each postoperative day as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Daily "Average" Pain Intensity Day 1	3 units on a scale Interval 1.0 to 4.3
Daily "Average" Pain Intensity Day 2	2 units on a scale Interval 0.9 to 3.3
Daily "Average" Pain Intensity Day 3	2 units on a scale Interval 0.0 to 3.0
Daily "Average" Pain Intensity Day 4	1 units on a scale Interval 0.0 to 2.3
Daily "Average" Pain Intensity Day 7	0 units on a scale Interval 0.0 to 1.1
Daily "Average" Pain Intensity Day 8	0 units on a scale Interval 0.0 to 1.1
Daily "Average" Pain Intensity Day 14	0 units on a scale Interval 0.0 to 1.3

SECONDARY outcome

Timeframe: postoperative Days 1, 2, 3, 4, 7, 8 and 14

The "worst" pain intensity score on each postoperative day as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Daily "Worst" Pain Intensity Day 1	5 units on a scale Interval 4.0 to 7.1
Daily "Worst" Pain Intensity Day 2	4.5 units on a scale Interval 3.1 to 6.3
Daily "Worst" Pain Intensity Day 3	4.3 units on a scale Interval 3.3 to 6.0
Daily "Worst" Pain Intensity Day 4	3 units on a scale Interval 0.4 to 4.0
Daily "Worst" Pain Intensity Day 7	1.8 units on a scale Interval 1.0 to 3.5
Daily "Worst" Pain Intensity Day 8	2 units on a scale Interval 0.0 to 3.0
Daily "Worst" Pain Intensity Day 14	2 units on a scale Interval 0.0 to 4.0

SECONDARY outcome

Timeframe: postoperative Days 1, 2, 3, 4, 7, 8 and 14

The cumulative opioid use from the previous 24 hours measured in oxycodone equivalents as recorded on Days 1-4, 7, 8, and 14

Outcome measures

Outcome measures
Measure	Experimental Treatment n=20 Participants RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Daily Opioid Consumption Day 1	0.3 milligrams Interval 0.0 to 2.0
Daily Opioid Consumption Day 2	0 milligrams Interval 0.0 to 1.3
Daily Opioid Consumption Day 3	0 milligrams Interval 0.0 to 1.0
Daily Opioid Consumption Day 4	0 milligrams Interval 0.0 to 0.0
Daily Opioid Consumption Day 7	0 milligrams Interval 0.0 to 0.0
Daily Opioid Consumption Day 8	0 milligrams Interval 0.0 to 0.0
Daily Opioid Consumption Day 14	0 milligrams Interval 0.0 to 0.0

Adverse Events

Experimental Treatment

Serious events: 0 serious events

Other events: 5 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Experimental Treatment n=20 participants at risk RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. If a patient's surgeon requests a postoperative continuous peripheral nerve block, a ropivacaine 0.2% infusion will be initiated in the recovery room. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7. Experimental Treatment: Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.
Surgical and medical procedures Baton separation from pulse generator during intentional removal	5.0% 1/20 • Number of events 1 • 14 days
Surgical and medical procedures Perineural catheter occlusion	15.0% 3/20 • Number of events 3 • 14 days
Surgical and medical procedures Accidental catheter dislodgment	5.0% 1/20 • Number of events 1 • 14 days

Additional Information

Baharin Abdullah

University of California San Diego

Phone: +1 858-220-5714

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place