Interscalene Brachial Plexus Block Washout to Reverse Inadvertent Phrenic Nerve Blockade

Stanford University

Status: Completed

Conditions: Phrenic Nerve Paralysis; Anesthesia, Local; Phrenic Nerve Palsy on the Right; Phrenic Nerve Palsy on the Left; Upper Extremity Injury

Treatments: Other: Placebo; Procedure: Normal saline injected via interscalene nerve catheter

Study type: Interventional

Funder types: Other

Identifiers

NCT03677778

46830

Details and patient eligibility

About

One of the most frequently performed peripheral nerve blocks (the injection of local anesthetic near nerves to block sensation/ movement to a specific part of the body) is the interscalene brachial plexus block for upper extremity surgeries. This type of block can unmask underlying respiratory issues such as shortness of breath due to a well-known and typically insignificant side effect of temporary diaphragmatic paralysis.

The nerve block may be able to use saline solution to wash out the local anesthetic and potentially reverse this respiratory side effect. Specifically, the goal of this study is to determine if the injection of saline through the nerve block catheter reverses blockade of the phrenic nerve supplying the diaphragm, without affecting the ability of the nerve block to provide pain control after surgery.

Enrollment: 43 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• All adult patients (18 years and over) scheduled for surgery requiring a continuous interscalene brachial plexus nerve block catheter as part of their anesthetic care.

Exclusion criteria

• Concomitant life-threatening injuries and other concomitant injuries causing significant pain
• Pregnant
• Any condition impairing patient's ability to consent to participation in study, and an existing condition contraindicating a nerve block, i.e. nerve injury, existing bleeding disorder, infection in the vicinity of the block, and patient refusal.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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43 participants in 2 patient groups, including a placebo group

Placebo group

Placebo Comparator group

Description:

After surgery, in the post-operative recovery room, patients randomized to both the intervention and control groups will have 10cc 0.5% ropivacaine bolused via their nerve catheters. After 30 minutes, the following will be measured/assessed: spirometry data, pain scores (using the Numeric Rating Scale), and, if time is sufficient, bilateral diaphragmatic excursion via ultrasonography and brachial plexus motor and sensory exams. This control group will have no normal saline injected into their nerve catheter (no intervention). Then, both the control and treatment groups will have the following measured/assessed after 5, 15 and 30 minutes: spirometry data, pain scores (using the Numeric Rating Scale), and, if time is sufficient, bilateral diaphragmatic excursion via ultrasonography and brachial plexus motor and sensory exams. Investigators will be blinded to whether the patient is in the intervention or treatment group.

Treatment:

Other: Placebo

Treatment group

Active Comparator group

Description:

After surgery, in the post-operative recovery room, patients randomized to both the intervention and control groups will have 10cc 0.5% ropivacaine bolused via their nerve catheters. After 30 minutes, the following will be measured/assessed: spirometry data, pain scores (using the Numeric Rating Scale), and, if time is sufficient, bilateral diaphragmatic excursion via ultrasonography and brachial plexus motor and sensory exams. This group will then have 30ml of normal saline injected into their nerve catheter. Then, both the control and treatment groups will have the following measured/assessed after 5, 15 and 30 minutes: spirometry data, pain scores (using the Numeric Rating Scale), and, if time is sufficient, bilateral diaphragmatic excursion via ultrasonography and brachial plexus motor and sensory exams. Investigators will be blinded to whether the patient is in the intervention or treatment group.

Treatment:

Procedure: Normal saline injected via interscalene nerve catheter