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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
43
With the catheter covered, treatment group patients will receive a normal saline (NS) bolus regimen (30cc 0.9% NS) via their interscalene nerve block catheter.
With the catheter covered, placebo group patients will go through the same steps as the treatment group, but no solution will be injected into the interscalene nerve block catheter.
Stanford Health Care (SHC)
Palo Alto, California, United States
Change in forced vital capacity (FVC)
Spirometry data will be collected using a digital spirometer before nerve block is placed, after surgery, and after receiving either the placebo or treatment.
Time frame: Before the nerve block placement, within 1 hour after the surgery, then in 5, 15, and 30 minutes after the saline injection/placebo (1 minute each for a total of 5 assessments)
Change in peak expiratory flow (PEF)
Spirometry data will be collected using a digital spirometer before nerve block is placed, after surgery, and after receiving either the placebo or treatment.
Time frame: Before the nerve block placement, within 1 hour after the surgery, then in 5, 15, and 30 minutes after the saline injection/placebo (1 minute each for a total of 5 assessments)
Change in forced expiratory volume in 1 second (FEV1)
Spirometry data will be collected using a digital spirometer before nerve block is placed, after surgery, and after receiving either the placebo or treatment.
Time frame: Before the nerve block placement, within 1 hour after the surgery, then in 5, 15, and 30 minutes after the saline injection/placebo (1 minute each for a total of 5 assessments)
Diaphragmatic excursion
Diaphragmatic excursion will be assessed via ultrasound before nerve block is placed, after surgery, and while receiving either the placebo or treatment.
Time frame: Before nerve block is placed, within 1 hour after the surgery, and while receiving either the placebo or treatment (5 minutes each for a total of 3 assessments.)
Brachial plexus sensory and motor exam
Brachial plexus sensory and motor exam changes will be assessed before nerve block is placed, after surgery, and while receiving either the placebo or treatment.
Time frame: Before nerve block is placed, within 1 hour after the surgery, and while receiving either the placebo or treatment (2 minutes each for a total of 3 assessments).
Pain scores
The Numerical Pain Rating Scale is a subjective measure in which individuals rate their pain on an eleven-point numerical scale. The scale is composed of 0 (no pain at all) to 10 (worst imaginable pain). Pain scores will be assessed before nerve block is placed, after surgery, while receiving either the placebo or treatment.
Time frame: Pain scores will be assessed before nerve block is placed, within 1 hour after the surgery, while receiving either the placebo or treatment. (1 minute each for a total of 3 assessments)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.