Neurologic Outcomes After Low-Volume, Ultrasound-Guided Interscalene Block and Ambulatory Shoulder Surgery.
OBJECTIVE
Postoperative neurologic symptoms after interscalene block and shoulder surgery have been reported to be relatively frequent. Reports of such symptoms after ultrasound-guided block have been variable. We evaluated 300 patients for neurologic symptoms after low-volume, ultrasound-guided interscalene block and arthroscopic shoulder surgery.


METHODS
Patients underwent ultrasound-guided interscalene block with 16 to 20 mL of 0.5% bupivacaine or a mix of 0.2% bupivacaine/1.2% mepivacaine solution, followed by propofol/ketamine sedation for ambulatory arthroscopic shoulder surgery. Patients were called at 10 days for evaluation of neurologic symptoms, and those with persistent symptoms were called again at 30 days, at which point neurologic evaluation was initiated. Details of patient demographics and block characteristics were collected to assess any association with persistent neurologic symptoms.


RESULTS
Six of 300 patients reported symptoms at 10 days (2%), with one of these patients having persistent symptoms at 30 days (0.3%). This was significantly lower than rates of neurologic symptoms reported in preultrasound investigations with focused neurologic follow-up and similar to other studies performed in the ultrasound era. There was a modest correlation between the number of needle redirections during the block procedure and the presence of postoperative neurologic symptoms.


CONCLUSIONS
Ultrasound guidance of interscalene block with 16- to 20-mL volumes of local anesthetic solution results in a lower frequency of postoperative neurologic symptoms at 10 and 30 days as compared with investigations in the preultrasound period.
From the *Acute Interventional Perioperative Pain Service, Department of Anesthesiology, School of Medicine, †Clinical and Translational Science Institute, and ‡Department of Physical Medicine and Rehabilitation, School of Medicine, University of Pittsburgh, Pittsburgh, PA.
Gaurav
G
Rajpal
Daniel G
DG
Winger
Megan
M
Cortazzo
Michael L
ML
Kentor
Steven L
SL
Orebaugh
D000328:Adult; D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D019162:Anesthetics, Combined / Q000008:administration & dosage* / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D001182:Arthroscopy / Q000009:adverse effects; D002045:Bupivacaine / Q000008:administration & dosage* / Q000009:adverse effects; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D009460:Neurologic Examination / Q000379:methods; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D012782:Shoulder / Q000294:innervation / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D008619:Mepivacaine; D002045:Bupivacaine