Surgery of Right Upper Extremity Clinical Trial
Official title:
Dose-Response Relationships for Hemidiaphragmatic Paresis Following Ultrasound-Guided Supraclavicular Brachial Plexus Blockade
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.
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.
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