Diaphragm-sparing Nerve Blocks for Shoulder Arthroplasty

Diaphragm-sparing Nerve Blocks for Shoulder Arthroplasty: an Exploratory Feasibility Study

The combination of a modified lateral sagittal infraclavicular block and a suprascapular nerve block has not been studied in a cohort of total arthroplasty patients. Such diaphragm-sparing nerve blocks for shoulder arthroplasty may provide a very good anesthetic alternative in lung diseased patients who are in need for total arthroplasty of the shoulder.

The investigators hypothesized that a combination of suprascapular nerve block and lateral sagittal infraclavicular block of the posterior and lateral cords would provide good postoperative analgesia for patients undergoing shoulder arthroplasty.

The primary aims of this study were to document numeric rating scale (NRS, 0-10) and use of morphine equivalents during the first 24 hours after surgery. Secondary aims were to determine the incidence of diaphragm paresis 30 minutes after the block and to quantify postoperative hand grip force at 1 hr.

Inclusion Criteria:

• 18-78 years old,
• BMI 20-35 kg.m-2
• ASA physical status 1-3

Exclusion Criteria:

• unable to consent,
• pregnancy,
• pre-existing severe respiratory disease,
• use of anticoagulation drugs other than acetylsalicylic acid or dipyridamol,
• allergy to local anaesthetics,
• patients on regular opioids,
• atrioventricular block,
• peripheral neuropathy.