This study will answer the question whether there is a difference in the effects and complication rates of ultrasound guided continuous interscalene block (CISB) and nerve stimulation-guided continuous cervical paravertebral block (CCPVB). The aim of this study is to evaluate the differences in efficacy and side effects - if any.

This is a prospective randomized double-blinded study that will compare two commonly used approaches for the continuous blockade of the brachial plexus: the CCPVB, which focusses on the six cervical nerve root (C6 root), and CISB, which focuses on the upper trunk of the brachial plexus. Data of sensory testing, motor strength, shoulder pain, phrenic nerve function, recurrent laryngeal nerve (RNL) function, ipsilateral Horner's syndrome, block time and medication doses used for block placement, will be collected. All observations and measurements will be made by a member of the research team who is unaware of patient allocation to any particular group.

Inclusion Criteria:

• The general inclusion will be those adult patients who:

  • are between the ages of 18 and 80 years
  • have an ASA Health Classification of I, II, or III
  • are scheduled for shoulder arthroplasty or rotator cuff repair surgery
  • Patients with a BMI of =to/< 40 Exclusion

The Exclusion criteria will include:

• Patient refusal to participate in the study or sign informed consent
• Patients with contraindications to any of the two blocks or allergy to any of the drugs used
• Patients with shoulder surgery that developed into any other surgery other than total shoulder arthroplasty or rotator cuff repair
• Patients with a BMI >40

Patients who are are scheduled for shoulder arthroplasty or rotator cuff repair surgery at an area hospital