Preoperative Maximum Inspiratory Pressure and Outcomes After Interscalene Block in Obese Patients

A Pilot Study on Inspiratory Dynamics and the Effect of Body Mass Index on Respiratory Outcomes After Temporary Hemi Diaphragmatic Paresis Related to Brachial Plexus Blocks

The study aims to explore if Maximum Inspiratory Pressure can predict postoperative breathlessness in obese patients receiving interscalene blocks for shoulder surgery.

The main question is: does baseline Maximum Inspiratory Pressure have any association with postoperative breathlessness after interscalene blocks in class 2 or higher obese patients (BMI>35).

Preoperative and postoperative lung volumes, pressures, breathlessness score and respiratory outcomes will be measured on participants already receiving shoulder surgery with interscalene blocks.

Inclusion Criteria Groups 1 and 2

• Adults >18 years of age receiving shoulder surgery with preoperative interscalene block and general anesthesia;
• Speak English;

Group 3

· Adults >18 years of age receiving cystoscopy or lower extremity procedures receiving general endotracheal anesthesia

Exclusion Criteria All Groups

• Less than 18 years of age;
• currently pregnant;
• currently incarcerated;
• those with significant neuromuscular disease, tracheo-bronchial structural abnormalities, severe respiratory or severe cardiovascular comorbidity;
• those undergoing intra-abdominal or intrathoracic surgeries due to the potential to independently effect breathing