Nausea after surgery may negatively influence patient satisfaction, may delay discharge, and cause unexpected hospital admissions. The trend toward ambulatory surgery has increased the focus on postoperative nausea, but published evidence is not based on standardized criteria for assessment. Therefore, the results for postoperative nausea are very diverse, especially reports on nausea incidence after regional anesthesia, i.e. spinal anesthesia. When peripheral nerve blocks have been applied for postoperative pain control, they significantly reduce postoperative pain, opioid consumption and side effects; patients receiving general anesthesia (GA) and nerve blocks are thought likely to have less nausea than patients receiving GA alone. This study is a pilot study looking at the incidence and intensity of nausea after orthopedic surgery under nerve blocks in foot and ankle (FA) patients and under nerve blocks with either sedation or GA in total shoulder arthroplasty (TSA) patients. The results of this study will help power a future randomized controlled trial, comparing the incidence and intensity of nausea in FA patients receiving GA through laryngeal mask airway (LMA) versus spinal anesthesia.

Nausea after surgery may negatively influence patient satisfaction, may delay discharge, and cause unexpected hospital admissions. The trend toward ambulatory surgery has increased the focus on postoperative nausea, but published evidence is not based on standardized criteria for assessment. Therefore, the results for postoperative nausea are very diverse, especially reports on nausea incidence after regional anesthesia, i.e. spinal anesthesia. This is due to varying data sources, such as nurse notes and/or patient reports, and a lack of a consistent antiemetic and pain medication protocol. The results of this study will help power a future randomized controlled trial, comparing the incidence and intensity of nausea in FA patients receiving GA through laryngeal mask airway (LMA) versus spinal anesthesia.

When peripheral nerve blocks have been applied for postoperative pain control, they significantly reduce postoperative pain, opioid consumption and side effects; patients receiving GA and nerve blocks are thought likely to have less nausea than patients receiving GA alone, due a reduction in pain leading to reduction in need for emetogenic opioids.

This study is a pilot study looking at the incidence and intensity of nausea after orthopedic surgery under nerve blocks in foot and ankle (FA) patients and under nerve blocks with either sedation or GA in total shoulder arthroplasty (TSA) patients. At the author's institution, TSA is commonly performed with a brachial plexus block and either GA or intravenous sedation. TSA patients represent a model system for the effect of GA on nausea among patients receiving nerve blocks.

Inclusion Criteria:

• Elective surgery
• Age 18-99
• Patients who are capable to provide informed consent and answer questions in English,
• For FA patients: Planned neuraxial anesthesia + nerve block for postsurgical analgesia,
• For TSA patients: Planned brachial plexus nerve block + either general anesthesia or IV sedation.

Exclusion Criteria:

• Incapable to provide informed consent
• Contraindications for regional or LMA anesthesia (anticoagulation, infection at injection site)
• Anticipated difficult airway
• Body mass index>35
• Anticipated surgical procedure time less than 1 hour or more than 4 hours,
• History of severe postoperative nausea and/or vomiting
• American Society of Anesthesiologists physical status classification >3
• Neuropathy
• Pregnant or nursing women
• Chronic opioid use (daily use of opioids one month prior to surgery/ patients requiring chronic pain interventions)
• Prone position planned for surgery
• Obstructive sleep apnea
• Known allergy/sensitivity to any study medications

Patients undergoing elective orthopedic surgery for foot and ankle or total shoulder replacement that are within the age limit and meet eligibility criteria.

Patients contributed baseline units by patient report (history of PONV, motion sickness, smoking status) and by granting access to their charts (age, gender, race, ethnicity, ASA status, BMI).

Adverse event data was collected during the period of enrollment and patient participation (Post-Operative Day 0 to Post-Operative Day 1).

Limitations included generalizability, as the study was limited by anesthetic regimen, type of surgery, and patient population. We felt it was inappropriate to randomize general or spinal anesthesia for the purpose of this study.