Our Team

Dr. Evans received his doctorate from the East Tennessee State University Quillen College of Medicine in Johnson City, TN. Dr. Evans completed his anesthesiology residency at the University of Virginia and his fellowship at the University of Alabama. He is board certified through the American Board of Anesthesiology, and is part of the American Society of Anesthesiologists. His professional affiliations include: the Tennessee Medical Association, the Tennessee Society of Anesthesiologists, the Virginia Society of Anesthesiologists, and the National Board of Echocardiography. Dr. Evans has also received his certification in Advanced Peri-operative Transesophageal Echocardiography and subspecialty training in cardiothoracic anesthesia. His clinical interest is cardiac anesthesia.

Bio coming soon.

Bio coming soon.

Dr. May has been practicing anesthesiology in the area since 1991. He is a 1987 graduate of University of Tennessee Health Sciences Center in Memphis. He completed his residency in anesthesiology in 1991 from UT Knoxville. He is board certified by the American Board of Anesthesiology. He has served on numerous medical staff and health system committees including the board of trustees of Mountain States Health Alliance and Ballad Health. He is the current chair of the Quality, Service, and Safety committee at Ballad Health. He is active in his community and enjoys spending time with his family.

Dr. Hughes joined Bristol Anesthesia Services in July 2012 after completing his Cardiothoracic Anesthesiology Fellowship at Wake Forest University in Winston Salem, NC. He completed his residency in Anesthesiology at the University of Alabama, Birmingham in June 2011. Dr. Hughes is a member of the Operating Room Committee and Director of Cardiothoracic Anesthesia. He is also past President of the Tennessee Society of Anesthesiologists. He is Board Certified through the American Board of Anesthesiology and Board Certified in Advanced Perioperative Transesophageal Echocardiography by the National Board of Echocardiography.

Bio coming soon.

Dr. Brown is a Bristol native who is proud to have served in the community since beginning practice in 2002. He received his medical degree from Wake Forest University School of Medicine and then completed a residency in Anesthesiology at the Medical University of South Carolina. He serves on the Board of Directors and Quality Assurance Committee at East Tennessee Ambulatory Surgery Center. Dr. Brown's primary focus is outpatient surgery. He is board certified by the American Board of Anesthesiology.

Dr. Lorna Ehrenfried received her medical degree from the University of Texas Medical Branch in Galveston in 1994. Dr. Ehrenfried remained in Galveston to complete her anesthesiology residency at the University of Texas Medical Branch. She joined East Tennessee Ambulatory Surgery Center in 2001 and is board certified through the American Board of Anesthesiology. Her professional affiliations include both the Tennessee Society of Anesthesiologists and the American Society of Anesthesiology.

Dr. Grenvik received his doctorate degree from the University of Pittsburgh in 1989. Dr. Grenvik completed his internship and anesthesiology residency at Mercy Hospital of Pittsburgh and joined Bristol Anesthesia Services in July 1993. He is board certified through the American Board of Anesthesiology, and is part of the American Society of Anesthesiologists. His professional affiliations include: the National Board of Echocardiography, the Anesthesia Section at Bristol Regional Medical Center (BRMC), and he is also a current member of the BRMC Trauma Committee and Infection Control Committee. Dr. Grenvik has also received his certification in Basic Perioperative Transesophageal Echocardiography from the National Board of Echocardiography. His clinical interest is cardiac anesthesia.

Bio coming soon.

Bio coming soon.

Bio coming soon.

Dr. Michael Long is a veteran of the United States Navy with over 30 years experience working in the operating room.  He received his doctorate degree in medicine from East Carolina University in Greenville, NC in 2008 and completed his Anesthesiology residency at the University of Alabama Birmingham in 2012.

He is board certified through the American Board of Anesthesiology, and testamur for Advanced Perioperative Transesophageal Echocardiography by the National Board of Echocardiography. He has memberships with the American Society of Anesthesiologists, American Society of Regional Anesthesia, and Undersea and Hyperbaric Medical Society.

His professional/faculty affiliations include: Chair Anesthesia Section Department of Surgery Bristol Regional Medical Center(BRMC), Clinical Assistant Professor of Internal Medicine East Tennessee State University School of Medicine (ETSU), Chair Physician Committee on Disaster Management and Emergency Preparedness (BRMC), Committee on Orthopedic Service Line (BRMC), the Committee on Critical Care (BRMC)

Dr. Long’s clinical interests include regional anesthesia, ultrasound/echocardiography, hyperbaric medicine, medical simulation education and emergency preparedness and disaster medicine.

Dr. Long continues his love for education/leadership by coaching a successful underwater robotics team at Dobyns-Bennett High School.

He is passionate about scuba diving, fishing and sailing, all of which he has been enjoying for nearly 40 years.

Dr. Macfarlane joined Bristol Anesthesia Services in 2007. He completed Medical School at Saba University. He completed a combined Internship and Anesthesiology residency at University of Wisconsin-Madison in 2007. Dr. Macfarlane has served as Chairman of the Anesthesia Section at Bristol Regional Medical Center. He is board Certified by the American Board of Anesthesiology.

Bio coming soon.

Bio coming soon.

Bio coming soon.

Dr. Brandon Seaver joined Bristol Anesthesia Services, P.C. in 2021 after completing his anesthesiology residency at the University of Alabama, Birmingham. He is an East Tennessee native, having graduated from ETSU Quillen College of Medicine in 2017. Dr. Seaver is a member of the Anesthesia Section at Bristol Regional Medical Center, where his clinical interests include regional and cardiovascular anesthesia. He is currently in the board certification process through the American Board of Anesthesiology and is looking forward to providing patient centered anesthesia care to the Tri-Cities area.

Bio coming soon.

Bio coming soon.

Born in Istanbul, Turkey, Dr. Yavas is a proud graduate of Towne Acres Elementary, Liberty Bell Middle, and Science Hill High Schools.  He would earn his M.D. degree at Vanderbilt University before completing his anesthesiology residency at the University of Florida.  Dr. Yavas has been practicing anesthesiology in the region since 2010.  Active in the medical community, Dr. Yavas has served on several medical staff and health system committees.  Dr. Yavas has also co-authored a number of peer-reviewed publications and helped develop several web simulations modeling the pharmacokinetics and pharmacodynamics of commonly-administered anesthetic medications.