Kathryn Raethel

Kathryn Raethel

Kathryn Raethel, F.A.C.H.E., M.H.A., M.P.H., R.N., assumed the presidency of Adventist Health Castle (AHCS) on December 5, 2011.

Prior to this appointment, Raethel had been vice president for patient care services at AHCS for eleven years. During this time, she provided administrative direction and clinical oversight of patient care at AHCS, and she oversaw numerous departments, including the nursing units, the Emergency Department, Quality Resources, and Risk Management.

Prior to joining AHCS, Raethel was the vice president of professional services and COO at Desert Valley Hospital in Victorville, California. She holds a master’s degree in public health and a master’s degree in health administration from Loma Linda University in California.

Raethel and her husband, Hilton, have four adult children and live in Kailua.

Kathryn Raethel

Ryan Ashlock
Operations Executive

Ryan Ashlock, CPA, MBA, joined Adventist Health Castle as operations executive in April 2019.

Ashlock comes to AH Castle from Adventist Health Feather River in California where he was the Finance Executive. Prior to that, he was director of Finance at that hospital. Ashlock has also worked at Adventist Health’s system office in Roseville, CA, as manager of Revenue Performance and corporate director of Performance Management.

Ashlock received his Bachelor of Science degree in Accounting from La Sierra University in California, and a graduate degree from UC Davis Graduate School of Management.

Laura WestphalErik Anderson, RN
Patient Care Executive

In August of 2019, Erik Anderson became Adventist Health Castle’s (AHCS) patient care executive. Anderson has worked at AHCS for 24 years. He began his career at AHCS in Education and Training in 1995 and worked in Health Information before receiving his EMT Certification at Kapiolani Community College and becoming and Emergency Room Technician in 1996.

In his nursing career, Anderson has been a charge nurse in ER and a Clinical Indicator Specialist before becoming the director of Quality Resources in 2015. He holds a Bachelor of Arts degree in Biology, and a Bachelor of Science in Nursing degree from Hawai'i Pacific University.

Anderson and his wife live in Kaneohe with their two sons, and a daughter.

Heidar ThordarsonHeidar Thordarson
Finance Officer

Heidar Thordarson, MBA, became AHCS’s vice president for Finance and its chief financial officer in August, 2017. Prior to coming to AHCS, Thordarson was Director of Finance, Assistant CFO, then Interim CFO at Vista Health System in Waukegan, IL.

He holds his BBA in Finance and MBA from Loma Linda University, and is a Certified Public Accountant.

Thordarson, his wife, Nora, and 3-year-old boxer, Ronaldo, reside in Kailua.

Alan H.S. CheungAlan H.S. Cheung

Medical Officer

Alan H.S. Cheung, M.D., M.B.A., F.A.C.S., began serving in the newly created position of vice president of medical affairs in January, 2009. He has been on the medical staff of AHCS since October, 1992.

Dr. Cheung is a general and transplant surgeon working with Surgical Associates, Inc., with offices in Kailua and Honolulu. He received his medical degree from Harvard Medical School in Boston, completed his internship and general surgery residency at the University of Washington, and was awarded a transplant fellowship by the University of Minnesota Medical School. He holds an M.B.A. in health care administration from the School of Public Health of Loma Linda University in California.

Dr. Cheung is currently the president of Surgical Associates, Inc., and is a clinical professor of surgery at the John A. Burns School of Medicine of the University of Hawai‘i. Dr. Cheung was voted one of the “Best Doctors in Hawai‘i” in 2009. He and his wife, Alyson, have a daughter and son and live in Kailua.