The people of Meridian

Dr. Mark Ettinger is a board-certified anesthesiologist with 20 years of clinical practice and physician leadership experience in Dallas–Fort Worth. He co-founded Meridian Anesthesia in 2025 with Val Gibson, MD, and serves as its President, leading clinical operations, recruiting, and quality across Meridian’s hospitals, which include two trauma centers.

From 2011 to 2025, Dr. Ettinger practiced with a physician-owned, multi-facility anesthesia group in Dallas, where he was a managing partner. At Medical City Arlington, a 500-bed Level II trauma center, he served as Chair and Medical Director of the Department of Anesthesiology, Director of the Preoperative Assessment Clinic, and Chair of the Hospital Ethics Committee, leading a department of more than 50 anesthesiologists, CRNAs, and support staff. In 2025 he led the hospital’s transition from a physician-only anesthesia group to a care-team model under Meridian and NPH.

Dr. Ettinger also designed and built Equinox, the software platform that runs Meridian’s practice — scheduling, credentialing, provider compensation, billing reconciliation, and analytics.

He earned his medical degree from LSU Health Sciences Center in New Orleans, where he graduated as valedictorian and was elected to Alpha Omega Alpha. He did a general surgery internship and three years of neurosurgery residency at UT Southwestern, then completed his anesthesiology residency at The Johns Hopkins Hospital. He is a Diplomate of the American Board of Anesthesiology. Since 2014 he has provided volunteer anesthesia leadership for Faith In Practice surgical missions in Guatemala.

Dr. Ettinger and his wife, Gena, have three children, Eli, Gavin, and Savannah. In his free time, he loves to play guitar, work out, travel to LSU football games, and spend time camping and hunting with his family and their German Shorthaired Pointer, Slick. He is also a commercial pilot and flight instructor.

Dr. Valentine Gibson is a board-certified anesthesiologist with nearly two decades of clinical and healthcare leadership experience. He graduated Magna Cum Laude with a Bachelor of Science in Chemical Engineering before earning his Doctor of Medicine from the West Virginia University School of Medicine. He completed his anesthesiology residency at the University of Texas at Houston Medical School, where he served as Chief Resident and received the Outstanding Resident Award.

Dr. Gibson has practiced anesthesiology at Medical City Arlington since 2007, where he has held numerous physician leadership positions, including Chief of Anesthesiology and Chief of the Medical Staff. Throughout his career, he has been dedicated to advancing patient safety, improving quality of care, and fostering collaboration among physicians, hospital leadership, and multidisciplinary care teams. He has a special interest in regional and obstetrical anesthesia and enjoys teaching through regional anesthesia workshops and educational lectures.

He is board certified by the American Board of Anesthesiology and is an active member of the American Society of Anesthesiologists and the Texas Society of Anesthesiologists. In 2025, he co-founded Meridian Anesthesia alongside Dr. Mark Ettinger, and as Vice President, Dr. Gibson is committed to delivering exceptional anesthesia care through clinical excellence, innovation, and a care-team approach that prioritizes patients, hospitals, and surgical partners alike.

Outside of his professional career, Dr. Gibson enjoys spending time with his wife and their children — Kendall, a practicing dermatologist in Dallas, Val, and Dru — and especially cherishes time with his grandson, Elias. He also enjoys staying active through regular workouts and finds time for faith and fellowship through attending church. Fun fact: Dr. Gibson once appeared on Family Feud, where his Obama impersonation added an unexpected highlight to his television debut.

Dr. Richard Teames is a dedicated anesthesiologist with a unique background in nursing who excels in working with trauma and critical care patients. He earned his medical degree from St. George’s University School of Medicine and completed his anesthesiology residency at UTHealth/Memorial Hermann in Houston, where he developed exceptional regional anesthesia skills and ultrasound technique across multiple nerve block modalities. He has been in clinical practice since 2015, is board-certified by the American Board of Anesthesiology (ABA), and is a Fellow of the American Society of Anesthesiologists (FASA).

Dr. Teames currently serves as Chair of the Department of Anesthesia and Director of Cardiothoracic & Acute Pain Anesthesia at Medical City Arlington. He is a retired Officer of the United States Army Reserve Medical Corps. His clinical interests include acute pain management, regional anesthesia, advanced airway techniques, and cardiovascular anesthesia. He has a genuine interest and enthusiasm for teaching clinical and acute pain/regional anesthesia and is a bilingual (English/Spanish) patient advocate.

Dr. Kimble Horak serves as Chief of Anesthesia at Medical City Las Colinas. He joined Meridian Anesthesia in 2025 and has more than thirteen years of clinical experience in anesthesiology, with practice spanning a broad range of surgical specialties, including obstetric, regional, cardiovascular, and ambulatory anesthesia.

Prior to joining Meridian, Dr. Horak practiced for more than a decade within the John Peter Smith Health Network in Fort Worth, where he held numerous clinical and administrative leadership positions. He served as Interim Chair of the Department of Anesthesiology, as a member of the Medical Executive Committee, and as Medical Director of the JPS Surgical Center Arlington. His leadership experience has also included hospital committees focused on surgical risk, operating room and endoscopy operations, credentialing, graduate medical education, and medication safety.

Dr. Horak earned his undergraduate degree in biology from Baylor University and his medical degree from the University of Texas Medical School at Houston. Following an internship in internal medicine at the University of Illinois at Chicago, he returned to Houston to complete his anesthesiology residency. He subsequently completed the Emerging Leaders Program through the American College of Physician Executives and Sheridan Healthcare, with advanced training in physician leadership, strategic planning, finance, negotiation, and high-reliability healthcare organizations.

Dr. Horak is a Diplomate of the American Board of Anesthesiology and has served as an Assistant Professor at the TCU Burnett School of Medicine. He has been recognized by Fort Worth Magazine as a Top Doctor each year from 2021 through 2026.

Guillermo Guardiola, CRNA, is an accomplished Chief Certified Registered Nurse Anesthetist with more than 18 years of experience spanning clinical excellence and advanced departmental leadership. A Texas Wesleyan University graduate, Guillermo has practiced anesthesia his entire career in the Dallas–Fort Worth area. Currently, he serves as Chief CRNA for Meridian Anesthesia at Medical City Arlington, where he advocates for provider teams and advises executive leadership on strategic hiring and team cohesion.

Previously, Guillermo served as Assistant Chief CRNA at Parkland Health and Hospital System—a premier Level I trauma center and regional burn center—where he also coordinated and managed professional staff for one of the busiest labor and delivery units in the country. Being fully bilingual in English and Spanish allows him to foster strong connections across diverse patient populations and teams.

Guillermo is board-certified through the National Board of Certification and Recertification for Nurse Anesthetists and is an active member of both the American Association of Nurse Anesthetists and the Texas Association of Nurse Anesthetists.

Tyler Comans is a Certified Registered Nurse Anesthetist with Meridian Anesthesia and serves as the group’s Director of CRNA Recruitment. A Mississippi native and one of several children in a close-knit family, Tyler grew up learning the value of hard work, relationships, and community—principles that continue to shape both his personal and professional life.

Tyler earned his Bachelor of Science in Nursing from Delta State University and began his career as a critical care nurse at the University of Mississippi Medical Center. He later earned his Doctor of Nursing Practice from the University of Southern Mississippi. His anesthesia training took him to clinical sites throughout Mississippi, from rural community hospitals to a Level I trauma center, providing broad experience across a wide range of patient acuities and surgical specialties. Before joining Meridian, Tyler worked as a locum CRNA from Texas and across the Southeastern US.

While in anesthesia school, Tyler and his wife began building their family in Mississippi before eventually making their home in Texas. His wife is also a CRNA, giving them a shared appreciation for the profession and the people who make it meaningful. Together, they have three children, and the family they have built is Tyler’s greatest source of pride and joy. Outside of work, he is happiest spending time with his family—whether on the golf course, at the baseball field, outdoors, or traveling together.

At the heart of Tyler’s leadership style is a genuine love for people and connection. As Director of CRNA Recruitment, he enjoys helping providers find opportunities where they can thrive, building lasting relationships, and strengthening the sense of community within Meridian. For Tyler, recruitment is about more than filling positions—it is about bringing the right people together and creating a place where they feel valued, supported, and proud to work.