Accute Care Associates Leadership


Dr. Lars Thestrup, MD

Managing Partner

Dr. Lars Thestrup was born and raised in Northern Virginia where he attended Mary Washington College earning his B.S. in Biology. He received his M.D. at the Medical College of Virginia and completed his emergency medicine residency at Johns Hopkins. Lars then completed his fellowship in North Carolina focusing on emergency medical services and disaster preparedness at the Carolinas Medical Center. Shortly after the completion of his fellowship, Lars accepted a position with the City of Houston as an Assistant Medical Director to the Houston Fire Department. His current role involves providing medical care and consultation to the Houston Fire and Police Department as well as assisting in the coordination of disaster preparedness for the City. He is also active with research focusing on cardiac arrest management and dispatch protocols. He has practiced clinically at St. Joseph’s and St. Luke’s Medical Center.  Currently he practices at Ben Taub, Texas Children’s Hospital, and St. Luke’s CHI Patient’s Hospital. He resides in Houston with his wife Heather and two kids.


Jesus M. Arroyo, MD

Managing Partner

Dr. Jesus Arroyo was born and raised in the island of Puerto Rico where he attended the University of Puerto Rico and completed his Pre Med program. Subsequently, he went on to receive his M.D. at the University of Puerto Rico, Medical Sciences Campus. Dr. Arroyo then embarked to the city of Houston to the University of Texas Medical School at Houston where he completed his emergency medicine residency. After the completion of his residency, he went on to practice in both  community and academic emergency department settings. Dr. Arroyo currently works as clinical faculty at UT Health Emergency Medicine Residency Program and also does work as a community physician. Dr. Arroyo has done humanitarian medical missions to both Nicaragua and Guatemala.   His interest in research has led him to work as a primary investigator with Pioneer Research Solutions, where he supervises pharmaceutical study protocols. He has practiced clinically at Memorial Hermann Southwest, Memorial City, M.D. Anderson Cancer Center, and in the city of Corpus Christi. In addition to working with the UT Health residency program, he currently practices at St. Luke’s/CHI Medical Center. He resides in Missouri City with his wife Inez and his two boys.


Darrell Calderon, MD

Managing Partner

Dr. Darrell Calderon was born in Donna, Texas. He received his Medical Degree from the University of Michigan and completed his residency in Emergency Medicine at the University of Texas Health Science Center in Houston.

After residency Dr. Calderon began working at St. Luke’s in the Texas Medical Center in 2001. During this time Dr. Calderon continued his service in the US Army Reserve as the Division Surgeon of the 75th Brigade Combat Training Division. While in the Army he trained numerous Army and National Guard units including the Texas National Guard’s 56th Brigade Combat Team of the 36th Division. He concluded his service with the Army Reserve in 2009 with the rank of Lieutenant Colonel.

Along with his Emergency Medicine work, Dr. Calderon performs Telemedicine with NuPhysicia, City of Houston Fire Department/EMS ETHAN Project. He also serves as an expert legal legal defense witness for Myers and Doyle Law Firm.

Dr. Calderon, along with his wife Beth and their two children Ryan (13) and Catherine (10) live in Houston. On his days off Dr. Calderon enjoys fly-fishing and spending time outdoors with his family.


Bary Diner, MD

Managing Partner


Barry Diner holds a bachelors degree in Biology from Yeshiva University and graduated in 1990 with honors (cum laude). His medical degree took him oversees to Israel where he graduated from the Tel-Aviv University, Sackler School of Medicine. He completed a residency in Emergency Medicine at The Brooklyn Hospital Center, Weill Medical College of Cornell Medical School and was appointed chief resident in his final year. After completion of his residency he returned to his native country of Canada and took his first academic job at the University of Alberta, where he completed a master’s in public health. Upon completion of his return-in-service commitment to Canada, Barry was appointed to the faculty at Emory University, Department of Emergency Medicine as an assistant professor. Barry’s area of interest is Atrial Fibrillation and systematic reviews and was funded by the CDC foundation with a Young Investigators award with a Public Health Research Training Grant. He was also the EBM section editor for the Israeli Journal of Emergency Medicine and served for 5 years as the chief methodologist on the Clinical Policy Committee for the American College of Emergency Physicians (ACEP).

Most recently, Barry moved to Houston, Texas to be near family. Barry serves on faculty at Baylor College of Medicine as an assistant professor of medicine in the division of Emergency Medicine. Clinically, Barry works at St Lukes Hospital which is home to the famous Texas Heart Institute, as well as Ben Taub, one of two major trauma centers in the Houston area. Recently, Barry joined the faculty at Texas Children’s Hospital. In addition, Barry also practices telemedicine for Ecare Group which provides medical direction for oil rigs all over the world, and the Houston Fire Department on the ETHAN telemedicine EMS project. Barry has a new interest in the area of Hospice Medicine, and has achieved board certification in this subspecialty. He is a team physician for Vitas Hospice Care.

In his free time Barry plays sports with his two sons Noah and Ariel and enjoys reading books with his daughter Maya. Barry is married to Elena Lichtiger his wife of 15 years, who is a native of Houston, Texas.