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Michael Mesisca, D.O., M.S., C.C.H.P.-P, M.B.A
  • Medical Director and Chair 
  • Department of Emergency Medicine RUHS 
  • Director, RUHS Disaster Medicine Team
  • Medical Director, RUHS Ancillary Services
  • C.M.O. Correctional Health RUHS
  • Hometown: Arcadia
  • Undergraduate Education: BS Neuroscience Claremont McKenna College
  • Medical Education: Western University of Health Sciences
  • Residency Program:  Arrowhead Regional Medical Center Emergency Medicine 2012
  • Passions in life include Family, Surfing, Soccer, Coaching, the Ocean, Drumming and Pearl Jam
  • Passions in Medicine include Leadership and Operations improvement; Critical Care; Public Health and Wellness; Correctional Health.
  • Awarded Emerging Leadership Award from the RUHS Medical Staff, June 2020

Mark Thomas, D.O.

Associate Medical Director and Vice Chair

  • Hometown:  Garden Grove, Ca
  • Undergrad Degree:  BS/BA Biology/Psychology UC Irvine
  • Medical School Degree:  Western University of Health Sciences
  • Residency Program:  LLUMC EM 1992
  • Passions in life include Family, Skiing, Mountain Biking and Travel
  • Passions in Medicine include Education
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Fairuz Despujos, M.D.

Assistant Medical Director

  • Hometown: Portuguesa, Venezuela

  • Undergraduate Education: University of Nevada, Las Vegas

  • Medical Education: University of Nevada, Reno Medical School

  • Residency Program: LLU EM

  • Passions: Wellness, Family

  • Passions in medicine: site operations and throughput


Korbin Haycock, M.D.

Director of Resuscitation, Ultrasound and Critical Care. Ultrasound Fellowship Director. 

  • Hometown: Scottsdale AZ

  • Undergraduate Education: La Sierra University, Riverside CA

  • Medical Education: LLU EM

  • Residency Program: Loma Linda EM

  • Passions in life: Celtic Football Club, Motorcycles, 

  • Passions in Medicine: Resuscitation, Echocardiography, POCUS

  • Current Research: VExUS, Sepsis, Intrarenal Doppler in resuscitation, Pulmonary ultrasound in CHF.  Pulmonary ultrasound in COVID, Hemodynamics in shock 

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Amy Russell, M.D.

Student Clerkship Director. Stroke Program Quality Director. Core Faculty. 

  • Hometown: Huntington Beach, CA

  • Undergraduate degree and university: UC San Diego

  • Medical school: Lewis Katz SOM at Temple University

  • Residency Program: LLU EM

  • Passions in life: Friends/family, beach going, board sports, dogs

  • Passions in medicine: Shock resuscitation and medical education

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Grant Nelson, M.D.

Fellowship and Clerkship Director: Wilderness Medicine

  • Hometown: Ontonagon, MI

  • Undergrad: Northern Michigan University, Marquette, MI

  • Medical School: Wayne State University, Detroit, MI

  • Residency: Ascension St. John Medical Center, Detroit, MI

  • Fellowship: Emergency Ultrasound @ Wayne State University, Detroit, MI

  • Passions in Medicine: POCUS, austere medicine, improving medical care and education through technology

  • Passions in Life: Travel, music, education, software development


Eugene Hu, M.D.

Attending Physician. Core Faculty. Ethics Champion. 

  • Hometown: Baton Rouge, Louisiana

  • Undergrad: Rice University, Houston, TX

  • Med school: Louisiana State University Health Sciences Center - New Orleans

  • Residency: LLU EM

  • Passions in life: being a dad, baking 

  • Resident Projects: Spiked Helmet Sign, Bilateral Tonsillitis Abscess, Bilateral, Asymmetrical Hip Dislocation

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Rolando Sy, M.D.

Attending Physician

  • Hometown: Philippines 

  • Undergraduate degree and Universities: University of Santo Tomas & SFSU (Degree: Biology)

  • Medical School: UCI

  • Residency: RUHS Family Medicine 

  • Passions in Life: Fishing, Basketball, Running

  • Passions in Medicine: Helping the indigent population

Director of Education,
Residency Program 


Thomas Minahan, D.O.

  • Hometown: Bellflower, California 

  • Undergraduate degree and university: UC Riverside, BS Biochemistry

  • Medical school: Western University

  • Residency Program: Midwestern University

  • Passions in life: Family, Family, Family

  • Passions in medicine: All things Epilepsy related

  • Current research: Utility of Instant EEG ability in the ER


Melanie Randall, M.D.

Director of Research and Quality. Pediatrics Champion. 

  • Hometown:  Loma Linda
  • Undergrad Degree:  BS Stanford University
  • Medical School Degree:  LLU School of Medicine
  • Residency Program:  LLUMC 2011
  • Fellowship: Pediatric EM
  • Current Research:  Adenosine
  • Passions in Medicine include Congenital Cardiac Disease  

Andrew Pachon, M.D.

EMS and Base Station Director. Core Faculty. Epic Champion. 

  • Hometown: Rancho Cucamonga, CA

  • Undergraduate degree and University: Claremont McKenna College, BA Psychology 

  • Graduate School: University of Southern California, Master of Public Administration 

  • Medical School: University of Illinois at Chicago 

  • Residency: LLU EM

  • Passions in Life: Family, Woodworking, Do-It-Yourself Projects, Cake Decorating 

  • Passions in Medicine: Prehospital & Disaster Medicine, Resuscitation 

  • Current Research: Prehospital quality improvement, Disaster Medicine


Kevin Chen, M.D.

Assistant Medical Director: Non-RUHS Residencies. Geriatric Champion. Core Faculty.  

  • Hometown: Simi Valley

  • Undergraduate Education: UCLA

  • Medical Education: Albert Einstein College of Medicine 

  • Residency: LLU EM

  • Passions in Life: Family, cooking, traveling

  • Research: Obstructive Infectious Urolithiasis, IM vs IV Migraine treatments 


Humberto Ochoa, M.D.

Attending Physician

  • Hometown: Cenotillo, Mexico; Later moved to San Bernardino

  • Undergraduate Education: University of California, Riverside

  • Medical Education: University of Utah, Medical School

  • Residency:

    • IM Internship: U of Las Vegas (83-84) 

    • Kern Medical Center (84-86)

  • Riverside County EMS Medical Director from 1992-2014. Attending at RUHS since 1987.

  • Passions in Medicine: Teaching, Sharing clinical experience, Patient compassion

  • Passions in Life: Golf, Soccer, Military History, Cooking, Foodie, Hot-tubbing with the family


Susan Munden, M.D.

Attending Physician

  • Hometown: East Lansing, Michigan

  • Undergrad Degree:  UC Irvine Biology

  • Medical School Degree:  UC Irvine

  • Residency Program: UC Irvine 1997

  • Passions in life include animals and having many pets

  • Passions in Medicine include teaching


Joel Labha, D.O.

Assistant Residency Director, PA Fellowship Director, Trauma Quality Director, Behavioral 
Health Liaison

  • Hometown: Dubai, U. A. E.

  • Undergraduate degree and university: Pacific Union College

  • Medical school: Western University

  • Residency Program: Arrowhead Regional Medical Center

  • Passions in life: Family, Soccer, Music

  • Passions in medicine: Education, Personal Growth and Development

  • Current research: How to deliver the perfect dad-joke every time: a prospective, randomized, double-blind, meta-analysis... of sorts. 


Stephanie Loe, M.D.

Assistant Medical Director for Disaster Medicine. Director of Global Health.

  • Hometown; Cypress, CA

  • Undergrad: UCLA B.S. Biology 

  • Med School: Wayne State University School of Medicine (Detroit, MI)

  • Residency: LLU EM

  • Current Research: COVID-19 

  • Passions in Life: pets, family, travel, challenges 

  • Passions in Medicine: International Mission Trips, Disaster Medicine 


Timothy Nesper, M.D.

Core Faculty. Associate Residency Director, Emergency Medicine LLUMC, Assistant Clinical Professor LLUMC

  • ​Hometown: San Clemente, CA

  • Undergrad Degree: UCSB Bio Science

  • Medical School Degree:  Keck School of Medicine, USC

  • Residency Program: LAC/USC 1986

  • Current Research:

  • Passions in life include Family, Faith and Friendship

  • Passions in Medicine include Team Work, Teaching, Patient Wellness


Oscar Salaiz, D.O.

Assistant Medical Director. MAT Champion. Core Faculty. 

  • Hometown: West Covina, CA

  • Undergraduate Education: UCSB

  • Medical Education: WesternU

  • Residency:

    • RUHS EM Class of 2024

  • Passions in Medicine: Teaching, Addiction Medicine, Med Sim, Harm Reduction, Mentoring, Performance Science 

  • Passions in Life: Family, coaching youth athletics, outdoor activities, soccer

  • First Generation Mexican-American

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Sarah Malcolm , M.D.

Wellness Director

  • Hometown: Anaheim, CA

  • Undergraduate Education: Cal State University, Fullerton

  • Medical Education: Albany Medical College

  • Residency: LLU EM

  • Passions in Medicine: Lifestyle medicine, health equity for underserved patients

  • Passions in Life: Surfing, paddle boarding, snorkeling, spearfishing

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