Dr. Drennan is a board-certified anesthesiologist with fellowship training and board certification in chronic pain management. Since completing his fellowship as a pain specialist, Dr. Drennan had been fortunate enough to establish a strong and growing chronic pain practice at the University of Utah. In addition to teaching residents and fellows at the University of Utah, Dr. Drennan also provided lectures to outside interest groups such as the Cancer Wellness House associated with Salt Lake Regional hospital, and the physical therapy school at the University of Utah. Additionally, he served as an editor for a pain management education course, a consultant for Oxford University Press, and an advisor for the Controlled Substances Task Force of the Utah Medical Association.

As for research, Dr. Drennan participated in a multi-center spinal cord stimulator trial for St. Jude Medical. He published a few short review papers for the Journal of Pain and Palliative Care Pharmacotherapy, and a systematic review of literature pertaining to topical NSAID therapy. Additionally, he was the primary investigator for a placebo-controlled randomized trial of vitamin D3 replacement in patients with chronic musculoskeletal pain.

After nearly three years at the University of Utah, Dr. Drennan reached his maximum capacity to see patients at that clinic, and he felt that starting Comprehensive Pain Specialists would allow him to deliver high quality pain management to more patients. He now resides and practices medicine in Colorado, serving the Boulder, Fort Collins, and Denver metro areas.

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Dr. Eric Mehlberg is a board certified anesthesiologist specializing in pain medicine. He completed his anesthesia residency at Stanford University Medical Center in Stanford, CA after completing medical school from the University of Illinois.  Dr. Mehlberg then completed his pain medicine fellowship at the University of California – San Francisco. Dr. Mehlberg was one of two students awarded as a Phi Alpha Chi Honor Society Member for graduating in the top five percent of class.  He was also awarded a Dean’s Scholarship for academic excellence. 
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Dr. Michelle Smith is originally from Franklin, Tennessee. She went to college at Louisiana State University, medical school at Tulane University, and moved to Colorado for residency training. She completed her residency training in Physical Medicine and Rehabilitation at the University of Colorado and her fellowship training in Pain Management at Texas Tech University. She specializes in treating pain from a multidisciplinary approach with a focus on helping people regain physical function and improve their quality of life. Dr. Smith loves the Colorado outdoors and particularly enjoys hiking and skiing with her friends and family. She is newly married to a Colorado native and is enjoying all that the great state has to offer.
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Yvonne DelZenero, PH.D is a Licensed Clinical Psychologist who graduated from Palo Alto University. She pursued an emphasis in Children and Families; however, she particularly enjoys working with adolescents and adults. Her specialty is treating athletes with injuries and individuals with chronic pain, PTSD from car accidents, grief, anxiety, and depression using an integrative approach. She does see individuals who are not pain patients, just call the main line to make an appointment. Cognitive Behavioral Therapy (CBT), Dialectal Behavioral Therapy (DBT), and Humanistic Therapy are modalities typically used. Her B.A. is in Secondary Education, American History and Government, and her first Master’s Degree is in Education, School Counseling. Dr. DelZenero worked as a high school counselor for 4 years in Illinois. Dr. DelZenero’s professional interests include neuropsychological assessment, prevention programming, and individual therapy. She enjoys running, hiking, and being outdoors.

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Board certified by the National Commission on Certification of Physician Assistants, with experience in Pain Management, Jeff started as a Certified Nursing Assistant in a nursing home while he went to Colorado State University. He graduated with Honors, on the Dean’s List, with a B.S. in Biological Sciences, Pre-Med, and a minor in Neuroanatomy. His first job was taken working in a clinical laboratory in a hospital as a Medical Technologist. He then attended Red Rocks Physician Assistant Program. He has since worked in Pain Management, Physical Medicine/Rehab, Geriatrics, Family Practice, and Urgent Care. He really enjoys helping those in pain, and finds it very rewarding.
Jeff was the recipient of the Merit Scholarship at Colorado State University, a Golden Key National Honor Society inductee, and a Red Rocks Phi Beta Kappa nominee. A native, he enjoys the outdoors of Colorado.
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Joshua has four years of experience as a physician assistant. He has a Bachelor of Science degree in Biological Chemistry from the Kent State University in 2009 and completed his Master of Health Science degree in Physician Assistant Studies at Cleveland State University in 2013. He has worked in the Orthopedic Department with sports medicine and total joint surgery for three years before transferring to pain management. In his free time, Josh enjoys spending time with his wife, hiking and photography.

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Kristen has eight years of experience as a physician assistant. She is an East Coast native, earning her Bachelor of Science degree in Exercise Science from the University of Delaware in 2007. Kristen completed her Master of Medical Science degree in Physician Assistant Studies at Nova Southeastern University in Fort Lauderdale, Florida in 2009. She has worked in adult spine surgery for the Orthopaedic Department at the Johns Hopkins Hospital in Baltimore, Maryland and total joint surgery for Colorado Orthopaedics in Lone Tree, Colorado. She also spent four years working in adult phlebology at the Albert Vein Institute in Lone Tree and Colorado Springs. Her background and experience has paved the way for a smooth transition into Pain Management. Outside of the office Kristen can be found competing and participating in local CrossFit events and out and about with her family exploring all that beautiful Colorado has to offer.
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Education: Bachelors of Science – Exercise Science – Eastern Washington University (2008) Doctorate of Physical Therapy – A.T. Still University (2011)
Josh is a physical therapist who loves working to get people moving again! He is certified in integrative dry needling, and utilizes many “outside of the box” treatments to get people feeling better quickly. He loves using hands-on techniques, followed by customized exercises to help maintain great results. Josh has worked at clinics where he had to juggle multiple patients at once, so he loves taking a lot of one-on-one time with each patient he works with. Having undergone a few big injuries himself, he realizes how frustrating it feel to be limited physically, and will do everything possible to speed the healing process. When not at work you can usually find him outside trail running, rock climbing, biking, skiing, or just relaxing with his wife and 2 rescue dogs, usually drinking a strong cup of coffee.
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Education: Master of Physical Therapy, Wichita State University in 2000; Doctorate of Physical Therapy at the University of St. Augustine in 2009.
Certifications: Certified Manual Therapist through the University of St. Augustine, Certified Dry Needling, Certified Pilates for Rehabilitation, Certified Kinesiotaping Practitioner Advanced Training: Dr. Angie, as most patients call her, has been practicing outpatient orthopedic physical therapy since 2000. In addition to the three years of extensive post graduate training for her manual therapy certification, she has had considerable training in spinal and extremity rehabilitation including soft tissue and joint mobilizations, muscle energy techniques, and myofascial release. She also enjoys integrating a mind and body approach in her practice with her background in Pilates and Yoga. She teaches mat Pilates one on one with specifications for each individual. She previously taught yoga in class settings at health clubs and healthcare clinics, and now instructs patients privately as part of their care. Dr. Angie is passionate about helping patients meet their goals by implementing an evidence based approach to treatment, and creating a positive physical therapy experience. She lives in Golden, CO with her husband and two daughters. They love spending time together, especially enjoying the great outdoors.
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Dr. Melissa Nguyen PT, DPT graduated with her Doctor of Physical Therapy degree from Wichita State University in 2012 and moved to Colorado where she has been practicing since. Her specialty is outpatient orthopedics while emphasizing a hands on, manual approach. The experience and continuing education in Colorado she has completed allows her to work with patients of all ages as she ensures individualized treatment for each of her patients. Dr. Melissa is certified to complete Functional Dry Needling (FDN) with training from Kinetacore- Level 1 and 2. She excels with FDN and Trigger Point Dry Needling (TDN) techniques and will utilize this tool as necessary for a variety of diagnoses including chronic pain.Outside of the office, she can be found in the mountains snowboarding, hiking, and camping with her husband and chocolate labrador, Leroy.

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