About Our Practice

Our Mission:

To provide comprehensive, personalized, and compassionate care to our pulmonary patients in Central Texas. Through our experienced interventional pulmonology service, we broaden the diagnostic and therapeutic options available to patients throughout the country.


Georgetown Pulmonary Associates, P.A. (GPA) was founded in 2009 on the premise of providing accessible, comprehensive pulmonary and critical care coverage to meet the growing health care demands in the Central Texas community. Our scope of practice includes the subspecialty of Interventional Pulmonology.

Dr. Fields, Dr. de Keratry, Dr. Audrey Nguyen, Dr. Mandeep Mangat are all board certified pulmonary and critical care physicians. Dr. Fields and Dr. deKeratry both have extensive experience in the performance of a wide-range of interventional pulmonology and pleural procedures. Dr. Mangat, our newest pulmonary and critical care physician, joined GPA in August 2017. He expands the capacity of our practice to provide state-of-the-art, evidence-based pulmonary and critical care services to our patients.

For diagnosing and treating a variety of respiratory diseases (see tab: Conditions We Treat), we offer an in-office, full service pulmonary function lab. This enables us to perform comprehensive diagnostic testing for patients with respiratory ailments.

In our office, while the patient is receiving procedural sedation and analgesia, we are able to perform diagnostic bronchoscopies and endobronchial ultrasound (EBUS). EBUS, commonly referred to as “medical mediastinoscopy”, allows us to sample lymph nodes in the chest with a minimally invasive technique. We are also able to perform chest ultrasound to evaluate pleural diseases (e.g. pleurisy, pleural effusions). The ultrasound provides a component of safety in draining pleural fluid by thoracentesis or during placement of a long-term tunneled pleural catheter (Pleur-X).

Our experienced, friendly and accommodating office staff includes registered nurses and medical assistants, as well as insurance and administrative coordinators.

Dr. Dominic deKeratry

Dr. Dominic deKeratry was born in Tulsa, Oklahoma and raised on the East Coast as part of a U.S. Navy family before settling in Amarillo, TX. He attended undergraduate school at Texas A&M University (TAMU) in College Station and medical school at the University of Texas Medical Branch at Galveston. He served in the U.S. Navy as a physician from 1993 to 2000 where he completed his internship and residency at Bethesda Naval Hospital. He served as a senior medical officer while being stationed aboard the USS Kearsarge out of Norfolk, VA for two years and earned his Surface Warfare Medical Department Officer qualification. During his last two years of service, he worked at the Uniformed Services University of Health Sciences in the department of tropical medicine in Bethesda. He completed his fellowship training in Pulmonary & Critical Care Medicine at Scott & White Memorial Hospital and TAMU Health Science Center in Temple with a special focus in the field of Interventional Pulmonology. He attended a sabbatical in Brussels, Belgium and Hemer, Germany developing expertise in therapeutic bronchoscopy as well as medical thoracoscopy. He is board certified in Pulmonology and Critical Care medicine and has presented work in the field of Interventional Pulmonology at International Meetings. After practicing in Temple for six years as a critical care physician and the director of interventional pulmonology, he moved to Georgetown and co-founded Georgetown Pulmonary Associates, P.A. He also serves as an assistant professor to the Texas A&M Medical School in Round Rock, Texas.

Dr. Esther Fields

Dr. Esther Fields was born and raised in New Jersey. She attended Ursinus College in Pennsylvania for her Bachelor’s in Science, then medical school at Philadelphia College of Osteopathic Medicine (PCOM). She continued her training at St. Luke’s Hospital in Bethlehem, Pennsylvania where she completed her residency in internal medicine. She moved to Texas in 2005 where she completed her fellowship in pulmonary & critical care medicine with special training in the field of interventional pulmonology at Scott & White Memorial Hospital and Texas A&M University Health Sciences Center. Her training included training with Dr. Dominic deKeratry, working with international experts in Brussels, Belgium and also the Cleveland Clinic in Ohio. After practicing Interventional Pulmonology & Critical Care for a year in Temple, TX, she co-founded Georgetown Pulmonary Associates, P.A in 2009. She is board certified in Internal Medicine, Pulmonology & Critical Care. She also serves as an assistant professor for the Texas A&M Medical School in Round Rock, Texas. Her work interests include intensive care medicine, mycobacterial lung disease, lung cancer, airway disease and interventional pulmonology. Her personal interests include raising her 2 young boys, traveling and running.

Dr. Audrey Nguyen

Dr. Audrey Nguyen was born and raised in Austin, TX.  She attended the University of Texas at Austin for her undergraduate education and graduated with a dual degree in 2002.  She spent the next several years at the University of Texas Medical Branch at Galveston, where she obtained her Doctor of Medicine degree and completed her Internal Medicine residency.  From there, she attended the University of Texas Health Science Center at Houston for her pulmonary and critical care fellowship, and finished her training in 2012.  For the past four years, Dr. Nguyen has been in private practice in Beaumont, TX, focusing on critical care medicine, hospitalist medicine, and pulmonology.  She is excited to return to the Central Texas area with her family.  She is board certified in Internal Medicine, Pulmonary Medicine, and Critical Care Medicine.

Dr. Mandeep Mangat

Mandeep Mangat, M.D. is a board certified pulmonologist and critical care physician. Dr. Mangat treats a variety of disorders including COPD, pulmonary lung infections and sepsis.

A Rice University graduate, Dr. Mangat earned his medical degree, completed his residency in Internal Medicine and fellowship in Pulmonary and Critical Care Medicine at the University of Texas Health Science Center at San Antonio.

He chose to purse medicine and Pulmonary/Critical Care to help others, with a focus on prevention and education, providing patients a clear understanding of their condition and treatment options. Dr. Mangat strives to take the time to listen to his patients and build a relationship with them to help individualize their treatment.  He believes in working as a team with his patients and families.

In his spare time, Dr. Mangat is a foodie and enjoys spending time with his family, wife and friends. He enjoys traveling, listening to Mariachi bands and supporting motorsports.  


Jamie Valencia, BSN, RN

Clinical Supervisor

Jamie joined us in January 2013, and serves as the patient triage and procedural nurse (including procedural sedation) at GPA. She lives in Georgetown with her husband, two children, and her labs. She has worked as an RN in the areas of cardiac critical care and ambulatory surgery. She enjoys spending time with her family and friends, camping and outdoor activities, and anything DIY.

Alina Smith, LVN

Alina recently joined us in August 2017.  She graduated in May 2017 from the Vocational Nursing Program at Temple College in Taylor, Tx.  Alina was born and raised in Central Texas.  She now lives in Hutto with her husband, daughter, and three dogs.  She enjoys spending time with her family and friends, taking picture of nature, gardening, bird watching, hiking, and camping.

Bethany Cottle

Administrative Supervisor

Bethany is a native of Texas, and moved from Fort Worth to Georgetown in May, 2011. She joined our staff in March 2012, and is responsible for the day to day operation of the administrative side of our clinic. She is also our Credentials manager, and our Insurance liaison. She loves spending time with people and getting to know more about them. She has a passion for helping, which is why she chose the medical field. She and her husband, Henry, and their son, Reagan, enjoy spending time outdoors – specifically hunting and fishing. She is a die-hard Dallas Cowboys fan, and is a lover of all things music.

Amy Russell

Front Desk Coordinator

Amy lives in Georgetown with her husband, Mack, and her sons, Marcus and Zach. She joined us in May 2014, and has worked in the medical field since 1996. Amy performs hospital billing and runs our front desk, check-in, and check-out process, as well as coordinates scheduling, insurance verifications, and confirmation calls, in addition to many other front desk responsibilities. She loves spending time with her family, and enjoys refinishing furniture and working on any DIY project.

Karon Moore

Front desk/Receptionist

Karon Moore is a native of Texas. She and her husband relocated to Pflugerville from Waco in January 2017. Together they have 5 wonderful children. She joined Georgetown Pulmonary Associates in March 2017 and serves our patient population as a Check-in/Check- out Specialist. She is very outgoing, always has a smile, and loves the simple things in life.

Jackie Muniz

Medical Assistant

Lives in Georgetown with her husband Joe and their two sons and daughter . She graduated from Richarte High School in 2005 and Allied Health Careers in 2006 for medical assisting. She joined our practice in 2010. She performs comprehensive pulmonary function testing, administers vaccinations, and serves as a patient educator as well as an advanced diagnostic bronchoscopy technician. She enjoys spending time with her family.

Angelica Ramirez

Medical Assistant

Angelica lives in Holland, TX. While in high school, she attended Temple College and received dual credits. Upon graduation, she decided to get her Medical Assistant certificate to gain experience. She plans on advancing her education and earning a bachelors degree in Nursing. She loves doing fun things and spending time with her family. She joined us in July 2014 after completing her externship with our clinic. She loves helping and taking care of patients, and seeing them happy. This is why she chose the medical field. Angelical performs pulmonary function tests, assists with procedures, administers immunizations, rooms our patients, and assists with front desk responsibilities.

Geanna McCallie

Medical Assistant

Geanna lives in Taylor, and attended Temple College where she worked toward her Social Worker degree. Because of her love for people, she obtained her medical assisting degree with Everest Institute. She joined our staff in 2014 after completing her externship with us. She chose medical assisting as her career so that she could spend time helping others. She loves football. Her teams are the Dallas Cowboys and the Texas Longhorns. Spending time with her family, significant other, and her dog Trixy, are the pleasures of her life. Geanna performs pulmonary function tests, assists with procedures, administers immunizations, rooms our patients, and assists with front desk responsibilities.

Andrew T. Pence II

Medical Assistant

Andrew T. Pence II is a resident of Georgetown for the last eight years, he grew up in Copperas Cove, TX and after graduating 1921th in a graduating class of 2000 he had no chose but, to enlist in the United States Army as a Cavalry Scout.  After achieving the rank of Staff Sargent and completing his enlistment of five and one half years he received an honorable discharge.  Andrew’s formal medical training is in emergency medicine which he obtained while working with Houston Fire Department.  Andrew is married and has two dogs and enjoy reading and being left to ponder the mysteries of the universe.