About Us

Come see the difference that our expert providers and staff can make in your health and well being!

We offer comprehensive pulmonary and sleep testing and treatment right in our office! Whatever the issue, we have a solution! We have the most highly trained and experienced pulmonary and sleep staff in the northwest suburbs!

Our Providers

Dennis Kellar MD, FCCP, FAASM

Dr. Dennis Kellar, owner, CEO, and physician of Northwest Pulmonary and Sleep Medicine, is a board-certified multispecialty physician. Some of his many areas of expertise include trauma/critical care, pulmonary diseases, sleep disorders, and complex long term respiratory and ventilator care. Dr. Kellar has been serving the community for over 20 years. He received his bachelor’s degree in biology from the University of South Florida and received his medical degree from Ross University School of Medicine. Dr. Kellar’s training includes internal medicine residency in Cook County Hospital, and completion of a fellowship in pulmonary, critical care, and sleep medicine as chief fellow at Rush University Medical Center in Chicago. Dr. Kellar has served as a clinical assistant professor of medicine at the University of Illinois Rockford. He is a veteran of the United States Army that served with the 101st airborne division. Dr. Kellar also holds numerous Director positions including Medical Director for several ventilator care and COVID units in the northwest suburbs. He serves as the previous Director for Respiratory Therapy for the State of Illinois and Director for Pulmonary Sleep services for a large health system in northern Illinois. Dr. Kellar has been published in numerous areas covering pulmonary and critical care, and was appointed as a special investigator of the Coroner’s office in Mchenry County.

Amanda Law, MS, APRN-CNP

Amanda is a board certified Adult Nurse Practitioner. She joined Northwest Pulmonary and Sleep Medicine in Algonquin, Illinois in 2007. She specializes in pulmonary and sleep medicine, and has extensive experience in critical care. Amanda holds a master’s of science degree and completed doctoral coursework at the University of Illinois in Biobehavioral Health science. She also has experience working as a nurse practitioner working in intensive care and oncology at Rush University Medical Center and Northwestern Memorial Hospitals. Amanda spends as much time with patients as needed in office and in the hospital to deliver the quality care and education that each patient deserves. Amanda has a strong interest in health and well-being and enjoys sleep coaching, teaching about disease process, and lifestyle medicine. She and stays up-to-date with the latest medical advancements in sleep and pulmonary medicine, as well as complimentary medicine and holistic treatments.

Madhu Gundavaram, MD

Dr. Madhu Gundavaram has been with Northwest Pulmonary and Sleep Medicine since 2013. She is board certified in internal medicine, pulmonary medicine, and critical care medicine. She received her medical degree from Kasturba Medical College in Manipal, India in 2001, and then moved to the United States to complete her internal medicine residency at Lois A. Weiss Memorial Hospital, University of Chicago Hospitals in 2005. After her residency, Dr. Gundavaram practiced internal medicine for five years. During her fellowship, Dr. Gundavaram also dedicated time to her training in sleep medicine, learning the latest advancements in sleep disorders and treatments. Dr. Gundavaram sees patients in the office, as well as in the hospital setting.

M. Christine Johansen, CNP

M. Christine Johansen is board certified as a Family Nurse Practitioner. She completed her Bachelor’s Degree in Nursing from Chamberlain University and Master’s Degree in Nursing from Olivet Nazarene University with Sigma Theta Tau Honors. She many years of experience in direct patient care, as well as, long-term care and rehabilitation, and in hospital medical planning. She is very passionate about patient care and providing quality health services to my patients.

Nonie Russell, DNP, APRN-CNP

Nonie is a board-certified acute care nurse practitioner with over 30 years of experience in critical care and pulmonary medicine. She joined Northwest Pulmonary and Sleep Medicine in 2009 and completed a doctorate in nursing practice at University of Illinois. She sees patients in that hospital setting, as well several long-term ventilator care facilities and nursing homes.

Nonie is well known for giftedness in managing complex patients on ventilators and successfully liberating patients from their ventilators and tracheostomies.

Our Team

Dawn Udesen


Jennifer Cantu, CRT, RCP


Nicole Kostic, RPSGT


Erica Guzman


Debbie Smith, RN


Kelli Arnolde, CMA, XRT


Amanda Sadoval


Jennifer Arnada


Norma Morales


Priscilla Madula


Nicole Anger


Vicky Van Duesen


Laura Jimenez


Ramiro Correa


Cori Jansen, RPSGT


Trisha Herner



At Northwest Pulmonary and Sleep Medicine, we accept Medicare and most major insurance plans. Please contact your insurance company or you may call our office at 815-477-7350 to find out if we accept your insurance plan. If your insurance plan requires you to pay a co-payment, co-insurance, and/or a deductible, you will need to pay at the time of your visit. For your convenience we accept cash, checks, Visa, and MasterCard. If you have a question related to your bill or insurance, please call our office and ask to speak to the billing department.

We are partnered with the following hospital systems:

Northwestern Medicine Huntley Hospital  |  Northwestern Medicine McHenry Hospital

(Preferred providers for NM Employees)

Advocate Good Shepherds Hospital  |  Advocate Sherman Hospital
Amita St. Alexius Medical Center  |  Amita Alexian Brothers Medical Center