Geriatric Care

Lisa Nelson, ARNP, provides Geriatric and Skilled Nursing care at Mahaska Health. For Lisa, she was led to providing geriatric care while she was completing her nurse practitioner degree at the University of Iowa in 2003. Her grandmother received care at a long-term care facility, and she realized quickly that she wanted to provide this…

Melissa Lamb, ARNP

Allergy & Pulmonology

Melissa Lamb, ARNP-BC specializes in the areas of allergy, immunology and pulmonology and has been with Mahaska Health since 2006. Lamb joined the team at Mahaska Health after 5 years of extensive pulmonary specialty experience at Mayo Clinic in Rochester, Minnesota. Melissa can empathize with patients because she has been on the patient side of…

Family Medicine

Gayle Johnson, ARNP joined Mahaska Health in November 2019. For more than 30 years, Gayle has been a caring nurse in Grinnell, Iowa. During her tenure there, she has worked in the Medical Surgical Unit as a charge nurse and served as clinical advisor for the medical surgical unit, intensive care unit, emergency department, and…

Tonya Johannes, DNP, ARNP-BC

Tonya Johannes, DNP, ARNP-BC has been a nurse practitioner at Mahaska Health since 2016 and has served the healthcare field since 2003 in nursing home, hospital and clinical settings. Johannes grew up in Albia, IA and chose the medical field after spending an entire summer in a hospital helping to care for her grandmother. She…

Hospitalist, Inpatient Medicine

Family Nurse Practitioner Robyn Griffiths is a full-time Hospitalist at Mahaska Health. She has a passion for nursing and pursued an advanced degree to be more involved in her patient’s healthcare decisions. Caring for people is an honor and a privilege for Robyn and she believes her Hospitalist role allows her to provide more personalized…