The Olive Louise Berger Collection focuses on her career as a nurse anesthetist at Johns Hopkins. It consists of detailed records of the administration of anesthesia to Alfred Blalock's patients, including three notebooks labeled: "Tetralogies," "Valvulotomies," and "P.O. Pneumonia." The notebooks describe early cases of cardiac surgery, including the first cases of surgical treatment of cyanotic congenital heart disease, and the first lung and mitral valve operation performed at the Johns Hopkins Hospital. Also included are articles by Berger, a letter of recommendation written on Berger's behalf by Thomas Cullen, and material concerning the Olive L. Berger Memorial Fund.