AccessMedicine has recently published 58 new cases available at Acid-Base Disturbance Cases. These are progressive, complex cases appropriate for the advanced medical student and resident level physician. These cases cover double and triple acid-base disturbances, and each question builds on the previous question. The questions are multiple choice and each one must be answered before moving on to the next page. Each question provides the user with a rationale for the correct answer to facilitate maximum learning. The cases may be found in AccessMedicine, by clicking the Cases drop-down menu at the top of the screen and selecting Acid-Base Disturbances. Off-campus users must log in to the library before accessing cases.