Effect of Initiation of Veno-venous ECMO on Urine Output and Acute Kidney Injury

With this study, the investigators want to find out whether the use of a "lung machine" (extracorporeal membrane oxygenation (ECMO)) togethet with giving the lungs "rest" (by minimizing ventilary support) in people with severe pneumonia has an effect on how well the kidneys work. The investigators will use information that was already collected while patients were staying in the intensive care unit. Patients do not need to do anything additional or undergo any additional procedures for this study.