RecruitingDevice studyNIV for Hypercapnic Respiratory Failure: AVAPS vs S/T BIPAPThe goal of this study is to compare two different modes of noninvasive ventilation in hypercapnic respiratory failure. The investigators will compare AVAPS and BIPAP S/T and hypothesize that AVAPS will result in a decreased length of stay in the ICU or on telemetry. Currently, noninvasive ventilation is the standard of care for hypercapnic respiratory failure. However, the most effective mode for patients with hypercapnic respiratory failure is unclear.