The care of critically ill patient within the intensive care unit requires a multidisciplinary approach. An understanding of the main principles of intensive care medicine is essential for surgeons, both for participating in the management of their own critically ill patients and also because surgical complications of critical care are well recognized. This article describes the main principles of intensive care medicine within the context of the COVID-19 pandemic, giving an overview of a systematic approach to assessment and treatment of organ dysfunction, and highlights some of the complex ethical and organizational challenges.