Analgesia and sedation are important treatment strategies in the intensive care unit (ICU). Due to the opioid crisis, opioid-sparing medications become the focus of clinical studies. Ketamine and its isomers (mainly esketamine) are intravenous anesthetics that possess sedative, analgesic, and anesthetic effects, which have recently attracted the attention of critical care physicians. However, the application of ketamine/esketamine in ICU is limited and inexperienced. Experts from the Critical Care Medicine Professional Committee of the Chinese Research Hospital Association drafted this consensus based on the current clinical evidence to provide recommendations for the application of ketamine/esketamine in different fields of critical care, including sepsis and septic shock, endotracheal intubation, neurocritical care, respiratory critical care, post cardiac surgery care, burn and depression in ICU. Meanwhile, this expert consensus also appeals for more high-quality clinical trials to facilitate more reasonable guidelines in this area.