Abstract Importance Synthetic cannabinoids (SCs), commonly known as K2, spice, or fake weed, are cheap, artificially manufactured recreational drugs that have emerged as a major public health threat in various regions of the US. Objective To describe the clinical manifestations of SC intoxication. Design, Setting, and Participants This case series assessed adults admitted to the intensive care unit from 2014 to 2016 with acute life-threatening complications of SC use. Data analysis was completed in October 2016. Exposures Use of SCs such as K2, spice, or other synthetic versions of cannabinoids. Main Outcomes and Measures Data collected included patient demographic data, medical history, presenting symptoms, physical findings, laboratory and imaging data, and intensive...