Cryoshock following cryoablation for hepatocellular carcinoma

We present a case of profound shock and lactic acidemia occurring in the context of a cryoablative procedure for hepatocellular carcinoma. After out ruling more common possible etiologies, we diagnosed our patient as having a rare cause of shock, unique to these types of cryoablative procedures, known as cryoshock. Cryoablation can result in multiple complications one of which is 'cryoshock', a life-threatening syndrome of multiorgan failure and coagulopathy that carries a high mortality, up to 40%. While the mechanism of cryoshock has not been completely elucidated, it appears to be mediated by the release of cytokines TNF-alpha, IL-1, and IL-6. It is causally associated with complete thaw prior to refreezing and double freeze cycles, as well as volume of and duration of cryotherapy. Cryoreaction, which is a milder phenomenon including chills fever, tachycardia, tachypnea and temporary renal damage has been described after 1% of cryoablation sessions. Reports of the management of cryoshock are scarce and the mainstay of treatment is organ support. While cryoshock has been described in radiology and surgical literature it has not previously been described in anesthesiology literature. We highlight this as a potential serious complication which should be considered by all clinicians involved in these cases.