Neuromuscular Blockade Resistance During Therapeutic

Therapeutic hypothermia is increas-ingly common in the intensive care unit (ICU), especially for protecting neu-rologic function after witnessed cardiac arrest.1,2 The effects of cooling on nor-mal physiologic functioning have been well described.3 A known consequence of therapeutic hypothermia is decreased metabolism of many drugs, resulting in prolonged and/or heightened effects of many medications during hypothermia.4-7 Neuromuscular blockers (NMBs) have amplified effects during hypothermia.5-7 Inverse correlations between the length and magnitude of drug effect and level of hypothermia have been proposed.4 As a result, doses of NMBs used during cooling are typically 25-50 % less than the recommended doses. Resistance to NMBs has been reported in critically ill patients.8-14 We are unaware of such re-ports in patients undergoing cooling, which usually requires dose reductions. We present the case of a patient undergo-ing therapeutic hypothermia who was unable to be paralyzed with high doses of various NMBs during the cooling pro-cess. Paradoxically, the patient became fully paralyzed when warmed and re-mained paralyzed hours after neuromus-cular blocking therapy was discontinued. Case Report A 64-year-old, 80-kg male with stage IV non–small-cell lung cancer presented to the emergency department with dyspnea. The patient had received an unknown regi