An alcoholic patient with history diabetic nephropathy and liver failure is posted for open abdomen surgery. The most appropriate muscle relaxant in this patient is:

Cisatracurium is a stereoisomer of atracurium that is four times more potent. Like atracurium, it undergoes degradation in plasma at physiological pH and temperature by organ-independent Hofmann elimination. The resulting metabolites (a monoquaternary acrylate and laudanosine) have no neuromuscular blocking effects. Because of cisatracurium's greater potency, the amount of laudanosine produced for the same extent and duration of neuromuscular blockade is much less than with atracurium. Nonspecific esterases are not involved in the metabolism of cisatracurium. Metabolism and elimination are independent of renal or liver failure hence can be given in hepatic and renal failure. Ref: Butterwoh IV J.F., Butterwoh IV J.F., Mackey D.C., Wasnick J.D., Mackey D.C., Wasnick J.D. (2013). Chapter 11. Neuromuscular Blocking Agents. In J.F. Butterwoh IV, J.F. Butterwoh IV, D.C. Mackey, J.D. Wasnick, D.C. Mackey, J.D. Wasnick (Eds), Morgan & Mikhail's Clinical Anesthesiology, 5e.