[The use of atracurium besylate (Tracrium) in patients undergoing kidney transplantation]

According to literature data Atracurium besylate is a nondepolarizing muscle relaxant akin to the "ideal", insofar as it is governed by the "dose-relaxation time" principle. To secure normal clinical effect, doses in the range 0.4-0.5 mg/kg body mass are recommended, with the maximal manifestation of neuromuscular block occurring within 4.6-7.7 min, and lasting for 35.1 to 39.2 minutes. Maintenance dose: 0.05-0.1 mg/kg body mass. Special emphasis is laid on the fact that at normal temperature and pH the dose/relaxation time ratio is strictly fixed which in turn renders relaxation readily controllable. For the purpose a special table is submitted by the producers (Wellcome Company). As it is well known Atracurium splitting runs a course by the so-called Hoffmann reaction, requiring normal pH and temperature. Atracurium is administered to ten chronic renal failure patients in the course of kidney transplantation, abiding to all requirements and doses recommended by the company. A significant muscle relaxation with virtually twice as long duration (35-101 min) is noted, attributable to the presence of metabolic acidosis ("0.605), interfering with the normal course of the Hoffmann reaction for Atracurium disintegration. In the genesis of the phenomena observed any central mechanisms, e.g. hyperventilation, overdosage of the anesthetic, hypothermia and the like, are ruled out. In patients with acidosis it is advised to handle the muscle relaxant with greater caution.