To the Editor:-Nimbex[trade mark sign](cisatracurium) is provided in 5-ml, 10-ml, and 20-ml vials. The 20-ml vial, intended for use in the intensive care unit (ICU) only, contains 10 mg/ml cisatracurium. The 20-ml vial has a similar appearance to the 10-ml operating room (OR) solution, differing in one color and having a notation on the bottom of the box as ICU use only (Figure 1). Recently, this ICU solution was placed by mistake in the OR anesthesia medication refrigerator.
It was used for anesthesia during bilateral urethral implantation in a 38-yr-old patient. This patient was a very muscular 78 kg, with medical history of hypertension and mild renal insufficiency. He was given 100 mg of cisatracurium rather than the intended 20 mg for intubation, without any hemodynamic change. Additional repeat doses of 10 mg (1 ml), 10 mg (1 ml), 10 mg (1 ml), 5 mg (0.5 ml) was given at about 65 min, 2 h, 4 h, and 5 h after the initial dose with the beginning of the recovery of first twitch out of four. A total of 135 mg cisatracurium was administered during a 5.5-h operation. At the end of the procedure, after the recovery of four out of four twitches, intravenous glycopyrrolate, 0.4 mg, and neostigmine, 2 mg, was given, and the patient was extubated without any residual neuromuscular block symptoms.
We cannot explain why this patient recovered twitch “normally” despite a fivefold overdose. This mistake was discovered only after finishing the case. Only one vial was opened during this case, and it was found to be an ICU vial, 20 ml volume and 10 mg/ml concentration.
All anesthesia personnel were notified of the existence of the ICU solution, and the ICU solution was segregated from the OR solution immediately.
Masako Nishio, M.D.
Chang-Shik Choi, M.D.
Clifford M. Gevirtz, M.D.
Associate Professor; Department of Anesthesiology; New York Medical College; Metropolitan Hospital Center; New York, New York;firstname.lastname@example.org
(Accepted for publication July 14, 1998.)