This study investigated the relationship between train-of-four (TOF) or double burst (DBS) ratios (T4:T1 or B2:B1) and twitch (T1) or burst (B1) magnitudes during the recovery from rocuronium-induced neuromuscular block in dogs and cats. The main hypothesis was that TOF or DBS ratios recover after the recovery of T1 or B1, and hence high ratio levels are sensitive indicators of restoration of the neuromuscular function.

Six anesthetized dogs and six anesthetized cats received 0.5 mg/kg of rocuronium intravenously. The amplitudes of T1 or B1 were measured with mechanomyography during neuromuscular block until the neuromuscular function recovered fully. The TOF or DBS ratio was recorded concurrently.

In dogs, recovery of T1 and B1 preceded the recovery of the TOF and DBS ratios, and T1 and B1 were always ≥90% of recovery when the respective ratio reached 0.9. In contrast, T1 was still depressed in 5/6 cats when the TOF ratio reached 0.9. At that moment, T1 was 72.5 ± 19.8% of recovery. Similarly, the DBS ratio returned to 0.9 when B1 was still <90% in 3/6 cats of recovery.

The TOF and DBS fade in dogs consistently disappeared after the magnitude of T1 or B1 were restored, and hence, ratios ≥0.9 are a sensitive indicator that the neuromuscular function recovered. Our observation in cats however show that the spontaneous recovery of neither the TOF nor the DBS ratio of 0.9 can reliably exclude residual block, as the magnitude of T1 or B1 was still depressed in several instances.

本研究调查了罗库溴铵诱导的神经肌肉阻滞恢复过程中四组 (TOF) 或双脉冲 (DBS) 比率（T4:T1 或 B2:B1）与抽搐 (T1) 或脉冲 (B1) 幅度之间的关系在狗和猫。主要假设是 TOF 或 DBS 比率在 T1 或 B1 恢复后恢复，因此高比率水平是神经肌肉功能恢复的敏感指标。

六只麻醉狗和六只麻醉猫静脉注射 0.5 mg/kg 罗库溴铵。在神经肌肉阻滞期间用机械肌动描记法测量 T1 或 B1 的幅度，直到神经肌肉功能完全恢复。同时记录TOF或DBS比率。

在狗中，T1 和 B1 的恢复先于 TOF 和 DBS 比率的恢复，当各自的比率达到 0.9 时，T1 和 B1 总是≥90% 的恢复。相比之下，当 TOF 比达到 0.9 时，5/6 猫的 T1 仍然下降。那时，T1 是恢复的 72.5 ± 19.8%。同样，当 3/6 的恢复猫的 B1 仍小于 90% 时，DBS 比率恢复到 0.9。

在 T1 或 B1 的幅度恢复后，狗的 TOF 和 DBS 衰减持续消失，因此，比率≥0.9 是神经肌肉功能恢复的敏感指标。然而，我们对猫的观察表明，TOF 和 DBS 比率 0.9 的自发恢复都不能可靠地排除残余阻滞，因为 T1 或 B1 的幅度在某些情况下仍然被抑制。