BACKGROUND: Acceleromyography used to monitor the neuromuscular transmission function is available in infants and children. However, information on the so-called staircase phenomenon during the baseline stabilization period in this population is limited. Our objective was to assess the characteristics of such phenomenon in infants in acceleromyography. METHODS: Thirty infants were divided into three groups: group A (aged 1-5 months, n = 10), group B (aged 6-11 months, n = 10), and group C (aged 12-24 months, n = 10). Anesthesia was induced and maintained without neuromuscular blocking agents. Patients received a supramaximal stimulus followed by TOF measurements every 15 s over the course of 30 min with a TOF-Watch(®) SX. All data were collected in a notebook computer using the TOF-Watch(®) SX Monitor software through optical fibers. RESULTS: The evoked T1 responses in younger infants (group A) were significantly lower than those in older infants (groups B and C) from 0-20 min. In group A, the signals increased to the maximum value of 121 ± 15% that of the control at 7.25 min and decreased toward a plateau of 113 ± 18% at 30 min. In group B, the signal heights increased to the maximum value of 143 ± 14% at 9.5 min, then decreased slowly to 136 ± 10% at 19.5 min, finally reaching 116 ± 12% at 30 min. In group C, the mean values of T1 reached the maximum of 139 ± 19% that of control at 9.5 min and finally reached 126 ± 22% of control at 30 min. CONCLUSIONS: The staircase effect presents in a shorter time course and at lower degrees in smaller infants. However, in older infants, staircase effect still presents in a long period and may influence the onset time and duration of twitch depression after muscle relaxants administration.
BACKGROUND: Acceleromyography used to monitor the neuromuscular transmission function is available in infants and children. However, information on the so-called staircase phenomenon during the baseline stabilization period in this population is limited. Our objective was to assess the characteristics of such phenomenon in infants in acceleromyography. METHODS: Thirty infants were divided into three groups: group A (aged 1-5 months, n = 10), group B (aged 6-11 months, n = 10), and group C (aged 12-24 months, n = 10). Anesthesia was induced and maintained without neuromuscular blocking agents. Patients received a supramaximal stimulus followed by TOF measurements every 15 s over the course of 30 min with a TOF-Watch(®) SX. All data were collected in a notebook computer using the TOF-Watch(®) SX Monitor software through optical fibers. RESULTS: The evoked T1 responses in younger infants (group A) were significantly lower than those in older infants (groups B and C) from 0-20 min. In group A, the signals increased to the maximum value of 121 ± 15% that of the control at 7.25 min and decreased toward a plateau of 113 ± 18% at 30 min. In group B, the signal heights increased to the maximum value of 143 ± 14% at 9.5 min, then decreased slowly to 136 ± 10% at 19.5 min, finally reaching 116 ± 12% at 30 min. In group C, the mean values of T1 reached the maximum of 139 ± 19% that of control at 9.5 min and finally reached 126 ± 22% of control at 30 min. CONCLUSIONS: The staircase effect presents in a shorter time course and at lower degrees in smaller infants. However, in older infants, staircase effect still presents in a long period and may influence the onset time and duration of twitch depression after muscle relaxants administration.
Authors: Manuel Martin-Flores; Chia T Tseng; Daniel M Sakai; Marta Romano; Luis Campoy; Robin D Gleed Journal: J Clin Monit Comput Date: 2016-02-16 Impact factor: 2.502