Shortening of the Twitch Stabilization Period by Tetanic Stimulation in Acceleromyography in Children and Young Adults
Condition: Train-of-Four-Monitoring
Study type: Interventional
Phase: Phase 4

Summary: 
      Repetitive nerve stimulation is used to monitor the neuromuscular transmission function in
      infants, children and adults after the application of muscle relaxants. During repetitive
      stimulation of a motor nerve, amplitude of contractions of the corresponding muscle will
      increase to a plateau (twitch potentiation), which is known as the staircase phenomenon.

      There is no systematic information about the staircase phenomenon of the adductor pollices
      muscle (ulnar nerve) in children between 1 month and 18 years .

      In adults , a 50-Hz tetanus administered before initial twitch stabilization is able to
      shorten the twitch stabilization period and to eliminate this staircase phenomenon.

      The purpose of this study is to investigate the characteristics of twitch potentiation in
      children between 1 month and 18 years by using acceleromyography.

      In addition we investigate whether application of a 50-Hz tetanic stimulation is able to
      eliminate the twitch potentiation like in adults.
    

Detailed description: 
      1. Background:

           Acceleromyography at the adductor pollices muscle (ulnar nerve stimulation) is used to
           monitor the neuromuscular transmission function in infants, children and adults after
           the application of muscle relaxants. During repetitive stimulation of a motor nerve,
           amplitude of contractions of the corresponding muscle will increase to a plateau (twitch
           potentiation), which is known as the staircase phenomenon. This effect may influence the
           onset time and duration of twitch depression after the application of muscle relaxants.
           The staircase effect during the baseline stabilization period presents in a shorter time
           course and at lower degrees in smaller infants. In older infants, staircase effect
           presents in a longer period and is able to influence duration of twitch depression after
           the administration of muscle relaxants.

           There is no information about the staircase phenomenon at the adductor pollices muscle
           (ulnar nerve stimulation) in children between 1 month and 21 years.

           In adults , a 50-Hz tetanus administered before initial twitch stabilization is able to
           shorten the twitch stabilization period and to eliminate this phenomenon.

        2. Aim of the study:

           The purpose of this controlled, randomised, pragmatic study is to investigate the
           characteristics of twitch potentiation (T1%, first twitch of TOF-stimulation; TOFR,
           Train-of-Four-ratio) in children between 1 month and 21 years by using
           acceleromyography. In addition we stimulate the right and the left arm simultaneously
           with acceleromyography (TOF-stimulation). At the one hand a 50 Hz tetanus will be
           administered before twitch stabilization (TOF-stimulation). At the other hand
           TOF-stimulation for twitch stabilization will be started without tetanic stimulation

        3. Methods:

           Anaesthesia will be induced and maintained without muscle relaxants by propofol and
           remifentanil. After this acceleromyography will be performed simultaneously at the right
           and the left arm (adductor pollices muscle, ulnar nerve). At the one hand a 50 Hz
           tetanus will be administered before twitch stabilization (TOF-stimulation). At the
           contralateral side TOF-stimulation for twitch stabilization will be started without
           tetanus. TOF measurements will be collected by 2 TOF Watch SX and two notebooks for the
           course of 30 minutes.

        4. Inclusion criterions/ groups

           -general anesthesia (total intravenous anaesthesia)

           Groups (total amount= 80)

             -  group A: 18-21 years; n= 10

             -  group B: 12-18 years; n= 10

             -  group C: 6-12 years; n= 10

             -  group D: 3-6 years; n= 10

             -  group E: 25-60 months; n= 10

             -  group F: 12-24 months; n= 10

             -  group G: 6-11 months; n= 10

             -  group H: 1-5 months; n= 10.

        5. Exclusion criterions

             -  participation in another trial

             -  refusal of participation

             -  state after burns

             -  diabetes mellitus

             -  reflux disease

             -  difficult airway

             -  pregnancy

      Medications:

        -  volatile anesthetics

        -  antibiotics (aminoglycosides, polymyxin, clindamycin, lincomycin, tetracyclines)

        -  local anesthetics

        -  magnesium

        -  lithium

        -  Ca-chanel-blockers

        -  furosemide

        -  theophylline

        -  phenytoin

        -  cyclophosphamide

        -  metoclopramide

        -  β-blockers
    

Intervention name(s): Tetanic stimulation; Staircase Stimulation
Intervention type(s): Other; Other
Intervention description(s): 50 Hz tetanic stimulation before TOF-twitch stabilization with the aim to eliminate the staircase phenomenon; TOF-twitch stabilization without 50 Hz tetanic stimulation with the aim to verify the staircase phenomenon
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Acceleromyography; staircase phenomenon; tetanic stimulation