Shortening of the Twitch Stabilization Period by Tetanic Stimulation in Acceleromyography in Children and Young Adults
Shortening of the Twitch Stabilization Period by Tetanic Stimulation in Acceleromyography in Children and Young Adults
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.
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
Inclusion Criteria:

 -  general anesthesia

 Exclusion Criteria:

 -  participation in another trial

 -  refusal of participation

 -  state after burns

 -  diabetes mellitus

 -  reflux disease

 -  difficult airway

 -  pregnancy

 Medications:

 -  volatile anesthetics

 -  antibiotics (Aminoglykoside, Polymyxin, Clindamycin, Lincomycin, Tetrazykline)

 -  local anesthetics

 -  magnesium

 -  Litium

 -  Ca-chanel-blockers

 -  furosemid

 -  theophyllin

 -  phenytoin

 -  cyclophosphamide

 -  metoclopramide

 -  β-blockers