Fade Upon TOF Stimulation Induced by Succinylcholine
Condition: Muscle Relaxants
MeSH terms: Muscle Hypotonia
Intervention: Succinylcholine
Intervention description: will be administered succinylcholine in a dose of 0.1 mg/kg in Arm 1, 0.15 mg/kg in Arm 2, 0.2 mg/kg in Arm 3, 0.25 mg/kgin Arm 4, 0.3 mg/kg in Arm 5.
Intervention MeSH terms: Succinylcholine
Phase: Phase 4
Study type: Interventional
Primary purpose: Other
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Enrollment: 19.0
Sex: All
Minimum age: 18 Years
Maximum age: 70 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: succinylcholine; depolarizing muscle relaxants; pharmacologic effects

Summary:

      Muscle relaxants are medications used during surgery to facilitate surgical access. The
      effect of the muscle relaxant medications is measured by stimulation a motor nerve and
      measuring the force of the resultant muscle contraction. Based on the mechanism of action,
      two kinds of muscle relaxants are described. First a nondepolarizing muscle relaxant and the
      second kind is the depolarizing muscle relaxant. These two kinds of muscle relaxants can be
      distinguished by rapidly stimulating the nerve 4 times over 2 seconds (Train of four or TOF).
      The nondepolarizing muscle relaxants produce fade ie successive muscle contractions are less
      forceful than the preceding ones. Whereas the depolarizing muscle relaxants are generally
      believed to produce four contractions of equal strength. However, there is some indication
      that this may not be entirely correct. There is evidence that depolarizing muscle relaxants
      also may produce fade. The investigators are conducting the following study to determine if
      indeed depolarizing muscle relaxants produce fade. The investigators would also like to
      characterize the fade ie differences during onset and offset of the block and the effect of
      the dose on the degree on the fade.
    

Eligibility criteria:

        Inclusion Criteria:

          -  ASA PS I or II,

          -  18-60 years of age of either sex,

          -  with a BMI<25Kg/m2

        Exclusion Criteria:

          -  presence of any disease involving the neuromuscular system.

          -  Presence of any neurologic illness eg . Paraplegia or hemiplegia, spinal cord
             injuries, stroke, multiple sclerosis.

          -  No liver or kidney disease.

          -  Known allergy to succinylcholine.

          -  Family history of malignant hyperthermia.

          -  Known pseudocholinesterase deficiency.

          -  Any skin burns within the last 1 year.

        We would also exclude subjects with;

          -  Central core disease,

          -  duchenne or Becker muscular dystrophy,

          -  osteogenesis imperfecta,

          -  Noonan syndrome,

          -  arthrogryposis multiplex,

          -  congenital,

          -  myotonia,

          -  neuroleptic malignant syndrome,

          -  multiminicore disease,

          -  King Denborough syndrome,

          -  Native American myopathy,

          -  hypokalemic periodic paralysis or

          -  a history of rhabdomyolysis.

        We would also exclude any subject with a history of cardiac arrhythmias.