title: Ulnar peripheral nerve stimulation by train-of-four technique in adult nonmedicated patients.
abstract: BACKGROUND
  Peripheral nerve stimulation is necessary to quantify the level of neuromuscular blockade and prevent prolonged paralysis related to drug accumulation. Some nurses and physicians are hesitant to administer nerve stimulation because of concerns about inflicting pain on the patient.
  
  
  OBJECTIVE
  To describe the feeling associated with train-of-four ulnar nerve stimulation, and to quantify discomfort, monitor heart rate response, and define the amount of current necessary to stimulate thumb adduction.
  
  
  METHODS
  Healthy, nonmedicated volunteer subjects (N = 39) were asked to describe train-of-four ulnar nerve monitoring at 3 current strengths. Heart rate was monitored throughout the testing procedure. The milliamperes delivered at each current strength and the occurrence of thumb adduction were recorded.
  
  
  RESULTS
  Subjects described nerve stimulation generally as an unusual prickly sensation. On a discomfort scale of 1 to 10, the mean discomfort score when stimulated with the current setting at 4 (15.5-23.6 mA) was 3.63. Level 4 stimulation produced thumb adduction in 54% of subjects. No heart rate change occurred in response to nerve stimulation.
  
  
  CONCLUSIONS
  Nerve stimulation by train-of-four method was moderately uncomfortable but not painful. Heart rate response could not be relied on as a measurement of discomfort. Protocols for stimulation should include testing at level 4 and increasing as necessary to cause thumb adduction.
authors.affiliation: University of California Medical Center, San Diego 92103-8929.
authors.forename: J E
authors.initials: JE
authors.lastname: Davidson
authors.forename: A
authors.initials: A
authors.lastname: Verderber
authors.forename: V
authors.initials: V
authors.lastname: Lake
authors.forename: M
authors.initials: M
authors.lastname: Weinger
authors.forename: B
authors.initials: B
authors.lastname: Partridge
authors.forename: B
authors.initials: B
authors.lastname: Munden
authors.forename: J
authors.initials: J
authors.lastname: Taylor
mesh_terms: D000328:Adult; D002985:Clinical Protocols; D016903:Drug Monitoring / Q000379:methods*; D004558:Electric Stimulation / Q000009:adverse effects* / Q000379:methods*; D004566:Electrodes; D006339:Heart Rate; D006801:Humans; D009466:Neuromuscular Blocking Agents / Q000009:adverse effects*; D010146:Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D010147:Pain Measurement; D010243:Paralysis / Q000139:chemically induced / Q000517:prevention & control; D013933:Thumb / Q000294:innervation / Q000502:physiology; D014459:Ulnar Nerve
chemical_list: D009466:Neuromuscular Blocking Agents