The Effect of Neuromuscular Blockade on the Composite Variability Index (CVI) During Laryngoscopy
Status:
Completed
Trial end date:
2013-12-01
Target enrollment:
Participant gender:
Summary
The Bispectral Index (BIS) monitor is used in many operating rooms to provide information to
the anesthesiologist about a patient's level of consciousness. The Composite Variability
Index (CVI) is a new index that may provide the anesthesiologist with more information about
the condition of the patient. The CVI is a measure of the combined variability in BIS
(bispectral index) and frontal electromyography (EMG) activity that may be useful in
assessing the nociception/anti-nociception balance for patients under general anesthesia.The
purpose of this study is to determine if a commonly used anesthetic drug (rocuronium) affects
the CVI measurement differently with different doses. Rocuronium is a neuromuscular blocking
agent (NMBA) routinely used during surgery. It is expected that the group given the highest
dose of rocuronium will have diminished CVI values.
This study will randomize patients to one of four doses of rocuronium: no rocuronium, 0.2,
0.4, and 0.6 milligrams per kilo of body weight; the last dose is the standard amount for
adults. It is expected that the group given the highest dose of rocuronium will have
diminished CVI values. By including intermediate doses, information about the function of CVI
in states of less than full muscle relaxation, or paralysis, will be obtained. This
information is critically important for the development of the composite variability index,
because during general anesthesia patients are usually maintained in a state of less than
full paralysis. If the CVI response to stimulation in the intermediate groups is similar to
the group receiving no rocuronium, the monitor may find wide clinical applicability. If the
response is similar to the maximal rocuronium group, the index may only be reliable in states
with no muscle relaxant, which will greatly limit clinical utility.