The Effect of Neuromuscular Blockade on the Composite Variability Index (CVI) During Laryngoscopy

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01450813
Recruitment Status : Completed
First Posted : October 12, 2011
Results First Posted : May 12, 2017
Last Update Posted : May 12, 2017
Information provided by (Responsible Party):
Medtronic - MITG

September 22, 2011
October 12, 2011
March 10, 2016
May 12, 2017
May 12, 2017
June 2009
December 2013   (Final data collection date for primary outcome measure)
The Mean Difference in CVI Between Pre-laryngoscopy and Post-laryngoscopy for Each of the Four Rocuronium Groups [ Time Frame: Six minutes after the dose of rocuronium with laryngoscopy at 3 minutes after the study intervention ]

The difference between the mean CVI in three minutes prior to laryngoscopy and three minutes following laryngoscopy reported as the mean change in CVI and the +/- 95% confidence interval for each group.

The Composite Variability Index (CVI) scale is a logistic regression of three measures of processed electroencephalography (EEG) signals. These signals are Bispectral Index (BIS), the variability of electromyelogram (sEMG), and the variability of BIS (sBIS). The scale ranges from 0 to 100 where a lower CVI value represents a lower likelihood of intraoperative somatic responses, and a higher CVI value represents a higher likelihood of intraoperative somatic responses.

The difference between the mean CVI value prior to laryngoscopy to the maximal CVI reading following laryngoscopy. [ Time Frame: The mean CVI value in the three minutes prior to laryngoscopy will be compared to the maximal CVI reading during the three minutes following laryngoscopy. ]
Complete list of historical versions of study NCT01450813 on Archive Site
The Average CVI During the Maintenance Phase of Anesthesia for the Two Remifentanil Groups [ Time Frame: Maintenance Anesthesia ]
Mean CVI from incision to propofol off reported as the mean CVI +/- 95% confidence interval for the two groups
The average CVI level during the maintenance phase of surgery. [ Time Frame: The maintenance phase is defined as the time from surgical incision to the time that the propofol is turned off. ]
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The Effect of Neuromuscular Blockade on the Composite Variability Index (CVI) During Laryngoscopy
The Effect of Rocuronium on the Response of Composite Variability Index (CVI) to Laryngoscopy

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.

Consented subjects randomized to one of four doses of rocuronium will be transported to the operating room and be connected to routine monitors that included a BIS (Covidien), M-Entropy sensor (GE Healthcare) and TOF (train of four) monitor. Following preoxygenation, general anesthesia will be induced with propofol and remifentanil using traditional syringe pumps. The induction doses given and subsequent infusion rates will be determined by utilizing pharmacokinetic (Pk) models (Marsh model for propofol, Minto model for remifentanil). Unconsciousness will be confirmed by performing the usual clinical assessments and by obtaining a BIS value between 40 and 50. Once the subject is unconsciousness, they will be given the assigned dose of rocuronium, after which the study anesthesiologist will perform a laryngoscopy. The anesthesiologist performing the laryngoscopy will not know what dose of rocuronium the subject received. Neuromuscular blockade (NMB) will be monitored by a train-of-four twitch monitor (TOF Watch-SX) at the adductor pollicis muscle (2 HZ, 50mAmp) every 15 seconds.

At three minutes after the rocuronium administration, a standardized 20-second laryngoscopy will be applied. The CVI, entropy, and hemodynamic responses (heart rate, blood pressure measurement each minute) and train-of-four measurements will be monitored for three minutes before and after the laryngoscopy.

Not Provided
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Basic Science
  • Anesthesia
  • Neuromuscular Blockade
  • Drug: Saline 0.06 ml/kg
    IV Infusion x1 prior to laryngoscopy
    Other Name: Normal Saline
  • Drug: Rocuronium 0.2 mg/kg
    IV Infusion x1 prior to laryngoscopy
    Other Name: Rocuronium bromide: Zemuron
  • Drug: Rocuronium 0.4 mg/kg
    IV Infusion x1 prior to laryngoscopy
    Other Name: Rocuronium bromide: Zemuron
  • Drug: Rocuronium 0.6 mg/kg
    IV Infusion x1 prior to laryngoscopy
    Other Name: Rocuronium bromide: Zemuron
  • Sham Comparator: Group 1
    Saline 0.06 ml/kg
    Intervention: Drug: Saline 0.06 ml/kg
  • Active Comparator: Group 2
    Rocuronium 0.2 mg/kg
    Intervention: Drug: Rocuronium 0.2 mg/kg
  • Active Comparator: Group 3
    Rocuronium 0.4 mg/kg
    Intervention: Drug: Rocuronium 0.4 mg/kg
  • Active Comparator: Group 4
    Rocuronium 0.6 mg/kg
    Intervention: Drug: Rocuronium 0.6 mg/kg
Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
December 2013
December 2013   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • American Society of Anesthesia (ASA) physical status class I or II.
  • Body mass index between 18 and 35 kg m-2.
  • No use of psychotropic or neuropsychiatric medications.
  • A airway assessment with no indication of a difficult intubation including a class I or II Mallampati airway and a mandible-to-hyoid distance of greater than three fingerbreadths.
  • Age between 18-75 years.

Exclusion Criteria:

  • Does not meet inclusion criteria.
Sexes Eligible for Study: All
18 Years to 75 Years   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
United States
Not Provided
Plan to Share IPD: No
Plan Description: Data collected was for device algorithm development
Medtronic - MITG
Medtronic - MITG
Not Provided
Principal Investigator: Donald M Mathews, MD University of Vermont
Medtronic - MITG
April 2017

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP