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Completed

NCT Number: NCT01450813

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

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Key information

Conditions

Anesthesia Neuromuscular Blockade

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Fletcher Allen Health Care

Burlington, Vermont, 05405, United States

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Saline 0.06 ml/kg

Drug

IV Infusion x1 prior to laryngoscopy

Other names: Normal Saline

Rocuronium 0.2 mg/kg

Drug

IV Infusion x1 prior to laryngoscopy

Other names: Rocuronium bromide: Zemuron

Rocuronium 0.4 mg/kg

Drug

IV Infusion x1 prior to laryngoscopy

Other names: Rocuronium bromide: Zemuron

Rocuronium 0.6 mg/kg

Drug

IV Infusion x1 prior to laryngoscopy

Other names: Rocuronium bromide: Zemuron

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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

Sponsors and collaborators

Lead sponsor

Medtronic - MITG

Industry

Registry information

Official study title

The Effect of Rocuronium on the Response of Composite Variability Index (CVI) to Laryngoscopy

Important dates

Study start
2009
Primary completion
2013
Study completion
2013
First posted
Oct 12, 2011
Registry last updated
May 12, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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