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

NCT ID: NCT00926718

Last Updated: 2009-06-23

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 80 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-06-30

Brief Summary

Eighty subjects will be recruited from those scheduled for surgery requiring general anesthesia at St Vincent's Hospital. Subjects must have American Society of Anesthesiologists (ASA) status of 1 or 2 (be fairly healthy), a BMI between 18-35 (reasonably healthy weight), and be between the ages of 18 and 75. They will not be eligible if they take certain medications or are expected to have a difficult intubation.

Subjects will be randomized (assigned by chance) to one of four rocuronium doses of 0, 0.2, 0.4, or 0.6 mg kg-1. All are acceptable clinical doses for performing a laryngoscopy. In the operating room, routine monitors will be applied, including a Bispectral Index (BIS) sensor and an M-Entropy sensor. Subjects will receive 0.025 mg kg-1 midazolam (a standard pre-op dose) and will be put to sleep. Once asleep, the subject will receive a rocuronium dose, followed by laryngoscopy three minutes later. The anesthesiologist performing the laryngoscopy will not know what dose of rocuronium the subject received. CVI, entropy, amount of muscle relaxation, and vital signs will be monitored and recorded throughout the procedure.

Subjects will receive propofol and remifentanil infusions during the case. These are commonly used medications for anesthesia. The subjects will also be randomized to two additional groups. One group will receive a remifentanil infusion of 2ng ml-1 and the other group will receive a 8ng ml-1 remifentanil infusion. Both doses are acceptable and often used during standard clinical care. The propofol infusion will be adjusted to keep the BIS number between 45-60. The anesthesiologist will not be able to see the CVI value. The times of certain intraoperative events, such as intubation and incision, will be recorded. All subjects will receive a morphine bolus (0.10-0.15 mg/kg) towards the end to reduce post-operative pain, as per standard clinical care. As the subject wakes up, time to eye opening and orientation will be recorded. The subject will rate their pain on a numerical pain scale and the quality of emergence will be assessed.

Upon arrival in the post anesthesia care unit (PACU), subjects will be asked to rate their pain again using the same pain scale. The pain score will be evaluated every 10 minutes for half an hour, then every hour until they are discharged from PACU.

Detailed Description

The Composite Variability Index (CVI, Aspect Medical System, Norwood MA) is a new parameter (measurement) that provides information about the amount of painful stimulation during surgery. It is part of the Bispectral Index (BIS, Aspect Medical Systems, Norwood MA), a well-established and widely used parameter that shows how awake/asleep patients are during general anesthesia and may indicate a need for more medication. The CVI component provides specific information about whether the patient needs pain medication (called opioids) and not just medication that makes you sleep (called hypnotics). The CVI is made of the BIS number and a measure of facial muscle movement (EMG). Both these components increase with painful stimulation, and decrease when pain medication is given.

Neuromuscular blocking drugs (NMD) are paralyzing medications that are often used during surgery to relax the body and make it easier for the surgeon to perform the surgery and the anesthesiologist to insert the breathing tube (called intubation). Facial muscles are resistant to NMD effects, but they might affect the EMG reading, making the CVI less useful when a patient needs NMD. The M-entropy monitor (GE Healthcare, Helsinki, Finland) is similar to the BIS monitor with CVI and is affected by large NMD doses. The purpose of this study is to examine the effect of rocuronium, a NMD, on the response of CVI and M-entropy to laryngoscopy under anesthesia. A laryngoscopy is the standard way of examining and opening the patient's airway before inserting the breathing tube. It is fairly stimulating so anesthesiologists sometimes, but not always, administer a NMD (in varying doses) before performing the laryngoscopy in standard care.

Eighty subjects will be recruited from those scheduled for surgery requiring general anesthesia at St Vincent's Hospital. Subjects must have ASA status of 1 or 2 (be fairly healthy), a BMI between 18-35 (reasonably healthy weight), and be between the ages of 18 and 75. They will not be eligible if they take certain medications or are expected to have a difficult intubation.

Subjects will be randomized (assigned by chance) to one of four rocuronium doses of 0, 0.2, 0.4, or 0.6 mg kg-1. All are acceptable clinical doses for performing a laryngoscopy. In the operating room, routine monitors will be applied, including a BIS sensor and an M-Entropy sensor. Subjects will receive 0.025 mg kg-1 midazolam (a standard pre-op dose) and will be put to sleep. Once asleep, the subject will receive a rocuronium dose, followed by laryngoscopy three minutes later. The anesthesiologist performing the laryngoscopy will not know what dose of rocuronium the subject received. CVI, entropy, amount of muscle relaxation, and vital signs will be monitored and recorded throughout the procedure.

Subjects will receive propofol and remifentanil infusions during the case. These are commonly used medications for anesthesia. The subjects will also be randomized (assigned by chance) to two additional groups. One group will receive a remifentanil infusion of 2ng ml-1 and the other group will receive a 8ng ml-1 remifentanil infusion. Both doses are acceptable and often used during standard clinical care. The propofol infusion will be adjusted to keep the BIS number between 45-60. The anesthesiologist will not be able to see the CVI value. The times of certain intraoperative events, such as intubation and incision, will be recorded. All subjects will receive a morphine bolus (0.10-0.15 mg/kg) towards the end to reduce post-operative pain, as per standard clinical care. As the subject wakes up, time to eye opening and orientation will be recorded. The subject will rate their pain on a numerical pain scale and the quality of emergence will be assessed.

Upon arrival in the PACU, subjects will be asked to rate their pain again using the same pain scale. The pain score will be evaluated every 10 minutes for half an hour, then every hour until they are discharged from PACU. The total dose of pain medications administered in PACU will be recorded. Upon PACU discharge, subjects will be asked to rate their overall experience with anesthesia. Demographic data will also be collected. All data will be kept in locked file cabinets and study results will be shared with research personnel at Aspect Medical Systems.

Conditions

Laryngoscopy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: DOUBLE

Study Groups

Dose 1a

Group Type: EXPERIMENTAL

remifentanil infusion

Intervention Type: DRUG

rocuronium dose 0 mg/kg + remifentanil infusion of 2ng ml-1

Dose 2a

Group Type: EXPERIMENTAL

rocuronium dose + remifentanil infusion

Intervention Type: DRUG

rocuronium dose 0.4 mg/kg+ remifentanil infusion of 2ng ml-1

Dose 3a

Group Type: EXPERIMENTAL

rocuronium dose + remifentanil infusion

Intervention Type: DRUG

rocuronium dose 0.6 mg/kg+ remifentanil infusion of 2ng ml-1

Dose 1b

Group Type: EXPERIMENTAL

remifentanil infusion

Intervention Type: DRUG

rocuronium dose 0 mg/kg + remifentanil infusion of 8ng ml-1

Dose 2b

Group Type: EXPERIMENTAL

rocuronium dose + remifentanil infusion

Intervention Type: DRUG

rocuronium dose 0.4 mg/kg+ remifentanil infusion of 8ng ml-1

Dose 3b

Group Type: EXPERIMENTAL

rocuronium dose + remifentanil infusion

Intervention Type: DRUG

rocuronium dose 0.6 mg/kg+ remifentanil infusion of 8ng ml-1

Interventions

remifentanil infusion

rocuronium dose 0 mg/kg + remifentanil infusion of 2ng ml-1

Intervention Type: DRUG

rocuronium dose + remifentanil infusion

rocuronium dose 0.4 mg/kg+ remifentanil infusion of 2ng ml-1

Intervention Type: DRUG

rocuronium dose + remifentanil infusion

rocuronium dose 0.6 mg/kg+ remifentanil infusion of 2ng ml-1

Intervention Type: DRUG

remifentanil infusion

rocuronium dose 0 mg/kg + remifentanil infusion of 8ng ml-1

Intervention Type: DRUG

rocuronium dose + remifentanil infusion

rocuronium dose 0.4 mg/kg+ remifentanil infusion of 8ng ml-1

Intervention Type: DRUG

rocuronium dose + remifentanil infusion

rocuronium dose 0.6 mg/kg+ remifentanil infusion of 8ng ml-1

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Presence of ASA physical status class I or II. (This will exclude subjects with significant medical problems).
• 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 Malampatti airway and a mandible-to-hyoid distance of greater than three fingerbreadths.
• Age between 18-75 years.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Medtronic - MITG

INDUSTRY

Sponsor Role: collaborator

St. Vincent's Medical Center

UNKNOWN

Sponsor Role: lead

Responsible Party

Saint Vincents Catholic Medical Centers

Locations

Saint Vincent Catholic Medical Centers

New York, New York, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Donald Mathews, MD

Role: CONTACT

dmathews@svcmcny.org

212-604-7566

Facility Contacts

Donald Mathews, MD

Role: primary

dmathews@svcmcny.org

212-604-7566

Other Identifiers

SVCMC_09_021

Identifier Type: -

Identifier Source: org_study_id