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

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.

Conditions

• Laryngoscopy

Interventions

DRUG

remifentanil infusion

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

DRUG

rocuronium dose + remifentanil infusion

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

DRUG

rocuronium dose + remifentanil infusion

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

DRUG

remifentanil infusion

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

DRUG

rocuronium dose + remifentanil infusion

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

DRUG

rocuronium dose + remifentanil infusion

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

Sponsors & Collaborators

• Medtronic - MITG

  collaborator INDUSTRY

• St. Vincent's Medical Center

  lead UNKNOWN

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2009-06-30

Primary Completion

2010-06-30

Countries

• United States

Study Locations