Intravenous Anesthetic Interaction Unrecognized Condition
Conditions
Brief summary
The purpose of this randomized clinical trial is to evaluate the interaction of lidocaine infusion initiated and maintained during surgery, on propofol requirements during general anesthesia.
Detailed description
Use of intravenous lidocaine as a coadjuvant agent during general anesthesia has increased. Lidocaine infusion during and after abdominal surgery decreases postoperative pain and reduces ileus duration, reducing patient´s hospital stay and opioid consumption. Intravenous lidocaine´s effect on other intravenous anesthetics is unclear, and there are no present studies evaluating its interaction on hypnotic anesthetic requirements when using a BIS (Bispectral Index) monitor to maintain an adequate depth of anesthesia. We therefore decided to conduct a randomized controlled trial to evaluate the interaction of systemic lidocaine infusion, initiated and maintained during surgery, on propofol requirements and anesthetic depth as measured by BIS.
Interventions
Once the dose of propofol required for general anesthesia is stabilized for 5 minutes with BIS values between 40 and 50, lidocaine 1% infusion is begun in a bolus of 1.5mg/kg for 5 minutes and then infused at 2 mg/kg/hr until the end of surgery (last skin suture is made).
OTHERPlacebo (0.9% saline infusion)
Once the dose of propofol required for general anesthesia is stabilized for 5 minutes with BIS values between 40 and 50, 0.9% saline infusion is begun in a bolus of 1.5mg/kg for 5 minutes and then infused at 2 mg/kg/hr until the end of surgery (last skin suture is made).
DRUGPropofol 1% (intravenous infusion)
Propofol is administered according to a widely-accepted pharmacokinetic model, initially dosed to a target controlled infusion (TCI) of 4.5 micrograms/ml, and titrated by step increases of 0.5 every minute until loss of conscience is obtained and BIS values are less than 50. During the maintenance phase of anesthesia propofol TCI is actively titrated to maintain BIS values between 40 and 50. If BIS is out of this range for more than 10 seconds, propofol is adjusted in 0.5 ug/mc to maintain BIS values in the predetermined limits.
PROCEDUREPlacement of arterial line
An arterial line was placed in the anesthetised patient´s right arm by the investigator and arterial samples were obtained every 10 minutes since initiation of the study infusion to determine plasmatic lidocaine and propofol levels (if the infusion was saline the samples were not analyzed). The arterial line was removed before the end of surgery.
Sponsors
Pontificia Universidad Catolica de Chile
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
20 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* ASA I-II patients, * Between 20 and 65 years of age * Programed for elective laparoscopic cholecystectomy * Eligible for total intravenous anesthesia with propofol
Exclusion criteria
* Unwillingness to participate in the study * Adverse reactions to the drugs used in the study * Use of medications that interfere in local anesthetic metabolism * History of liver disease, kidney failure, hypoalbuminemia, hypocalcemia or hypophosphatemia * History of drug or alcohol abuse * Chronic use of benzodiazepines
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total propofol requirements during bispectral index guided general anesthesia | DAY 1. | During and after elective laparoscopic cholecystectomy. Patients' anesthetic depth will be monitored during the intra-operative period using a BIS monitor. Patients' follow up considers the immediate post-operative period at the recovery room (PACU), and it will continue until patients' discharge from the hospital (average 3 days postoperatively). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Evaluate effect of intravenous lidocaine infusion on waking time after general anesthesia | DAY 1. | Immediately after elective laparoscopic cholecystectomy, during PACU stay. Patients' follow up considers the immediate post-operative period at the recovery room (PACU), and it will continue until patients' discharge from the hospital (average 3 days postoperatively). |
Countries
Chile
Outcome results
None listed