None listed
Conditions
Brief summary
General anaesthesia is a complex process requiring many drugs being given to a patient and monitoring their effect on organs like the heart, lungs and brain. These drugs can have similar actions but the combined effects can be complicated and difficult to predict because of large variations of drug dosing and differences in patient responses. This study aims to establish the interaction between sevofularane and remifentanil across a wide variety of doses for different anaesthesia and endpoints
Interventions
That response surface methodology (a technique that models the pharmacodynamic effect of two and three drug combinations) can define the interaction between sevoflurane and remifentanil for the duration of a general anaesthetic (approx 2 hrs). Remifentanil intravenously dose range 0.05 & 0.25%mcg/kg/min, and will be incremented. Sevoflurane dose range will be 0.25-1.25% mcg/kg/min.
One drug will be randomly assigned as the start drug and ramped up to a preset randomly selected dose within the d
That response surface methodology (a technique that models the pharmacodynamic effect of two and three drug combinations) can define the interaction between sevoflurane and remifentanil for the duration of a general anaesthetic (approx 2 hrs). Remifentanil intravenously dose range 0.05 & 0.25%mcg/kg/min, and will be incremented. Sevoflurane dose range will be 0.25-1.25% mcg/kg/min. One drug will be randomly assigned as the start drug and ramped up to a preset randomly selected dose within the dose range (sevoflurane 0.25, 0.5, 0.75, 1.0 or 1.25%, remifentanil 0.05, 0.1, 0.15, 0.2 or 0.25%mcg/kg/min) then second drug will be introduced and ramped up until OASS score of 5 is attained. Doses will be incremented once 5 plasma half times have elapsed to allow equilibration at the effect site. This will approximately 5 mins for each increment. Increments will be ceased when patient is OASS 5 (unconscious and able to tolerate laryngoscopy) at which stage the patient will be intubated and preparations for surgery to be continued.
Sponsors
Dr Doug Campbell
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
1) American Society Anaesthesiology Grade (ASA) grade 1-3 (healthy or with mild or moderate but stable disease). 2) Surgery usually associated with minimal blood loss and expected to last at least 1.5hrs.
Exclusion criteria
1) Contraindication to using reminfentanil or sevoflurane - including allergy and malignant hyperpyrexia2) inability to converse fluently in English.
Outcome results
None listed