Propofol for Supreme LMA Insertion With and Without Remifentanil (SC50)

ED 50 of Propofol for Supreme LMA Insertion With and Without Remifentanil. A Randomized Trial

The aims of this study were to determine the clinically required concentration of propofol for LMA Supreme insertion, and to examine to what extent remifentanil reduces the dose of propofol and improves conditions for it's insertion.

Study Overview

• Status: Completed
• Conditions: Patients Requiring Ambulatory Surgery Under General Anesthesia
• Intervention / Treatment: Drug: propofol; Drug: propofol and remifentanil

Detailed Description

The single-use Laryngeal Mask Airway SupremeTM (SLMA, Laryngeal Mask Company Limited, Singapore) is a new single use supraglottic airway device introduced recently that present combined features of the LMA ProSealTM (PLMA, Laryngeal Mask Company Limited) and the LMA FastrachTM (FLMA, Laryngeal Mask Company Limited). The mask has an anatomically shaped airway tube, elliptical in cross-section that facilitates easy insertion and minimizes accidental rotation. The cuff bowl is designed to prevent airway kinking and offer higher airway seal pressures around the laryngeal opening than the LMA ClassicTM (CLMA, Laryngeal Mask Company Limited) It has a drain tube that provides functional separation of the respiratory and digestive tracts to prevent gastric aspiration. Even though insertion of the SLMA is associated with a higher initial success rate, fewer airway manipulations and a safe and effective airway during anaesthesia, the anaesthetic techniques for its insertion were not standardised. Most available data on the requirements of anaesthetic drugs and co-induction agents used for insertion of SLMA originate from research involving other assessments of the SLMA such as the seal with respiratory and gastrointestinal tract.We tested for differences in the predicted concentration of propofol with and without remifentanil for insertion of the SLMA.

Methods: 50 patients ASA class I or II aged 18-75 years undergoing ambulatory elective surgery will be randomized to one of two groups: those who receive propofol + saline (control group: n = 25) or propofol + remifentanil (propofol-remifentanil group: n=25). We will use target-controled infusions (Alaris®PK) for both drugs: propofol (Marsh et al.´s pharmacokinetic model) and remifentanil (Minto et al.´s pharmacokinetic model). The patients wil be premedicated with midazolam 1 mg iv before surgery. The target concentration for each patient was determined using the Dixon´s up-and-down method. Predetermined propofol and remifentanil blood and effect site concentrations were held constant for at least 10 min. After equilibration of plasma and effect site propofol concentrations, the SLMA will be inserted, and secured according to the manufacture´s recommendations, without the use of muscle relaxants. In control group, propofol concentrations will start at 4 μg ml-1, with 0,5 μg ml-1 as the step size, with the coadministration of saline. In propofol-remifentanil group, propofol + remifentanil at a target-controlled infusion 5 ng/mL will be coadministered. A single measurement will be obtained from each patient. If the patient reacted with movement, the propofol concentration for the next patient was increased by 0.5 μg ml-1 ±1 ; if there was no movement, it was decreased by 0.5 μg ml-1 ±1 . Movement was defined as bucking or gross purposeful muscular movement within 1 min of LMA insertion. Values of Cp 50 wil be determined by calculating the midpoint concentration after at least seven crossover points (movement/non movement) will be obtained in each group.

• Study Type: Interventional
• Enrollment (Actual): 59
• Phase: Phase 4

Contacts and Locations

Study Locations

• Spain
  • Madrid, Spain, 28007
    • Hospital General Universitario Gregorio Marañon Servicio de Anestesiologia y Reanimación

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• ASA II-II patients Scheduled to ambulatory surgery Need of general anaesthesia General anaesthesia usually performed with laryngeal mask Negative pregnancy test in women. Signed informed consent.

Exclusion Criteria:

• Patients with a potentially difficult airway o (Mallampati III or IV, a limited mouth opening and/or cervical spine disease) Patients with reactive airway disease Signs of upper respiratory infection, Patients who had a risk of gastric aspiration

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: propofol; In control group, propofol concentrations will start at 4 μg ml-1, with 0,5 μg ml-1 as the step size, with the coadministration of saline.	Drug: propofol
Experimental: propofol and remifentanil; In propofol-remifentanil group, propofol + remifentanil at a target-controlled infusion 5 ng/mL will be coadministered.	Drug: propofol and remifentanil

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The concentration of propofol with and without remifentanil for insertion of the SLMA	Comparison of he concentration of propofol with and without remifentanil for insertion of the SLMA	at insertion of SLMA

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
changes in Systolic Blood Pressure, Diastolic Blood Pressure and Heart Rate		basal and every 3 minutes until 6 minutes after insertion of the SLMA
BIS	BIS data after SLMA insertion with both anaesthetic techniques	before and after SLMA insertion(every min until min 6)
Fibrescope evaluation	Fibrescope evaluation of the SLMA Of the view of the glottis	after SLMA insertion
blood pressure(Hypertension or hypotension)		before and after SLMA insertion(every min until min 6)
heart rate (tachycardia or bradycardia)	tachycardia or bradycardia requiring treatment	before and after SLMA insertion(every min until min 6)

Collaborators and Investigators

• Sponsor: Hospital General Universitario Gregorio Marañon
• Collaborators: Ministry of Health, Spain
• Investigators: Principal Investigator: Matilde Zaballos, PhD, Hospital General Universitario Gregorio Marañón

Publications and helpful links

General Publications

• Zaballos M, Bastida E, Agusti S, Portas M, Jimenez C, Lopez-Gil M. Effect-site concentration of propofol required for LMA-Supreme insertion with and without remifentanil: a randomized controlled trial. BMC Anesthesiol. 2015 Oct 6;15:131. doi: 10.1186/s12871-015-0115-8.

Study record dates

Study Major Dates

• Study Start: May 1, 2012
• Primary Completion (Actual): June 1, 2013
• Study Completion (Actual): June 1, 2013

Study Registration Dates

• First Submitted: October 21, 2013
• First Submitted That Met QC Criteria: October 25, 2013
• First Posted (Estimate): November 1, 2013

Study Record Updates

• Last Update Posted (Estimate): November 1, 2013
• Last Update Submitted That Met QC Criteria: October 25, 2013
• Last Verified: October 1, 2013

More Information

Terms related to this study

• Keywords: propofol; remifentanil; ED50; Laryngeal Mask Airway Supreme; effective dose of intravenous propofol
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics, Intravenous; Anesthetics, General; Anesthetics; Analgesics, Opioid; Narcotics; Hypnotics and Sedatives; Remifentanil; Propofol
• Other Study ID Numbers: FIBHGMECNC002-2011