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Preoperative Dexmedetomidine & EC50 of Propofol (PreopDXM)

24 mars 2014 mis à jour par: Hee-Pyoung Park, Seoul National University Hospital

Preoperative Dexmedetomidine Reduces the EC50 of Propofol for Successful i-gelTM Insertion Without Muscle Relaxants

Dexmedetomidine is a useful anaesthetic adjuvant for general anaesthesia. In this prospective randomised study, we determined whether preoperative dexmedetomidine administration could reduce the half maximal effective concentration (EC50) of propofol for successful i-gelTM insertion without muscle relaxants.

Aperçu de l'étude

Description détaillée

Propofol is a useful induction agent for LMA insertion without muscle relaxants because it profoundly inhibits pharyngeal and laryngeal reactivity. A previous report showed that the effect-site concentration of propofol for successful classic LMA insertion in 50% of adults (EC50) without muscle relaxants in healthy male patients was 8.72 (0.55) µg ml-1. The EC50 of propofol may be dependent on the type of LMA used. A previous study comparing the EC50 of the propofol concentration between classic and proseal LMA insertions demonstrated that the EC50 of propofol needed for proseal LMA insertion was 35% greater than that needed for classic LMA insertion. Unfortunately, no investigation has been performed to determine the EC50 of the propofol concentration required for i-gel insertion without muscle relaxants.

Dexmedetomidine (DEX), a selective alpha-2 agonist, has sympatholytic, sedative, and analgesic properties. Such beneficial characteristics make DEX a useful anaesthetic adjuvant for general anaesthesia. Many reports have revealed the beneficial effects of DEX in terms of reducing intraoperative anaesthetic requirements, postoperative analgesic demand, and increased haemodynamic responses to noxious stimuli such as endotracheal intubation. A previous investigation showed that preoperative clonidine, an alpha-2 agonist, decreased the EC50 required for LMA insertion.

We hypothesised that preoperative DEX administration can reduce the propofol concentration required for i-gel insertion. In this study, we compared the EC50 of propofol needed for successful i-gel insertion without muscle relaxants between DEX and placebo groups

Type d'étude

Interventionnel

Inscription (Réel)

37

Phase

  • Phase 4

Contacts et emplacements

Cette section fournit les coordonnées de ceux qui mènent l'étude et des informations sur le lieu où cette étude est menée.

Lieux d'étude

Critères de participation

Les chercheurs recherchent des personnes qui correspondent à une certaine description, appelée critères d'éligibilité. Certains exemples de ces critères sont l'état de santé général d'une personne ou des traitements antérieurs.

Critère d'éligibilité

Âges éligibles pour étudier

20 ans à 65 ans (Adulte, Adulte plus âgé)

Accepte les volontaires sains

Non

Sexes éligibles pour l'étude

Tout

La description

Inclusion Criteria:

  • ASA physical status I-II patients who were 20-65 years old and scheduled for general anaesthesia for urologic surgery

Exclusion Criteria:

  • Patients with an allergy to alpha-2 adrenergic agonists or propofol
  • Patients who anticipated difficult airway (cervical spinal disease, Mallampati score of III or IV, a mouth opening of <2.5 cm, and/or body mass index of >30 kg m-2), unstable teeth
  • Patients with bradycardia of <50 beats/min, heart block greater than first degree, severe cardiorespiratory dysfunction
  • Patients with symptoms of upper respiratory infection

Plan d'étude

Cette section fournit des détails sur le plan d'étude, y compris la façon dont l'étude est conçue et ce que l'étude mesure.

Comment l'étude est-elle conçue ?

Détails de conception

  • Objectif principal: Soins de soutien
  • Répartition: Randomisé
  • Modèle interventionnel: Affectation à un seul groupe
  • Masquage: Tripler

Armes et Interventions

Groupe de participants / Bras
Intervention / Traitement
Expérimental: Group D : Dexmedetomidine + propofol group
In Group D, DEX (1 µg kg-1) was intravenously loaded for 10 min before induction of anaesthesia.

All patients were pre-oxygenated with 100% oxygen with spontaneous breathing for 3 min before the end of loading of dexmedetomidine. Anaesthesia was induced with predetermined effect-site propofol concentrations using a target-controlled infusion device (Orchestra; Fresenius-Vial, Brezins, France). The first patient in Group D received an effect-site propofol concentration of 3 and 5 µg mL-1, respectively, over 5 min.

After equilibration of the plasma and effect-site propofol concentrations, i-gel (size 4 for patients weighing 50-90 kg, size 3 for patients weighing 30-50 kg) was inserted using the standard technique by a single anaesthesiologist staff member with expertise in i-gel insertion and who entered the operating room immediately before i-gel insertion to blind him to the group assignment.

Comparateur placebo: Group C : Saline + propofol group
In Group C, 0.9% of normal saline (1 µg kg-1) was loaded 10 min before induction of anaeshtesia.

All patients were pre-oxygenated with 100% oxygen with spontaneous breathing for 3 min before the end of loading of normal saline. Anaesthesia was induced with predetermined effect-site propofol concentrations using a target-controlled infusion device (Orchestra; Fresenius-Vial, Brezins, France). The first patient in Group C received an effect-site propofol concentration of 3 and 5 µg mL-1, respectively, over 5 min.

After equilibration of the plasma and effect-site propofol concentrations, i-gel (size 4 for patients weighing 50-90 kg, size 3 for patients weighing 30-50 kg) was inserted using the standard technique by a single anaesthesiologist staff member with expertise in i-gel insertion and who entered the operating room immediately before i-gel insertion to blind him to the group assignment

Que mesure l'étude ?

Principaux critères de jugement

Mesure des résultats
Description de la mesure
Délai
EC50 of propofol required for successful i-gel insertion
Délai: During i-gel insertion anticipated up to 1 min
The EC50 of propofol for successful i-gel insertion was determined by a modification of Dixon's up-and-down method. The response of each patient determined the effect-site propofol concentration for the next patient. If the response was deemed 'successful', the next target concentration of propofol was decreased by 0.5 µg mL-1. If the response was deemed a 'failure', the target concentration was increased by the same dose. The process was repeated until the sixth crossover point (success/failure) was obtained.
During i-gel insertion anticipated up to 1 min

Mesures de résultats secondaires

Mesure des résultats
Description de la mesure
Délai
the total dose of propofol infused before i-gel insertion
Délai: During i-gel insertion time anticipated upto 1min
The total amount of propofol infused before i-gel insertion was noted. The insertion time, defined as the time from picking up the i-gel until the initiation of mechanical ventilation.
During i-gel insertion time anticipated upto 1min
the presence/severity of airway trauma after i-gel insertion
Délai: At the time point of removing the i-gel from patient's mouth
After removing the i-gel, airway trauma (defined as any blood staining on the device) was recorded.
At the time point of removing the i-gel from patient's mouth

Collaborateurs et enquêteurs

C'est ici que vous trouverez les personnes et les organisations impliquées dans cette étude.

Les enquêteurs

  • Directeur d'études: Hee Pyung Park, MD PhD, Professor
  • Chercheur principal: Young Cheol Kim, Md PhD, Professor

Publications et liens utiles

La personne responsable de la saisie des informations sur l'étude fournit volontairement ces publications. Il peut s'agir de tout ce qui concerne l'étude.

Dates d'enregistrement des études

Ces dates suivent la progression des dossiers d'étude et des soumissions de résultats sommaires à ClinicalTrials.gov. Les dossiers d'étude et les résultats rapportés sont examinés par la Bibliothèque nationale de médecine (NLM) pour s'assurer qu'ils répondent à des normes de contrôle de qualité spécifiques avant d'être publiés sur le site Web public.

Dates principales de l'étude

Début de l'étude

1 mai 2012

Achèvement primaire (Réel)

1 août 2012

Achèvement de l'étude (Réel)

1 août 2012

Dates d'inscription aux études

Première soumission

24 mars 2014

Première soumission répondant aux critères de contrôle qualité

24 mars 2014

Première publication (Estimation)

27 mars 2014

Mises à jour des dossiers d'étude

Dernière mise à jour publiée (Estimation)

27 mars 2014

Dernière mise à jour soumise répondant aux critères de contrôle qualité

24 mars 2014

Dernière vérification

1 mars 2014

Plus d'information

Ces informations ont été extraites directement du site Web clinicaltrials.gov sans aucune modification. Si vous avez des demandes de modification, de suppression ou de mise à jour des détails de votre étude, veuillez contacter register@clinicaltrials.gov. Dès qu'un changement est mis en œuvre sur clinicaltrials.gov, il sera également mis à jour automatiquement sur notre site Web .

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