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Canadian Journal of Anaesthesia

, Volume 45, Issue 1, pp 23–27 | Cite as

The laryngeal mask airway reduces blood flow in the common carotid artery bulb

  • Sally-Ann Colbert
  • Deirdre M. Ohanlon
  • Fidelma Flanagan
  • Rory Page
  • Denis C. Moriarty
Reports of Investigation

Abstract

Purpose

The introduction of the laryngeal mask airway (LMA) has had a major impact on anaesthetic practice in the last ten years. Previous authors have demonstrated pressures equivalent to mean arterial blood pressure within the cuff of the LMA. This study examined the effects of cuff inflation on the cross sectional area, flow and velocity of blood flow at the level of the carotid sinus.

Methods

Seventeen patients scheduled to have LMAs inserted as part of routine anaesthetic management were recruited into the study. Measurements of the common carotid artery bulb area, peak velocity and blood flow were performed upon LMA cuff inflation and deflation using a 5 MHz pulse wave Doppler probe.

Results

Deflation of the cuff resulted in an increase in the cross sectional area (from 0.58 ± 0.05 to 0.64 ± 0.04 cm2;P < 0.005), an increase in blood flow (from 65.6 ± 5.6 to 73.9 ± 5.6 cm3· sec−1; P < 0.05) and a slight but non significant increase in velocity of blood flow.

Conclusion

This study demonstrates that inflation of the cuff on the LMA results in a decrease in carotid bulb cross sectional area which results in a decrease in blood flow.

Keywords

Carotid Artery Laryngeal Mask Airway Carotid Sinus Cuff Inflation Intracuff Pressure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Résumé

Objectif

Au cours des dix dernières années, l’introduction du masque laryngé (ML) a eu un impact considérable sur la pratique de l’anesthésie. Certains auteurs ont déjà démontré des valeurs de pression interne de la manchette du ML équivalentes à la pression artérielle moyenne. Cette étude examine les effets de l’insufflation de la manchette sur la surface transversale du sinus carotidien et sur le débit et la vélocité du sang à ce niveau.

Méthodes

Dix-sept patients programmés pour l’insertion d’un ML au cours d’une anesthésie normale ont participé à l’étude. Des mesures avec une sonde Doppler utilisant une onde puisée de 5 MHz de la surface du bulbe carotidien, de la vélocité de pointe et du débit sanguin ont été effectuées au moment du gonflement et du dégonflement de la manchette.

Résultats

Le dégonflement de la manchette a provoqué une augmentation de la surface sagittale (de 0,58 ± 0,05 à 0,64 ± 0,04 cm2;P < 0,005), une augmentation du débit sanguin (de 65,6 ± 5,6 à 73,9 ± 0,56 cm3· s−1 ; P < 0,05) et une légère augmentation non significative de la vélocité du flot sanguin.

Conclusion

Cette étude montre que le gonflement de la manchette du ML produit une baisse de la surface transversale du bulbe carotidien et une baisse du débit sanguin.

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Copyright information

© Canadian Anesthesiologists 1998

Authors and Affiliations

  • Sally-Ann Colbert
    • 1
  • Deirdre M. Ohanlon
    • 3
  • Fidelma Flanagan
    • 2
  • Rory Page
    • 1
  • Denis C. Moriarty
    • 1
  1. 1.Department of AnaesthesiaThe Mater Misericordiae HospitalDublin 7Ireland
  2. 2.Department of RadiologyThe Mater Misericordiae HospitalDublin 7Ireland
  3. 3.Department of SurgeryThe Mater Misericordiae HospitalDublin 7Ireland

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