Abstract
Purpose: To determine how anterior advancement of the mandible (ADM) affects spontaneous breathing through the nasal route in healthy human volunteers sedated with intravenous midazolam.
Methods: In four subjects who exhibited nasal breathing during midazolam sedation (intravenous dose: 0.09 ± 0.02 mg·kg−1, mean±SD), we measured respiratory rate (RR), peak nasal inspiratory airflow rate\(\left( {\dot V_{nlpeak} } \right)\), peak nasal expiratory airflow rate\(\left( {\dot V_{nEpeak} } \right)\), duty ratio (Ti/Ttot) and nasal resistance (Rn) before and after ADM. Nasal resistance was calculated by dividing the difference between nasal mask and oropharyngeal pressure by airflow rate at peak nasal inspiratory airflow.
Results: The RR,\(\left( {\dot V_{nlpeak} } \right)\), and\(\left( {\dot V_{nEpeak} } \right)\) increased following ADM (P<0.001, respectively). On the contrary, Ti/Ttot decreased after ADM (P<0.001). Consequently, ADM decreased Rn from 30.4±40.8 to 5.0±5.6 (cmH2O·1−1·sec−1)(mean±SD) (P<0.001). In these four subjects, no respiratory airflow was observed through the oral route before and after ADM.
Conclusion: Advancement of the mandible decreases nasal resistance, thereby facilitating spontaneous breathing through the nasal route in normal humans sedated with midazolam.
Résumé
Objectif: Déterminer l’effet de la mobilisation antérieure de la mandibule (MM) sur la respiration nasale spontanée chez des volontaires sains qui reçoivent du midazolam par voie intraveineuse.
Méthode: Chez quatre sujets qui présentaient une respiration nasale pendant la sédation avec du midazolam (dose intraveineuse: 0,09±0,02 mg·kg−1, moyenne±écart type), nous avons mesuré la fréquence respiratoire (FR), la vitesse maximale de l’écoulement d’air inspiratoire nasal\(\left( {\dot V_{maxln} } \right)\), la vitesse maximale de l’écoulement d’air expiratoire nasal\(\left( {\dot V_{maxEn} } \right)\), le coefficient de durée (Ti/Ttot) et la résistance nasale (Rn) avant et après la MM. On obtient la résistance nasale en divisant la pression différentielle masque nasal-oropharynx par la vitesse d’écoulement de l’air lors de l’inspiration nasale maximale.
Résultats: La FR, la\(\left( {\dot V_{maxln} } \right)\), et la\(\left( {\dot V_{maxEn} } \right)\) ont augmenté après la MM (P<0,001, respectivement). Par contre, Ti/Ttot a diminué après la MM (P<0,001). En conséquence, la MM a réduit la Rn de 30,4±40,8 à 5,0±5,6 (cmH2O·l−1·{−1) (moyenne±écart type) (P < 0,001). Chez les quatre sujets, aucun écoulement de l’air par voie orale n’a été noté avant et après la MM.
Conclusion: La mobilisation antérieure de la mandibule réduit la résistance nasale et facilite ainsi la respiration nasale spontanée chez des humains normaux qui reçoivent du midazolam.
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Kawauchi, Y., Oshima, T., Suzuki, S. et al. Advancement of the mandible facilitates nasal breathing in human subjects sedated with midazolam. ja]Can J Anaesth 47, 215–219 (2000). https://doi.org/10.1007/BF03018915
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DOI: https://doi.org/10.1007/BF03018915