Canadian Journal of Anaesthesia

, Volume 47, Issue 3, pp 215–219 | Cite as

Advancement of the mandible facilitates nasal breathing in human subjects sedated with midazolam

  • Yasuko Kawauchi
  • Tsutomu Oshima
  • Satomi Suzuki
  • Yuhji Saitoh
  • Hidenori Toyooka
Reports Of Investigation


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.


Obstructive Sleep Apnea Duty Ratio Nasal Resistance Mandibular Advancement Nasal Breathing 
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.


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.


  1. 1.
    Montravers P, Dureuil B, Demonts JM. Effects of i.v. midazolam on upper airway resistance. Br J Anaesth 1992; 68: 27–31.PubMedCrossRefGoogle Scholar
  2. 2.
    Oshima T, Masaki Y, Toyooka H. Flumazenil antagonizes midazolam-induced airway narrowing during nasal breathing in humans. Br J Anaesth 1999; 82: 698–702.PubMedGoogle Scholar
  3. 3.
    Ferguson KA, Love LL, Ryan CF. Effects of mandibular and tongue protrusion on upper airway size during wakefulness. Am J Respir Crit Care Med 1997; 155: 1748–54.PubMedGoogle Scholar
  4. 4.
    Oshima T, Vazquez JC, Masuda A, Tsai WH, Hajduk E, Remmers JE. Effercts of incremental mandibular protrusion on cross-sectional area of the passive pharynx during medicated sleep in patients with patients with obstructive sleep apnea (OSA). Am J Respir Crit Care Med 1997; 155: A676.Google Scholar
  5. 5.
    Isono S, Tanaka A, Sho Y, Konno A, Nishino T. Advancement of the mandible improves velopharyngeal airway patency. J Appl Physiol 1995; 79: 2132–8.PubMedGoogle Scholar
  6. 6.
    Nishino T, Sugiyama A, Tanaka A, Ishikawa T. Effects of nasal anaesthesia on shift of breathing route in adults. Lancet 1992; 339: 1497–500.PubMedCrossRefGoogle Scholar
  7. 7.
    Nishino T, Kochi T. Effects of sedation produced by thiopentone on responses to nasal occlusion in female adults. Br J Anaesth 1993; 71: 388–92.PubMedCrossRefGoogle Scholar
  8. 8.
    O’Sullivan RA, Hillman DR, Mateljan R, Pantin C, Finucane KE. Mandibular advancement splint: an appliance to treat snoring and obstructive sleep apnea. Am J Respir Crit Care Med 1995; 151: 194–8.PubMedGoogle Scholar
  9. 9.
    Smith PL, Wise RA, Gold AR, Schwartz AR, Permutt S. Upper airway pressure-flow relationships in obstructive sleep apnea. J Appl Physiol 1988; 64: 789–95.PubMedGoogle Scholar
  10. 10.
    Dawson SV, Elliott EA. Wave-speed limitation and expiratory flow — a unifying concept. J Appl Physiol: Respir Environ Exer Physiol 1977; 43: 498–515.Google Scholar
  11. 11.
    Condos R, Norman RG, Krishnasamy I, Peduzzi N, Goldring RM, Rapoport DM. Flow limitation as a noninvasive assessment of residual upper-airway resistance during continuous positive airway pressure therapy of obstructive sleep apnea. Am J Respir Crit Care Med 1994; 150: 475–80.PubMedGoogle Scholar
  12. 12.
    Isono S, Tanaka A, Tagaito Y, Sho Y, Nishino T. Pharyngeal patency in response to advancement of the mandible in obese anesthetized persons. Anesthesiology 1997; 87: 1055–62.PubMedCrossRefGoogle Scholar
  13. 13.
    Reber A, Wetzel SG, Schnabel K, Bongartz G, Frei FJ. Effect of combined mouth closure and chin lift on upper airway dimensions during routine magnetic response imaging in pediatric patients sedated with propofol. Anesthesiology 1999; 90: 1617–23.PubMedCrossRefGoogle Scholar
  14. 14.
    Oshima T, Tsai WH, Hajduk E, Remmers JE. Mandibular protrusion decreases genioglossal EMG during sleep in patients with obstructive sleep apnea. Am J Respir Crit Care Med 1998; 157: A655.Google Scholar

Copyright information

© Canadian Anesthesiologists 2000

Authors and Affiliations

  • Yasuko Kawauchi
    • 1
  • Tsutomu Oshima
    • 2
  • Satomi Suzuki
    • 1
  • Yuhji Saitoh
    • 1
  • Hidenori Toyooka
    • 3
  1. 1.From the Department of Anesthesiology, School of MedicineTokyo Medical and Dental UniversityJapan
  2. 2.Department of TokyoGifu University School of MedicineJapan
  3. 3.Gifu and the Institute of Clinical MedicineUniversity of TsukubaIbarakiJapan

Personalised recommendations