TY - JOUR
T1 - Upper airway extraluminal tissue pressure fluctuations during breathing in rabbits
AU - Kairaitis, Kristina
AU - Parikh, Radha
AU - Stavrinou, Rosie
AU - Garlick, Sarah
AU - Kirkness, Jason P.
AU - Wheatley, John R.
AU - Amis, Terence C.
PY - 2003/10/1
Y1 - 2003/10/1
N2 - Transmural pressure at any level in the upper airway is dependent on the difference between intraluminal airway and extraluminal tissue pressure (ETP). We hypothesized that ETP would be influenced by topography, head and neck position, resistive loading, and stimulated breathing. Twenty-eight male, New Zealand White, anesthetized, spontaneously breathing rabbits breathed via a face mask with attached pneumotachograph to measure airflow and pressure transducer to monitor mask pressure. Tidal volume was measured via integration of the airflow signal. ETP was measured with a pressure transducer-tipped catheter inserted in the tissues of the lateral (ETPlat, n = 28) and anterior (ETPant, n = 21) pharyngeal wall. Head position was controlled at 30, 50, or 70°, and the effect of addition of an external resistor, brief occlusion, or stimulated breathing was examined. Mean ETPlat was ∼0.7 cmH2O greater than mean ETPant when adjusted for degree of head and neck flexion (P < 0.05). Mean, maximum, and minimum ETP values increased significantly by 0.7-0.8 cmH2O/20° of head and neck flexion when adjusted for site of measurement (P < 0.0001). The main effect of resistive loading and occlusion was an increase in the change in ETPlat (maximum - minimum ETPlat) and change in ETPant at all head and neck positions (P < 0.05). Mean ETPlat and ETPant increased with increasing tidal volume at head and neck position of 30° (all P < 0.05). In conclusion, ETP was nonhomogeneously distributed around the upper airway and increased with both increasing head and neck flexion and increasing tidal volume. Brief airway occlusion increased the size of respiratory-related ETP fluctuations in upper airway ETP.
AB - Transmural pressure at any level in the upper airway is dependent on the difference between intraluminal airway and extraluminal tissue pressure (ETP). We hypothesized that ETP would be influenced by topography, head and neck position, resistive loading, and stimulated breathing. Twenty-eight male, New Zealand White, anesthetized, spontaneously breathing rabbits breathed via a face mask with attached pneumotachograph to measure airflow and pressure transducer to monitor mask pressure. Tidal volume was measured via integration of the airflow signal. ETP was measured with a pressure transducer-tipped catheter inserted in the tissues of the lateral (ETPlat, n = 28) and anterior (ETPant, n = 21) pharyngeal wall. Head position was controlled at 30, 50, or 70°, and the effect of addition of an external resistor, brief occlusion, or stimulated breathing was examined. Mean ETPlat was ∼0.7 cmH2O greater than mean ETPant when adjusted for degree of head and neck flexion (P < 0.05). Mean, maximum, and minimum ETP values increased significantly by 0.7-0.8 cmH2O/20° of head and neck flexion when adjusted for site of measurement (P < 0.0001). The main effect of resistive loading and occlusion was an increase in the change in ETPlat (maximum - minimum ETPlat) and change in ETPant at all head and neck positions (P < 0.05). Mean ETPlat and ETPant increased with increasing tidal volume at head and neck position of 30° (all P < 0.05). In conclusion, ETP was nonhomogeneously distributed around the upper airway and increased with both increasing head and neck flexion and increasing tidal volume. Brief airway occlusion increased the size of respiratory-related ETP fluctuations in upper airway ETP.
KW - Head and neck flexion
KW - Hyperpnea
KW - Resistive breathing
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U2 - 10.1152/japplphysiol.00432.2003
DO - 10.1152/japplphysiol.00432.2003
M3 - Article
C2 - 12832428
AN - SCOPUS:0141790405
SN - 0161-7567
VL - 95
SP - 1560
EP - 1566
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 4
ER -