Late response of the upper airway of the rat to inhaled antigen

1990 ◽  
Vol 69 (4) ◽  
pp. 1360-1365 ◽  
Author(s):  
L. J. Xu ◽  
D. H. Eidelman ◽  
J. H. Bates ◽  
J. G. Martin
Keyword(s):  
Time Course ◽  
Airway Resistance ◽  
Upper Airway ◽  
Brown Norway ◽  
Control Group ◽  
Late Response ◽  
Lung Elastance ◽  
Upper Airway Resistance ◽  
Airway Responses ◽  
Peak Value

We studied the magnitude and time course of changes in upper airway resistance (Ruaw) of actively sensitized Brown-Norway rats after aerosol challenge with ovalbumin (OA). Two weeks after sensitization, eight rats were challenged by inhalation of aerosolized OA through the nose. The airway responses of these rats 5-10 h after OA challenge were compared with those of seven animals challenged with saline. Seven of eight test rats had increased Ruaw, and six displayed discrete late responses (LR). Ruaw during expiration was highly alinear so analysis was confined to Ruaw during inspiration (Ruaw,I). The Ruaw,I averaged over 5 h was 1.262 +/- 0.09 (SE) cmH2O.ml-1.s, 2.6 times the value for saline-challenged animals (0.476 +/- 0.143 cmH2O.ml-1.s), and it reached a peak value of 3.454 +/- 0.45 cmH2O.ml-1.s. The time to the peak of the LR was 446 +/- 37.3 min. The duration of the LR in the upper airway was 146 +/- 34.9 min. At the time corresponding to the peak value of Ruaw,I, the lung elastance in the test rats was double the value preceding the peak. Lung elastance was unchanged in the control group. We conclude that inhalation of antigen through the upper airway of the sensitized rat results in a substantial increase in upper airway resistance and a distinct LR. The predominant site of the change in respiratory system resistance is in the upper airway.

391 Upper Airway Resistance Syndrome is associated with high Cyclic Alternating Pattern

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A155-A156
Author(s):  
Luciana Godoy ◽  
Letícia Soster ◽  
Clarissa Bueno ◽  
Sonia Togeiro ◽  
Dalva Poyares ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Upper Airway ◽  
Sleep Fragmentation ◽  
Control Group ◽  
Flow Limitation ◽  
Upper Airway Resistance Syndrome ◽  
Arousal Index ◽  
Upper Airway Resistance ◽  
Cyclic Alternating Pattern ◽  
Cap Rate

Abstract Introduction Upper Airway Resistance Syndrome (UARS) is suspected in individuals with excessive daytime sleepiness, fatigue, and sleep fragmentation associated with increased respiratory effort. UARS can negatively impact daytime function. Conventional polysomnography parameters do not demonstrate significant abnormalities in UARS patients but increase in RERAs and arousal index. Cyclic alternating pattern (CAP) is a periodic electroencephalogram activity of non-REM sleep that expresses a condition of sleep instability. The objective of the study was to compare CAP components between UARS patients and health individuals. Methods Fifteen subjects with UARS and 15 age- and sex- matched controls had their sleep study blinded analyzed. UARS criteria were the presence of sleepiness (Epworth Sleepiness Scale – ESS - ≥ 10) and/or fatigue (Modified Fatigue Impact Scale ≥ 38) associated with an apnea/hypopnea index (AHI) ≤ 5 and a respiratory disturbance index (RDI) > 5 events/hour of sleep, and/or flow limitation in more than 30% of total sleep time. Control group criteria were AHI < 5 events/hour, RDI ≤ 5 events/hour and < 30% of TST with flow limitation and ESS < 10, without sleep, clinical, neurological, or psychiatric disorder. CAP electroencephalogram of both groups was analyzed. Results We found higher CAP rate (p = 0.05) and CAP index in N1 stage (p < 0.001) and in N3 stage (p < 0.001) in UARS patients compared to control group. Considering only CAP phase A1 analysis, UARS patients presented higher CAP rate (p = 0.05) and CAP index in N1 stage (p < 0.001) as well as CAP index in N3 stage (p < 0.001) compared to control group. Considering only CAP phase A2 analysis, UARS patients also presented higher number of CAP in N1 stage (p = 0.05). There was no significant difference for CAP phase A3 between groups. Conclusion Although UARS is associated with high arousal index, we found increase in CAP phase A1 and A2, which do not include necessarily AASM arousals, suggesting not only sleep fragmentation but also sleep instability. Support (if any) Associação Fundo de Incentivo à Pesquisa (AFIP) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).

Partitioning of airway responses to inhaled methacholine in the rat

1987 ◽  
Vol 62 (3) ◽  
pp. 1317-1323 ◽  
Author(s):  
G. U. DiMaria ◽  
C. G. Wang ◽  
J. H. Bates ◽  
R. Guttmann ◽  
J. G. Martin
Keyword(s):  
Airway Resistance ◽  
Upper Airway ◽  
Lower Airway ◽  
Control Value ◽  
Upper Airway Resistance ◽  
Lower Airways ◽  
Airway Responses ◽  
Spontaneously Breathing

We measured the changes in upper and lower airway resistance after inhalation of aerosols of methacholine (MCh) in doubling concentrations (16, 32, 64, and 128 mg/ml) in 11 anesthetized nonintubated spontaneously breathing rats. Upper airway resistance (Ru) increased from a control value of 0.48 +/- 0.04 cmH2O X ml-1 X s (mean +/- SE) to 0.85 +/- 0.15 after 128 mg/ml MCh, whereas lower airway resistance (Rlo) increased from 0.11 +/- 0.03 to 0.21 +/- 0.04. However, there was no correlation between the magnitudes of the changes in Ru and Rlo. In a further seven anesthetized spontaneously breathing rats aerosols of MCh were delivered into the lower airways via a tracheostomy and resulted in increases in Rlo from a control value of 0.20 +/- 0.03 to 0.66 +/- 0.12 after 128 mg/ml MCh. Ru also increased to approximately double its control value. We conclude that inhaled MCh causes narrowing of both Ru and Rlo in the anesthetized rat, the changes in Ru and Rlo are not correlated, and changes in Ru can occur when MCh deposition occurs only in the lower airways.

Motor responses to positive-pressure breathing in the developing opossum

1985 ◽  
Vol 58 (5) ◽  
pp. 1489-1495 ◽  
Author(s):  
J. P. Farber
Keyword(s):  
Airway Resistance ◽  
Upper Airway ◽  
Abdominal Muscle ◽  
Positive Pressure ◽  
Postnatal Life ◽  
Abdominal Muscles ◽  
Upper Airways ◽  
Motor Responses ◽  
Upper Airway Resistance ◽  
Upper Airway Muscles

The suckling opossum exhibits an expiration-phased discharge in abdominal muscles during positive-pressure breathing (PPB); the response becomes apparent, however, only after the 3rd-5th wk of postnatal life. The purpose of this study was to determine whether the early lack of activation represented a deficiency of segmental outflow to abdominal muscles or whether comparable effects were observed in cranial outflows to muscles of the upper airways due to immaturity of afferent and/or supraspinal pathways. Anesthetized suckling opossums between 15 and 50 days of age were exposed to PPB; electromyogram (EMG) responses in diaphragm and abdominal muscles were measured, along with EMG of larynx dilator muscles and/or upper airway resistance. In animals older than approximately 30 days of age, the onset of PPB was associated with a prolonged expiration-phased EMG activation of larynx dilator muscles and/or decreased upper airway resistance, along with expiratory recruitment of the abdominal muscle EMG. These effects persisted as long as the load was maintained. Younger animals showed only those responses related to the upper airway; in fact, activation of upper airway muscles during PPB could be associated with suppression of the abdominal motor outflow. After unilateral vagotomy, abdominal and upper airway motor responses to PPB were reduced. The balance between PPB-induced excitatory and inhibitory or disfacilitory influences from the supraspinal level on abdominal motoneurons and/or spinal processing of information from higher centers may shift toward net excitation as the opossum matures.

The evaluation of physiologic decannulation readiness according to upper airway resistance measurement

2008 ◽  
Vol 139 (4) ◽  
pp. 535-540 ◽  
Author(s):  
Chunli Gao ◽  
Liang Zhou ◽  
Chunsheng Wei ◽  
Matthew R. Hoffman ◽  
Cai Li ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Operating Characteristic ◽  
Upper Airway ◽  
High Sensitivity ◽  
Deep Breathing ◽  
Clinical Criteria ◽  
Receiver Operating Characteristic Curves ◽  
Upper Airway Resistance ◽  
Laryngeal Disease ◽  
Subglottal Pressure

Objective To measure the upper-airway resistance in patients with tracheostomies and determine the value representing decannulation readiness. Subjects and Methods Fifty-six patients with tracheostomies resultant to laryngeal disease participated in this study. Forty patients met clinical criteria for decannulation; 16 did not. Subglottal pressure was measured with a tube connected to the tracheostomy tube, and airflow was monitored simultaneously using a facemask. Upper-airway resistance measurements were recorded during shallow and deep breathing. Results During both shallow and deep breathing, the inspiratory and expiratory resistances were significantly higher for the group unsuitable for decannulation ( P < .0001). The areas under the receiver operating characteristic curves were 0.938 or greater for the four curves, indicating a high sensitivity and specificity of resistance measures for diagnosis. Conclusions Objective measurement of upper-airway resistance during shallow and deep breathing may be a useful parameter in determining decannulation readiness of tracheostomized patients.

Influence of lung volume dependence of upper airway resistance during continuous negative airway pressure

1994 ◽  
Vol 77 (2) ◽  
pp. 840-844 ◽  
Author(s):  
F. Series ◽  
I. Marc
Keyword(s):  
Lung Volume ◽  
Airway Pressure ◽  
Airway Resistance ◽  
Upper Airway ◽  
Random Order ◽  
Pressure Increase ◽  
Nasal Mask ◽  
Upper Airway Resistance ◽  
Volume Dependence ◽  
Negative Airway Pressure

To quantify the contribution of lung volume dependence of upper airway (UA) on continuous negative airway pressure (CNAP)-induced increase in upper airway resistance, we compared the changes in supralaryngeal resistance during an isolated decrease in lung volume and during CNAP in eight normal awake subjects. Inspiratory supralaryngeal resistance was measured at isoflow during four trials, during two CNAP trials where the pressure in a nasal mask was progressively decreased in 3- to 5-cmH2O steps and during two continuous positive extrathoracic pressure (CPEP) trials where the pressure around the chest (in an iron lung) was increased in similar steps. The CNAP and CPEP trials were done in random order. During the CPEP trial, the neck was covered by a rigid collar to prevent compression by the cervical seal of the iron lung. In each subject, resistance progressively increased during the experiments. The increase was linearily correlated with the pressure increase in the iron lung and with the square of the mask pressure during CNAP. There was a highly significant correlation between the rate of rise in resistance between CNAP and CPEP: the steeper the increase in resistance with decreasing lung volume, the steeper the increase in resistance with decreasing airway pressure. Lung volume dependence in UA resistance can account for 61% of the CNAP-induced increase in resistance. We conclude that in normal awake subjects the changes in supralaryngeal resistance induced by CNAP can partly be explained by the lung volume dependence of this resistance.

Arousal and upper airway resistance (UAR)

2002 ◽  
Vol 3 ◽  
pp. S15-S20 ◽  
Author(s):  
Christian Guilleminault ◽  
Dalva Poyares
Keyword(s):  
Airway Resistance ◽  
Upper Airway ◽  
Upper Airway Resistance
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