scholarly journals The influence of end-expiratory lung volume on measurements of pharyngeal collapsibility

2010 ◽  
Vol 108 (2) ◽  
pp. 445-451 ◽  
Author(s):  
Robert L. Owens ◽  
Atul Malhotra ◽  
Danny J. Eckert ◽  
David P. White ◽  
Amy S. Jordan
Keyword(s):  
Lung Volume ◽  
Airway Pressure ◽  
Upper Airway ◽  
Similar Amount ◽  
Volume Changes ◽  
Pressure Drops ◽  
Control Subjects ◽  
Obstructive Sleep ◽  
Upper Airway Collapsibility ◽  
And Control

Changes in end-expiratory lung volume (EELV) affect upper airway stability. The passive pharyngeal critical pressure (Pcrit), a measure of upper airway collapsibility, is determined using airway pressure drops. The EELV change during these drops has not been quantified and may differ between obese obstructive sleep apnea (OSA) patients and controls. Continuous positive airway pressure (CPAP)-treated OSA patients and controls were instrumented with an epiglottic catheter, magnetometers (to measure change in EELV), and a nasal mask/pneumotachograph. Subjects slept supine in a head-out plastic chamber in which the extrathoracic pressure could be lowered (to raise EELV) while on nasal CPAP. The magnitude of EELV change during Pcrit measurement (sudden reductions of CPAP for 3–5 breaths each minute) was assessed at baseline and with EELV increased ∼500 ml. Fifteen OSA patients and 7 controls were studied. EELV change during Pcrit measurement was rapid and pressure dependent, but similar in OSA and control subjects (74 ± 36 and 59 ± 24 ml/cmH2O respectively, P = 0.33). Increased lung volume (mean +521 ml) decreased Pcrit by a similar amount in OSA and control subjects (−3.1 ± 1.7 vs. −3.9 ± 1.9 cmH2O, P = 0.31). Important lung volume changes occur during passive Pcrit measurement. However, on average, there is no difference in lung volume change for a given CPAP change between obese OSA subjects and controls. Changes in lung volume alter Pcrit substantially. This work supports a role for lung volume in the pathogenesis of OSA, and lung volume changes should be a consideration during assessment of pharyngeal mechanics.

scholarly journals Upper airway collapsibility and patterns of flow limitation at constant end-expiratory lung volume

2012 ◽  
Vol 113 (5) ◽  
pp. 691-699 ◽  
Author(s):  
Robert L. Owens ◽  
Bradley A. Edwards ◽  
Scott A. Sands ◽  
James P. Butler ◽  
Danny J. Eckert ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Lung Volume ◽  
Upper Airway ◽  
Inspiratory Pressure ◽  
Flow Limitation ◽  
Pressure Drops ◽  
Obstructive Sleep ◽  
Airway Collapsibility ◽  
Measure Change ◽  
Upper Airway Collapsibility

The passive pharyngeal critical closing pressure (Pcrit) is measured using a series of pressure drops. However, pressure drops also lower end-expiratory lung volume (EELV), which independently affects Pcrit. We describe a technique to measure Pcrit at a constant EELV. Continuous positive airway pressure (CPAP)-treated obstructive sleep apnea (OSA) patients and controls were instrumented with an epiglottic catheter, magnetometers (to measure change in EELV), and nasal mask/pneumotachograph and slept supine on nasal CPAP. Pcrit was measured in standard fashion and using our novel “biphasic technique” in which expiratory pressure only was lowered for 1 min before the inspiratory pressure was dropped; this allowed EELV to decrease to the drop level before performing the pressure drop. Seven OSA and three controls were studied. The biphasic technique successfully lowered EELV before the inspiratory pressure drop. Pcrit was similar between the standard and biphasic techniques (−0.4 ± 2.6 vs. −0.6 ± 2.3 cmH2O, respectively, P = 0.84). Interestingly, we noted three different patterns of flow limitation: 1) classic Starling resistor type: flow fixed and independent of downstream pressure; 2) negative effort dependence within breaths: substantial decrease in flow, sometimes with complete collapse, as downstream pressure decreased; and 3) and negative effort dependence across breaths: progressive reductions in peak flow as respiratory effort on successive breaths increased. Overall, EELV changes do not influence standard passive Pcrit measurements if breaths 3–5 of pressure drops are used. These results also highlight the importance of inspiratory collapse in OSA pathogenesis. The cause of negative effort dependence within and across breaths is not known and requires further study.

scholarly journals Upper airway collapsibility measured using a simple wakefulness test closely relates to the pharyngeal critical closing pressure during sleep in obstructive sleep apnea

SLEEP ◽  
2019 ◽  
Vol 42 (7) ◽  
Author(s):  
Amal M Osman ◽  
Jayne C Carberry ◽  
Peter G R Burke ◽  
Barbara Toson ◽  
Ronald R Grunstein ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Airway Pressure ◽  
Pressure Sensors ◽  
Upper Airway ◽  
Apnea Hypopnea Index ◽  
Pharyngeal Airway ◽  
Obstructive Sleep ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility

AbstractStudy ObjectivesA collapsible or crowded pharyngeal airway is the main cause of obstructive sleep apnea (OSA). However, quantification of airway collapsibility during sleep (Pcrit) is not clinically feasible. The primary aim of this study was to compare upper airway collapsibility using a simple wakefulness test with Pcrit during sleep.MethodsParticipants with OSA were instrumented with a nasal mask, pneumotachograph and two pressure sensors, one at the choanae (PCHO), the other just above the epiglottis (PEPI). Approximately 60 brief (250 ms) pulses of negative airway pressure (~ –12 cmH2O at the mask) were delivered in early inspiration during wakefulness to measure the upper airway collapsibility index (UACI). Transient reductions in the continuous positive airway pressure (CPAP) holding pressure were then performed during sleep to determine Pcrit. In a subset of participants, the optimal number of replicate trials required to calculate the UACI was assessed.ResultsThe UACI (39 ± 24 mean ± SD; range = 0%–87%) and Pcrit (–0.11 ± 2.5; range: –4 to +5 cmH2O) were quantified in 34 middle-aged people (9 female) with varying OSA severity (apnea–hypopnea index range = 5–92 events/h). The UACI at a mask pressure of approximately –12 cmH2O positively correlated with Pcrit (r = 0.8; p < 0.001) and could be quantified reliably with as few as 10 replicate trials. The UACI performed well at discriminating individuals with subatmospheric Pcrit values [receiver operating characteristic curve analysis area under the curve = 0.9 (0.8–1), p < 0.001].ConclusionsThese findings indicate that a simple wakefulness test may be useful to estimate the extent of upper airway anatomical impairment during sleep in people with OSA to direct targeted non-CPAP therapies for OSA.

Effects of continuous negative airway pressure-related lung deflation on upper airway collapsibility

1993 ◽  
Vol 75 (3) ◽  
pp. 1222-1225 ◽  
Author(s):  
F. Series ◽  
I. Marc
Keyword(s):  
Lung Volume ◽  
Airway Pressure ◽  
Linear Regression Analysis ◽  
Upper Airway ◽  
Flow Limitation ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility ◽  
Lung Deflation ◽  
The Relationship ◽  
Negative Airway Pressure

Continuous negative airway pressure (CNAP) causes a decrease in lung volume, which is known to increase upper airway resistance by itself. We studied how this lung volume change could modify upper airway collapsibility with five normal awake subjects. In a first trial, pressure in a nasal mask (Pm) was progressively decreased in 3- to 5-cmH2O steps (CNAP). In a second trial, changes in lung volumes resulting from CNAP were prevented by applying simultaneously an equivalent level of negative extrathoracic pressure into a poncho-type respirator [isovolumetric CNAP (CNAPisovol)]. For each trial, we examined the relationship between the maximal inspiratory airflow of each flow-limited inspiratory cycle and the corresponding Pm by least-squares linear regression analysis and determined the critical pressure. We also determined the Pm threshold corresponding to the first Pm value below which flow limitation occurred. Flow limitation was observed in each subject with CNAP but in only two subjects with CNAPisovol. In these two subjects, the Pm threshold values were -20 and -9 cmH2O with CNAP and -39 and -16 cmH2O with CNAPisovol, respectively. Critical pressures for the same two subjects were -161 and -96 cmH2O with CNAP and -202 and -197 cmH2O with CNAPisovol, respectively. We conclude that CNAP-induced decreases in lung volume increase upper airway collapsibility.

scholarly journals Desipramine improves upper airway collapsibility and reduces OSA severity in patients with minimal muscle compensation

2016 ◽  
Vol 48 (5) ◽  
pp. 1340-1350 ◽  
Author(s):  
Luigi Taranto-Montemurro ◽  
Scott A. Sands ◽  
Bradley A. Edwards ◽  
Ali Azarbarzin ◽  
Melania Marques ◽  
...  
Keyword(s):  
Crossover Trial ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
Sleep Apnoea ◽  
Double Blind ◽  
Healthy Humans ◽  
Dilator Muscle ◽  
Obstructive Sleep ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility

We recently demonstrated that desipramine reduces the sleep-related loss of upper airway dilator muscle activity and reduces pharyngeal collapsibility in healthy humans without obstructive sleep apnoea (OSA). The aim of the present physiological study was to determine the effects of desipramine on upper airway collapsibility and apnoea–hypopnea index (AHI) in OSA patients.A placebo-controlled, double-blind, randomised crossover trial in 14 OSA patients was performed. Participants received treatment or placebo in randomised order before sleep. Pharyngeal collapsibility (critical collapsing pressure of the upper airway (Pcrit)) and ventilation under both passive (V′0,passive) and active (V′0,active) upper airway muscle conditions were evaluated with continuous positive airway pressure (CPAP) manipulation. AHI was quantified off CPAP.Desipramine reduced activePcrit(median (interquartile range) −5.2 (4.3) cmH2O on desipramineversus−1.9 (2.7) cmH2O on placebo; p=0.049) but not passivePcrit(−2.2 (3.4)versus−0.7 (2.1) cmH2O; p=0.135). A greater reduction in AHI occurred in those with minimal muscle compensation (defined asV′0,active−V′0,passive) on placebo (r=0.71, p=0.009). The reduction in AHI was driven by the improvement in muscle compensation (r=0.72, p=0.009).In OSA patients, noradrenergic stimulation with desipramine improves pharyngeal collapsibility and may be an effective treatment in patients with minimal upper airway muscle compensation.

scholarly journals Upper Airway Collapsibility During REM Sleep in Children with the Obstructive Sleep Apnea Syndrome

SLEEP ◽  
2009 ◽  
Vol 32 (9) ◽  
pp. 1173-1181 ◽  
Author(s):  
Jingtao Huang ◽  
Laurie R. Karamessinis ◽  
Michelle E. Pepe ◽  
Stephen M. Glinka ◽  
John M. Samuel ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Obstructive Sleep Apnea Syndrome ◽  
Rem Sleep ◽  
Sleep Apnea Syndrome ◽  
Upper Airway ◽  
Obstructive Sleep ◽  
Airway Collapsibility ◽  
Apnea Syndrome ◽  
Upper Airway Collapsibility

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.

scholarly journals A Detection and Therapeutic Device to Overcome Sleep Apnea in Infants

2020 ◽  
Vol 2 (1) ◽  
pp. 35
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Airway Pressure ◽  
Upper Airway ◽  
Periodic Breathing ◽  
Breathing Patterns ◽  
Efficient System ◽  
Pressure Therapy ◽  
Obstructive Sleep ◽  
Upper Airway Structure

Among the various sleep-disordered breathing patterns infant’s experience, like periodic breathing, premature apnea, obstructive sleep apnea, has been considered a major cause of concern. Upper airway structure, mechanics of the pulmonary system, etc., are a few reasons why the infants are vulnerable to obstructive sleep-disordered. An imbalance in the viscoelastic properties of the pharynx, dilators, and pressure can lead to airway collapse. A low level of oxygen in blood or hypoxemia is considered a characteristic in infants with severe OSA. Invasive treatments like nasopharyngeal tubes, continuous positive airway pressure (CPAP), or tracheostomy are found to be helpful in most cases where infants experience sleep apnea. This paper proposes an efficient system for monitoring obstructive sleep apnea in infants on a long-term basis, and if any anomaly is detected, the device provides Continuous Airway Pressure therapy until the abnormality is normalized.

scholarly journals A frequent phenotype for paediatric sleep apnoea: short lingual frenulum

2016 ◽  
Vol 2 (3) ◽  
pp. 00043-2016 ◽  
Author(s):  
Christian Guilleminault ◽  
Shehlanoor Huseni ◽  
Lauren Lo
Keyword(s):  
Clinical Investigation ◽  
Upper Airway ◽  
Sleep Apnoea ◽  
Obstructive Sleep Apnoea Syndrome ◽  
Systematic Screening ◽  
Obstructive Sleep ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility ◽  
Oral Anatomy ◽  
Symptoms And Signs

A short lingual frenulum has been associated with difficulties in sucking, swallowing and speech. The oral dysfunction induced by a short lingual frenulum can lead to oral-facial dysmorphosis, which decreases the size of upper airway support. Such progressive change increases the risk of upper airway collapsibility during sleep.Clinical investigation of the oral cavity was conducted as a part of a clinical evaluation of children suspected of having sleep disordered breathing (SDB) based on complaints, symptoms and signs. Systematic polysomnographic evaluation followed the clinical examination. A retrospective analysis of 150 successively seen children suspected of having SDB was performed, in addition to a comparison of the findings between children with and without short lingual frenula.Among the children, two groups of obstructive sleep apnoea syndrome (OSAS) were found: 1) absence of adenotonsils enlargement and short frenula (n=63); and 2) normal frenula and enlarged adenotonsils (n=87). Children in the first group had significantly more abnormal oral anatomy findings, and a positive family of short frenulum and SDB was documented in at least one direct family member in 60 cases.A short lingual frenulum left untreated at birth is associated with OSAS at later age, and a systematic screening for the syndrome should be conducted when this anatomical abnormality is recognised.

Sign in / Sign up

Export Citation Format

Share Document