Effects of negative upper airway pressure on pattern of breathing in sleeping infants

1989 ◽  
Vol 66 (4) ◽  
pp. 1599-1605 ◽  
Author(s):  
B. T. Thach ◽  
A. P. Menon ◽  
G. L. Schefft
Keyword(s):  
Tidal Volume ◽  
Airway Pressure ◽  
Upper Airway ◽  
Face Mask ◽  
Inhibitory Effect ◽  
Lower Airway ◽  
Quiet Sleep ◽  
Reflex Mechanism ◽  
Inspiratory Muscles ◽  
Reflex Latency

Negative upper airway (UAW) pressure inhibits diaphragm inspiratory activity in animals, but there is no direct evidence of this reflex in humans. Also, little is known regarding reflex latency or effects of varying time of stimulation during the breathing cycle. We studied effects of UAW negative pressure on inspiratory airflow and respiratory timing in seven tracheostomized infants during quiet sleep with a face mask and syringe used to produce UAW suction without changing lower airway pressure. Suction trials lasted 2–3 s. During UAW suction, mean and peak inspiratory airflow as well as tidal volume was markedly reduced (16–68%) regardless of whether stimulation occurred in inspiration or expiration. Reflex latency was 42 +/- 3 ms. When suction was applied during inspiration or late expiration, the inspiration and the following expiration were shortened. In contrast, suction applied during midexpiration prolonged expiration and tended to prolong inspiration. The changes in flow, tidal volume, and timing indicate a marked inhibitory effect of UAW suction on thoracic inspiratory muscles. Such a reflex mechanism may function in preventing pharyngeal collapse by inspiratory suction pressure.

Influence of upper airway negative pressure reflex on response to airway occlusion in sleeping infants

1989 ◽  
Vol 67 (2) ◽  
pp. 749-755 ◽  
Author(s):  
B. T. Thach ◽  
G. L. Schefft ◽  
D. L. Pickens ◽  
A. P. Menon
Keyword(s):  
Upper Airway ◽  
Inspiratory Pressure ◽  
Reflex Response ◽  
Lower Airway ◽  
Pressure Waveform ◽  
Inspiratory Time ◽  
Quiet Sleep ◽  
Airway Occlusion ◽  
Inspiratory Muscles ◽  
Airway Reflex

Artificially produced upper airway suction inhibits the diaphragm in animals and infants; however, the effects of spontaneously generated suction in humans are unknown. We studied nine tracheostomized infants because separation of the upper from the lower airway allowed us to channel suction created by an occluded inspiratory effort to both upper and lower airways (upper + lower airway occlusions) or to the lower airway only (lower airway occlusion). The tracheostomy airway was briefly occluded at end expiration during quiet sleep. In upper + lower airway occlusions, peak airway pressure of the first occluded breath was less negative and rate of pressure decrease slower than that of lower airway occlusions, indicating that upper airway suction inhibits thoracic inspiratory muscles. The threshold for this response was less than or equal to 4 cmH2O suction pressure. The effect on inspiratory time was variable. A decrease in slope of the inspiratory pressure waveform occurring at approximately 0.12 s after inspiration onset was more marked in upper + lower airway occlusions. We conclude that infants have an upper airway reflex response to inspiratory pressure that alters not only the peak and slope but also the shape of the inspiratory pressure waveform.

Comparison of arousal responses to tracheal and face mask occlusions in sleeping newborn piglets

1992 ◽  
Vol 72 (6) ◽  
pp. 2482-2486 ◽  
Author(s):  
K. J. Barrington ◽  
R. G. Allen
Keyword(s):  
Oxygen Saturation ◽  
Potential Role ◽  
Arterial Oxygen Saturation ◽  
Upper Airway ◽  
Face Mask ◽  
Arterial Oxygen ◽  
Active Sleep ◽  
Quiet Sleep ◽  
Tracheal Occlusion ◽  
Newborn Piglets

The arousal responses after occlusion of the airway at the mid-trachea were compared with the responses after occlusion of the airway in a face mask in chronically instrumented 3- to 5-day-old piglets. For each site of occlusion arousal latency was significantly longer from active sleep than from quiet sleep. There was a significant increase in the frequency of early arousals after face mask occlusions compared with tracheal occlusions in both sleep states. During quiet sleep the frequency of arousal by 1 s after occlusion was 0.55 with face mask occlusions compared with 0.28 with tracheal occlusion (P less than 0.01). During active sleep the frequency of arousal by 3 s after a face mask occlusion was 0.32 compared with 0.08 after tracheal occlusion (P less than 0.05). Arousal from quiet sleep occurred before changes in arterial oxygen saturation. During active sleep mean saturation at arousal was not different between face mask and tracheal occlusions. Exposure of the upper airway to the pressures generated during airway occlusions results in earlier arousal in both quiet and active sleep, indicating a potential role for upper airway mechanoreceptors in initiating arousal in the newborn piglet.

Decrease in lung volume-related feedback enhances laryngeal reflexes to negative pressure

1992 ◽  
Vol 73 (3) ◽  
pp. 832-836 ◽  
Author(s):  
S. Zhang ◽  
O. P. Mathew
Keyword(s):  
Lung Volume ◽  
Negative Pressure ◽  
Upper Airway ◽  
Pressure Change ◽  
Inspiratory Flow ◽  
Lower Airway ◽  
Excitatory Effect ◽  
Peak Inspiratory Flow ◽  
Inspiratory Muscles ◽  
Pressure Pulses

Negative pressure applied to the upper airway has an excitatory effect on the activity of upper airway muscles and an inhibitory effect on thoracic inspiratory muscles. The role of lung volume feedback in this response was investigated in 10 anesthetized spontaneously breathing adult rabbits. To alter lung volume feedback, the lower airway was exposed to SO2 (250 ppm for 15 min), thereby blocking slowly adapting receptors (SARs). Negative pressure pulses (5, 10, and 20 cmH2O, 300-ms duration) were applied to the functionally isolated upper airway before and after SAR blockade. Tracheal airflow and electromyogram (EMG) of the genioglossus and alae nasi were recorded. Peak EMG, peak inspiratory flow, tidal volume, and respiratory timing of control breaths (3 breaths immediately preceding test) and test breaths were determined. Analysis of variance was used to determine the significance of the effects. Negative pressure pulses increased peak EMG of genioglossus and alae nasi and inspiratory duration and decreased peak inspiratory flow. These effects were larger after SAR blockade. We conclude that a decrease in volume feedback from the lung augments the response to upper airway pressure change.

Neonatal mannequin comparison of the Upright self-inflating bag and snap-fit mask versus standard resuscitators and masks: leak, applied load and tidal volumes

2017 ◽  
Vol 103 (6) ◽  
pp. F562-F566 ◽  
Author(s):  
Anthony Richard Rafferty ◽  
Lucy Johnson ◽  
Peter G Davis ◽  
Jennifer Anne Dawson ◽  
Marta Thio ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Airway Pressure ◽  
Applied Load ◽  
Face Mask ◽  
The Other ◽  
Mask Ventilation ◽  
Additional Load ◽  
The Face

ObjectiveNeonatal mask ventilation is a difficult skill to acquire and maintain. Mask leak is common and can lead to ineffective ventilation. The aim of this study was to determine whether newly available neonatal self-inflating bags and masks could reduce mask leak without additional load being applied to the face.DesignForty operators delivered 1 min episodes of mask ventilation to a mannequin using the Laerdal Upright Resuscitator, a standard Laerdal infant resuscitator (Laerdal Medical) and a T-Piece Resuscitator (Neopuff), using both the Laerdal snap-fit face mask and the standard Laerdal size 0/1 face mask (equivalent sizes). Participants were asked to use pressure sufficient to achieve ‘appropriate’ chest rise. Leak, applied load, airway pressure and tidal volume were measured continuously. Participants were unaware that load was being recorded.ResultsThere was no difference in mask leak between resuscitation devices. Leak was significantly lower when the snap-fit mask was used with all resuscitation devices, compared with the standard mask (14% vs 37% leak, P<0.01). The snap-fit mask was preferred by 83% of participants. The device-mask combinations had no significant effect on applied load.ConclusionsThe Laerdal Upright Resuscitator resulted in similar leak to the other resuscitation devices studied, and did not exert additional load to the face and head. The snap-fit mask significantly reduced overall leak with all resuscitation devices and was the mask preferred by participants.

Effect of sleep state and hypercapnia on alae nasi and diaphragm EMGs in preterm infants

1983 ◽  
Vol 54 (6) ◽  
pp. 1590-1596 ◽  
Author(s):  
W. A. Carlo ◽  
R. J. Martin ◽  
E. F. Abboud ◽  
E. N. Bruce ◽  
K. P. Strohl
Keyword(s):  
Tidal Volume ◽  
Preterm Infants ◽  
Upper Airway ◽  
Preterm Neonates ◽  
Emg Activity ◽  
Sleep State ◽  
Quiet Sleep ◽  
Airway Patency ◽  
Temporal Relationships ◽  
End Tidal

A coordinated activation of upper airway and chest wall muscles may be crucial in maintaining airway patency and ventilation. The alae nasi (AN) and diaphragm (DIA) electromyograms (EMG) were recorded with surface electrodes in 17 unsedated healthy preterm infants during both active (AS) and quiet sleep (QS). Airflow was measured via a nasal mask pneumotachograph and integrated to obtain tidal volume. Studies were performed during inhalation of room air and mixtures of 2 and 4% CO2 in air. In room air, phasic AN EMG accompanied 45 +/- 7% of breaths during AS compared with 14 +/- 5% of breaths during QS (P less than 0.001); however, with inhalation of 4% CO2 the incidence of AN EMG increased to comparable levels in both sleep states. During room air breathing onset of AN EMG preceded that of the DIA EMG and inspiratory airflow by 41 +/- 8 ms (P less than 0.01) and 114 +/- 29 ms (P less than 0.05), respectively. Peak AN activity preceded peak DIA activity by 191 +/- 36 ms (P less than 0.01). Alteration in sleep state or increasing chemical drive did not significantly alter these temporal relationships. Nevertheless, with each increase in end-tidal CO2, peak DIA EMG and tidal volume increased while peak AN EMG only showed a consistent increase during 4% CO2 inhalation. We conclude that although there exists a mechanism that temporally coordinates AN and DIA activation, the amount of AN EMG activity with each breath is not clearly correlated with DIA activation, which may contribute to the high incidence of respiratory dysrhythmias in preterm neonates.

Changes in respiratory activity induced by mastication in humans

1992 ◽  
Vol 72 (2) ◽  
pp. 779-786 ◽  
Author(s):  
G. A. Fontana ◽  
T. Pantaleo ◽  
F. Bongianni ◽  
F. Cresci ◽  
L. Viroli ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Respiratory Activity ◽  
Minute Ventilation ◽  
Respiratory Rhythm ◽  
Upper Airway ◽  
Muscular Activity ◽  
Electromyographic Activity ◽  
Complex Interactions ◽  
Inspiratory Muscles ◽  
Response To Exercise

We studied the influence of mastication on respiratory activity in nine healthy volunteers who were requested to masticate a 5-g chewing gum bolus at a spontaneous rate (SR) for 5 min and “at the maximum possible rate” (MPR) for 1 min. Significant increases in respiratory frequency were induced by SR mastication due to a decrease in both the inspiratory and expiratory time. Tidal volume displayed slight nonsignificant decreases, but minute ventilation and mean inspiratory flow significantly increased. The duty cycle (TI/TT) did not change significantly. Total airway resistance significantly increased. Both peak and rate of rise of the integrated electromyographic activity of inspiratory muscles presented marked increases, accompanied by the appearance of a low level of tonic muscular activity. Similar but more intense effects on respiratory activity were induced by MPR mastication; in addition, a significant decrease in tidal volume and a significant increase in TI/TT were observed. Rhythmic handgrip exercise performed at metabolic rates comparable to those attained during SR or MPR mastication induced similar changes in the drive and time components of the breathing pattern, although accompanied respectively by nonsignificant or significant increases in tidal volume. Furthermore, the frequency of SR mastication significantly entrained the respiratory rhythm. The results suggest that mastication-induced hyperpnea does not merely represent a ventilatory response to exercise but also reflects complex interactions between respiratory and nonrespiratory functions of the upper airway and chest wall muscles.

Time of application of negative pressure pulses and upper airway muscle activity

1989 ◽  
Vol 67 (1) ◽  
pp. 366-370 ◽  
Author(s):  
D. L. Woodall ◽  
J. A. Hokanson ◽  
O. P. Mathew
Keyword(s):  
Negative Pressure ◽  
Upper Airway ◽  
Inhibitory Effect ◽  
Important Variable ◽  
Breathing Cycle ◽  
Time Of Application ◽  
Inspiratory Muscles ◽  
Pressure Pulses ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles

Effect of upper airway pressure changes on thoracic inspiratory muscles has been shown to depend on the time of application during the breathing cycle. The present study was designed to investigate the importance of the time of application of upper airway negative pressure pulses on upper airway muscles. The upper airway was functionally isolated into a closed system in 24 anesthetized spontaneously breathing rabbits. Negative pressure pulses were applied in early (within the first 200 ms) and late (greater than or equal to 200 ms) inspiration, while electromyograms (EMG) of the diaphragm (Dia), genioglossus (GG), alae nasi (AN), and/or posterior cricoarytenoid (PCA) muscles were simultaneously monitored. When negative pressure pulse was applied in early inspiration, the increase in GG activity was greater [0.49 +/- 0.37 to 4.24 +/- 3.71 arbitrary units (AU)] than when negative pressure was applied in late inspiration (0.44 +/- 0.29 to 2.64 +/- 3.05 AU). Similarly, increased activation of AN (2.63 +/- 1.01 to 4.26 +/- 1.69 AU) and PCA (3.46 +/- 1.16 to 6.18 +/- 2.93 AU) was also observed with early inspiratory application of negative pressure pulses; minimal effects were seen in these muscles with late application. An inhibitory effect on respiratory timing consisting of a prolongation in inspiration (TI) and a decrease in peak Dia EMG/TI was observed as previously reported. These results indicate that the time of application of negative pressure during the breathing cycle is an important variable in determining the magnitude of the response of upper airway muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Heated Humidification or Face Mask To Prevent Upper Airway Dryness During Continuous Positive Airway Pressure Therapy

CHEST Journal ◽  
2000 ◽  
Vol 117 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Maria Teresa Martins de Araújo ◽  
Sérgio Barros Vieira ◽  
Elisardo Corral Vasquez ◽  
Bernard Fleury
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
Face Mask ◽  
Pressure Therapy ◽  
Positive Airway Pressure Therapy ◽  
Heated Humidification

Role of respiratory muscles in upper airway narrowing induced by inspiratory loading in preterm infants

1994 ◽  
Vol 77 (1) ◽  
pp. 30-36 ◽  
Author(s):  
S. Duara ◽  
G. Silva Neto ◽  
N. Claure
Keyword(s):  
Preterm Infants ◽  
Airway Pressure ◽  
Minute Ventilation ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Esophageal Pressure ◽  
Intraluminal Pressure ◽  
Respiratory Resistance ◽  
Quiet Sleep ◽  
Airway Narrowing

Extrathoracic airway (ETA) narrowing is induced in preterm infants by inspiratory flow-resistive loading (IRL), which reduces intraluminal pressure within the region. Neuromuscular load compensation was evaluated over time in 10 infants [body wt 1.5 +/- 0.17 (SD) kg, gestational age 33 +/- 2.3 wk, age 12 +/- 5.2 days] during quiet sleep. Baseline (BL) studies were followed by IRL (125 cmH2O.l–1.s at 1 l/min). Minute ventilation, changes in esophageal pressure (Pes) and proximal airway pressure, and moving time averages of posterior cricoarytenoid (PCA), submental genioglossus (SM), and diaphragm (DIA) electromyograms were obtained during BL and 1 and 5 min of IRL. Total respiratory resistance was calculated from pressure and flow changes and was used to estimate ETA narrowing: there was an increase in total respiratory resistance from 90 +/- 15 to 120 +/- 34 and 151 +/- 86 cmH2O.l–1.s after 1 and 5 min of IRL, respectively (P < 0.05, 1-min IRL vs. BL), in association with a sustained decline in minute ventilation (P < 0.05) and increases in Pes and proximal airway pressure (P < 0.05). Phasic PCA activity was always present, but its duration was only transiently prolonged with IRL (P < 0.05, 1-min IRL vs. BL). SM activity was present in only one infant during BL and was recruited in two additional infants during IRL. The decline in Pes from 1 to 5 min of IRL occurred despite continuing increases in peak and average activities of the DIA moving time average, which may reflect an onset of DIA fatigue. The transient prolongation of phasic PCA activity and occasional recruitment of SM activity with sustained loading explain, in part, the ETA instability detectable by moderate IRL in sleeping preterm infants.

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