Active glottal closure during central apneas limits oxygen desaturation in premature lambs

2003 ◽  
Vol 94 (5) ◽  
pp. 1949-1954 ◽  
Author(s):  
Philippe Reix ◽  
Julie Arsenault ◽  
Valérie Dôme ◽  
Pierre-Hugues Fortier ◽  
Joëlle Rouillard Lafond ◽  
...  
Keyword(s):  
Lung Volume ◽  
Respir Crit ◽  
Periodic Breathing ◽  
Oxygen Desaturation ◽  
Emg Activity ◽  
Quiet Sleep ◽  
Glottal Closure ◽  
Central Apneas ◽  
Alveolar Oxygen ◽  
Thyroarytenoid Muscle

Our laboratory previously reported that active glottal closure was present in 90% of spontaneous central apneas in premature lambs while maintaining a high-apneic lung volume (Renolleau S, Letourneau P, Niyonsenga T, and Praud JP. Am J Respir Crit Care Med 159: 1396–1404, 1999.) The present study aimed at testing whether this mechanism limits postapnea oxygen desaturation. Four premature lambs were instrumented for recording states of alertness, thyroarytenoid muscle and diaphragm electromyographic (EMG) activity, nasal airflow, lung volume changes, and pulse oximetry. One thousand four hundred fifty-two spontaneous central apneas (isolated or during periodic breathing) were analyzed in nonsedated lambs. Apneas, with high lung volume maintained by active glottal closure, were compared with apneas, with a tracheostomy opened at apnea onset. Oxygen desaturation slopes were lower when high-apneic lung volume was actively maintained during both wakefulness and quiet sleep. Furthermore, oxygen desaturation slopes were lower after isolated apneas with continuous thyroarytenoid EMG during wakefulness, compared with apneas with noncontinuous thyroarytenoid EMG (= glottis opened shortly after apnea onset). These results highlight the importance of maintaining high-alveolar oxygen stores during central apneas by active glottal closure to limit desaturation in newborns.

Hypercapnia increases expiratory braking in preterm infants

1993 ◽  
Vol 75 (6) ◽  
pp. 2665-2670 ◽  
Author(s):  
E. C. Eichenwald ◽  
R. A. Ungarelli ◽  
A. R. Stark
Keyword(s):  
Tidal Volume ◽  
Premature Infants ◽  
Lung Volume ◽  
Newborn Infants ◽  
Emg Activity ◽  
Quiet Sleep ◽  
Activity Peak ◽  
Posterior Cricoarytenoid ◽  
Respiratory Muscle Activity ◽  
Ventilatory Response To Co2

In contrast to adults, newborn infants breathe from an elevated end-expiratory lung volume, determined by the interaction of airflow retardation (braking) by the diaphragm and larynx, and expiratory duration. To determine the effect of hypercapnia on this strategy, we examined changes in respiratory muscle activity and the ventilatory response to CO2 breathing in eight premature infants 33–34 wk gestational age in the first 3 postnatal days. We recorded tidal volume, airflow, and electromyograms (EMG) of the laryngeal abductor [posterior cricoarytenoid (PCA)], which abducts the vocal cords, and diaphragm during behaviorally determined quiet sleep in room air and during steady-state inhalation of 2% CO2 in air. As expected, tidal volume increased (P < 0.0005) without a change in inspiratory duration with hypercapnia. Unexpectedly, in all subjects, expiratory duration was longer during CO2 inhalation (P < 0.001), accompanied by marked changes in expiratory flow patterns consistent with increased expiratory braking. Diaphragm post-inspiratory EMG activity increased with hypercapnia (P < 0.005) with no change in baseline diaphragm or PCA EMG activity. Peak inspiratory EMG activity of the diaphragm and PCA increased with CO2 (10 and 37%, respectively; P < 0.05). We conclude that the mechanisms used to elevate end-expiratory lung volume are enhanced during hypercapnia in premature infants. This breathing strategy may be important in maintaining gas exchange in infants with lung disease.

Regulation of end-expiratory lung volume during sleep in premature infants

1987 ◽  
Vol 62 (3) ◽  
pp. 1117-1123 ◽  
Author(s):  
A. R. Stark ◽  
B. A. Cohlan ◽  
T. B. Waggener ◽  
I. D. Frantz ◽  
P. C. Kosch
Keyword(s):  
Tidal Volume ◽  
Premature Infants ◽  
Lung Volume ◽  
Emg Activity ◽  
Active Sleep ◽  
Sleep State ◽  
Quiet Sleep ◽  
Volume Curve ◽  
Variable Extent ◽  
Expiratory Flow

To investigate the regulation of end-expiratory lung volume (EEV) in premature infants, we recorded airflow, tidal volume, diaphragm electromyogram (EMG), and chest wall displacement during sleep. In quiet sleep, EEV during breathing was 10.8 +/- 3.6 (SD) ml greater than the minimum volume reached during unobstructed apneas. In active sleep, no decrease in EEV was observed during 28 of 35 unobstructed apneas. Breaths during quiet sleep had a variable extent of expiratory airflow retardation (braking), and inspiratory interruption occurred at substantial expiratory flow rates. During active sleep, the expiratory flow-volume curve was nearly linear, proceeding nearly to the volume axis at zero flow, and diaphragm EMG activity terminated near the peak of mechanical inspiration. Expiratory duration (TE) and inspiratory duration (TI) were significantly shortened in quiet sleep vs. active sleep although tidal volume was not significantly different. In quiet sleep, diaphragmatic braking activity and shortened TE combined to maintain EEV during breathing substantially above relaxation volume. In active sleep, reduced expiratory braking and prolongation of TE resulted in an EEV that was close to relaxation volume. We conclude that breathing strategy to regulateEEV in premature infants appears to be strongly influenced by sleep state.

scholarly journals Laryngeal and abdominal muscle electrical activity during periodic breathing in nonsedated lambs

1998 ◽  
Vol 84 (2) ◽  
pp. 669-675 ◽  
Author(s):  
Irenej Kianicka ◽  
Véronique Diaz ◽  
Sylvain Renolleau ◽  
Emmanuel Canet ◽  
Jean-Paul Praud ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Electrical Activity ◽  
Muscle Contraction ◽  
Periodic Breathing ◽  
Abdominal Muscle ◽  
Glottic Closure ◽  
Cricothyroid Muscle ◽  
Jean Paul ◽  
Central Apneas ◽  
Thyroarytenoid Muscle

Kianicka, Irenej, Véronique Diaz, Sylvain Renolleau, Emmanuel Canet, and Jean-Paul Praud. Laryngeal and abdominal muscle electrical activity during periodic breathing in nonsedated lambs. J. Appl. Physiol. 84(2): 669–675, 1998.—We recently reported that glottic closure was present throughout central apneas in awake lambs. The present study tested whether glottic closure was also observed during periodic breathing (PB). We attempted to induce PB in 21 nonsedated lambs on return from hypocapnic hypoxia to room air. Airflow and thyroarytenoid (a laryngeal constrictor, n = 16), cricothyroid (a laryngeal dilator, n = 10), and abdominal ( n = 9) muscle electrical activity (EMG) were monitored continuously. PB was observed in 16 lambs, with apneic phases in 8 lambs. Thyroarytenoid muscle EMG was observed at the nadir of PB, either throughout apnea or with prolonged expiration during the lowest respiratory efforts. Phasic inspiratory cricothyroid muscle EMG and phasic expiratory abdominal EMG disappeared at the nadir of PB. Active glottic closure at the nadir of PB, without abdominal muscle contraction, could be a beneficial mechanism, preserving alveolar gas stores for continuing gas exchange during the apneic/hypopneic phase of PB. However, consequences of active glottic closure on ventilatory instability, either enhancing or reducing, are unknown.

Profound oxygen desaturation due to central apneas associated with interictal generalized spike-wave discharges

2011 ◽  
Vol 12 (3) ◽  
pp. 302-305
Author(s):  
Brendan P. Lucey ◽  
Cristina Toedebusch ◽  
Stephen P. Duntley
Keyword(s):  
Oxygen Desaturation ◽  
Spike Wave Discharges ◽  
Central Apneas ◽  
Spike Wave

Hypoxic Arousal Responses in Normal Infants

PEDIATRICS ◽  
1992 ◽  
Vol 89 (5) ◽  
pp. 860-864 ◽  
Author(s):  
Sally L. Davidson Ward ◽  
Daisy B. Bautista ◽  
Thomas C. Keens
Keyword(s):  
Ventilatory Response ◽  
Arterial Oxygen Saturation ◽  
Periodic Breathing ◽  
High Risk Group ◽  
Arterial Oxygen ◽  
Sudden Infant ◽  
Hypoxic Ventilatory Response ◽  
Quiet Sleep ◽  
Term Infants ◽  
Increased Risk

Failure to arouse in response to hypoxia has been described in infants at increased risk for sudden infant death syndrome (SIDS) and has been suggested as a possible mechanism for SIDS. However, most SIDS victims are not in a high-risk group before death. Thus, if a hypoxic arousal disorder is an important contributor to SIDS, normal infants might fail to arouse from sleep in response to hypoxia. To test this hypothesis, the authors studied hypoxic arousal responses in 18 healthy term infants younger than 7 months of age (age 12.1 ± 1.7 [SEM] weeks; 56% girls). Hypoxic arousal challenges were performed during quiet sleep by rapidly decreasing inspired oxygen tension (Pio2) to 80 mm Hg for 3 minutes or until arousal (eye opening, agitation, and crying) occurred. Tests were performed in duplicate when possible. Only 8 infants (44%) aroused in response to one or more hypoxic challenges; arousal occurred during 8 (32%) of 25 trials. There were no significant differences in lowest Pio2 or arterial oxygen saturation during hypoxia between those infants who aroused and those who failed to arouse. All 18 infants had a fall in their end-tidal carbon dioxide tension during hypoxia, suggesting that each had a hypoxic ventilatory response despite failure to arouse in the majority. Periodic breathing occurred following hypoxia in only 1 (13%) of the 8 trials that resulted in arousal, compared with 16 (94%) of 17 trials without arousal (P &lt; .005). It is concluded that the majority of normal infants younger than 7 months of age fail to arouse from quiet sleep in response to hypoxia, despite the apparent presence of a hypoxic ventilatory response.

Respiratory Characteristics During Sleep in Healthy Small-for-Gestational Age Newborns

PEDIATRICS ◽  
1996 ◽  
Vol 97 (4) ◽  
pp. 554-559
Author(s):  
Lilia Curzi-Dascalova ◽  
Patricio Peirano ◽  
Emilia Christova
Keyword(s):  
Gestational Age ◽  
Small For Gestational Age ◽  
Respiratory Function ◽  
Respiratory Rhythm ◽  
Periodic Breathing ◽  
Respiratory Frequency ◽  
Quiet Sleep ◽  
Age Related ◽  
Appropriate For Gestational Age ◽  
The Impact

Objective. Small-for-gestational age (SGA) infants born with intrauterine growth retardation (IUGR) differ from appropriate-for-gestational age (AGA) infants by: a) alterations in a number of neurologic and neurophysiologic characteristics; b) modified heart rate variability during the neonatal period; and c) increased morbidity rates during the first months of life. However, there are no data on the impact of IUGR on respiratory function control at birth. Methods. We studied 57 newborns who were 35 to 36, 37 to 38, and 39 to 41 weeks' conceptional age (CA): 31 were AGA and 26 were SGA. All were clinically and neurologically normal at birth and none exhibited abnormal events during the first year of life. Polygraphic recordings were performed between two meals during the normal postnatal stay in the maternity ward. Results. During both active sleep (AS) and quiet sleep (QS), SGA infants in all CA groups had significently higher values for the incidence of 2 to 4.9 seconds and 5 to 9.9 seconds central respiratory pauses (RP), the apnea index (AI) [AI = % of nonbreathing time], and the time spent with periodic breathing (PB), as compared with AGA infants Respiratory frequency was usually similar in SGA and AGA infants. In addition, the trend of age-related respiratory modifications was disturbed in SGA infants, as compared with AGA infants: at 39 to 41 weeks CA, SGA infants had no significant decreases in RP, AI, or PB, and no increase in respiratory frequency. However, between-state differences were similar in both groups. In all AGA and SGA infant groups respiratory frequency seemed to be an individual characteristic: infants who breathed faster during AS breathed faster during QS, and vice-versa. Conclusion. Our data demonstrate significant modifications in the establishment of respiratory rhythm control in SGA infants, whereas the patterns of state-related and subject-dependent breathing characteristics were similar in SGA and AGA infants. We speculate that the dysregulation of respiratory function control maturation observed in healthy SGA infants may be related to subtle brainstem modifications attributable to the decreased blood supply and chronic hypoxia associated with IUGR.

Reduction of Sleep Apnea and Bradycardia in Preterm Infants on Oscillating Water Beds: A Controlled Polygraphic Study

PEDIATRICS ◽  
1978 ◽  
Vol 61 (4) ◽  
pp. 528-533
Author(s):  
Anneliese F. Korner ◽  
Christian Guilleminault ◽  
Johanna Van den Hoed ◽  
Roger B. Baldwin
Keyword(s):  
Birth Weight ◽  
Sleep Apnea ◽  
Preterm Infants ◽  
Premature Infants ◽  
Gestational Age ◽  
Periodic Breathing ◽  
Quiet Sleep ◽  
Severe Bradycardia

The sleep and respiratory patterns of eight apneic preterm infants were polygraphically recorded for 24 hours. This polygraphic study was designed to test and extend our previous finding that gently oscillating water beds reduce apnea in premature infants. The infants who ranged in gestational age from 27 to 32 weeks and in birth weight from 1,077 to 1,650 gm served as their own controls, off and on the water bed. The 24-hour recordings were divided into four time blocks with the infant being placed on the water bed during alternate six-hour periods. Apnea was significantly reduced while the infants were on the oscillating water beds, with the longest apneic periods and those associated with severe bradycardia being reduced the most. Reduction of apnea was most consistent during indeterminate sleep and most pronounced during quiet sleep. Short respiratory pauses and periodic breathing were not significantly reduced. Reductions of central, obstructive, and mixed apneas were approximately equal.

Thyroarytenoid muscle activity during hypoxia in awake lambs

1990 ◽  
Vol 69 (6) ◽  
pp. 1998-2003 ◽  
Author(s):  
J. P. Praud ◽  
E. Canet ◽  
D. Dalle ◽  
A. Bairam ◽  
M. Bureau
Keyword(s):  
Lung Volume ◽  
Muscle Activity ◽  
Early Life ◽  
Face Mask ◽  
Flow Volume ◽  
Adductor Muscles ◽  
Thyroarytenoid Muscle

It is generally accepted that hypoxia in early life results in active laryngeal braking of expiratory airflow via the recruitment of glottic adductor muscles. We examined the electromyogram expiratory activity of the thyroarytenoid muscle in seven 11- to 18-day-old awake nonsedated lambs exposed to an inspired O2 fraction of 0.08 for 18 min. The lambs breathed through a face mask and a pneumotachograph. During baseline prehypoxic breathing, the thyroarytenoid muscle was largely inactive in each awake lamb. Unexpectedly, no recruitment of the thyroarytenoid muscle was recorded during hypoxia in any of the seven lambs; simultaneous examination of the flow-volume curves revealed an absence of expiratory airflow braking. Also unexpectedly, marked expiratory activity of the thyroarytenoid muscle was recorded, with each expiration occurring within less than 10 s after the return to room air. The resulting delay of expiration was apparent in the flow-volume loops. Thus, in awake 11- to 18-day-old lambs, 1) active expiratory glottic adduction is absent during hypoxia and 2) a return from hypoxia to room air results in prolonged expiration as well as active glottic adduction that controls end-expiratory lung volume.

Chest wall and trunk muscle activity during inspiratory loading

1992 ◽  
Vol 73 (6) ◽  
pp. 2373-2381 ◽  
Author(s):  
S. J. Cala ◽  
J. Edyvean ◽  
L. A. Engel
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Normal Subjects ◽  
Systematic Difference ◽  
Erector Spinae ◽  
Inspiratory Pressure ◽  
Emg Activity ◽  
Consistent Difference ◽  
Lung Volumes ◽  
Resistive Loading

We measured the electromyographic (EMG) activity in four chest wall and trunk (CWT) muscles, the erector spinae, latissimus dorsi, pectoralis major, and trapezius, together with the parasternal, in four normal subjects during graded inspiratory efforts against an occlusion in both upright and seated postures. We also measured CWT EMGs in six seated subjects during inspiratory resistive loading at high and low tidal volumes [1,280 +/- 80 (SE) and 920 +/- 60 ml, respectively]. With one exception, CWT EMG increased as a function of inspiratory pressure generated (Pmus) at all lung volumes in both postures, with no systematic difference in recruitment between CWT and parasternal muscles as a function of Pmus. At any given lung volume there was no consistent difference in CWT EMG at a given Pmus between the two postures (P > 0.09). However, at a given Pmus during both graded inspiratory efforts and inspiratory resistive loading, EMGs of all muscles increased with lung volume, with greater volume dependence in the upright posture (P < 0.02). The results suggest that during inspiratory efforts, CWT muscles contribute to the generation of inspiratory pressure. The CWT muscles may act as fixators opposing deflationary forces transmitted to the vertebral column by rib cage articulations, a function that may be less effective at high lung volumes if the direction of the muscular insertions is altered disadvantageously.

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