Persistence of the Hering-Breuer reflex beyond the neonatal period

1991 ◽  
Vol 71 (2) ◽  
pp. 474-480 ◽  
Author(s):  
P. S. Rabbette ◽  
K. L. Costeloe ◽  
J. Stocks
Keyword(s):  
Spontaneous Breathing ◽  
Neonatal Period ◽  
Tidal Breathing ◽  
Natural Sleep ◽  
Airway Occlusion ◽  
Conflicting Evidence ◽  
Healthy Infants ◽  
Occlusion Technique ◽  
Relative Change ◽  
Stimulation Of

There is conflicting evidence regarding the persistence of the Hering-Breuer reflex (HBR) beyond the 1st wk of life. This study was designed to assess the influence of postnatal age on the HBR. The airway occlusion technique was used to assess changes in respiratory timing during stimulation of the HBR in healthy full-term unsedated infants measured shortly after birth and at 6–8 wk of life. The strength of the HBR was assessed from the relative change in expiratory time (TE) after end-inspiratory occlusion compared with resting TE during spontaneous breathing. Paired studies were performed in 31 infants at approximately 2 days and 6 wk of age. There was a significant increase in TE during each occlusion in every infant irrespective of age at measurement. No maturational changes were observed. The increase in TE after end-inspiratory occlusion was 91.9 +/- 31.6% (SD) (range 38–158%) at approximately 2 days and 89.8 +/- 30.7% (range 44–175%) at approximately 6 wk. We conclude that the activity of the HBR during tidal breathing persists beyond the neonatal period and that there is no statistically significant change in its strength during the first 2 mo life in healthy infants during natural sleep.

Hering-Breuer reflex and respiratory system compliance in the first year of life: a longitudinal study

1994 ◽  
Vol 76 (2) ◽  
pp. 650-656 ◽  
Author(s):  
P. S. Rabbette ◽  
M. E. Fletcher ◽  
C. A. Dezateux ◽  
H. Soriano-Brucher ◽  
J. Stocks
Keyword(s):  
Respiratory System ◽  
Relative Strength ◽  
Reflex Response ◽  
Respiratory System Compliance ◽  
Lung Inflation ◽  
Airway Occlusion ◽  
Age Related ◽  
Healthy Infants ◽  
Occlusion Technique ◽  
Relative Change

The airway occlusion technique for measuring passive respiratory mechanics in infants relies on an ability to evoke the Hering-Breuer lung inflation reflex (HBR). However, there is conflicting evidence regarding the persistence of the HBR beyond the early newborn period. This study was designed to assess maturational changes in HBR activity and passive total respiratory system compliance (Crs) in healthy infants during the 1st yr of life. The strength of the HBR was assessed from the relative change in expiratory time (TE) after brief end-inspiratory airway occlusions compared with resting TE during spontaneous breathing. Crs was measured using the multiple-occlusion technique. Paired measurements of HBR activity and Crs were obtained during sedated sleep in 30 infants at 4–8 wk and at 1 yr of age. Significant HBR activity during tidal breathing persisted throughout the 1st yr of life, with TE increasing during occlusion by at least 26% in every infant. However, the relative strength of the reflex response decreased from a mean of 88.3% (range, 34–160%) at approximately 6 wk to 50.3% (range, 26–125%) by 1 yr of age (P < 0.001). All infants showed an increase in Crs with age, with mean Crs increasing from 60.1 +/- 8.9 (SD) to 149.0 +/- 20.6 ml/kPa between 6 wk and 1 yr. However, there was no apparent relationship between the magnitude of decline in HBR response and the age-related changes in Crs.(ABSTRACT TRUNCATED AT 250 WORDS)

Volume of activation of the Hering-Breuer inflation reflex in the newborn infant

2001 ◽  
Vol 90 (3) ◽  
pp. 763-769 ◽  
Author(s):  
A. Hassan ◽  
J. Gossage ◽  
D. Ingram ◽  
S. Lee ◽  
A. D. Milner
Keyword(s):  
Lung Volume ◽  
Polynomial Regression ◽  
Neonatal Period ◽  
Face Mask ◽  
Progressive Increase ◽  
Inspiratory Time ◽  
Tidal Breathing ◽  
Expiratory Time ◽  
Healthy Infants ◽  
Residual Capacity

Although the Hering-Breuer inflation reflex (HBIR) is active within tidal breathing range in the neonatal period, there is no information regarding whether a critical volume has to be exceeded before any effect can be observed. To explore this, effects of multiple airway occlusions on inspiratory and expiratory timing were measured throughout tidal breathing range using a face mask and shutter system. In 20 of the 22 healthy infants studied, there was significant shortening of inspiration because the volume at which occlusion occurred rose from functional residual capacity (FRC) to end-inspiratory volume [14.9% reduction in inspiratory time (per ml/kg increase in lung volume at occlusion)]. All infants showed a significant increase in expiratory time [17.1% increase (per ml/kg increase in lung volume at occlusion)]. Polynomial regression analyses revealed a progressive increase in strength of HBIR from FRC to ∼4 ml/kg above FRC. Eighteen infants showed no further shortening of inspiratory time and 10 infants no further lengthening of expiratory time with increasing occlusion volumes, indicating maximal stimulation of the reflex had been achieved. There was a significant relationship between strength of HBIR and respiratory rate, suggesting that HBIR modifies the breathing pattern in the neonatal period.

Pharyngeal airway-stabilizing function of sternohyoid and sternothyroid muscles in the rabbit

1984 ◽  
Vol 57 (6) ◽  
pp. 1790-1795 ◽  
Author(s):  
J. L. Roberts ◽  
W. R. Reed ◽  
B. T. Thach
Keyword(s):  
Upper Airway ◽  
Progressive Increase ◽  
Electromyographic Activity ◽  
Tidal Breathing ◽  
Mechanical Tension ◽  
Airway Occlusion ◽  
Pharyngeal Airway ◽  
Airway Collapse ◽  
Closing Pressure ◽  
Stimulation Of

The upper airway is vulnerable to collapse from negative intraluminal pressures during inspiration. The tongue muscles, the genioglossi and geniohyoids, by contracting during inspiration, appear to function to resist this collapse. This study supports the hypothesis that two cervical strap muscles, the sternohyoid and sternothyroid, have a similar function. First, phasic inspiratory electromyographic activity was recorded from the sternohyoid and sternothyroid muscles of nine anesthetized rabbits during tidal breathing. Furthermore, each muscle showed a progressive increase in electromyographic activity with airway occlusion. Second, in eight rabbits, by determining the amount of negative pressure required to collapse the upper airway (airway closing pressure determination), it was shown that upper airway stability improved with electrical stimulation of either the paired sternohyoid or sternothyroid muscles. In addition, in 12 freshly killed rabbits, mechanical tension, mimicking the contraction of either the sternohyoid or sternothyroid, improved airway stability. Finally, observations of the pharyngeal lumen utilizing a fiber-optic endoscope, revealed concentric narrowing of the oro- and nasopharynx when airway pressure was lowered and concentric widening when tension was increased in the sternohyoid or sternothyroid muscles. These findings support the hypothesis that phasic inspiratory contraction of the sternohyoid and sternothyroid muscles functions to resist pharyngeal airway collapse due to negative intraluminal pressures.

Apnea of Prematurity: II. Respiratory Reflexes

PEDIATRICS ◽  
1984 ◽  
Vol 74 (1) ◽  
pp. 63-66
Author(s):  
Tilo Gerhardt ◽  
Eduardo Bancalari
Keyword(s):  
Preterm Infants ◽  
Inspiratory Effort ◽  
Control Group ◽  
Load Compensation ◽  
Airway Occlusion ◽  
Functional Immaturity ◽  
Occlusion Technique ◽  
Apnea Of Prematurity ◽  
Respiratory Reflexes

Airway obstruction is a cause of apnea in preterm infants. The activity of protective respiratory reflexes was determined in 18 preterm infants with apnea (mean of 32 episodes of more than 20 seconds duration per day) and in 18 neonates without apnea used as control subjects. This was done in order to elucidate the role of respiratory reflexes in apnea of prematurity. The infants were matched for birth weight (1,068 g v 1,065 g), gestational age (30.2 weeks v 30.2 weeks), and postnatal age (8.6 days v 8.3 days). The airway occlusion technique was used to determine the inspiratory prolongation of the occluded breath and the effective elastance of the respiratory system. Inspiratory prolongation is a measure for the reflex influence on inspiratory duration, and effective elastance reflects load compensating ability. Inspiratory prolongation was 7.3% ± 33.5% in infants with apnea and 30.6% ± 22.7% in the control group (P &lt; .025). Effective elastance was 1.1 ± 0.5 cm H2O/mL in the apneic group and 1.5 ± 0.5 cm H2O/mL in the infants without apnea (P &lt; .025). The results indicate that during exposure to respiratory loads, the infants with apnea maintained inspiratory effort poorly and had a decreased ability for load compensation. Their respiratory reflexes were significantly more immature than the reflex activity of the infants without apnea. This functional immaturity of respiratory reflexes may be a contributing factor in the etiology of apnea of prematurity.

Metabolic Fuel and Hormone Responses to Fasting in Newborn Infants

PEDIATRICS ◽  
1979 ◽  
Vol 64 (5) ◽  
pp. 613-619
Author(s):  
Charles A. Stanley ◽  
Endla K. Anday ◽  
Lester Baker ◽  
Maria Delivoria-Papadopolous
Keyword(s):  
Gestational Age ◽  
Plasma Glucose ◽  
Neonatal Period ◽  
Newborn Infants ◽  
Older Children ◽  
Glucose Levels ◽  
Metabolic Fuel ◽  
Healthy Infants ◽  
Lower Plasma Glucose ◽  
Appropriate For Gestational Age

To examine why newborn infants frequently cannot maintain adequate levels of plasma glucose in the interval between delivery and the time they are first fed, circulating metabolic fuel and regulatory hormone concentrations were determined in 44 healthy infants at the end of an eight-hour postnatal fast. Plasma glucose fell below 40 mg/100 ml prior to eight hours in four of 24 term-appropriate-for-gestational-age (AGA), two of nine preterm-AGA, five of six term-small-for-gestational-age (SGA), and three of five preterm-SGA infants. Fuel and hormone patterns in the premature and SGA infants were not different from those found in term-AGA infants. Results in these neonates differed in two areas from the response to fasting seen later in life. In fasted term-AGA infants, ketones were low (β-hydroxybutyrate 0.29 ± 0.04 mM/liter) despite elevated concentrations of fatty acid precursors (1.4 ± 0.07 mM/liter), and the group of infants studied failed to demonstrate the increase in plasma ketones with lower glucose levels (r = +.23, P = .07) which is found in older children. Levels of glucose precursors were two to three times higher in term-AGA infants (lactate 2.9 ± 0.2 mM/liter; alanine 0.48 ± 0.02 mM/liter) than levels found beyond the neonatal period and, in contrast to older children and adults, were not diminished in infants with lower plasma glucose (lactate, r = -.28, P = .035; alanine, r = -.33, P = .02). These differences between the responses to postnatal fasting and those seen beyond the neonatal period suggest that the capacity for both hepatic ketone synthesis and gluconeogenesis is not fully developed at birth.

Prolongation of inspiration during lower airway occlusion in children

1987 ◽  
Vol 62 (5) ◽  
pp. 1860-1864 ◽  
Author(s):  
M. K. Witte ◽  
W. A. Carlo
Keyword(s):  
Initial Rate ◽  
Neonatal Period ◽  
Vagal Afferents ◽  
Lower Airway ◽  
Occlusion Pressure ◽  
Endotracheal Tubes ◽  
Airway Occlusion ◽  
Normal Breathing ◽  
Human Adults ◽  
Human Neonates

Inspiration is strongly inhibited by volume-related vagal afferents in human neonates and animals, but this reflex is not as active in human adults during normal breathing. To determine whether volume-related inspiratory inhibition occurs beyond the neonatal period, we performed 10 +/- 1 end-expiratory occlusions in nine asleep children, ages 2–29 mo, with cuffed tracheostomy or endotracheal tubes in place. Airflow, tidal volume, occlusion pressure, and surface diaphragm electromyogram (DIA EMG) were simultaneously recorded. Occlusion consistently increased mechanical (P less than 0.002) and neural inspiratory times (P less than 0.001). During occluded respiratory efforts, peak amplitude of DIA EMG increased by 22 +/- 10% (P less than 0.002). In contrast, initial rate of rise of DIA EMG did not change. We conclude that in children with isolated lower airways, end-expiratory occlusions prolonged inspiratory duration as measured by both mechanical and neural parameters. The lack of an associated increase in rate of rise of DIA EMG strongly suggests that inspiration is prolonged by release of volume-related inhibition of inspiration rather than by facilitation. These data provide evidence for the presence of the Hering-Breuer reflex beyond the neonatal period.

Effects of baclofen on the Hering-Breuer inspiratory-inhibitory and deflation reflexes in rats

1998 ◽  
Vol 274 (2) ◽  
pp. R462-R469 ◽  
Author(s):  
Erin Seifert ◽  
Teresa Trippenbach
Keyword(s):  
Aminobutyric Acid ◽  
Type B ◽  
Rapid Adaptation ◽  
Inspiratory Time ◽  
Airway Occlusion ◽  
Acid Type ◽  
Tracheal Pressure ◽  
The Difference ◽  
Respiratory Phases ◽  
Stimulation Of

The objective of this study was to evaluate effects of baclofen, a γ-aminobutyric acid type B (GABAB) receptor agonist, injected into the nucleus of the solitary tract, on the Hering-Breuer inspiratory-inhibitory (Ti-inhibitory) and deflation reflexes in urethan-anesthetized adult Wistar rats ( n = 7). The Ti-inhibitory reflex was estimated from changes in peak amplitude of the integrated diaphragmatic electromyogram and inspiratory time (Ti) provoked by airway occlusion at end expiration. The deflation reflex was evaluated from changes in Ti and expiration (Te) of the first two breaths (Ti-1, Te-1 and Ti-2, Te-2) immediately after a decrease in tracheal pressure (Ptr). Under control conditions, airway occlusion at end-Te prolonged Ti (66 ± 5%; mean ± SE) and the following Te (54 ± 11%). Decreases in Ptr, from −2 to −5 cmH2O, evoked an increase in Ti and shortening of Te of both breaths. Both effects were Ptr dependent, and Ti-1 and Te-1 differed from Ti-2 and Te-2, suggesting a rapid adaptation to the stimulus. At Ptr of −5 cmH2O, Ti-1 and Ti-2 increased by 30 ± 2 and 43 ± 6%, respectively, and Te-1 and Te-2 decreased by 53 ± 4 and 33 ± 7%, respectively. During unloaded breathing, 60 pmol baclofen prolonged Ti by 120 ± 11% and left Te unaffected. Baclofen abolished vagally mediated changes in Te. On the other hand, the Ti increases caused by either airway occlusion (24 ± 8%) or Ptr of −5 cmH2O (Ti-1; 16 ± 5%) were still significant, but Ti-1 and Ti-2 were not different. A GABAB receptor antagonist, CGP-35348 (2.8 nmol), reversed these effects of baclofen. These results imply that stimulation of GABAB receptors attenuates but does abolish vagally mediated control of Ti. The difference in effects of baclofen on the central and vagal control of Ti and Te suggests different distribution of GABAB receptors in neuronal networks controlling each of these respiratory phases.

Decreased Mitochondrial Function Among Healthy Infants Exposed to Antiretrovirals During Gestation, Delivery and the Neonatal Period

2015 ◽  
Vol 34 (12) ◽  
pp. 1349-1354 ◽  
Author(s):  
Antoni Noguera-Julian ◽  
Constanza Morén ◽  
Núria Rovira ◽  
Glòria Garrabou ◽  
Marc Catalán ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Neonatal Period ◽  
Healthy Infants

Respiratory resistance by end-inspiratory occlusion and forced oscillations in intubated patients

1996 ◽  
Vol 80 (4) ◽  
pp. 1105-1111 ◽  
Author(s):  
L. Beydon ◽  
P. Malassine ◽  
A. M. Lorino ◽  
C. Mariette ◽  
F. Bonnet ◽  
...  
Keyword(s):  
Forced Oscillation ◽  
Forced Oscillations ◽  
Forced Oscillation Technique ◽  
Respiratory Impedance ◽  
Respiratory Resistance ◽  
Airway Occlusion ◽  
Residual Capacity ◽  
Occlusion Technique ◽  
Air Compression ◽  
Good Agreement

Measurement of respiratory impedance by the forced oscillation technique (FOT) in intubated patients requires corrections for the flow-dependent resistance, inertance, and air compression inside the endotracheal tube (ETT). Recently, we published a method to correct respiratory impedance for the mechanical contribution of the ETT. To validate this correction, we compared the respiratory resistance obtained with this method (Rfo) to the intrinsic (Rmin) and total resistances (RT) measured by the airway-occlusion technique (OCT) in 16 intubated sedated paralyzed ventilated patients. The FOT was applied at functional residual capacity in the 4- to 32-Hz frequency range, whereas the OCT was performed at the end of a normal constant-flow inspiration. Rmin corrected with Rfo measured at 16 and 32 Hz [Rfo(16) = 1.10 x Rmin + 0.10 cmH2O.s.l-1, r = 0.96, P < 0.001; Rfo(32) = 0.93 x Rmin + 0.72 cmH2O.s.l-1, r = 0.97, P < 0.001]. RT corrected with Rfo at 4 Hz [Rfo(4) = 1.11 x RT - 1.48 cmH2O.s.l-1; = 0.92; P < 0.001]. We conclude that the FOT improved by correction for the behavior of the ETT is in good agreement with the OCT in intubated patients.

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