Posterior cricoarytenoid and diaphragm activities during tidal breathing in neonates

1988 ◽  
Vol 64 (5) ◽  
pp. 1968-1978 ◽  
Author(s):  
P. C. Kosch ◽  
A. A. Hutchinson ◽  
J. A. Wozniak ◽  
W. A. Carlo ◽  
A. R. Stark
Keyword(s):  
Newborn Infants ◽  
Emg Activity ◽  
Time Interval ◽  
Sudden Increase ◽  
Tidal Breathing ◽  
Term Neonates ◽  
Dynamic Maintenance ◽  
Sequential Activation ◽  
Vagal Reflex ◽  
Posterior Cricoarytenoid

To investigate airflow regulation in newborn infants, we recorded airflow, volume, diaphragm (Di), and laryngeal electromyogram (EMG) during spontaneous breathing in eight supine unsedated sleeping full-term neonates. Using an esophageal catheter electrode, we recorded phasic respiratory activity consistent with that of the principal laryngeal abductors, the posterior cricoarytenoids (PCA). Sequential activation of PCA and Di preceded inspiration. PCA activity typically peaked early in inspiration followed by either a decrescendo or tonic EMG activity of variable amplitude during expiration. Expiratory airflow retardation, or braking, accompanied by expiratory prolongation and reduced ventilation, was commonly observed. In some subjects we observed a time interval between PCA onset and a sudden increase in expiratory airflow just before inspiration, suggesting that release of the brake involved an abrupt loss of antagonistic adductor activity. Our findings suggest that airflow in newborn infants is controlled throughout the breathing cycle by the coordinated action of the Di and the reciprocal action of PCA and laryngeal adductor activities. We conclude that braking mechanisms in infants interact with vagal reflex mechanisms that modulate respiratory cycle timing to influence both the dynamic maintenance of end-expiratory lung volume and ventilation.

Developmental changes in sequential activation of laryngeal abductor muscle and diaphragm in infants

1992 ◽  
Vol 73 (4) ◽  
pp. 1425-1431 ◽  
Author(s):  
E. C. Eichenwald ◽  
R. G. Howell ◽  
P. C. Kosch ◽  
R. A. Ungarelli ◽  
J. Lindsey ◽  
...  
Keyword(s):  
Premature Infants ◽  
Newborn Infants ◽  
Upper Airway ◽  
Full Term ◽  
Emg Activity ◽  
Term Infants ◽  
Posterior Cricoarytenoid Muscle ◽  
Human Adults ◽  
Sequential Activation ◽  
Posterior Cricoarytenoid

In animals and human adults, upper airway muscle activity usually precedes inspiratory diaphragm activity. We examined the interaction of the posterior cricoarytenoid muscle (PCA), which abducts the larynx, and the diaphragm (DIA) in the control of airflow in newborn infants to assess the effect of maturation on respiratory muscle sequence. We recorded tidal volume, airflow, and DIA and PCA electromyograms (EMG) in 12 full-term, 14 premature, and 10 premature infants with apnea treated with aminophylline. In most breaths, onset of PCA EMG activity preceded onset of DIA EMG activity (lead breaths). In all subjects, we also observed breaths (range 6–61%) in which PCA EMG onset followed DIA EMG onset (lag breaths). DIA neural inspiratory duration and the neuromechanical delay between DIA EMG onset and inspiratory flow were longer in lag than in lead breaths (P < 0.05 and P < 0.01, respectively). The frequency of lag breaths was greater in the premature infants [33 +/- 4% (SE)] than in either the full-term infants (21 +/- 3%, P < 0.03) or the premature infants with apnea treated with aminophylline (16 +/- 2%, P < 0.01). We conclude that the expected sequence of onset of PCA and DIA EMG activity is frequently disrupted in newborn infants. Both maturation and respiratory stimulation with aminophylline improve the coordination of the PCA and DIA.

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.

Respiratory Activity of the Rat Posterior Cricoarytenoid Muscle

1997 ◽  
Vol 106 (11) ◽  
pp. 897-901 ◽  
Author(s):  
Robert G. Berkowitz ◽  
John Chalmers ◽  
Qi-Jian Sun ◽  
Paul M. Pilowsky
Keyword(s):  
Phrenic Nerve ◽  
Muscle Activity ◽  
Electrophysiological Study ◽  
Emg Activity ◽  
Diaphragmatic Muscle ◽  
Posterior Cricoarytenoid Muscle ◽  
Inspiratory Activity ◽  
Intramuscular Nerve ◽  
Posterior Cricoarytenoid ◽  
Nerve Discharge

An anatomic and electrophysiological study of the rat posterior cricoarytenoid (PCA) muscle is described. The intramuscular nerve distribution of the PCA branch of the recurrent laryngeal nerve was demonstrated by a modified Sihler's stain. The nerve to the PCA was found to terminate in superior and inferior branches with a distribution that appeared to be confined to the PCA muscle. Electromyography (EMG) recordings of PCA muscle activity in anesthetized rats were obtained under stereotaxic control together with measurement of phrenic nerve discharge. A total of 151 recordings were made in 7 PCA muscles from 4 rats. Phasic inspiratory activity with a waveform similar to that of phrenic nerve discharge was found in 134 recordings, while a biphasic pattern with both inspiratory and post-inspiratory peaks was recorded from random sites within the PCA muscle on 17 occasions. The PCA EMG activity commenced 24.6 ± 2.2 milliseconds (p < .0001) before phrenic nerve discharge. The results are in accord with findings of earlier studies that show that PCA muscle activity commences prior to inspiratory airflow and diaphragmatic muscle activity. The data suggest that PCA and diaphragm motoneurons share common or similar medullary pre-motoneurons. The earlier onset of PCA muscle activity may indicate a role for medullary pre-inspiratory neurons in initiating PCA activity.

Neurotoxicity of Hexachlorophene in the Human: I. A Clinicopathologic Study of 248 Children

PEDIATRICS ◽  
1974 ◽  
Vol 54 (6) ◽  
pp. 689-695
Author(s):  
Robert M. Shuman ◽  
Richard W. Leech ◽  
Ellsworth C. Alvord
Keyword(s):  
Birth Weight ◽  
Gestational Age ◽  
Newborn Infants ◽  
Whole Body ◽  
Human Beings ◽  
Term Neonates ◽  
Experimental Animals ◽  
Clinicopathologic Study ◽  
Neurotoxic Effects ◽  
Sick Children

To assess the susceptibility of human beings to the neurotoxic effects of hexachlorophene demonstrated in experimental animals, a blind clinicopathologic analysis was made of 248 children coming to autopsy over a 7.5-year period in the two Seattle institutions to which practically all premature or sick children are referred. Repeated whole-body bathing of premature newborn infants in 3% hexachlorophene-bearing soap (undiluted pHisoHex) is associated with a vacuolar encephalopathy of the brainstem reticular formation. The prevalence of the vacuolar encephalopathy appears to be related to the number of exposures to hexachlorophene, to the concentration of hexachiorophene, to the birth weight (gestational age), to the length of survival and to the thoroughness of rinsing. From these observations we conclude that hexachlorophene should not be used on neonates under 1,400 gm birth weight and should be used only sparingly in full-term neonates with thorough rinsing.

scholarly journals Motor Cortical Activity During Drawing Movements: Population Representation During Spiral Tracing

1999 ◽  
Vol 82 (5) ◽  
pp. 2693-2704 ◽  
Author(s):  
Daniel W. Moran ◽  
Andrew B. Schwartz
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Prediction Interval ◽  
Premotor Cortex ◽  
Cortical Activity ◽  
Simultaneous Action ◽  
Emg Activity ◽  
Radius Of Curvature ◽  
Time Interval ◽  
Population Vector

Monkeys traced spirals on a planar surface as unitary activity was recorded from either premotor or primary motor cortex. Using the population vector algorithm, the hand's trajectory could be accurately visualized with the cortical activity throughout the task. The time interval between this prediction and the corresponding movement varied linearly with the instantaneous radius of curvature; the prediction interval was longer when the path of the finger was more curved (smaller radius). The intervals in the premotor cortex fell into two groups, whereas those in the primary motor cortex formed a single group. This suggests that the change in prediction interval is a property of a single population in primary motor cortex, with the possibility that this outcome is due to the different properties generated by the simultaneous action of separate subpopulations in premotor cortex. Electromyographic (EMG) activity and joint kinematics were also measured in this task. These parameters varied harmonically throughout the task with many of the same characteristics as those of single cortical cells. Neither the lags between joint-angular velocities and hand velocity nor the lags between EMG and hand velocity could explain the changes in prediction interval between cortical activity and hand velocity. The simple spatial and temporal relationship between cortical activity and finger trajectory suggests that the figural aspects of this task are major components of cortical activity.

scholarly journals Reaction to a Visual Stimulus: Anticipation with Steady and Dynamic Contractions

2019 ◽  
Vol 69 (1) ◽  
pp. 17-27
Author(s):  
Agostina Casamento-Moran ◽  
Stefan Delmas ◽  
Seoung Hoon Park ◽  
Basma Yacoubi ◽  
Evangelos A. Christou
Keyword(s):  
Reaction Time ◽  
Planning Process ◽  
Dynamic Condition ◽  
Motor Planning ◽  
Reaction Time Task ◽  
Emg Activity ◽  
Time Interval ◽  
Variable Direction ◽  
The Moment ◽  
Study Participants

Abstract Reacting fast to visual stimuli is important for many activities of daily living and sports. It remains unknown whether the strategy used during the anticipatory period influences the speed of the reaction. The purpose of this study was to determine if reaction time (RT) differs following a steady and a dynamic anticipatory strategy. Twenty‐two young adults (21.0 ± 2.2 yrs, 13 women) participated in this study. Participants performed 15 trials of a reaction time task with ankle dorsiflexion using a steady (steady force at 15% MVC) and a dynamic (oscillating force from 10‐20% MVC) anticipatory strategy. We recorded primary agonist muscle (tibialis anterior; TA) electromyographic (EMG) activity. We quantified RT as the time interval from the onset of the stimulus to the onset of force. We found that a dynamic anticipatory strategy, compared to the steady anticipatory strategy, resulted in a longer RT (p = 0.04). We classified trials of the dynamic condition based on the level and direction of anticipatory force at the moment of the response. We found that RT was longer during the middle descending relative to the middle ascending and the steady conditions (p < 0.01). All together, these results suggest that RT is longer when preceded by a dynamic anticipatory strategy. Specifically, the longer RT is a consequence of the variable direction of force at which the response can occur, which challenges the motor planning process.

"COMPARATIVE STUDY OF EARLY NEONATAL MORBIDITIES OF LATE PRETERM AND TERM NEONATES"

2021 ◽  
pp. 23-25
Author(s):  
Jatin Manocha ◽  
Kusum Mahajan ◽  
Anuj Kumar
Keyword(s):  
Preterm Infants ◽  
Prospective Observational Study ◽  
Neonatal Period ◽  
Newborn Infants ◽  
Late Preterm ◽  
Preterm Neonates ◽  
Feeding Problems ◽  
Term Neonates ◽  
Late Preterm Infants ◽  
Study Results

Background- Newborn infants are unique in their physiology and the health problems that they experience. Neonatal period is dened from birth to under four weeks of age. Late preterm infants may physiologically and physically appear like infants born at term, but most late preterm infants may undergo complications like respiratory distress, apnea, hypothermia, feeding problems, hypoglycemia, hyperbilirubinemia, sepsis, and mortality. AIM-To compare the clinical prole of late preterm neonates with term neonates. MATERIALAND METHODS: This prospective observational study was carried out in neonatal division of department of pediatrics MMIMSR, Mullana. Eligible neonates delivered at MMIMSR, Mullana born from 34 weeks up to 42 weeks gestation were included. All infants enrolled in the study was followed daily till rst 7 days of life for any morbidity by clinical evaluation and review of hospital records.104 preterms included in the study and 226 term neonates were included in the study. Results- Preterms born via LSCS and NVD were(58%vs.42%).Morbidities in late preterms were Hypoglycemia (21.2% vs. 9.3%), Hypothermia (15.4%vs5.7%), hypocalcaemia (38.4% vs. 5.3%), neonatal hyperbilirubinemia(67.3% vs. 30.5%), feeding difculties(44.2% vs. 14.6%), sepsis(40.4% vs. 19.5%), respiratory support(53% vs. 47%)

scholarly journals Influence of volume dependency and timing of airway occlusions on the Hering-Breuer reflex in infants

1998 ◽  
Vol 85 (6) ◽  
pp. 2033-2039 ◽  
Author(s):  
Patricia S. Rabbette ◽  
Janet Stocks
Keyword(s):  
Respiratory Mechanics ◽  
Newborn Infants ◽  
Tidal Range ◽  
First Year ◽  
Similar Response ◽  
Inspiratory Time ◽  
Tidal Breathing ◽  
Age Related ◽  
The Difference ◽  
First Year Of Life

Both end-inspiratory (EIO) and end-expiratory (EEO) airway occlusions are used to calculate the strength of the Hering-Breuer inflation reflex (HBIR) in infants. However, the influence of the timing of such occlusions is unknown, as is the extent to which changes in volume within and above the tidal range affect this reflex. The purpose of this study was to compare both techniques and to evaluate the volume dependency of the HBIR in healthy, sleeping infants up to 1 yr of age. The strength of the HBIR was expressed as the ratio of expiratory or inspiratory time during EIO or EEO, respectively, to that recorded during spontaneous breathing, i.e., as the “inhibitory ratio” (IR). Paired measurements of the EIO and EEO in 26 naturally sleeping newborn and 15 lightly sedated infants at ∼1 yr showed no statistically significant differences in the IR according to technique: mean (95% CI) of the difference (EIO − EEO) being −0.02 (−0.17, 0.13) during the first week of life and 0.04 (−0.14, 0.22) at 1 yr. During tidal breathing, a volume threshold of ∼4 ml/kg was required to evoke the HBIR. Marked volume and age dependency were observed. In newborn infants, occlusions at ∼10 ml/kg during sighs always resulted in an IR > 4, whereas a similar response was only evoked at 25 ml/kg in older infants. Age-related changes in the volume threshold may reflect maturational changes in the control of breathing and respiratory mechanics throughout the first year of life.

scholarly journals Production of granulocyte colony-stimulating factor in vitro by monocytes from preterm and term neonates [see comments]

Blood ◽  
1993 ◽  
Vol 82 (8) ◽  
pp. 2478-2484 ◽  
Author(s):  
KR Schibler ◽  
KW Liechty ◽  
WL White ◽  
RD Christensen
Keyword(s):  
Newborn Infants ◽  
Preterm Neonates ◽  
Granulocyte Colony Stimulating Factor ◽  
Serum Concentrations ◽  
Colony Stimulating Factor ◽  
Term Infants ◽  
Term Neonates ◽  
And Function ◽  
Stimulating Factor

Abstract We postulated that defective generation of granulocyte colony- stimulating factor (G-CSF) by cells of newborn infants might underlie their deficiencies in upregulating neutrophil production and function during bacterial infection. To test this, we isolated monocytes from the blood of preterm neonates, term neonates, and adults and, after stimulation with various concentrations of interleukin-1 alpha (IL-1 alpha) or lipopolysaccharide (LPS), quantified G-CSF concentrations in cell supernatants and G-CSF mRNA in cell lysates. When stimulated with plateau concentrations of IL-1 alpha for 24 hours, G-CSF concentrations were higher in supernatants of adult cells (8,699 +/- 5,529 pg/10(6) monocytes) than in those from term infants (2,557 +/- 442 pg, P < .05) or from preterm infants (879 +/- 348 pg, P < .05 v adults). When stimulated with plateau concentrations of LPS, supernatants of monocytes from preterm neonates had less G-CSF than did those from term neonates or adults. G-CSF mRNA content was low in cells from preterm infants, higher in those from term infants, and highest in those from adults. On the basis of the in vitro studies, we speculated that serum G-CSF concentrations might be less elevated in neutropenic neonates than in neutropenic adults. Indeed, serum concentrations were relatively low in all nonneutropenic subjects; 92 +/- 34 pg/mL (mean +/- SEM) in 10 preterm neonates, 114 +/- 21 pg/mL in 16 term neonates, and 45 +/- 13 pg/mL in 11 healthy adults. Serum concentrations were not elevated in 7 neutropenic neonates (39 +/- 17 pg/mL) but were in 8 neutropenic adults (2101 +/- 942 pg/mL, P < .05 v healthy adults). Other studies suggested that the lower G-CSF production in neonates is not counterbalanced by a heightened sensitivity of G-CSF--responsive progenitors to G-CSF. Therefore, we speculate that newborn infants, particularly those delivered prematurely, generate comparatively low quantities of G-CSF after inflammatory stimulation, and that this might constitute part of the explanation for their defective upregulation of neutrophil production and function during infection.

Intrinsic Laryngeal Muscle Activity in a Spastic Dysphonia Patient

1985 ◽  
Vol 50 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Thomas Shipp ◽  
Krzysztof Izdebski ◽  
Charles Reed ◽  
Philip Morrissey
Keyword(s):  
Muscle Activity ◽  
Emg Activity ◽  
Muscle Paralysis ◽  
Normal Morphology ◽  
Laryngeal Muscles ◽  
Laryngeal Muscle ◽  
Intrinsic Laryngeal Muscle ◽  
Posterior Cricoarytenoid ◽  
Recurrent Laryngeal Nerves ◽  
Intrinsic Laryngeal Muscles

EMG activity from four intrinsic laryngeal muscles (thyroarytenoid, posterior cricoarytenoid, interarytenoid, and cricothyroid) was obtained from one female spastic dysphonia patient while she performed a variety of speech and nonspeech tasks. These tasks were performed before and during a period of temporary unilateral laryngeal muscle paralysis. In the nonparalyzed condition, adductory muscle activity showed intermittent sudden increases that coincided with momentary voice arrests. These muscle patterns and accompanying voice interruptions were not present either when speech was produced in falsetto register or at anytime during the paralysis condition. The data suggest that individuals with this type of spastic dysphonia have normal morphology of recurrent laryngeal nerves and intrinsic laryngeal muscles, which means that the triggering mechanism(s) for spastic dysphonia symptoms must be located at some point neurologically upstream from the larynx.

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