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.

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.

Specificity of esophageal electrode recordings of posterior cricoarytenoid muscle activity

1989 ◽  
Vol 66 (3) ◽  
pp. 1501-1505 ◽  
Author(s):  
G. Insalaco ◽  
G. Sant'Ambrogio ◽  
F. B. Sant'Ambrogio ◽  
S. T. Kuna ◽  
O. P. Mathew
Keyword(s):  
Marked Decrease ◽  
Upper Airway ◽  
Emg Activity ◽  
Small Reduction ◽  
Posterior Cricoarytenoid Muscle ◽  
Intramuscular Electrodes ◽  
Inspiratory Activity ◽  
Recorded Activity ◽  
Posterior Cricoarytenoid ◽  
The Right

Esophageal electrodes have been used for recording the electromyographic (EMG) activity of the posterior cricoarytenoid muscle (PCA). To determine the specificity of this EMG technique, esophageal electrode recordings were compared with intramuscular recordings in eight anesthetized mongrel dogs. Intramuscular wire electrodes were placed in the right and left PCA, and the esophageal electrode was introduced through the nose or mouth and advanced into the upper esophagus. On direct visualization of the upper airway, the unshielded catheter electrode entered the esophagus on the right or left side. Cold block of the recurrent laryngeal nerve (RLN) ipsilateral to the esophageal electrode was associated with a marked decrease in recorded activity, whereas cold block of the contralateral RLN resulted only in a small reduction in activity. After supplemental doses of anesthesia were administered, bilateral RLN cold block essentially abolished the activity recorded with the intramuscular electrodes as well as that recorded with the esophageal electrode. Before supplemental doses of anesthesia were given, especially after vagotomy, the esophageal electrode, and in some cases the intramuscular electrodes, recorded phasic inspiratory activity not originating from the PCA. Therefore, one should be cautious in interpreting the activity recorded from esophageal electrodes as originating from the PCA, especially in conditions associated with increased respiratory efforts.

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.

SULFONAMIDE ADMINISTRATION IN NEWBORN AND PREMATURE INFANTS

PEDIATRICS ◽  
1956 ◽  
Vol 18 (1) ◽  
pp. 50-58
Author(s):  
Elaine G. Fichter ◽  
John A. Curtis
Keyword(s):  
Body Weight ◽  
Single Dose ◽  
Premature Infants ◽  
Initial Dose ◽  
Newborn Infants ◽  
Full Term ◽  
Therapeutic Concentration ◽  
Term Infants ◽  
Single Subcutaneous Injection ◽  
Oral Preparation

All newborn infants, both full-term and premature, who received, on the first day of life, a single subcutaneous injection of sulfadiazine, 100 mg./kg. body weight, maintained a satisfactory concentration of sulfonamide in the blood for 48 hours thereafter. This therapeutic concentration was subsequently maintained by single 24-hour doses of 50 mg./kg. body weight given subcutaneously, or by single 12-hour doses of 50 mg./kg. body weight given orally. A therapeutic concentration in the blood is generally considered to be a minimum of 5 mg./100 ml. Based on these data the authors recommend the following sulfonamide dosage schedules: A. Infants under 24 hours of age, full-term and premature: 1) subcutaneous sodium sulfadiazine, initial dose 100 mg./ kg. body weight, followed in 48 hours by 50 mg./kg. body weight as a single dose, and repeated each 24-hour period thereafter, or 2) subcutaneous sodium sulfadiazine, initial dose 100 mg./kg. body weight, followed in 48 hours by an oral preparation in the amount of 50 mg./kg. as a single oral dose, each 12-hour period thereafter. (This was evaluated only in full-term infants.) B. Premature infants over 48 hours of age. (This dosage schedule is comparable to that generally accepted for older infants and children): 1) subcutaneous sodium sulfadiazine, initial dose 100 mg./kg. body weight, followed in 12 hours by 50 mg./kg. body weight as a single dose, each 12-hour period thereafter, or 2) oral sulfonamide preparation, initial dose 100 mg./kg. body weight, followed in 12 hours by 50 mg./kg. body weight as a single dose, each 12-hour period thereafter.

Apnea duration is related to ventilatory oscillation characteristics in newborn infants

1984 ◽  
Vol 57 (2) ◽  
pp. 536-544 ◽  
Author(s):  
T. B. Waggener ◽  
A. R. Stark ◽  
B. A. Cohlan ◽  
I. D. Frantz
Keyword(s):  
Premature Infants ◽  
Newborn Infants ◽  
Face Mask ◽  
Full Term ◽  
Minimum Phase ◽  
Breathing Patterns ◽  
Term Infants ◽  
Apnea Duration ◽  
Band Pass ◽  
The Relationship

The occasional short apneas seen in full-term infants within the first postnatal week are related to the minimum phase of oscillatory breathing patterns. To determine the relationship between breathing patterns and the longer and more frequent apneas seen in premature infants, we monitored respiration in 14 premature infants using a face mask and pneumotachograph. Tidal volume, breath duration, and ventilation were calculated on a breath by breath basis, converted to time-axis data strings, and filtered with a comb of zero phase shift digital band pass filters to detect breathing patterns. Compared with full-term infants, premature infants had breathing patterns that occurred more often and had twice the average amplitude. Of 182 apneas greater than or equal to 3 s long, 94% occurred at the minimum phase of oscillatory breathing patterns. All of the 38 apneas greater than or equal to 10 s long occurred at the minimum phase of oscillatory breathing patterns. Duration of apnea was related to breathing pattern characteristics, e.g., longer apneas were related to stronger, longer cycle-time breathing patterns. Apnea in the premature infant is not an isolated event but is one aspect of an underlying pattern.

DEVELOPMENT OF NEONATAL ELECTROLYTE HOMEOSTASIS

PEDIATRICS ◽  
1951 ◽  
Vol 8 (1) ◽  
pp. 68-78
Author(s):  
BRUCE D. GRAHAM ◽  
JAMES L. WILSON ◽  
MAKEPEACE U. TSAO ◽  
MARY L. BAUMANN ◽  
SHIRLEY BROWN
Keyword(s):  
Premature Infants ◽  
Newborn Infants ◽  
Full Term ◽  
Similar Data ◽  
Term Infants ◽  
Base Content ◽  
Essentially Normal ◽  
Blood Ph ◽  
Electrolyte Homeostasis ◽  
Total Base

A study was made of the development of chemical homeostasis in the newborn infant. In a series of 43 essentially healthy, full term, newborn infants, serial determinations during the first day of life of blood pH, plasma CO2, chloride and total base content, and serum protein were made. Comparison with similar data on premature infants and adults is presented. Most full term infants at birth are in a state of metabolic acidosis with a lowered blood pH and plasma CO2 content, but have essentially normal plasma chlorides and total base values. The majority of these infants within a few hours have a blood pH of adult level but maintain for some time a lowered CO2 content.

FURTHER STUDIES ON THE EFFECTS OF HYPOXIA ON THE RESPIRATION OF NEWBORN INFANTS

PEDIATRICS ◽  
1955 ◽  
Vol 16 (1) ◽  
pp. 93-103
Author(s):  
Herbert C. Miller ◽  
Ned W. Smull
Keyword(s):  
Tidal Volume ◽  
Respiratory Rate ◽  
Premature Infants ◽  
Newborn Infants ◽  
Full Term ◽  
The Other ◽  
Cent Oxygen ◽  
Term Infants ◽  
Other Hand ◽  
Hypoxic State

The response to breathing 12 per cent oxygen by newborn premature and full-term infants and premature infants several weeks old has been studied. Comparisons show that newborn premature and full-term infants during the first days after birth failed to respond with increases in respiratory rate or tidal volume during the hypoxic state. In fact, there was some decrease in ventilation which was largely related to reductions in tidal volume. Premature infants several weeks old, on the other hand, showed an immediate and significant hyperpnea while breathing 12 per cent oxygen. The younger infants, particularly the premature infants, seemed to be less disturbed by the hypoxia than older infants. These results substantiated previous results obtained on full-term infants. The hypothesis was advanced that the chemoreceptor reflexes were less active immediately following birth than later on in life.

THE EFFECT OF POSITION ON THE RESPIRATORY RATE OF PREMATURE AND MATURE NEWBORN INFANTS

PEDIATRICS ◽  
1958 ◽  
Vol 22 (3) ◽  
pp. 432-435
Author(s):  
Harvey Kravitz ◽  
Lawrence Elegant ◽  
Bernard Block ◽  
Mary Babakitis ◽  
Evelyn Lundeen
Keyword(s):  
Respiratory Rate ◽  
Premature Infant ◽  
Prone Position ◽  
Premature Infants ◽  
Supine Position ◽  
Newborn Infants ◽  
Full Term ◽  
Term Infants ◽  
Definite Effect

Values for respiratory rates in the supine and prone positions in 96 premature and 49 full-term infants have been presented. Premature infants have a significant increase in respiratory rate in the prone position compared to the supine position. This difference decreases with increasing weight and age. Mature infants show a slight increase in respiratory rate in the prone compared to the supine position. The position of the premature infant has a definite effect on the physiology of respiration. Further studies must be done to establish whether the supine or prone position is superior. Irregularity of rate and amplitude of respirations are noted in the supine position, while respirations of regular rate and amplitude are frequently found in the prone position. The amplitude of respiration was greater in the supine position than in the prone position.

Upper airway stability and respiratory muscle activity during inspiratory loading in full-term neonates

1994 ◽  
Vol 77 (1) ◽  
pp. 37-42 ◽  
Author(s):  
S. Duara ◽  
M. Rojas ◽  
N. Claure
Keyword(s):  
Upper Airway ◽  
Receptor Activation ◽  
Full Term ◽  
Respiratory Resistance ◽  
Inspiratory Time ◽  
Quiet Sleep ◽  
Term Infants ◽  
Posterior Cricoarytenoid ◽  
Pressure Changes ◽  
Extrathoracic Airway

To investigate the role of genioglossus and posterior cricoarytenoid (PCA) activity in stabilizing the extrathoracic airway (ETA) of full-term infants during inspiratory flow-resistive loading (IRL), 10 unsedated full-term infants were evaluated in quiet sleep. IRLs were randomly imposed (L2, 125 cmH2O.l–1.s; L3, 250 cmH2O.l–1.s). Ventilation, total respiratory resistance (a correlate of ETA resistance), and moving time averages of PCA, submental activity of the genioglossus (SM), and diaphragm electromyogram were obtained. Results revealed no phasic activity in the SM during baseline breathing or with either IRL. Phasic PCA activity was always observed; burst duration increased with L2 and L3 (P < 0.01) and commenced earlier in relation to the onset of inspiratory airflow with both loads (P < 0.05). PCA activity always preceded that of the diaphragm and invariably outlasted it other than with L3. The upper airway negative pressure changes induced by IRL were insufficient to recruit SM activity; other potential stimuli such as transcutaneous PO2, transcutaneous PCO2, and pulmonary stretch receptor activation (increase in tidal volume) remained unchanged. Ventilation decreased with both loads (L3: P < 0.01), esophageal and mouth pressures increased (P < 0.01), and inspiratory time and inspiratory time divided by total time were both prolonged (P < 0.01). Total respiratory resistance remained unchanged with L2 but increased with L3 (P < 0.01). We concluded that ETA narrowing may be induced in full-term infants during quiet sleep with moderately large-sized IRL and that it is not entirely ameliorated by activation of the SM or PCA or by arousal.

VITAMIN E BLOOD LEVELS IN PREMATURE AND FULL TERM INFANTS

PEDIATRICS ◽  
1951 ◽  
Vol 7 (3) ◽  
pp. 386-393
Author(s):  
STANLEY W. WRIGHT ◽  
LLOYD J. FILER ◽  
KARL E. MASON
Keyword(s):  
Vitamin E ◽  
Premature Infants ◽  
Placental Transfer ◽  
Newborn Infants ◽  
Full Term ◽  
Blood Levels ◽  
Rapid Decline ◽  
Term Infants ◽  
Breast Fed

Newborn infants showed serum tocopherol levels approximately one-fifth those of the maternal levels. During the first six days after birth, the serum tocopherols of breast-fed infants increased much more rapidly than those of bottle-fed infants. These differences were still evident at 1 to 4, and at 5 to 8, months of age. Premature infants fed an artificial formula low in vitamin E showed a rapid decline in serum tocopherol levels. These studies confirm and amplify other evidence that placental transfer of vitamin E is decidedly limited while mammary transfer is much more extensive.

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