Pediatric pulmonology
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The present study was designed to investigate the development of respiratory control during feeding in premature infants. Cardiorespiratory disturbances during feeding were evaluated with polygraphic monitoring in 24 premature infants within 1 week of beginning nipple feeds. During the initial study, 15 infants exhibited one or more episodes of short apnea (greater than or equal to 10 sec) and three infants exhibited prolonged apnea (greater than or equal to 20 sec). ⋯ Short apnea persisted during sleep in four infants during reevaluation. Most of the apneic episodes in both studies were mixed apnea. The high frequency of cardiorespiratory disturbances during the first 2 weeks of nipple feeding indicates that in most preterm infants respiratory control during feeding is still immature at the postconceptional age of 35-36 weeks.
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Pediatric pulmonology · Jan 1988
Airway obstruction and airway wall instability in cystic fibrosis: the isolated and combined effect of theophylline and sympathomimetics.
Multiple aspects of lung function were measured in 17 cystic fibrosis (CF) patients on four occasions: without therapy (0); with oral theophylline medication (Th); after inhalation of salbutamol (beta 2); and with combined medication (Th + beta 2). In addition to routine measurements, partial and maximum expiratory flow-volume (MEFV) curves were superimposed, and the flow transient equivalent of the MEFV curve was determined. Its volume dimension (volume of airway contribution, VACMEFV) partially reflects airway distensibility. ⋯ Early expired volume and flow rates as well as VACMEFV showed no significant difference between beta 2 alone and Th + beta 2; airway resistance even decreased significantly with this drug combination. End-expiratory flow rate, however, was significantly lower after Th + beta 2 than after beta 2 alone. Although theophylline does not alter lung function in most patients with CF, sympathomimetics relieve bronchospasm in many, but they enhance airway compressibility and thereby decrease peripheral expiratory airflow in some.(ABSTRACT TRUNCATED AT 250 WORDS)
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Pediatric pulmonology · Jan 1988
ReviewNoninvasive determination of respiratory mechanics during mechanical ventilation of neonates: a review of current and future techniques.
Study of the mechanical properties of the respiratory system is needed to help provide a better understanding of the pathogenesis of diseases causing respiratory failure. The nature of neonatal intensive care requires that any technique for monitoring respiratory mechanics be simple, noninvasive, and allow continued free access to the neonate. The peak airway pressure developed during volume cycled ventilation reflects the mechanical properties of the respiratory system but cannot distinguish between changes in the flow-resistive or elastic properties. ⋯ Furthermore, flow-volume loops are markedly distorted by the presence of an endotracheal tube, which must be corrected for, before calculating values of resistance and compliance. To provide the information to understand better the physiologic processes and adaptive mechanisms in diseased states causing acute respiratory failure, it is necessary to use a method that is based on a more detailed and realistic model of the respiratory system. Two such techniques that appear to warrant further investigation in ventilated infants are the interrupter technique and the forced-oscillation technique.
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Even in the high-technology medical imaging arena, the decision of how to first image pediatric chest disease is quite simple: by plain chest radiograph, including frontal and lateral views. The diagnosis can often be made or suggested on the basis of these films or with other basic imaging procedures, such as fluoroscopy or esophagram. From this point onward the decision how to proceed with further imaging such as ultrasound, computed tomography, nuclear medicine imaging, or magnetic resonance imaging, will depend on the probability of gaining further helpful information. ⋯ One must keep in mind that in some cases the diagnosis cannot be made radiologically and must be left to the pathologist. In these cases the work-up should end when no further progress is possible toward making the diagnosis. In the pediatric age group, one should always strive to limit the amount of unnecessary radiation exposure.
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Pediatric pulmonology · Jan 1988
Stimulus parameters for phrenic nerve pacing in infants and children.
Phrenic nerve pacing has been used since 1966 to support breathing in quadriplegics and patients with central hypoventilation syndrome (CHS). Recently, using low-frequency, long-inspiratory-time (Ti) stimulation, phrenic nerve pacing has been used successfully to support breathing 24 hours per day in adults and older children. However, no similar experience exists for infants and young children. ⋯ At an average respiratory rate of 21 +/- 8 breaths/min it was thus possible to maintain adequate ventilation despite a marked reduction in the number of phrenic nerve stimuli. Theoretically, these reductions in phrenic nerve stimulation should minimize the chance of pacing-induced diaphragmatic damage. These results suggest that 24 hour per day phrenic nerve pacing may be a realistic goal in selected infants and children.