Pediatric pulmonology
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Pediatric pulmonology · Jan 1990
Prospective pneumogram recordings in preterm infants with and without clinical apnea and bradycardia.
Recordings of breathing movements and heart rate (pneumograms) were obtained prospectively in 89 preterm infants at 0-28 days of age to determine if those who develop apnea and/or bradycardia with cyanosis (Group 1) differ from those who do not (Group 2). The 148 pneumograms were blindly analyzed for periodic breathing, bradycardia, longest apnea, and quiet time. Pneumograms were compared between groups at weekly intervals during the first 4 weeks. ⋯ It is concluded that preterm infants who develop apnea and/or bradycardia with cyanosis have a lower mean birthweight and mean weight at recording at less than or equal to 7 days of age than similar asymptomatic preterm infants. Periodic breathing at less than or equal to 7 days of age is associated with the occurrence of clinical symptoms of apnea and/or bradycardia. Normal pneumogram values for groups of 6-21 asymptomatic preterm infants are provided for the first 4 weeks of life.
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Pediatric pulmonology · Jan 1990
Measurements of pulmonary mechanics prior to the elective extubation of neonates.
We measured total respiratory system compliance (CRS) and resistance (RRS) by the passive expiratory flow technique prior to the elective extubation of 61 neonates with a history of respiratory distress syndrome. Successful trials of extubation were characterized by a higher mean value of CRS when compared to trials that led to reintubation (1.52 vs. 1.10 mL/cm H2O, P = 0.004). ⋯ A higher mean value of RRS was recorded in the group of infants who failed extubation when compared to those who were successful (0.22 vs. 0.17 cm H2O/mL/s, P = 0.042). We propose that measurements of pulmonary mechanics, particularly CRS, may be useful in identifying infants who will be at risk for extubation failure.
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Pediatric pulmonology · Jan 1990
Pulmonary mechanics and energetics of normal, non-ventilated low birthweight infants.
Pulmonary mechanics and energetics were determined in 33 healthy low birthweight infants (less than 1,500 g, 28-34 weeks gestation) who had never received ventilatory support. Tidal volume, dynamic pulmonary compliance, pulmonary resistance, pressure-volume relationships, and tidal flow-volume measurements were obtained by pneumotachography and the esophageal balloon technique. Standardized data collection and software data analysis by least mean squares technique yielded data at 0.5, 1, 2, and 4 weeks postnatally, as a function of gestational age (less than 30, 30-32, and greater than 32 weeks gestation). ⋯ Changes in pulmonary mechanics resulted in increasing resistive work of breathing. Our findings suggest a postnatal retardation of pulmonary and airway growth, relative to gestation maturation. These data can provide an objective base of comparison for data in sick, low birthweight neonates.
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Pediatric pulmonology · Jan 1990
Correspondence between forced oscillation and body plethysmography during bronchoprovocation with carbachol in children.
We compared dose-response curves obtained with the forced oscillation technique (FOT) and with body plethysmography during bronchoprovocation in children. In 40 stable asthmatic children (age, 5-16 yr) we performed challenges with doubling concentrations of inhaled carbachol (0.15-10 mg/mL) until specific airway resistance SRaw had increased by 100% (PC100SRaw). The FOT-response was assessed by total respiratory system resistance (Rrs, cmH2O.1(-1).s) and reactance (Xrs, cmH2O.1(-1).s) from 8 to 26 Hz, expressed as mean Rrs (Rrs), mean Xrs (Xrs), Rrs at 8 Hz (Rrs8), and mean slope of Rrs (dRrs/df). ⋯ Multiple regression analysis revealed only the absolute change of Xrs (delta Xrs), baseline Rrs and age as significantly (P less than 0.001) correlated with the percentage change of SRaw (delta %SRaw). Best correlation (r = 0.86) with delta %SRaw was found for the function: FOT score = -102.5 X delta Xrs X exp(-0.196 X Rrs + 0.038 X age). Provocative concentrations estimated by this FOT score differed from PC100SRaw by less than one (two) concentration steps in 34 (40) out of 40 children.(ABSTRACT TRUNCATED AT 250 WORDS)