Pediatric pulmonology
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Pediatric pulmonology · Jan 1990
Comparative StudyEffect of spontaneous and mechanical breathing on dynamic lung mechanics in hyaline membrane disease.
We measured then compared the dynamic lung mechanics of spontaneous breaths and mechanical breaths in 9 mechanically ventilated neonates with hyaline membrane disease. All were receiving intermittent mandatory ventilation. All breathed spontaneously between ventilator breaths. ⋯ Peak inspiratory and expiratory gas flows were also higher (P less than 0.01) during mechanical breathing. The spontaneous breaths generated by patients and the mechanical breaths generated by mechanical ventilators are different. The lung mechanics measurements of these two different types of breathing should be collected, analyzed, and reported separately.
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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)
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Pediatric pulmonology · Jan 1990
Evaluation of a mainstream capnometer and end-tidal carbon dioxide monitoring in mechanically ventilated infants.
We evaluated a new lightweight capnometer with a less than 1 mL deadspace neonatal airway adapter and endotracheal tube connector unit (NAC) for use in mechanically ventilated neonates. The evaluation consisted of: 1) a bench test comparison of air flow resistance between the standard endotracheal tube and connector with the new NAC (flow rates, 1.5 to 12.8 L/min); 2) a determination of the effect of NAC placement on Paco2; 3) pre- and post-NAC pulmonary mechanics; and 4) analysis of paired PetCO2 and PACO2 in 16 infants requiring mechanical ventilation. ⋯ All post-NAC placement Paco2 were smaller than pre-placement values; there were no differences in pulmonary mechanics, and Petco2 correlated closely with Paco2 (n = 132, r = 0.79) defined as Petco2 = 0.68. Paco2 + 5.52; means +/- 1 SD, Paco2 -Petco2 was 4.7 +/- 4.7 torr and Petco2/Paco2 was 0.86 +/- 0.14.
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Pediatric pulmonology · Jan 1990
Compliance, alveolar-arterial oxygen difference, and oxygenation index changes in patients managed with extracorporeal membrane oxygenation.
Eighteen patients with meconium aspiration syndrome who failed conventional management were treated with extracorporeal membrane oxygenation (ECMO) for reversible respiratory failure. Dynamic lung compliance measurements were made prior to, during, and after ECMO support. ⋯ P(A-a)O2 and OI decreased significantly from before to after ECMO. The improvement in oxygenation allowing removal from ECMO does not appear to be related to improved pulmonary mechanics, but may rather be secondary to increased effective pulmonary capillary blood flow.
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Considerable practice is necessary to develop the skills essential to successful and safe performance of flexible bronchoscopy, especially in pediatric patients. We review a number of model systems, both mechanical and living, for learning and maturing bronchoscopic skills. For each of the animal models (canine, feline, leporine, and simian), the relevant anatomy and anesthetic techniques as well as the relative advantages and disadvantages of each model are discussed.