Pediatric pulmonology
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Pediatric pulmonology · Apr 1996
Randomized Controlled Trial Comparative Study Clinical TrialChest physiotherapy and post-extubation atelectasis in infants.
We investigated the role of chest physiotherapy (CPT) in preventing post-extubation atelectasis (PEA) in infants. Sixty-three infants who were admitted to the neonatal intensive care unit and intubated for more than 24 hours and who showed no evidence of atelectasis by chest x-ray prior to extubation were enrolled in the study. Infants were randomly assigned to 2-hourly CPT, 4-hourly CPT, or a no CPT group. ⋯ In the 24-hour period following extubation, the incidence of PEA was not statistically significant in the three groups (P = 0.33). Two infants in the 2-hourly CPT group were placed on nasal continuous positive airway pressure; two in each of the 2-hourly and the no CPT groups required re-intubation and intermittent positive pressure ventilation to treat symptomatic atelectasis. We conclude that post extubation chest physiotherapy as used in this study did not prevent atelectasis in extubated infants.
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Pediatric pulmonology · Apr 1996
Changes in respiratory rate affect tidal expiratory flow indices in infants with airway obstruction.
Among the tidal expiratory flow measurements that have been suggested as surrogate tests for airway obstruction, a short time to reach peak tidal expiratory flow (t(pef)) is the most widely used. Time to peak expiratory flow is most often expressed as the ratio between t(pef) and total expiratory time (t(e)). As te strictly depends inversely on respiratory rate (RR), we studied the hypothesis that an increase in RR (and a fall in t(e)) with the development of airway obstruction during methacholine or histamine challenge in infants could mask a decrease of t(pef) when expressed as t(pef)/t(e). ⋯ The change in t(pef)/t(e) was positively correlated with the change in RR (r = 0.51, P = 0.003). To analyze better the effect of changes in RR on various indices, we divided the patients into two groups: in 17 subjects with a small increase in RR (< 10%), t(e) did not change significantly, while t(pef) and t(pef)/t(e) did; in 16 subjects with a more marked increase in RR (> or = 10%), the shortening of te masked the simultaneous shortening of t(pef), so that t(pef)/t(e) did not change. These data demonstrate that t(pef)/t(e) cannot be reliably used to evaluate changes in airway obstruction when concomitant changes in RR occur.
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Pediatric pulmonology · Apr 1996
Lung volume measurements immediately after extubation by prediction of "extubation failure" in premature infants.
To test the hypothesis that premature infants in whom extubation fails in the first 10 days of life have low volume lungs, functional residual capacity (FRC) was measured in the first hour after extubation. Once extubated, infants received the appropriate level of inspired oxygen necessary to maintain acceptable arterial oxygen saturation. After humidification, oxygen was bled into a headbox, and FRC was assessed using a helium gas dilution technique and a specially designed infant circuit. ⋯ In the infants who failed extubation, the median FRC was 19 ml/kg (range, 12-27 ml/kg), which was lower than that of the infants in whom extubation was successfully accomplished (median, 28 ml/kg; range, 19-37 ml/kg; P < 0.01). An FRC of less than 26 ml/kg had a sensitivity of 71% and specificity of 77% in predicting extubation failure. These results support the hypothesis that a very low lung volume relates to extubation failure in the first 10 days of life.