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STUDY OBJECTIVES Pulse-oximetry (SpO2 ) allows the identification of important clinical physiology. However, summary statistics such as mean values and desaturation incidence do not capture the complexity of the information contained within continuous recordings. The aim of this study was to develop an objective method to quantify important SpO2 characteristics; and assess its utility in healthy infant and preterm neonate cohorts. METHODS An algorithm was developed to calculate the desaturation incidence, depth, and duration. These variables are presented using three plots: SpO2 cumulative-frequency relationship; desaturation-depth versus incidence; desaturation-duration versus incidence. This method was applied to two populations who underwent nocturnal pulse-oximetry: (1) thirty-four healthy term infants studied at 2-weeks, 3, 6, 12, and 24-months of age and (2) thirty-seven neonates born

Background: In adults, ventilation is preferentially distributed towards the dependent lung. A reversal of the adult pattern has been observed in infants using radionuclide ventilation scanning. But these results have been obtained in infants and children with lung disease. In this study we investigate whether healthy infants have a similar reverse pattern of ventilation distribution. Study Design: Measurement of regional ventilation distribution in healthy newborn infants during non-REM sleep in comparison to adults. Methods: Twenty-four healthy newborns and 13 adults were investigated with electrical impedance tomography (EIT) in supine and prone position. Regional ventilation distribution was assessed with profiles of relative impedance change. The phase lag between dependent and non-dependent ventilation was calculated as a measure of asynchronous ventilation. Results: In newborns and adults the geometric center of ventilation was centrally located in the lung at 52.2 +/- 6.2% from anterior to posterior and at 50.5 +/- 14.7%, respectively Using impedance profiles, ventilation was equally distributed to the dependent and non-dependent lung regions in newborns. Ventilation distribution in adults was similar Phase lag characteristics of the impedance signal showed that infants had slower emptying of the dependent lung than adults. Conclusion: The speculated reverse pattern of regional ventilation distribution in healthy infants compared to adults could not be demonstrated. Gravity had little effect on ventilation distribution in both infants and adults measured in supine and prone position. Pediatr Pulmonol. 2009;44:851-858. (C) 2009 Wiley-Liss, Inc.

High-resolution computed tomography (HRCT) is a sensitive technique for early visualisation and location of cystic fibrosis (CF) bronchopathology, and has been shown to detect acute reversible and chronic changes. It would be expected to correlate with markers of the underlying pathological processes, such as sputum cytokines and cytology, as well as with pulmonary function tests (PFTs). Our aim was to study the relationship between PFTs, sputum cytology, and sputum cytokine interleukin-8 (IL-8) and HRCT in CIF patients. Prospective standardized collection of sputum samples was performed at the time of routine annual high-resolution CT scans. Forced expired volume in 1 sec (FEV1) and forced vital capacity (FVC) were recorded. Sputum processing was selective, with dispersal by the three-enzyme technique. IL-8 measurements were by kit assay. HRCT scans were scored by a pediatric radiologist, blinded to clinical condition, using a modified Bhalla score.Forty-three CT scans were performed on 34 children with CIF between March 1998 and April 2000. Mean age was 12.3 years (range, 6-21 years), FEV1 (% predicted) was 67% (range, 23-120%), and mean modified Bhalla score was 11.2 (range, 0-22). Sputum IL-8 concentration (mean, 86; range, 4-150 ng/mL) and total cell count (mean, 31.9 x 10(6)/mL; range, 21.8-42.0 x 10(6)/mL) were high. FEV1 and FVC correlated with modified Bhalla score (r = -0.66, P < 0.0001 for both), and most individual components of the score, especially mosaic perfusion (r = -0.64, r = -0.61 respectively, P < 0.0001) and extent of bronchiectasis (r = -0.61, P < 0.0001 for both). The combination of these two predicted 58% of the variability in FEV1 on analysis of variance (P < 0.0001). Sputum total cell count correlated weakly with modified Bhalla score (r = 0.38, P < 0.05) and with FEV1 and FVC (r = -0.36, P < 0.05; and r= -0.46, P < 0.01). Differential cell counts, cell viability, and IL-8 did not correlate with modified Bhalla scores, or with reversible components such as mucus plugging, centrilobular nodules, or peribronchial thickening.In conclusion, pathological changes on HRCT correlated with lung function but not with sputum markers of inflammation. (C) 2002 Wiley-Liss, Inc.

In adults, ventilation is preferentially distributed towards the dependent lung. A reversal of the adult pattern has been observed in infants using radionuclide ventilation scanning. But these results have been obtained in infants and children with lung disease. In this study we investigate whether healthy infants have a similar reverse pattern of ventilation distribution.Measurement of regional ventilation distribution in healthy newborn infants during non-REM sleep in comparison to adults.Twenty-four healthy newborns and 13 adults were investigated with electrical impedance tomography (EIT) in supine and prone position. Regional ventilation distribution was assessed with profiles of relative impedance change. The phase lag between dependent and non-dependent ventilation was calculated as a measure of asynchronous ventilation.In newborns and adults the geometric center of ventilation was centrally located in the lung at 52.2 +/- 6.2% from anterior to posterior and at 50.5 +/- 14.7%, respectively. Using impedance profiles, ventilation was equally distributed to the dependent and non-dependent lung regions in newborns. Ventilation distribution in adults was similar. Phase lag characteristics of the impedance signal showed that infants had slower emptying of the dependent lung than adults.The speculated reverse pattern of regional ventilation distribution in healthy infants compared to adults could not be demonstrated. Gravity had little effect on ventilation distribution in both infants and adults measured in supine and prone position.

Objective: Our aim was to determine the safety of BAL in young children

Despite the importance of pulmonary exacerbations in CF in both clinical and research settings, both published evidence and consensus are lacking concerning the criteria used to define an exacerbation. The use of hospitalization as a surrogate measure presupposes uniformity among clinicians in diagnosis and treatment of exacerbations. Our aims were to evaluate consensus among clinicians about the variables considered helpful in diagnosing an exacerbation requiring treatment. A comprehensive list of symptoms, signs, and investigations used to define exacerbations was compiled from published trials. A written self-administered questionnaire included the list in age-appropriate groups to survey opinion about the helpfulness of each item, and the estimated proportion of patients admitted within a month of diagnosis of an exacerbation. This was sent to all clinicians managing CF patients in Australia. There were replies from 59/91 clinicians (65%), 41/60 (68%) from those managing children and 18/31 (58%) from those managing adults. Responses of those managing children and adults differed for 7/32 variables (Mann-Whitney test, P0.05). Clinic grouping did not show greater consensus among responses of pediatricians (Kruskal-Wallis test, P = 0.362). Consensus,74% or26% of respondents rating a variable helpful/very helpful, was found in only 50% of variables listed. Estimated admission rate within a month of diagnosis was 61% (30-100%) for those managing adults and 48% %5-100%) for pediatricians. A lack of consensus was found among clinicians managing CF about the variables considered in diagnosing an exacerbation. The estimated proportion admitted within a month of diagnosis was very variable. This demonstrated inhomogeneity in approach to diagnosis and management of an exacerbation suggests a significant heterogeneity of clinical care.