ABSTRACT: Pediatric asthma exacerbations may correlate with changes in weather, yet this relationship is not well defined.
To determine the effects of fluctuations in climatic factors (temperature, humidity, and barometric pressure) on pediatric asthma exacerbations.
A retrospective study was performed at 1 large urban hospital during a 2-year period (January 1, 2004, to December 31, 2005). Children presenting to the emergency department (ED) for an asthma exacerbation were included. Data on climactic factors, pollutants, and aeroallergens were collected daily. The relationship of daily (intraday) or between-day (interday) changes in climactic factors and asthma ED visits was evaluated using time series analysis, controlling for seasonality, air pollution, and aeroallergen exposure. The effects of climactic factors were evaluated on the day of admission (T=0) and up to 5 days before admission (T-5 through T-1).
There were 25,401 asthma ED visits. A 10% intraday increase in humidity on day T-1 or day T-2 was associated with approximately 1 additional ED visit for asthma (P < .001 and P = .01, respectively). Interday changes in humidity from day T - 3 to T-2 were also associated with more ED visits (P < .001). Interday changes in temperature from T-1 to T = 0 increased ED visits, with a 10 degrees F increase being associated with 1.8 additional visits (P = .006). No association was found with changes in barometric pressure.
Fluctuations in humidity and temperature, but not barometric pressure, appear to influence ED visits for pediatric asthma. The additional ED visits occur 1 to 2 days after the fluctuation.
Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 09/2009; 103(3):220-4. · 2.83 Impact Factor
ABSTRACT: The reproducibility of exhaled nitric oxide (FE(NO)) measurements performed in pediatric hospitalized asthmatics has not been previously evaluated.
To evaluate the reproducibility of FE(NO) measurements in the hospital; to look for differences between those who were and were not able to perform FE(NO) measurements; and to assess any factors correlated with FE(NO) measurements.
89 hospitalized pediatric asthmatics performed FE(NO), FEV1, and peak expiratory flow rate (PEFR) maneuvers in triplicate at the time of discharge. Reproducibility was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). Demographic and measured variables were compared between those who were and were not able to perform FE(NO) measurements. Correlation of FE(NO) with other variables was investigated.
FE(NO) measurements showed clinically acceptable ICC and CV values (0.973 and 5.59%, respectively). These values were superior to the values obtained for FEV1 and PEFR. Subjects who successfully performed the FE(NO) measurements were older, had higher PEFR readings, and had a lower asthma dyspnea score. No correlation was found between FE(NO) and traditional asthma factors, though multiple factors did trend towards significance.
FE(NO) measurements can be obtained in hospitalized pediatric patients with good reproducibility. While the majority of children will be able to provide such readings, those who are younger and with a more severe exacerbation may be unsuccessful in doing so. Further research is needed to determine how best to incorporate FE(NO) values into the hospital setting.
Journal of Asthma 11/2008; 45(8):670-4. · 1.52 Impact Factor
ABSTRACT: Fraction of exhaled nitric oxide (FE(NO)) measurements performed on patients with acute asthma in the emergency department (ED) have previously shown poor reproducibility.
To evaluate the reproducibility of FE(NO) measurements in the ED using a new monitoring device, to evaluate any factors that may correlate with FE(NO) measurements, and to investigate if FE(NO) levels predict the need for admission to the hospital.
Thirty-five adult patients with asthma seen in the ED performed FE(NO), forced expiratory volume in 1 second, and peak expiratory flow rate maneuvers in triplicate. Reproducibility was evaluated using the intraclass correlation coefficient and the coefficient of variation. Associations between FE(NO), demographic, and traditional asthma measurements were investigated. The FE(NO) levels between patients admitted for further care and those discharged home were compared.
The FE(NO) measurements showed acceptable intraclass correlation coefficient and coefficient of variation values (0.98 and 9.42%, respectively) for reproducibility. These values were superior to the values obtained for forced expiratory volume in 1 second and peak expiratory flow rate. No correlation was found between FE(NO) and traditional asthma factors, although length of the asthma attack trended toward statistical significance (P = .08). The FE(NO) levels did not differ between those admitted and those discharged home (P = .53).
Fraction of exhaled nitric oxide measurements can be obtained in the ED setting with good reproducibility. These measurements may provide useful information not obtainable by other means. Further research is needed to determine how best to incorporate FE(NO) values into the ED setting.
Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 06/2008; 100(5):415-9. · 2.83 Impact Factor
ABSTRACT: The time required for fractional excretion of nitric oxide (FE(NO)) measurements to acutely change after systemic corticosteroids is unknown, limiting the usefulness of this biomarker in hospital treatment and discharge decisions. The purpose of this study was to follow FE(NO) measurements of hospitalized adult patients with asthma receiving therapy and to correlate FE(NO) with forced expiratory volume in 1 second percent predicted (FEV(1)%). Ten acute asthmatic patients who required hospitalization were recruited and treated with standard therapy. FE(NO) measurements were performed at presentation to the emergency department (baseline), as well as 1, 4, 6, 8, 12, and 24 hours after the initiation of therapy. FEV(1)% was measured at baseline, 1, 6, 12, and 24 hours. Subjects also were called 3 days after discharge to assess if symptoms had improved. The baseline FE(NO) was 57.5 parts per billion (ppb). There was no significant change over the first 8 hours. At 12 hours, there was an increase to 96.5 ppb (p = 0.01). Compared with baseline, all 10 subjects showed an increase at the 12-hour time point, with an average increase of 52%. The correlation between change in FE(NO) and change in FEV(1)% approached significance (p = 0.089). Subjects who improved after discharge had a greater percent increase in FE(NO) than those who did not (p = 0.043). FE(NO) measurements increase in hospitalized asthmatic patients receiving therapy. This augmentation appears to be associated with improvements in FEV(1). Asthmatic patients who show a greater increase in FE(NO) may have better outcomes after discharge.
Allergy and Asthma Proceedings 29(2):171-6. · 2.17 Impact Factor