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Reference Equations (reference + equation)

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Medical Sciences88%

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Reference equation for 6-min walk distance in healthy North African children 6,16 years old,

PEDIATRIC PULMONOLOGY, Issue 4 2009
Helmi Ben Saad MD
Abstract Rationale To assess the need for a 6-min walk distance (6-MWD) reference equation for healthy North African children 6,16 years old. Methods Prospective cross-sectional study. Anthropometric data and 6-MWD were measured in 200 healthy Tunisian children (100 girls) from 6 to 16 years old. Results Published reference equations did not reliably predict measured 6-MWD in North African children. The 6-MWD was significantly correlated with age, height, and weight (P,<,0.001, each). The combination of these parameters explained 60% of the 6-MWD variability in the equation: 6-MWD (m),=,4.63,×,height (cm),,,3.53,×,weight (kg),+,10.42,×,age (years),+ 56.32. In an additional group of 41 children prospectively studied to validate the equation, the agreement between measured and predicted 6-MWD was satisfactory. Conclusion This reliable 6-MWD reference equation enriches the World Bank and provides a useful reference for the care of pediatric patients. Pediatr Pulmonol. 2009; 44:316,324. © 2009 Wiley-Liss, Inc. [source]

Pulmonary diffusion and aerobic capacity: is there a relation?

ACTA PHYSIOLOGICA, Issue 4 2010
Does obesity matter?
Abstract Aim:, We sought to determine whether pulmonary diffusing capacity for nitric oxide (DLNO), carbon monoxide (DLCO) and pulmonary capillary blood volume (Vc) at rest predict peak aerobic capacity (O2peak), and if so, to discern which measure predicts better. Methods:, Thirty-five individuals with extreme obesity (body mass index or BMI = 50 ± 8 kg m,2) and 26 fit, non-obese subjects (BMI = 23 ± 2 kg m,2) participated. DLNO and DLCO at rest were first measured. Then, subjects performed a graded exercise test on a cycle ergometer to determine O2peak. Multivariate regression was used to assess relations in the data. Results:, Findings indicate that (i) pulmonary diffusion at rest predicts O2peak in the fit and obese when measured with DLNO, but only in the fit when measured with DLCO; (ii) the observed relation between pulmonary diffusion at rest and O2peak is different in the fit and obese; (iii) DLNO explains O2peak better than DLCO or Vc. The findings imply the following reference equations for DLNO: O2peak (mL kg,1 min,1) = 6.81 + 0.27 × DLNO for fit individuals; O2peak (mL kg,1 min,1) = 6.81 + 0.06 × DLNO, for obese individuals (in both groups, adjusted R2 = 0.92; RMSE = 5.58). Conclusion:, Pulmonary diffusion at rest predicts O2peak, although a relation exists for obese subjects only when DLNO is used, and the magnitude of the relation depends on gender when either DLCO or Vc is used. We recommend DLNO as a measure of pulmonary diffusion, both for its ease of collection as well as its tighter relation with O2peak. [source]

Reference equation for 6-min walk distance in healthy North African children 6,16 years old,

PEDIATRIC PULMONOLOGY, Issue 4 2009
Helmi Ben Saad MD
Abstract Rationale To assess the need for a 6-min walk distance (6-MWD) reference equation for healthy North African children 6,16 years old. Methods Prospective cross-sectional study. Anthropometric data and 6-MWD were measured in 200 healthy Tunisian children (100 girls) from 6 to 16 years old. Results Published reference equations did not reliably predict measured 6-MWD in North African children. The 6-MWD was significantly correlated with age, height, and weight (P,<,0.001, each). The combination of these parameters explained 60% of the 6-MWD variability in the equation: 6-MWD (m),=,4.63,×,height (cm),,,3.53,×,weight (kg),+,10.42,×,age (years),+ 56.32. In an additional group of 41 children prospectively studied to validate the equation, the agreement between measured and predicted 6-MWD was satisfactory. Conclusion This reliable 6-MWD reference equation enriches the World Bank and provides a useful reference for the care of pediatric patients. Pediatr Pulmonol. 2009; 44:316,324. © 2009 Wiley-Liss, Inc. [source]

Forced inspiratory flow volume curve in healthy young children

PEDIATRIC PULMONOLOGY, Issue 2 2009
Daphna Vilozni PhD
Abstract Introduction Spirometry testing should include both expiratory and inspiratory measurements. Inspiratory forced maneuvers can demonstrate extrathoracic airway abnormalities, of which various symptoms may suggest asthma. However, the inspiratory portion of the forced flow/volume maneuver in young healthy children has not yet been described. Objectives To document and analyze the forced inspiratory flow volume curve indices in healthy young children. Settings and Participants Healthy preschool children (age 2.5,6.5 years) from community kindergartens around Israel. Methods The teaching method included multi-target, interactive spirometry games and accessory games for inspiration (e.g., inspiratory whistle). Results One hundred and fourteen out of a total of 157 children performed duplicate full adequate inspiratory maneuvers. Repeatability between two maneuvers was 5.6%, 4.0%, 5.1%, 7.3% for inspiratory capacity (IC), forced inspiratory vital capacity (FIVC), peak inspiratory flow (PIF), and mid inspiratory flow (FIF50). Inspiratory flow indices were significantly lower than the expiratory flow indices. The time to reach PIF was significantly longer (mean,±,SD; 229,±,21 msec) than the time to reach peak expiratory flow (92,±,8 msec; P,<,0.0001). The shape of the inspiratory curve was parabolic and did not vary with age. The formed predicted equations were in agreement with the extrapolated values for older healthy children. Conclusions The majority of healthy young children can perform reliable maximum inspiratory flow volume curves. Our results provide a framework of reference equations for maximum inspiratory flow volume curve in the young children. The clinical applications of these equations have to be explored. Pediatr Pulmonol. 2009; 44:105,111. © 2009 Wiley-Liss, Inc. [source]

Comparison of Indian reference equations for spirometry interpretation

RESPIROLOGY, Issue 5 2007
Ashutosh N. AGGARWAL
Background and objectives: It would be desirable in a large country such as India that a single set of reference equations be used to interpret lung function tests performed across the entire country. This study compared north, west and south reference equations in interpreting spirometry results in north Indian patients. Methods: Spirometric records of 27383 patients aged 16,65 years were assessed. Spirometric values for FVC, FEV1 and FEV1%FVC values derived from north, west and south Indian reference equations were compared. Differences in the lower limit of normal (LLN) were studied across the age and height range of the study group to determine if there was any clinically significant difference in the three derived values. Results: The north and west Indian equations was discordant in 22.1% instances, and the north and south Indian equations in 12.9% instances, with kappa estimates of agreement being 0.626 and 0.781, respectively. Most of the patients with abnormal spirometry using north Indian equations were erroneously interpreted to have normal spirometry using west or south Indian equations. The south Indian equations underpredicted LLN for FVC and FEV1 for most men and women. The west Indian equations underpredicted LLN for FVC and FEV1 in all men, and in younger and short statured women. Conclusions: North, west and south Indian reference equations do not yield equivalent results for spirometry interpretation in north Indian patients. [source]