Standard and double dose ipratropium bromide and combined ipratropium bromide and inhaled metaproterenol in COPD.

Inhaled ipratropium bromide (IPR) is effective in the management of COPD. The purpose of this study was to determine if doubling the standard dose of IPR resulted in greater bronchodilation and if the addition of an inhaled beta-agonist was superior to standard dose IPR alone. Twelve male patients with stable COPD completed a double blind, randomized trial. On each of three consecutive days, following baseline spirometry, all patients inhaled two puffs of IPR. This was followed by either two additional puffs of IPR, two puffs of metaproterenol (META), or two puffs of placebo. All inhalants were delivered by an InspirEase spacer. Spirometry was repeated at 30, 60, 120, and 180 minutes. The group mean percentage increases in the FEV1 and FVC from baseline were similar at all times tested for the three protocols. In conclusion, for the group, there was no objective benefit to doubling the standard dose of IPR or combining IPR with META. Two of 12 patients benefited from combining the two bronchodilators. A potential sequence for bronchodilator testing is suggested.

Prediction of normal spirometric values for adults incapable of standing.

A significant problem exists in predicting normal values for pulmonary function in subjects unable to stand for measurement of height. We studied 196 normal men and women to determine the relationship between sitting and standing height. Two predictors of standing height are recommended: (1) standing-to-sitting height ratio; and (2) multiple regression equations using sitting height and age. Either of these relationships can be selected as a predictor of height for substitution into any standard spirometric prediction equations. Spirometric prediction equations using age and sitting height are also presented.

Fifteen-year interval spirometric evaluation of the Oregon predictive equations.

The 1969 Oregon spirometric predictive equations were evaluated by retesting 199 of the 988 original sample population after 15 years. The 1969 data were used to test for sample bias between the retested and not-retested groups. There was no significant difference in mean values for age, height, or test results except for a five-year age difference in men. Regression analysis of residuals and the differences between calculated and predicted values of annual decrements of FVC, FEV1, and FEF25-75% on age revealed no statistically significant age trend. Although residual means were statistically significant for FVC and FEV1 for men and FVC and FEF25-75% for women, the differences between calculated and predicted annual decrements were significant only for women in FEF25-75%. Although group performance was accurately predicted for most tests, test SDs and SEMs demonstrated considerable individual variation. Lower limits of normality are suggested to assist in evaluating previously-tested patients.

Comparison of lung volume measurements by single breath helium and multiple breath nitrogen equilibration methods in normal subjects and COPD patients.

The validity of the single breath helium dilution method for accurate measurement of the total lung capacity (TLC) was investigated. Comparison was made with the multiple breath nitrogen equilibration technique in 22 normal subjects and 37 patients with chronic obstructive pulmonary disease (COPD). The single breath method underestimated the TLC in all the normal individuals and 33 of 37 patients with COPD. Possible explanations for the falsely low lung volumes include uneven distribution of inspired air due to closing volumes and induced bronchoconstriction.