The 20 male patients participating in the study had an age range of 60 to 91 years, with a mean of 67.9 ± 7.1 years. Their spirometry on admission showed an FEVi of 0.71 ±0.26 L, an FVC of 1.77±0.52 L, and an FEVi/FVC ratio of a 0.41 ±0.11. Thus, the patients were quite elderly and had severe airflow obstruction. The arterial blood gas levels for the group were pH of 7.42±0.03, PaC02 of 40±9 mm Hg, and Pa02 of 68 ± 9 mm Hg. While of four of the 20 patients had a PaC02 greater than 45 mm Hg, all of these patients had well-compensated respiratory acidosis, and none had a pH less than 7.30. Four patients were receiving oxygen at 1 to 2 L/min by nasal cannula at the time of arterial blood gas analysis.

Following bronchodilator treatment, there was a significant increase in the FEV! and FVC and a decrease in the Borg scores (before vs 1 h after, p<0.002). These results are listed in Table 1. Note that groups 1 and 2 refer to patients receiving active medication by MDI-spacer in the first and second treatment blocks, respectively. The type of treatment (MDI-spacer vs nebulizer) did not influence this result (no significant interaction between type of treatment and the before-vs-after factor for the FEVj, FVC, or Borg scores). The type of treatment did have an effect on the FVC when both values before and after were considered, with higher values being found when the active medication was administered via the nebulizer (p<0.01). There was no significant effect of the type of treatment on the overall FEV! or Borg scores.
The mean change and percent change in the FEVj and FVC and the change in the Borg scores are listed in Table 2. Although the increases in the FEVi and FVC were slightly larger after active drug via nebulizer, and the decreases in the Borg scores were slightly larger after active drug via MDI-spacer, these differences were not statistically significant. There was poor correlation between improvements in either the FEV! or FVC (change or percent change) after MDI-spacer and nebulizer treatments. Only the changes in the FEVi after MDI-spacer and nebulizer treatments were significantly correlated (r = 0.44; p = 0.047), and this correlation became nonsignificant when one outlier point was dropped.
Table 1—Sptrometric Data and Borg Scores before and One Hour after Treatment

Croup and Treatment Block FEV,, L FVC, L Borg Score
Before After Before After Before After
Group 1
Block 1; S 0.99 ±0.40 1.09±0.40 2.35 ±0.83 2.71 ±0.72 3.9 ±2.0 2.3± 1.1
Block 2; N 1.07 ±0.43 1.19 ±0.49 2.54±0.69 2.89 ±0.88 2.7 ± 1.2 2.6 ± 1.2
Group 2
Block 1; N 0.69 ±0.28 0.84 ±0.37 1.86 ±0.52 2.14 ±0.60 4.0± 1.8 2.6± 1.5
Block 2; S 0.74 ±0.36 0.85±0.48 1.97 ±0.65 1.99±0.63 3.6±2.0 3.0 ±2.0
Combined
S 0.86 ±0.39 0.97 ±0.44 2.16 ±0.75 2.35 ±0.76 3.7 ±2.0 2.7 ±1.6
N 0.88 ±0.41 1.00±0.46 2.20±0.69 2.51 ±0.83 3.3± 1.6 2.6± 1.3

Table 2—Change One Hour after Treatment

Data MDI-Spacer Nebulizer
Change in FEV„ ml 103 ±167 139 ±149
Percent change in FEV, 13.4 ±20.5 16.7 ±17.0
Change in FVC, ml 190 ±360 310 ±370
Percent change in FVC 11.7±21.1 14.7 ±16.2
Change in Borg score -1.08 ±2.01 — 0.73 ±1.75