Comparison of Outpatient Nebulized vs Metered Dose Inhaler Terbutaline in Chronic Airflow Obstruction: Results

Acute Response Study
There was no difference in bronchodilatation achieved with MDI and NEB after one ujiit dose or at FEVi plateau (Table 2). The average doqe required to achieve maximal bronchodilatation was 5.8 mg for NEB and 2.8 mg for MDI (five times the usual recommended MDI dose). The significant increase in 6MWD after maximum bronchodilatation was similar for both MDI and NEB. No patient experienced significant side effects of tremor or palpitations during this or the domiciliary study.

Outpatient Study
Spirometry: There was no change in baseline FEVj after either of the treatment fortnights. Tjiere was a small, but significant improvement in baseline VC seen after both treatment fortnights with no significant difference between MDI and NEB (Table 3). Exercise performance: There was a significant improvement in 6M WD after each treatment period and no significant difference between the MDJ and NEB fortnights.
Subjective patient preference: Ten patients preferred the active NEB treatment fortnight, whereas six preferred the active MDI treatment fortnight. Two patients expressed no preference for either period. The patients who preferred the NEB fortpight were analyzed separately. The results were similar to those for the whole group, apart from a significantly greater sputum production during the NEB treatment fortnight.
Several previous studies using standard doses of bronchodilator have suggested that nebulized bron-chodilator therapy is more efficacious than MDI bronchodilator therapy in patients with chronic airflow obstruction. Wilson and Connellan recominended the use of nebulized salbutamol at home in patients with severe chronic airflow obstruction, basing this recommendation on a comparison of nebulized salbutamol with nebulized placebo. McGivern et al demonstrated that asthma symptoms, and in some cases PEFR, improved when twice daily nebulized terbutaline was added to and compared with their normal treatment. Neither of these studies compared me-tered-dose inhalers and nebulizers in a double-blind fashion.
Table 2—Results: Acute Response Study

MDI(%) NEB(%) P
Change in Fltv,
—after 1 dose* 28 ±7.8 28 ±5.9 NS
—plateauf 58 ±10.9 51 ±9.0 NS
Change in VC
—after 1 ddse 19 ±3.8 19 ±4.5 NS
—plateau 92 ±10.4 89 ±13.2 NS
Change in 6MWD
—plateau 4 ±0.9 5± 1.9 NS

Table 3—Results: Outpatient Study

Pre-Study End 2 Week Rx
FEVl 1.0±0.10 0.99 ±0.09 1.0±0.11 1.0±0.08
VC. 3.3±0.21 3.20±0.1 3.4 ± 1.19* 3.4 ±0.18*
6MWD 475 ±23.6 467 ±23.3 493 ±24.5* 482 ±24.5*
Symptom Scores, t
Wheeze 1.30±0.17 1.20±0.17
Cough 0.90±0.15 0.84 ±0.14
Sleep 0.99 ±0.17 0.84 ±0.18
Dyspnea 2.20 ±0.15 2.20 ±0.12
Sputum . 1.10±0.12 1.30 ±0.14
Extra beta-agonist use 1.00±0.40 0.75 ±0.33