Whether nebulized
ipratropium bromide is of benefit to mechanically ventilated patients with
chronic bronchitis is not well defined. The objective of the study was to determine the effect of
ipratropium bromide as a nebulized
solution on ventilatory function in patients with severe airflow limitation and under
ventilator treatment because of
respiratory failure. The design was a randomized, double-blind, controlled trial. Forty-two ventilated patients (43 to 83 years old) with acute airflow obstruction and
wheezing or coughing were chosen. The patients were randomly allocated to treatment every 6 h with either 500 micrograms of nebulized
ipratropium bromide or 0.9 percent
saline solution. Comparison was made between
ipratropium bromide and placebo. Their responses were assessed in terms of arterial blood gas analysis, pulmonary mechanics, and respiratory symptoms. No significant differences in oxygenation, arterial CO2 tension, or static lung compliance attributable to
ipratropium were found. However, a significant tendency to decreased mean airway resistance, peak inspiratory pressure, mean airway pressure, and improved symptom status 24 h after giving
ipratropium was observed. We conclude that ventilated patients with
obstructive lung disease could obtain incremental benefit from adding nebulized
ipratropium to
aminophylline. Their responses may be explained by the bronchodilating effect of
ipratropium that resulted in a reduced airway resistance and a lower mean airway pressure.