Nebulized ipratropium bromide in ventilator-assisted patients with chronic bronchitis

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.