Certified Transport Registered Nurse Certification Practice Exam

In which condition would a decreased inspiratory: expiratory (I:E) ratio be therapeutic?

1. Chronic bronchitis

2. Acute asthma exacerbation

3. Pneumonia

4. Chronic obstructive pulmonary disease

The correct answer is: Acute asthma exacerbation

The decreased inspiratory: expiratory (I:E) ratio is particularly therapeutic in the context of an acute asthma exacerbation. Asthma is characterized by bronchoconstriction and airway inflammation, leading to airflow limitation primarily during expiration. In this scenario, patients often exhibit prolonged expiratory phases due to the difficulty in expelling air from the lungs. By implementing a decreased I:E ratio, where the expiratory phase is extended relative to the inspiratory phase, the airway can be allowed more time to fully empty. This strategy helps reduce air trapping and hyperinflation, alleviating the respiratory distress experienced during an asthma attack. The increased focus on prolonging expiration can help normalize the patient's breathing pattern, providing better gas exchange and improving overall ventilation efficiency during an acute exacerbation. In contrast, conditions like chronic bronchitis and chronic obstructive pulmonary disease (COPD) could also be managed with altered I:E ratios, but the specifics of treatment may differ fundamentally due to the nature of airflow obstruction and air trapping over time rather than sudden exacerbations. Meanwhile, pneumonia typically involves infectious processes in the lung parenchyma, and standard I:E adjustments would not be as pivotal in its management.