NBRC RRT Prep Online

In volume-controlled ventilation, an increase in peak inspiratory pressure with an unchanged plateau pressure indicates increased airway resistance rather than a change in lung compliance. A common cause is partial obstruction of the endotracheal tube from secretions, kinking, or biting. Decreased lung compliance would typically increase both peak and plateau pressures. A disconnected circuit or a cuff leak more often triggers low pressure/low exhaled volume alarms and would not be expected to cause a sustained high inspiratory pressure alarm.

The blood gas shows acute hypercapnic respiratory acidosis (elevated PaCO2 with low pH) with persistent increased work of breathing and fatigue despite initial bronchodilators and controlled oxygen. In an acute COPD exacerbation with hypercapnic acidosis, non-invasive positive pressure ventilation is the preferred next step because it improves alveolar ventilation, decreases PaCO2, reduces the work of breathing, and can prevent the need for endotracheal intubation. Increasing oxygen flow may raise PaO2 but does not address ventilatory failure and can worsen CO2 retention in some COPD patients. Systemic corticosteroids and additional bronchodilators are important treatments for COPD exacerbations, but they do not rapidly correct hypercapnic acidosis when ventilatory failure is developing.

BAL is primarily a diagnostic procedure used to collect fluid and cells from the distal airways and alveoli. The sample can be sent for tests such as Gram stain and culture, fungal/AFB studies, and cytology/cell differential to help determine whether an infiltrate is due to an infection or an inflammatory process. Testing for chronic chemical exposure is not the typical purpose of BAL in routine clinical care. BAL is not primarily performed as a therapeutic suctioning procedure for wheezing, and lung volumes are measured with pulmonary function testing rather than lavage.