Neonatal Nurse Practitioner Practice Exam

A term neonate on a ventilator presents with an arterial blood gas showing pH 7.23; PCO₂ 49 mm Hg; PO₂ 36 mm Hg; HCO₃ 19 mEq/L. What should be the initial management?

1. Bicarbonate administration

2. Increasing peak inspiratory pressure

3. Increasing positive end expiratory pressure

4. Reducing ventilator rate

The correct answer is: Increasing peak inspiratory pressure

The initial management in this scenario focuses on addressing the abnormal arterial blood gas values, particularly the high PCO₂ level of 49 mm Hg and low pH of 7.23, which indicate a respiratory acidosis with some metabolic compensation. The high PCO₂ suggests that the neonate is experiencing hypoventilation, leading to inadequate removal of carbon dioxide from the body. Increasing the peak inspiratory pressure on the ventilator is the appropriate response because it enhances the tidal volume delivered to the neonate. This increased pressure can help improve ventilation, allowing for greater clearance of carbon dioxide and thus correcting the hypercapnia. It can effectively promote better gas exchange in the alveoli, ultimately leading to an improvement in both the PCO₂ and pH levels. Other options, such as bicarbonate administration, are generally not indicated for acute respiratory acidosis because they do not address the underlying problem of hypoventilation, and may even exacerbate issues related to oxygen delivery and ventilation. Increasing positive end-expiratory pressure could lead to further hypoventilation in a patient already struggling to remove CO₂ effectively. Reducing the ventilator rate might worsen the hypoventilation and elevate CO₂ levels further, which is contrary to the