Fundamentals of Nursing Q 44
A prescribed amount of oxygen is needed for a patient with COPD to prevent:
A. Cardiac arrest related to increased partial pressure of carbon dioxide in arterial blood (PaCO2).
B. Circulatory overload due to hypervolemia.
C. Respiratory excitement.
D. Inhibition of the respiratory hypoxic stimulus.
Correct Answer: D. Inhibition of the respiratory hypoxic stimulus.
Delivery of more than 2 liters of oxygen per minute to a patient with chronic obstructive pulmonary disease (COPD), who is usually in a state of compensated respiratory acidosis (retaining carbon dioxide (CO2)), can inhibit the hypoxic stimulus for respiration. Long-term oxygen therapy is used for COPD if the client has low levels of oxygen in the blood (hypoxia). It is used mostly to slow or prevent right-sided heart failure. It can help the client live longer.
Option A: An increased partial pressure of carbon dioxide in arterial blood (PACO2) would not initially result in cardiac arrest. Long-term oxygen therapy should be used for at least 15 hours a day with as few interruptions as possible. Regular use can reduce the risk of death from low oxygen levels.. To get the most benefit from oxygen, the client should use it 24 hours a day. Supplemental oxygen is a well-established therapy with clear evidence for benefit in patients with COPD and severe resting hypoxemia, which is defined as a room air Pao2 ? 55 mm Hg or ? 59 mm Hg with signs of right-sided heart strain or polycythemia.
Option B: Long-term use of supplemental oxygen improves survival in patients with COPD and severe resting hypoxemia. However, the role of oxygen in symptomatic patients with COPD and more moderate hypoxemia at rest and desaturation with activity is unclear. The few long-term reports of supplemental oxygen in this group have been of small size and insufficient to demonstrate a survival benefit.
Option C: Circulatory overload and respiratory excitement have no relevance to the question. Short-term trials have suggested beneficial effects other than survival in patients with COPD and moderate hypoxemia at rest. In addition, supplemental oxygen appeared to improve exercise performance in small short-term investigations of patients with COPD and moderate hypoxemia at rest and desaturation with exercise, but long-term trials evaluating patient-reported outcomes are lacking.