A client with severe COPD and chronic hypercapnia is brought… | MyMerci
Medical EmergenciesPA
Question
A client with severe COPD and chronic hypercapnia is brought to the ED with worsening dyspnea, SpO2 86%. Which is the most appropriate initial oxygen prescription?
1Place the client on a CPAP at 100% FiO2
2No supplemental oxygen — the body will compensate
3High-flow oxygen at 15 L/min via non-rebreather mask
4Titrate oxygen to maintain SpO2 88-92% via nasal cannula 2 L/min, monitoring for changes in mental status and ventilation✓ Correct answer
Explanation
Correct (2): COPD clients with chronic CO2 retention rely partly on hypoxic respiratory drive; excessive O2 can blunt the drive and worsen CO2 retention, causing somnolence and respiratory acidosis. Target SpO2 88-92% with the lowest effective flow. Monitor neuro status and consider ABG. (1) High-flow can cause CO2 narcosis. (3) CPAP at 100% inappropriate as initial step in this scenario. (4) Hypoxia must be treated.
In-depth explanation
Memory Tip COPD = "88-92" target. Cardiac/respiratory arrest, sepsis: target 94-98%. CPG If somnolence develops on O2, suspect CO2 narcosis — check ABG and consider NIV (BiPAP).
Clinical scenario
Scenario 71-year-old male with severe COPD and chronic CO2 retention (baseline PaCO2 58). ED presentation: dyspnea, RR 28, SpO2 86% on room air, alert, mild lethargy.
Key concepts
Hypoxic respiratory drive — Backup ventilatory drive in chronic CO2 retainers; excessive O2 may suppress it.
COPD oxygen target — SpO2 88-92% with titration; avoid hyperoxia.
CO2 narcosis — CNS depression from rising PaCO2; presents as somnolence and confusion after high-flow O2.