A nurse is working in the emergency department when a patient arrives with suspected carbon monoxide poisoning. What is the priority nursing action?

The priority action for suspected carbon monoxide poisoning is immediate administration of 100% oxygen via non-rebreather mask to displace carbon monoxide from hemoglobin and restore oxygen-carrying capacity.

Carbon monoxide (CO) poisoning is a life-threatening emergency requiring immediate intervention. Carbon monoxide has an affinity for hemoglobin that is about 200-250 times greater than oxygen, forming carboxyhemoglobin (COHb), which cannot effectively carry oxygen, leading to tissue hypoxia.

The priority nursing action is to immediately administer 100% oxygen via a non-rebreather mask. High-concentration oxygen therapy displaces carbon monoxide from hemoglobin through competitive binding, reducing the half-life of carboxyhemoglobin from 4-6 hours in room air to about 60-90 minutes with 100% oxygen administration. This intervention directly addresses the pathophysiology of CO poisoning and can prevent further tissue damage.

The patient's symptoms of headache, dizziness, and nausea are typical early signs of carbon monoxide poisoning, occurring along with a history of exposure in an enclosed space with a running car engine. These symptoms result from cerebral hypoxia, as the brain is highly sensitive to oxygen deprivation.

Arterial blood gas analysis, securing intravenous access, and neurological assessment are all important interventions, but they are secondary to the need for immediate oxygen therapy. Arterial blood gas analysis helps confirm the diagnosis by measuring COHb levels, but treatment should not be delayed while waiting for test results.

Clinical Judgment The core issue in this situation is understanding the pathophysiology of Carbon Monoxide Poisoning. Carbon monoxide (CO) has an affinity for hemoglobin that is 200-250 times greater than that of oxygen, forming Carboxyhemoglobin (COHb), which severely impairs the transport and release of oxygen to tissues. The patient's symptoms (headache, dizziness, nausea) and exposure history (a garage with a running car) strongly suggest this. Notify HCP! The top priority in this situation is to immediately halt tissue hypoxia and dissociate CO from hemoglobin. The single most effective initial intervention for this is the administration of 100% oxygen. All other actions must follow this life-saving measure.

Memory Tip
CO poisoning = Think "CO Brake." CO puts a 'brake' on oxygen transport, and 100% oxygen is the key that 'releases' that brake. The principle is "Oxygen First, Tests Later."

KR vs US
The initial response principle for CO poisoning (administering 100% oxygen) is the same in both Korea and the US. The difference may lie mainly in subsequent treatment approaches. In the US, there is a tendency to consider Hyperbaric Oxygen Therapy (HBOT) more actively for severe patients, and the criteria for its use (altered consciousness, pregnancy, high COHb levels, etc.) are often clearly defined in protocols.

Clinical Practice Guide 1. Administer the highest possible concentration of oxygen (FiO2 90-95% or higher) using a Non-rebreather Mask (NRB). 2. An arterial blood gas (ABG) or CO-oximetry test to measure COHb levels must be reported immediately, but this should be done after treatment has been initiated. 3. Continuous Neurological Assessment is crucial. CO poisoning can cause Delayed Neuropsychiatric Sequelae (DNS).
Caution It is rare for CO poisoning patients to have "cherry red" skin. This is a sign that may only appear in very severe conditions just before death. Most patients present with nonspecific symptoms such as headache, dizziness, and vomiting, so identifying the exposure history is key to diagnosis.