What is a sign of oxygen toxicity?

A. To confirm proper tube placement: An end-tidal CO2 (ETCO2) detector measures the concentration of carbon dioxide in exhaled air. A sudden presence of CO2 after intubation indicates that the tube is correctly positioned in the trachea rather than the esophagus, providing immediate confirmation of placement.

B. To measure oxygen saturation: ETCO2 monitoring does not assess oxygen saturation. Oxygen saturation is measured using pulse oximetry, which provides information about hemoglobin oxygenation rather than CO2 levels.

C. To assess respiratory rate: While ETCO2 waveforms can provide indirect information about the rate of exhalation, its primary purpose immediately after intubation is to verify tracheal placement, not to monitor respiratory rate.

D. To determine acid-base status: ETCO2 reflects ventilatory status and CO2 elimination but does not provide a full assessment of acid-base balance. Arterial blood gas analysis is required for accurate evaluation of pH and acid-base status.

A. Blurred vision: Oxygen toxicity, especially from prolonged exposure to high concentrations of oxygen, can affect the eyes and central nervous system. Blurred vision is a recognized early symptom of CNS oxygen toxicity and indicates the need to reduce oxygen exposure.

B. Low oxygen saturation (SpO2): Low SpO2 indicates hypoxemia, not oxygen toxicity. Oxygen toxicity occurs when oxygen levels are excessively high, not when they are low.

C. Joint pain: Joint pain is not associated with oxygen toxicity. It is unrelated to oxygen therapy and would prompt evaluation for other causes.

D. Low hemoglobin level: Hemoglobin levels reflect oxygen-carrying capacity, not toxicity from oxygen administration. Oxygen toxicity is linked to cellular and tissue damage from high oxygen partial pressures rather than hemoglobin deficiency.