Following placement of pulse oximetry and capnography, which value pair indicates normal readings?

• A. Spo2 98%, Capnography value within normal limits.
• B. Spo2 94%, Capnography fluctuating.
• C. Spo2 100%, Capnography not measurable.
• D. Spo2 90%, Capnography trending downward.

Answer: (A)

When pulse oximetry and capnography show normal readings, it means both oxygenation and ventilation are adequate. A pulse oximeter reading of 98% indicates the blood is well-saturated with oxygen. Capnography that is within normal limits reflects a stable end-tidal CO2 level—typically about 35–45 mmHg—with a clear, regular waveform—signaling effective ventilation and CO2 elimination. This combination confirms the airway is patent, ventilation is sufficient, and oxygen delivery is appropriate. In contrast, a capnography value that fluctuates can suggest variable ventilation, which isn’t as reassuring; capnography not measurable points to a potential disconnection or device issue; and a low SpO2 with a downward capnography trend indicates deteriorating ventilation or airway problems.