Final answer:
Secretions and moisture can lead to a low PETCO2 reading, as they may interfere with the sensor or occlude the sampling tube. Maintaining clear sampling lines and sensors is critical for accurate capnography measurements. So option (b) is correct.
Step-by-step explanation:
Secretions and moisture can indeed affect the PETCO2 reading, which refers to the end-tidal carbon dioxide concentration measured during capnography. Capnography is a non-invasive monitoring tool used to assess a patient's ventilation by measuring CO2 levels in exhaled air. The presence of secretions or moisture can lead to a low reading of PETCO2 because they may cause partial occlusion of the sampling tube or interfere with the infrared sensor used in most capnographs. This occlusion or interference can prevent an accurate measurement of CO2 levels, thus falsely suggesting lower than actual CO2 levels. To ensure accurate readings, it’s important for medical practitioners to maintain clear sampling lines and sensors when performing capnography.