During the night, the technician notices a gradual decline of the SpO2 by 8%. Which of the following would help determine the cause of this event?

The gradual decline in SpO2 (oxygen saturation) is an important observation that can indicate potential respiratory issues during sleep. To accurately determine the cause of this decline, one must first ensure that the data being collected is reliable and representative of the patient’s condition.

The quality of the signal from the oximeter plays a crucial role in understanding any changes in oxygen saturation. If the signal is poor or inaccurate due to movement, poor placement, or interference, the information being monitored may not accurately reflect the patient’s true SpO2 levels. A reliable signal is essential to distinguish between actual physiological events and artifacts caused by technical issues. Therefore, evaluating the quality of the oximeter signal directly impacts the technician's ability to assess the SpO2 decline accurately and identify its underlying cause.

While knowing airflow and respiratory effort is essential for analyzing respiratory patterns, the first step is ensuring that the oximeter's readings are valid. Likewise, the placement of the oxygen sensor is important but less relevant if the signal quality is compromised. The pigment of the patient’s skin can affect oximeter readings, but focusing on the signal quality will provide a more immediate and actionable avenue to investigate the cause of the decline in SpO2.