A comfortable, alert client with cold hands has an unexpectedly low pulse-oximeter reading. A manually counted pulse is regular at 75/min. After sensor checks, the nurse reviews these recordings. Click the recording that best supports a reliable pulse-oximeter assessment before interpreting its saturation value.

B. B has a consistent pulsatile waveform and a pulse rate matching the manually counted 75/min.

An isolated saturation number is insufficient when peripheral perfusion is poor. Check that the detected pulsations agree with the clinical pulse and that the waveform is stable. B best satisfies both checks here; continue clinical assessment rather than declaring oxygenation normal from this signal alone.

The observations are fictional teaching data. Apply the stated context; the selected feature does not by itself replace a complete bedside assessment.

Check signal quality and pulse agreement before trusting the saturation display.

Check signal quality and pulse agreement before trusting the saturation display.

A detects twice the manual pulse rate. C has a weak signal and a much lower detected rate. D prints 75/min but has an irregular noisy trace, so the matching number alone is not enough.

• Pulse-oximeter signal quality and pulse agreement — Check signal quality and pulse agreement before trusting the saturation display.
• Comparison with context — D has the same printed pulse as B but lacks a stable pulsatile signal.