Which BP measurement device should be used with caution in patients with arrhythmia?

• A. Oscillometric devices
• B. Mercury sphygmomanometer with stethoscope
• C. Automatic wrist devices without auscultation
• D. Digital infrared thermometer

Answer: (A)

In arrhythmia, the heartbeat is irregular, which disrupts the regular pulsing pattern that automatic oscillometric devices rely on. These devices detect small cuff-pressure oscillations as the cuff deflates and translate them into systolic and diastolic values using algorithms that assume a relatively steady rhythm. When the rhythm is irregular, the amplitude and timing of those oscillations vary, making the algorithm less reliable and often producing inaccurate blood pressure readings.

Because of this, oscillometric devices should be used with caution in patients with arrhythmia. The preferred approach is manual measurement using a mercury (or calibrated aneroid) sphygmomanometer with a stethoscope, which allows the clinician to listen for Korotkoff sounds and determine the pressures based on direct auscultation, reducing the risk of error due to rhythm irregularity. Automatic devices that don’t involve auscultation, such as wrist-based units, can also be less accurate in this context due to both cuff position and algorithm limitations.

The option that reads a temperature with a digital infrared device isn’t a blood pressure measurement method at all, so it wouldn’t provide BP data. If an oscillometric device must be used in this setting, taking multiple readings and confirming with manual measurement improves reliability.