Continuous mean arterial pressure measurement in the fingers: the influence of local arm cooling.

Two different methods were studied for non-invasive beat-to-beat finger mean arterial pressure (MAP) measurement in 14 healthy volunteers during local arm cooling to 17 degrees C. Fingertip skin blood flow was recorded by a laser Doppler instrument. The difference between the oscillometric beat-to-beat blood pressure measurement device (UT9201) and volume clamp monitor (Finapres) before cooling was -1.5+/-1.1 mmHg, and, although statistically significant, (p< 0.01), this difference cannot be considered clinically meaningful. The results obtained using the two devices during arm cooling showed a systematic disagreement in the continuously recorded MAP. After a 30s period of cooling, the group-averaged difference of UT9201 minus Finapres, calculated as change from the baseline, reached (mean +/- SD) 8.8+/-6.3 mmHg (statistically significant, p< 0.01).