LAUSR

Objective: Currently non-invasive blood pressure (BP) levels measured by cuff-based devices are considered the gold standard, with 24 hour ambulatory measurements being recommended by international guidelines. However, many patients poorly tolerate the devices, especially during the night, which may cause falsely elevated BP readings. We therefore investigated the influence of cuff inflations on systolic BP levels using a cuffless, non-invasive device. Figure. No caption available. Design and method: Between May and October 2017, 20 individuals were prospectively enrolled. Main exclusion criteria were age < 25 years or a difference in blood pressure > 10 mmHg between both upper extremities. Non-invasive, cuffless 24 h BP-measurements based on pulse-transit-time were performed twice within 4 days on the left arm. During the first measurement, the participants wore an automatic, cuff-based 24 h BP-measurement device on the right arm, simultaneously. The cuff was inflated every 20 minutes from 08:00 to 22:00 and every 30 minutes in the remaining time period. During the second measurement, the participants wore solely the cuffless device. Means (±standard deviation) of systolic 24 h, awake and asleep BP levels and the difference of systolic awake and asleep BP (dipping) levels of the first and the second cuffless measurements were compared using paired t-tests. Results: Mean age was 46 (±15) years and 45% were male. Four (20%) participants took antihypertensive drugs and mean BMI was 25 (±4.6) kg/m2. Mean systolic 24 h BP levels were 137.2 (±22.1) and 135.3 (±26.4) mmHg for the first, simultaneously, and the second, solely, taken BP measurement, respectively (p = 0.6). The differences between awake and asleep systolic BP levels were 2.9 (±5.3) and 4.3 (±5.4) for the first and second measurement, respectively (p = 0.3). Additionally, there was no statistical significant difference for separate awake (p = 0.7) and asleep (p = 0.5) BP levels (Table 1) Conclusions: In our study we could not show a large impact of cuff-inflations on the BP values during a 24 h BP measurement evaluated by a cuff-less BP device. However mean values were numerically lower for the second cuff-less measurement, therefore larger participant numbers may be needed to show a statistically significant difference.