Blood pressure monitoring has come a long way from the initial observations made by Reverend Hales in the 18th century. There are none that deny the importance of monitoring perioperative blood pressure; however, the limited ability of the current prevalent technology (oscillometric blood pressure monitoring) to offer continuous blood pressure measurements leaves room for improvement. Invasive monitoring is able to detect beat-to-beat blood pressure measurement, but the risks inherent to the procedure make it unsuitable for routine use except when this risk is outweighed by the benefits. This review focuses on the discoveries which have led up to the current blood pressure monitoring technologies, and especially the creation of those offering non-invasive but continuous blood pressure monitoring capabilities, including their methods of measurement and limitations.

No abstract

The Nexfin device allows for non-invasive beat-to-beat blood pressure monitoring (BP(NXF)). Perioperative hypotension and hypertension have been shown to be associated with poor clinical outcomes. The goal of the present study was to assess the ability of this device to decrease the duration of significant intraoperative hypo- or hypertension compared to standard BP monitoring by cuff (BP(CUFF)). We studied25 patients (ASA I-III) undergoing either abdominal or orthopedic surgery. BP(CUFF) was monitored every 5 min from the introduction of anesthesia, while BP(NXF) was monitored continuously on the opposite arm. When systolic BP(NXF) (SBP(NXF)) decreased or increased more than 20% relative to baseline SBP(NXF), a standard BP(CUFF) measurement was taken to compare values. In addition, the time interval between the 20% change in SBP(NXF) and the next scheduled standard SBP(CUFF) measurement was recorded for each event. The mean length of surgery was 3.0 ± 0.3 h. Patients presented with 11 ± 4 episodes of hypotension and 12 ± 4 episodes of hypertension during the surgery. If BP(CUFF) had been used, this would have resulted in 21 ± 7 min of hypotension and 20 ± 10 min of hypertension. If hemodynamic changes seen by SBP(NXF) were appropriately treated, an average of 7 ± 1 min/h of hypotension time, 7 ± 2 min/h of hypertension time and 14 ± 3 min per hour of hypo- or hypertension time may have been identified. The Nexfin BP has the potential to decrease the time of hypotension and hypertension compared to conventional intermittent BP(CUFF) monitoring. Therefore, this device has the potential to positively impact clinical outcomes.

Level III, therapeutic study.