Noninvasive Techniques for Blood Pressure Measurement Are Not a Reliable Alternative to Direct Measurement: A Randomized Crossover Trial in ICU

Table 2

BHS grade of agreement between noninvasive and direct-invasive methods: cumulative percentage of absolute difference (mmHg) between IBP and other studied methods (ABP and OBP). Grades are derived from percentages of readings within 5, 10, and 15 mmHg: to achieve a grade, all three percentages must be equal to or greater than the tabulated values. For example, to achieve the “A” grade, sixty percent of the measured BP values with IBP and ABP must be within 5 mmHg, 85% within 10 mmHg, and 95% within 15 mmHg. The limit of ≤20 mmHg does not belong to the BHS criteria and has been inserted to highlight in particular the poor agreement for SAP.

	≤5 mmHg	≤10 mmHg	≤15 mmHg	≤20 mmHg	BHS grade
IBP versus ABP
Systolic	31%	53%	63%	77%	D (very poor)
Diastolic	51%	76%	94%	98%	B (good)
Mean	50%	85%	97%	99%	B (good)
IBP versus OBP
Systolic	20%	40%	63%	74%	D (very poor)
Diastolic	62%	91%	96%	99%	A (very good)
Mean	40%	72%	96%	100%	C (poor)

IBP: invasive blood pressure; ABP: auscultatory-aneroid blood pressure; OBP: oscillometric automated blood pressure; BHS: British Hypertension Society.