Oscillometric versus invasive blood pressure measurement in patients with shock: a prospective observational study in the emergency department

Agnes S. Meidert,Michael E. Dolch,Josef Briegel,Stephan Czerner,Konstanze Mühlbauer,Bernhard Zwissler,Matthias Klein

doi:10.1007/s10877-020-00482-2

Abstract

In emergency medicine, blood pressure is often measured by an oscillometric device using an upper arm cuff. However, measurement accuracy of this technique in patients suffering from hypotensive shock has not been sufficiently evaluated. We designed a prospective observational study investigating the accuracy of an oscillometric device in hypotensive patients admitted to the resuscitation area of the emergency department. Patients admitted to the resuscitation area of a university hospital, who were equipped with an arterial catheter and found to be hypotensive (mean arterial pressure (MAP) < 60 mmHg) were eligible for the study. Blood pressure was measured simultaneously via upper arm cuff and invasively under routine clinical conditions. After data extraction, Bland–Altman analysis, correlation coefficient and percentage error of mean and systolic blood pressure pairs were performed. We analysed 75 simultaneously obtained blood pressure measurements of 30 patients in hypotension, 11 (37%) were female, median age was 76.5 years (IQR 63–82). Oscillometric MAP was markedly higher than invasive MAP with a mean of the differences of 13 ± 15 mmHg (oscillometric—invasive), 95% limits of agreement − 16 to 41 mmHg, percentage error was 76%. In 64% of readings, values obtained by the upper arm cuff were not able to detect hypotension. Oscillometric blood pressure measurement is not able to reliably detect hypotension in emergency patients. Therefore, direct measurement of blood pressure should be established as soon as possible in patients suffering from shock.

Highlights

Shock is defined as a “life threatening, generalised form of acute circulatory failure associated with inadequate oxygen utilisation by the cells” [1]
We aimed to investigate the accuracy of noninvasive intermittent blood pressure meas‐ urement via an oscillometric upper arm cuff in 30 patients suffering from shock treated in the resuscitation area in a clinical method comparison study using invasive blood pres‐ sure measurement as the reference method
Within the study period 33 patients with simultaneous inva‐ sive and noninvasive blood pressure measurement who had a mean arterial pressure below 60 mmHg were admitted to the emergency department

Summary

Introduction

Shock is defined as a “life threatening, generalised form of acute circulatory failure associated with inadequate oxygen utilisation by the cells” [1]. Shock usually includes but is not limited to the presence of hypotension [1]. In order to detect hypotension in a patient, accurate and reliable blood pressure measurement is of utmost importance and guides the treatment of shock. Usually only critically ill patients in the resus‐ citation area or on intensive care unit (ICU) are equipped with an arterial catheter. In emergency medicine, both in and out of the hospital, a patient’s blood pressure is meas‐ ured noninvasively via an upper arm cuff. Data com‐ paring oscillometric with intra-arterial pressure measure‐ ments in hypotensive emergency patients with shock are sparse.

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Conclusion