Continuous hemodynamic monitoring in acute stroke: an exploratory analysis.

INTRODUCTION: Non-invasive, continuous hemodynamic monitoring is entering the clinical arena. The primary objective of this study was to test the feasibility of such monitoring in a pilot sample of Emergency Department (ED) stroke patients. Secondary objectives included analysis of hemodynamic variability and correlation of continuous blood pressure measurements with standard measurements. METHODS: This study was a secondary analysis of 7 stroke patients from a prospectively collected data set of patients that received 2 hours of hemodynamic monitoring in the ED. Stroke patients were included if hemorrhagic or ischemic stroke was confirmed by neuroimaging, and symptom onset was within 24 hours. They were excluded for the presence of a stroke mimic or transient ischemic attack. Monitoring was performed using the Nexfin device (Edwards Lifesciences, Irvine CA). RESULTS: The mean age of the cohort was 71 ± 17 years, 43% were male, and the mean National Institute of Health Stroke Scale (NIHSS) was 6.9 ± 5.5. Two patients had hemorrhagic stroke. We obtained 42,456 hemodynamic data points, including beat-to-beat blood pressure measurements with variability of 18 mmHg and cardiac indices ranging from 1.8 to 3.6 l/min/m2. The correlation coefficient between continuous blood pressure measurements with the Nexfin device and standard ED readings was 0.83. CONCLUSION: This exploratory investigation revealed that continuous, noninvasive monitoring in the ED is feasible in acute stroke. Further research is currently underway to determine how such monitoring may impact outcomes in stroke or replace the need for invasive monitoring.

The inability of emergency physicians to adequately clinically estimate the underlying hemodynamic profiles of acutely ill patients.

OBJECTIVE: Emergency physicians (EPs) estimate the underlying hemodynamics of acutely ill patients and use them to help both diagnose and formulate a treatment plan. This trial compared the EP clinically derived estimates of cardiac output (CO) and systemic vascular resistance (SVR) to those measured noninvasively. METHODS: Forty acutely ill emergency department patients with a broad range of diagnosis and blood pressure (BP) and pulse were monitored for 2 hours using novel noninvasive finger cuff technology (Nexfin; BMEYE, Amsterdam, The Netherlands). The Nexfin device provides continuous BP monitoring and, from the resulting pulse pressure waveform, calculates beat-to-beat CO and SVR. At baseline assessment and after 2 hours of testing and therapy, treating EPs were asked to estimate the CO and SVR (low, normal, or high), and these were compared with Nexfin measurements. RESULTS: Twenty-five men and 15 women were enrolled with a mean age of 62.2 years (SD, 12.6 years). Eighteen had acute shortness of breath; 11, with probable stroke syndrome; 3, with suspected sepsis; and 8, with a systolic BP greater than 180 or less than 100 mm Hg. Concordance tables showed that there was very little agreement (κ values) between either the compared initial CO (-0.0873) and SVR (-0.0645) or the 2-hour values (-0.0645 and -0.1949, respectively). CONCLUSIONS: Emergency physicians cannot accurately estimate the underlying hemodynamic profiles of acutely ill patients when compared with more objective measurements. This inaccuracy may have important clinical ramifications. Further study is needed to determine how to use these measured continuous CO and SVR monitoring values.

Noninvasive continuous or intermittent blood pressure and heart rate patient monitoring in the ED.

OBJECTIVE: Continuous invasive blood pressure (BP) and heart rate (HR) monitoring in the emergency department (ED) is valuable in managing critically ill patients. Novel noninvasive finger cuff technology allows this same uninterrupted monitoring for almost any individual. This exploratory study compares ED noninvasive continuous to intermittent measurements of these variables. METHODS: A variety of acutely ill ED patients (n = 40) with broad ranges of BP and HR underwent simultaneous monitoring using interval standard automated ED devices and continuous finger cuff technology (Nexfin; Bmeye, Amsterdam, The Netherlands) over a period of 2 hours. At baseline and at 15-minute intervals, simultaneous measurements for BP and HR were recorded and compared. RESULTS: There were 25 men and 15 women enrolled with a mean age of 62.2 years (SD, 12.6). Eighteen had acute dyspnea, 11 with probable stroke syndrome, 3 with suspected sepsis, and 8 with a systolic BP greater than 180 or less than 100 mm Hg. Blood pressure and HR values (n = 344) simultaneously measured by automated ED equipment and the Nexfin finger cuff device were compared. The Pearson correlation coefficients were high, and the Bland-Altman plots showed good agreement between the 2 determinations. CONCLUSION: Continuous BP and HR monitoring measured by the Nexfin finger cuff device in this trial showed reasonable agreement when compared with the intermittent values obtained by automated ED equipment. However, theoretically, noninvasive and continuous monitoring of the BP and HR might better reflect underlying hemodynamics than these same measurements obtained intermittently and, thus, could be important in patient management. More study is needed to determine the optimal method of monitoring these parameters.