Accuracy and Reliability of a Disposable Vascular Pressure Device for Arterial Pressure Monitoring in Critical Care Transport.

ABSTRACT

OBJECTIVE: Arterial catheterization is a commonly performed procedure in intensive care units to guide the management of critically ill patients who require precise hemodynamic monitoring; however, this technology is not always available in the transport setting because of cumbersome and expensive equipment requirements. We compared the accuracy and reliability of a disposable vascular pressure device (DVPD) with the gold standard (ie, the transducer pressure bag invasive arterial monitoring system) used in intensive care units to determine if the DVPD can be reliably used in place of the traditional pressure transducer setup. METHODS: This study was a single-center, prospective, observational study performed in the adult intensive care unit of a large academic university hospital. A convenience cohort of hemodynamically stable, adult critically ill patients with femoral, brachial, or radial arterial catheters was recruited for this study. The Compass pressure device (Centurion Medical Products, Williamston, MI) is a disposable vascular pressure-sensing device used to assure venous access versus inadvertent arterial access during central line placement. The DVPD was attached to an in situ arterial catheter and measures the mean intravascular pressure via an embedded sensor and displays the pressure via the integrated LCD screen. Using a 3-way stopcock, the DVPD was compared with the standard arterial setup. We compared the mean arterial pressure (MAP) in the standard setup with the DVPD using Bland-Altman plots and methods that accounted for repeated measures in the same subject. RESULTS: Data were collected on 14 of the 15 subjects enrolled. Five measurements were obtained on each patient comparing the DVPD with the standard arterial setup at 1-minute intervals over the course of 5 minutes. A total of 70 observations were made. Among the 15 subjects, most (10 [67%]) were radial or brachial sites. The average MAP scores and standard deviation values obtained by the standard setup were 83.5 mm Hg (14.8) and 81.1 mm Hg (19.3) using the DVPD. Just over half (51.4%) of the measurements were within a ± 5-mm Hg difference. Using Bland-Altman plotting methods, standard arterial measurements were 2.4 mm Hg higher (95% confidence interval, 0.60-4.1) than with the DVPD. Differences between the 2 devices varied significantly across MAP values. The standard arterial line measurements were significantly higher than the DVPD at low MAP values, whereas the DVPD measurements were significantly higher than the standard arterial line at high MAP values. CONCLUSION: The DVPD provides a reasonable estimate of MAP and may be suitable for arterial pressure monitoring in settings where standard monitoring setups are not available. The DVPD appears to provide "worst-case" values because it underestimates low arterial blood pressure and overestimates high arterial blood pressure. Future trials should investigate the DVPD under different physiological conditions (eg, hypotensive patients, patients with ventricular assist devices, and patients on extracorporeal membrane oxygenation), different patient populations (such as pediatric patients), and in different environments (prehospital, air medical transport, and austere locations).