Early vesus differed arterial catheterisation in critically ill patients with acute circulatory failure: a multicentre, open-label, pragmatic, randomised, non-inferiority controlled trial: the EVERDAC protocol

Noninvasive Monitoring of Arterial Pressure: Finger or Lower Leg As Alternatives to the Upper Arm: A Prospective Study in Three ICUs

OBJECTIVES

When the upper arm is inaccessible for measurements of arterial pressure (AP), the best alternative site is unknown. We performed a between-site comparison of the agreement between invasive and noninvasive readings of AP taken at the lower leg, the finger, and the upper arm. The risk associated with measurement errors and the trending ability were also assessed.

DESIGN

Prospective observational study.

SETTING

Three ICUs.

PATIENTS

Patients having an arterial catheter and an arm circumference less than 42 cm.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three triplicates of AP measurements were collected via an arterial catheter (reference AP), a finger cuff system (ClearSight; Edward Lifesciences, Irvine, CA), and an oscillometric cuff (at the lower leg then the upper arm). Trending ability was assessed through an additional set of measurements after a cardiovascular intervention. The default bed backrest angle was respected. Failure to measure and display AP occurred in 19 patients (13%) at the finger, never at other sites. In 130 patients analyzed, the agreement between noninvasive and invasive readings was worse at the lower leg than that observed at the upper arm or the finger (for mean AP, bias ± sd of 6.0 ± 15.8 vs 3.6 ± 7.1 and 0.1 ± 7.4 mm Hg, respectively; p < 0.05), yielding a higher frequency of error-associated clinical risk (no risk for 64% vs 84% and 86% of measurements, respectively, p < 0.0001). According to the International Organization for Standardization (ISO) 81060-2:2018 standard, mean AP measurements were reliable at the upper arm and the finger, not the lower leg. In 33 patients reassessed after a cardiovascular intervention, both the concordance rate for change in mean AP and the ability to detect a therapy-induced significant change were good and similar at the three sites.

CONCLUSIONS

As compared with lower leg measurements of AP, finger measurements were, when possible, a preferable alternative to upper arm ones.

Hemodynamic monitoring in cardiogenic shock

Cardiogenic shock (CS) is a life-threatening condition characterized by acute end-organ hypoperfusion due to inadequate cardiac output that can result in multiorgan failure, which may lead to death. The diminished cardiac output in CS leads to systemic hypoperfusion and maladaptive cycles of ischemia, inflammation, vasoconstriction, and volume overload. Obviously, the optimal management of CS needs to be readjusted in view of the predominant dysfunction, which may be guided by hemodynamic monitoring. Hemodynamic monitoring enables (1) characterization of the type of cardiac dysfunction and the degree of its severity, (2) very early detection of associated vasoplegia, (3) detection and monitoring of organ dysfunction and tissue oxygenation, and (4) guidance of the introduction and optimization of inotropes and vasopressors as well as the timing of mechanical support. It is now well documented that early recognition, classification, and precise phenotyping via early hemodynamic monitoring (e.g., echocardiography, invasive arterial pressure, and the evaluation of organ dysfunction and parameters derived from central venous catheterization) improve patient outcomes. In more severe disease, advanced hemodynamic monitoring with pulmonary artery catheterization and the use of transpulmonary thermodilution devices is useful to facilitate the right timing of the indication, weaning from mechanical cardiac support, and guidance on inotropic treatments, thus helping to reduce mortality. In this review, we detail the different parameters relevant to each monitoring approach and the way they can be used to support optimal management of these patients.