Direct Oral Anticoagulants in Patients With Nonvalvular Atrial Fibrillation: Update and Periprocedural Management.

Vitamin K antagonists (eg, warfarin) have been the standard of care for stroke prophylaxis in atrial fibrillation. The direct oral anticoagulants dabigatran (direct thrombin inhibitor) and rivaroxaban, apixaban, and edoxaban (direct factor Xa inhibitors) are as efficacious as and in some instances superior to vitamin K antagonists in the prevention of stroke, systemic embolism, and major bleeding compared with warfarin for nonvalvular atrial fibrillation. Benefits of direct oral anticoagulants include a rapid onset of therapeutic effect, fixed dose-response relationships without the need for routine monitoring, a short half-life, and infrequent need for periprocedural bridging with a parenteral agent. However, direct oral anticoagulants differ in subsets of patients. Critical care and advanced practice nurses must understand these differences, prescribing considerations, drug aherence interventions, drug-drug interactions, and periprocedural management. This article presents an update and review of direct oral antigcoagulants based on the latest national guidelines.

Noninvasive Blood Pressure Monitoring and Prediction of Fluid Responsiveness to Passive Leg Raising.

BACKGROUND: Intravenous fluid boluses are administered to patients in shock to improve tissue hypoperfusion. However, fluid boluses result in clinically significant stroke volume increases in only about 50% of patients. Hemodynamic responses to passive leg raising measured with invasive and minimally invasive methods are accurate predictors of fluid responsiveness. However, few studies have used noninvasive blood pressure measurement to evaluate responses to passive leg raising. OBJECTIVE: To determine if passive leg raising-induced increases in pulse pressure or systolic blood pressure can be used to predict clinically significant increases in stroke volume index in healthy volunteers. METHODS: In a repeated-measures study, hemodynamic measurements were obtained in 30 healthy volunteers before, during, and after passive leg raising. Each participant underwent the procedure twice. RESULTS: In the first test, 20 participants (69%) were responders (stroke volume index increased by ≥ 15%); 9 (31%) were nonresponders. In the second test, 15 participants (50%) were responders and 15 (50%) were nonresponders. A passive leg raising-induced increase in pulse pressure of 9% or more predicted a 15% increase in stroke volume index (sensitivity, 50%; specificity, 44%). There was no association between passive leg raising-induced changes in systolic blood pressure and fluid responsiveness. CONCLUSION: A passive leg raising-induced change in stroke volume index measured by bioreactance differentiated fluid responders and nonresponders. Pulse pressure and systolic blood pressure measured by oscillometric noninvasive blood pressure monitoring were not sensitive or specific predictors of fluid responsiveness in healthy volunteers.

Passive Leg-Raising and Prediction of Fluid Responsiveness: Systematic Review.

Fluid boluses are often administered with the aim of improving tissue hypoperfusion in shock. However, only approximately 50% of patients respond to fluid administration with a clinically significant increase in stroke volume. Fluid overload can exacerbate pulmonary edema, precipitate respiratory failure, and prolong mechanical ventilation. Therefore, it is important to predict which hemodynamically unstable patients will increase their stroke volume in response to fluid administration, thereby avoiding deleterious effects. Passive leg-raising (lowering the head and upper torso from a 45° angle to lying supine [flat] while simultaneously raising the legs to a 45° angle) is a transient, reversible autotransfusion that simulates a fluid bolus and is performed to predict a response to fluid administration. The article reviews the accuracy, physiological effects, and factors affecting the response to passive-leg raising to predict fluid responsiveness in critically ill patients.