Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Dec 2015
ReviewHemodynamic Monitoring for the Evaluation and Treatment of Shock: What Is the Current State of the Art?
Hemodynamic monitoring has become a fundamental and ubiquitous, if not defining, aspect of critical care medicine practice. Modern monitoring techniques have changed significantly over the past few years and are now able to rapidly identify shock states earlier, define the etiology, and monitor the response to therapies. Many of these techniques are now minimally invasive or noninvasive. ⋯ Minimally invasive and noninvasive measure of arterial pressure and cardiac output are also possible and often remain as accurate as invasive measures. Importantly, such advanced monitoring provides the foundation for goal-directed therapies for the treatment of shock. When coupled with functional hemodynamic monitoring analyses, these measures markedly extend the diagnostic and therapeutic potential of all monitoring modalities by defining preload reserve, vasomotor tone, cardiac performance, and tissue perfusion.
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Semin Respir Crit Care Med · Dec 2015
ReviewProtocol-Based Care versus Individualized Management of Patients in the Intensive Care Unit.
The delivery of evidence-based care in the high-acuity environment of the intensive care unit can be challenging. In an effort to help turn guidelines and standards of care into consistent and uniform practice, physicians and hospitals turn toward protocol-based medical care. A protocol can help guide a practitioner to make correct interventions, at the right time, and in the proper order when managing a given disease. ⋯ In addition to the care the protocol delivers, it must overcome other barriers to gain acceptance. These include concerns about protocol usage among medical trainees, physician concern regarding loss of autonomy, and the ceiling effect protocol-driven care places on expert practitioners, among other concerns. The aim of this article is to critically appraise what it means for a protocol to be considered successful with an aim toward improving protocol design and implementation in the future.
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The right heart failure (RHF) syndrome is a pathophysiologically complex state commonly associated with dysfunction of the right ventricle (RV). The normal RV is suited for its purposes of distributing venous blood to the low-resistance pulmonary circulation. Myriad stresses imposed upon it, though, can ultimately result in its failure, with the threat of cardiovascular collapse being the most dreaded outcome. ⋯ Appropriate use of diagnostic tools is paramount for understanding the key components of RV function: the preload state of the RV, its contractility, and the afterload burden placed on it. In making these assessments, it remains crucial to understand the limitations of these tools when managing RHF in the intensive care unit. An understanding of each of these components allows for the understanding of the physiology and the clinical presentation which can guide the use of therapies appropriately tailored to manage the condition.
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Semin Respir Crit Care Med · Dec 2015
Review Meta AnalysisMetabolic Management during Critical Illness: Glycemic Control in the ICU.
Hyperglycemia is a commonly encountered metabolic derangement in the ICU. Important cellular pathways, such as those related to oxidant stress, immunity, and cellular homeostasis, can become deranged with prolonged and uncontrolled hyperglycemia. There is additionally a complex interplay between nutritional status, ambient glucose concentrations, and protein catabolism. ⋯ In this review, we will explore the impact of hyperglycemia upon critical cellular pathways and how nutrition provided in the ICU affects blood glucose. Additionally, important clinical trials to date will be summarized. A practical and comprehensive approach to glucose management in the ICU will be outlined, touching upon important issues such as glucose variability, target population, and hypoglycemia.
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Semin Respir Crit Care Med · Dec 2015
ReviewControversies in the Management of Severe ARDS: Optimal Ventilator Management and Use of Rescue Therapies.
Groundbreaking research into the pathophysiology of the adult acute respiratory distress syndrome (ARDS) and the prevention of ventilator-induced lung injury has led to dramatic improvements in survival. Investigations over the last two decades have revolved around the development of rescue therapies that can be used for patients with severe ARDS and refractory hypoxemia. To date, the techniques of using high levels of positive end-expiratory pressure (PEEP), prompt institution of neuromuscular blockade, and early prolonged prone positioning have been shown to reduce mortality in patients with severe ARDS. ⋯ A major randomized controlled trial conducted during this period showed a significant mortality benefit for patients with severe ARDS who were referred to a center with ECMO capabilities. The routine use of inhaled nitric oxide for patients with severe ARDS has not been shown to lead to more than a transient and limited improvement in oxygenation, which may hinder its use as a sole rescue therapy. Finally, recent studies have found that the routine use of high-frequency oscillatory ventilation in severe ARDS does not result in decreased mortality, although the technique has not been specifically investigated as rescue therapy for severe refractory hypoxemia.