REVIEW URRENT C OPINION
Evolving practices in critical care and their influence on acute kidney injury Jennifer G. Wilson a,, Brad W. Butcher b,, and Kathleen D. Liu b
Purpose of review This review highlights the principal advances in critical care over the past year, and discusses the impact of these advances on the diagnosis and management of acute kidney injury (AKI). Recent findings Recent literature has focused on assessment of volume status and fluid management, particularly in the setting of respiratory and cardiac failure. Other critical care topics are reviewed using a system-based approach. Summary The incidence of AKI appears to be increasing, and despite advances in the provision of critical care and renal replacement therapies, there has been little improvement in its associated morbidity and mortality. Nonetheless, recent advances in critical care will impact the diagnosis and management of AKI, as well as shape the future research agenda. Continued work in the fields of critical care and nephrology will undoubtedly be centered on improved biomarkers for the detection of AKI, specific therapies to mitigate or reverse AKI, and techniques to prevent the development of AKI in the critically ill population. Keywords acute kidney injury, critical care, fluid therapy
INTRODUCTION The incidence of acute kidney injury (AKI) appears to be increasing, and despite advances in the provision of critical care and renal replacement therapies (RRTs), there has been little improvement in its associated morbidity and mortality [1–3]. The purpose of this review is to highlight the principal advances in critical care over the past year and discuss their impact on the diagnosis and management of AKI. After a discussion of volume status and fluid management, particularly in the setting of respiratory and cardiac failure, we will systematically address recent noteworthy clinical studies and their relevance to AKI.
FLUID MANAGEMENT Over the past year, there has been significant interest in specific questions related to fluid management in the critical care literature, including fluid selection, assessment of intravascular volume status, and optimal fluid strategies in various disease states. A separate article in this issue will focus on these issues, but as an important and evolving area in critical care practice, they merit brief mention here as well.
Fluid selection and assessment of intravascular volume status Several recent studies have demonstrated the potentially adverse renal effects of certain intravenous fluids, including hydroxyethyl starch and chloriderich solutions; these are reviewed in another article in this issue [4–6]. We focus here on assessment of volume status and recent developments in fluid management strategies for patients with respiratory and cardiac failure. Assessment of intravascular volume status remains challenging and has taken on even greater a Department of Medicine and Anesthesia, Division of Critical Care Medicine and bDepartment of Medicine and Anesthesia, Divisions of Nephrology and Critical Care Medicine, University of California, San Francisco, California, USA
Correspondence to Kathleen D. Liu, MD, PhD, MAS, Associate Professor, Department of Medicine, Division of Nephrology, University of California, San Francisco, Box 0532 California, USA. Tel: +1 415 476 2172; fax: +1 415 476 3381; e-mail: [email protected] Jennifer G. Wilson and Brad W. Butcher contributed equally to the writing of the article.
Curr Opin Crit Care 2013, 19:523–530 DOI:10.1097/MCC.0000000000000040
1070-5295 ß 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-criticalcare.com
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Renal system
be considered in the management of patients with AKI.
KEY POINTS Fluid management is a focus of the recent critical care literature, including research around fluid selection, assessment of intravascular volume, and fluid strategies in various disease states. Changes to the definition of ARDS include a recognition that ARDS may coexist with volume overload and heart failure, a requirement for a minimal level of positive end-expiratory pressure, and elimination of ALI in favor of mild, moderate, and severe ARDS (PaO2:FiO2 ratio 201–300, 101–200, and 100, respectively). Multiple studies continue to support a ‘conservative’ hemoglobin target in critically ill patients, even in the presence of active bleeding or known coronary artery disease. Newer oral anticoagulants present new dosing and reversal challenges, especially in patients with AKI. Appropriate antibiotic therapy remains the cornerstone of sepsis management, and there is growing evidence that patients with AKI on RRT often fail to meet target antibiotic levels.
importance, as evidence mounts that volume overload is associated with worse outcomes in several disease states, including AKI [7,8 ,9]. Given the limitations of physical examination and static measurements, such as central venous pressure, there is increasing interest in dynamic parameters, including stroke volume variation and inferior vena cava collapsibility (cIVC), to predict fluid responsiveness [10]. Although evidence exists that dynamic variables predict response to volume expansion in sedated, mechanically ventilated patients, their use in spontaneously ventilated patients remains controversial [11]. Two recent observational studies have addressed whether ultrasound assessment of cIVC is reliable for predicting fluid responsiveness in spontaneously breathing patients [11,12]. Although either large (>50%) or small (80 or body weight
Evolving practices in critical care and their influence on acute kidney injury Jennifer G. Wilson a,, Brad W. Butcher b,, and Kathleen D. Liu b
Purpose of review This review highlights the principal advances in critical care over the past year, and discusses the impact of these advances on the diagnosis and management of acute kidney injury (AKI). Recent findings Recent literature has focused on assessment of volume status and fluid management, particularly in the setting of respiratory and cardiac failure. Other critical care topics are reviewed using a system-based approach. Summary The incidence of AKI appears to be increasing, and despite advances in the provision of critical care and renal replacement therapies, there has been little improvement in its associated morbidity and mortality. Nonetheless, recent advances in critical care will impact the diagnosis and management of AKI, as well as shape the future research agenda. Continued work in the fields of critical care and nephrology will undoubtedly be centered on improved biomarkers for the detection of AKI, specific therapies to mitigate or reverse AKI, and techniques to prevent the development of AKI in the critically ill population. Keywords acute kidney injury, critical care, fluid therapy
INTRODUCTION The incidence of acute kidney injury (AKI) appears to be increasing, and despite advances in the provision of critical care and renal replacement therapies (RRTs), there has been little improvement in its associated morbidity and mortality [1–3]. The purpose of this review is to highlight the principal advances in critical care over the past year and discuss their impact on the diagnosis and management of AKI. After a discussion of volume status and fluid management, particularly in the setting of respiratory and cardiac failure, we will systematically address recent noteworthy clinical studies and their relevance to AKI.
FLUID MANAGEMENT Over the past year, there has been significant interest in specific questions related to fluid management in the critical care literature, including fluid selection, assessment of intravascular volume status, and optimal fluid strategies in various disease states. A separate article in this issue will focus on these issues, but as an important and evolving area in critical care practice, they merit brief mention here as well.
Fluid selection and assessment of intravascular volume status Several recent studies have demonstrated the potentially adverse renal effects of certain intravenous fluids, including hydroxyethyl starch and chloriderich solutions; these are reviewed in another article in this issue [4–6]. We focus here on assessment of volume status and recent developments in fluid management strategies for patients with respiratory and cardiac failure. Assessment of intravascular volume status remains challenging and has taken on even greater a Department of Medicine and Anesthesia, Division of Critical Care Medicine and bDepartment of Medicine and Anesthesia, Divisions of Nephrology and Critical Care Medicine, University of California, San Francisco, California, USA
Correspondence to Kathleen D. Liu, MD, PhD, MAS, Associate Professor, Department of Medicine, Division of Nephrology, University of California, San Francisco, Box 0532 California, USA. Tel: +1 415 476 2172; fax: +1 415 476 3381; e-mail: [email protected] Jennifer G. Wilson and Brad W. Butcher contributed equally to the writing of the article.
Curr Opin Crit Care 2013, 19:523–530 DOI:10.1097/MCC.0000000000000040
1070-5295 ß 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-criticalcare.com
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Renal system
be considered in the management of patients with AKI.
KEY POINTS Fluid management is a focus of the recent critical care literature, including research around fluid selection, assessment of intravascular volume, and fluid strategies in various disease states. Changes to the definition of ARDS include a recognition that ARDS may coexist with volume overload and heart failure, a requirement for a minimal level of positive end-expiratory pressure, and elimination of ALI in favor of mild, moderate, and severe ARDS (PaO2:FiO2 ratio 201–300, 101–200, and 100, respectively). Multiple studies continue to support a ‘conservative’ hemoglobin target in critically ill patients, even in the presence of active bleeding or known coronary artery disease. Newer oral anticoagulants present new dosing and reversal challenges, especially in patients with AKI. Appropriate antibiotic therapy remains the cornerstone of sepsis management, and there is growing evidence that patients with AKI on RRT often fail to meet target antibiotic levels.
importance, as evidence mounts that volume overload is associated with worse outcomes in several disease states, including AKI [7,8 ,9]. Given the limitations of physical examination and static measurements, such as central venous pressure, there is increasing interest in dynamic parameters, including stroke volume variation and inferior vena cava collapsibility (cIVC), to predict fluid responsiveness [10]. Although evidence exists that dynamic variables predict response to volume expansion in sedated, mechanically ventilated patients, their use in spontaneously ventilated patients remains controversial [11]. Two recent observational studies have addressed whether ultrasound assessment of cIVC is reliable for predicting fluid responsiveness in spontaneously breathing patients [11,12]. Although either large (>50%) or small (80 or body weight
