Advances in chronic kidney disease
-
Adv Chronic Kidney Dis · Jul 2008
ReviewRenal replacement therapy in acute kidney injury: intermittent versus continuous? How much is enough?
Approximately 4% of all critically ill patients will require renal replacement therapy (RRT). Despite its potential reversibility, acute kidney injury has a significant impact on morbidity and mortality. Numerous studies have addressed the questions of modality choice and dose of RRT in the intensive care unit setting. ⋯ Another key aspect in the treatment of acute kidney injury is the consequence of RRT on long-term renal function. Although cohort studies have shown that continuous RRT shortens dialysis-dependence compared with intermittent hemodialysis, randomized trials and meta-analyses do not support these findings. Several unanswered questions, such as the timing of initiation and cessation of RRT, the modification of dialysis parameters over the course of acute kidney injury and the influence of fluid status need to be addressed in future trials in order to improve outcomes related to this condition.
-
Adv Chronic Kidney Dis · Jul 2008
ReviewAcute kidney injury and chronic kidney disease after cardiac surgery.
Kidney dysfunction is common after cardiac surgery and predicts mortality risk and poorer long-term outcome, particularly when acute injury superimposes upon chronic kidney disease. Numerous insults contribute to perioperative renal impairment including major surgical trespass, procedure-specific interventions (eg, deep hypothermic circulatory arrest), and postoperative complications. Regardless of cause, evidence supports a role for renal impairment and accumulation of "uremic toxins" as direct contributors to adverse outcome. ⋯ Despite considerable research focus, progress in development of interventions aimed at perioperative renoprotection has been disappointing. However, practice modifications can influence the likelihood of acute kidney injury, and several recent advances provide hope for the future. We review pathophysiologic understanding of this disorder; evaluate the confusing relationship (causal v epiphenomena) among acute kidney injury, chronic kidney disease, and adverse outcome after cardiac surgery; and provide an evidence-based assessment of the conduct of cardiac surgery and renoprotection strategies.
-
The development of respiratory failure in patients with AKI is a particularly devastating consequence that greatly increases patient mortality. When respiratory failure and AKI occur together, the mortality is greater than 80%. A clear understanding of the mechanisms leading to respiratory failure is of great clinical relevance to patients with AKI in order to prevent and treat this life-threatening complication. ⋯ In this review, these mechanisms are presented in historical context including the original descriptions of pathology and pathophysiology, recent epidemiologic data, and experimental studies in animals. Although volume overload is a well-accepted mechanism of pulmonary edema in patients with AKI, the purpose of this review was to highlight the evidence showing that noncardiogenic edema and acute lung injury also occur. By recognizing that the pulmonary complications of AKI are not simply from volume overload, specific treatment strategies may be discovered and used to improve outcomes in patients with the ominous and life threatening combination of AKI and respiratory failure.
-
The diagnosis of acute kidney injury (AKI) is usually based on measurements of blood urea nitrogen (BUN) and serum creatinine. BUN and serum creatinine are not very sensitive or specific for the diagnosis of AKI because they are affected by many renal and nonrenal factors that are independent of kidney injury or kidney function. ⋯ These early biomarkers of AKI are being tested in different types of AKI and in larger clinical studies. Biomarkers of AKI may also predict long-term kidney outcomes and mortality.
-
Acute kidney injury (AKI) is common in the intensive care unit and is associated with significant morbidity and mortality. Based on the RIFLE criteria, AKI occurs in up to 67% of patients in the intensive care unit (ICU), with approximately 4% of critically ill patients requiring renal replacement therapy (RRT). It is well known that this subset of AKI patients who require RRT have an in-hospital mortality rate exceeding 50%. ⋯ According to the United States Renal Data System, "acute tubular necrosis without recovery" as a cause of end-stage kidney disease increased from 1.2% in 1994 to 1998 to 1.7% in 1999 to 2003. The incidence will likely continue to rise with the aging population, increase in comorbidities, and expansion of intensive care unit capabilities. AKI is an underrecognized cause of chronic kidney disease (CKD) and patients who survive should be followed closely for new CKD and/or progression of underlying CKD.