Pathophysiology of oliguria and acute kidney injury

2016 ◽  
Author(s):  
Rinaldo Bellomo ◽  
John R. Prowle
Keyword(s):  
Acute Kidney Injury ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Kidney Injury ◽  
Experimental Models ◽  
Volume Depletion ◽  
Icu Patients ◽  
Tubular Necrosis ◽  
Inflammatory Processes ◽  
Extravascular Volume

Oliguria and acute kidney injury (AKI) are common in critically-ill patients with studies reporting AKI affecting more than 50% of critically-ill patients. AKI is independently associated with increased mortality and is a potentially modifiable aspect of critical illness. The pathogenesis of AKI is complex and varies according to aetiology. The most common trigger in ICU patients is sepsis—the pathophysiology of septic AKI is poorly understood and probably involves intrarenal haemodynamic and inflammatory processes. In the setting of septic AKI, the classic acute tubular necrosis described in experimental models does not occur and histological changes are only minor. Activation of neurohormonal mechanisms is also important, particularly in the hepatorenal syndrome, where activation of the remain-angiotensin system appears to play a major role. The treatment of oliguria and AKI in ICU patients has traditionally relied on the administration of intravenous fluids. While such therapy is warranted in patients with a clear history, and physical examination suggestive of intravascular and extravascular volume depletion, its usefulness in other patients (e.g. septic patients) remains controversial. Removal of nephrotoxins, rapid treatment of the triggering factors, and attention to cardiac output and mean arterial pressure remain the cornerstones of the prevention and treatment of AKI in ICU.

Survival in Critically Ill Patients with Acute Kidney Injury Treated with Early Hemodiafiltration

2012 ◽  
Vol 35 (12) ◽  
pp. 1039-1046 ◽  
Author(s):  
Nicolas Boussekey ◽  
Benoit Capron ◽  
Pierre-Yves Delannoy ◽  
Patrick Devos ◽  
Serge Alfandari ◽  
...  
Keyword(s):  
Risk Factors ◽  
Acute Kidney Injury ◽  
Critically Ill ◽  
Mortality Risk ◽  
Critically Ill Patients ◽  
Kidney Injury ◽  
Icu Patients ◽  
Impact On Survival ◽  
Baseline Characteristics ◽  
The Moment

Purpose Early renal replacement therapy (RRT) initiation should theoretically influence many physiological disorders related to acute kidney injury (AKI). Currently, there is no consensus about RRT timing in intensive care unit (ICU) patients. Methods We performed a retrospective analysis of all critically ill patients who received RRT in our ICU during a 3 year-period. Our goal was to identify mortality risk factors and if RRT initiation timing had an impact on survival. RRT timing was calculated from the moment the patient was classified as having acute kidney injury in the RIFLE classification. Results A hundred and ten patients received RRT. We identified four independent mortality risk factors: need for mechanical ventilation (OR = 12.82 (1.305 - 125.868, p = 0.0286); RRT initiation timing >16 h (OR = 5.66 (1.954 - 16.351), p = 0.0014); urine output on admission <500 ml/day (OR = 4.52 (1.666 - 12.251), p = 0.003); and SAPS II on admission >70 (OR = 3.45 (1.216 - 9.815), p = 0.02). The RRT initiation <16 h and RRT initiation >16 h groups presented the same baseline characteristics, except for more severe gravity scores and kidney failure in the early RRT group. Conclusions Early RRT in ICU patients with acute kidney injury or failure was associated with increased survival.

Conservative Management of Acute Kidney Injury

2018 ◽  
Author(s):  
Rolando Claure-Del Granado ◽  
Etienne Macedo ◽  
Ravindra L. Mehta
Keyword(s):  
Acute Kidney Injury ◽  
Critically Ill ◽  
Fluid Resuscitation ◽  
Critically Ill Patients ◽  
Multiorgan Failure ◽  
Kidney Injury ◽  
Care Environment ◽  
Icu Patients ◽  
Fluid Removal ◽  
Risk Of Mortality

Acute kidney injury (AKI) is one of the most common complications occurring among intensive care unit (ICU) patients and is independently associated with a higher risk of mortality. In critically ill patients, AKI presentation is heterogeneous, varying from asymptomatic elevations in serum creatinine to the need for dialysis in the context of multiorgan failure. Within this range of clinical presentation, the kidney is often overlooked because improving and maintaining cardiac performance are the focus. In addition, aggressive fluid resuscitation may impose significant demands on the kidney wherein the normal excretory capacity may be overwhelmed. ICU patients often have underlying comorbidities, including chronic kidney disease and heart failure, which further limit the range of renal capacity. Drug and nutritional administration contribute to the demand for fluid removal to maintain fluid balance. The dissimilarities of the critical care environment and the extra demand kidney capacity highlight the need for different strategies for management and treatment of AKI in the critically ill patients. We focus this review on the general and nondialytic therapy of AKI. This reference contains 5 figures, 3 tables and 90 references Key words: Acute kidney injury, fluid resuscitation, loop diuretics, vasoactive agents, fluid overload, hiperkalemia, and metabolic acidosis.  

scholarly journals Renal Replacement Therapy in Critically Ill: Current Trend and New Direction

2015 ◽  
Vol 3 (1) ◽  
pp. 17-21
Author(s):  
Sarwar Iqbal ◽  
Mohammad Omar Faruq
Keyword(s):  
Acute Kidney Injury ◽  
Renal Replacement Therapy ◽  
Serum Creatinine ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Early Identification ◽  
Kidney Injury ◽  
Hemodynamic Instability ◽  
Acid Base ◽  
Icu Patients

Critically ill patients often present with renal dysfunction. Acute kidney injury (AKI) is common in intensive care unit (ICU) patients and is often a component of multiple organ dysfunction syndrome (MODS). Renal replacement therapy (RRT) plays a significant role in management of acute and chronic renal failure in ICU. During the last decade RRT has made remarkable progress in management of renal dysfunction of critically ill. The Acute Dialysis Quality Initiative conceived in 2002 proposed RIFLE classification for AKI (risk, injury, failure, loss, end-stage kidney disease) using serum creatinine and urine output in critically ill patients. More recently, the Acute Kidney Injury Network (AKIN) has been introduced for staging AKI. Studies have shown that mortality increases proportionately with increasing severity of AKI. In patients with severe AKI requiring RRT mortality is approximately 50% to 70% according to one study and even a small changes in serum creatinine are associated with increased mortality. The most common causes of AKI in ICU are sepsis, hypovolemia, low cardiac output and drugs. The various techniques of RRT used in ICU include intermittent hemodialysis (IHD), continuous RRT (CRRT), sustained low efficiency dialysis (SLED) and peritoneal dialysis (PD). It is preferable to use RRT at either RIFLE injury type or at AKIN stage II in critically ill patients. IHD is commonly used in hemodynamically stable ICU patients. Because of high dialysate (500ml/min) IHD may cause hypotension in some patients. Solute removal may be episodic and often result in inferior uraemic control and acid base control. CRRT is usually initiated with a blood flow of 100 to 200 ml/min. and thus hemodynamic instability associated with IHD is avoided. Major advantages of CRRT include continuous control of fluid status, hemodynamic stability and control of acid base status. It is expensive and there is high risk of bleeding because of use of high dose of IV heparin. SLED has been found to be safe and effective in critically ill patients with hemodynamic instability. It uses the same dialysis machine of IHD and combines the effectiveness of CRRT in unstable patients and easy operability of IHD. It is also cost effective. PD is initiated in ICU for AKI patients when bedside IHD is not available. It is good for hemodynamically unstable patients when IHD or CRRT is difficult. In patients on mechanical ventilator, PD interferes with function of diaphragm causing decrease in lung compliance. Early identification of AKI with bio markers is an important step in improving outcomes of AKI. These bio markers help early detection of AKI before the onset of rise in serum creatinine. Serum cystatin C is one of the sensitive bio markers of small changes in Glomerular filtration rate (GFR) and has been found to be useful. AKI in the ICU most commonly results from multiple insults. Therefore appropriate and early identification of patients at risk of AKI provides an opportunity to prevent subsequent renal insults. This strategy will influence overall ICU morbidity and mortality.Bangladesh Crit Care J March 2015; 3 (1): 17-21

Conservative Management of Acute Kidney Injury

2018 ◽  
Author(s):  
Rolando Claure-Del Granado ◽  
Etienne Macedo ◽  
Ravindra L. Mehta
Keyword(s):  
Acute Kidney Injury ◽  
Critically Ill ◽  
Fluid Resuscitation ◽  
Critically Ill Patients ◽  
Multiorgan Failure ◽  
Kidney Injury ◽  
Care Environment ◽  
Icu Patients ◽  
Fluid Removal ◽  
Risk Of Mortality

Acute kidney injury (AKI) is one of the most common complications occurring among intensive care unit (ICU) patients and is independently associated with a higher risk of mortality. In critically ill patients, AKI presentation is heterogeneous, varying from asymptomatic elevations in serum creatinine to the need for dialysis in the context of multiorgan failure. Within this range of clinical presentation, the kidney is often overlooked because improving and maintaining cardiac performance are the focus. In addition, aggressive fluid resuscitation may impose significant demands on the kidney wherein the normal excretory capacity may be overwhelmed. ICU patients often have underlying comorbidities, including chronic kidney disease and heart failure, which further limit the range of renal capacity. Drug and nutritional administration contribute to the demand for fluid removal to maintain fluid balance. The dissimilarities of the critical care environment and the extra demand kidney capacity highlight the need for different strategies for management and treatment of AKI in the critically ill patients. We focus this review on the general and nondialytic therapy of AKI. This reference contains 5 figures, 3 tables and 90 references Key words: Acute kidney injury, fluid resuscitation, loop diuretics, vasoactive agents, fluid overload, hiperkalemia, and metabolic acidosis.  

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