MANAGEMENT OF POSTRENAL AZOTEMIA David J. When discussing azotemia, there are three pathophysiological classifications including prerenal azotemia, intrarenal azotemia, & postrenal azotemia. Relief of the obstruction is the mainstay of therapy for postrenal azotemia. 8mg/dL. acute glomerulonephritis C. The BUN is 88mg/dL; the creatinine is 2. Detection of postrenal azotemia requires attentiveness to the history and physical examination findings and to the results of specifically directed diagnostic tests. However, it is important to appreciate that prolonged or profound prerenal azotemia can result in ischemic damage to the kidney and thus there is spectrum from prerenal azotemia to ischemic AKI. ARF will not include increases in blood urea due to reversible renal vasoconstriction (prerenal azotemia) or urinary tract obstruction (postrenal azotemia). Apr 5, 2017 · Azotemia 가 있다면. Increased serum calcium C. Osborne, DVM, PhD, and Joseph W. An obstruction or infection may block urine flow, or the issue may be due to a congenital abnormality. Renal azotemia is a condition where the kidneys fail to filter out nitrogenous waste products from the blood. Prerenal azotemia is a form of azotemia in which the kidneys fail to adequately filter waste products from the blood, due to reduced renal perfusion. Postrenal azotemia is characterized by blockages in the tubes leaving the kidney. Nov 15, 2022 · INTRODUCTION. This clinical assessment is most consistent with: A. O pueden estar presentes los síntomas de las causas de la azotemia prerrenal. In all of these cases mentioned, azotemia can disappear when the underlying condition is treated in a timely manner. e. Postrenal azotemia is azotemia that results from obstruction to the free flow of urine from the Jul 17, 2024 · La azotemia o aumento de creatinina y urea, puede ocurrir por diversas situaciones en los gatos. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Urine output still may be present if overflow (in bladder outlet obstruction) or partial ureteral obstruction is present. Entre las principales sustancias que se pueden mencionar están: Urea: sustancia que se forma por la descomposición de proteína en el hígado. Causas de la azotemia prerrenal La azotemia prerrenal es algo común, especialmente en personas hospitalizadas. This is accomplished by performing fluid replacement to increase urine production and the GFR to the ureters, allowing the ureters to expand near the occlusion. postrenal azotemia, The APN sees a 68-year-old woman with heart failure. Jan 1, 2020 · Prompt correction of postrenal causes of azotemia limits the potential for intrinsic renal damage and can contribute to a positive clinical outcome; therefore, postrenal azotemia should be Oct 19, 2022 · When nitrogen waste products, such as creatinine and urea, build up in the body, the condition is called azotemia. These types of azotemia may have somewhat different treatments, causes, Nov 30, 2021 · Studies To Assess For Prerenal, Intrarenal, and Postrenal Acute Kidney Injury (AKI) Studies: Prerenal AKI: Intrarenal AKI: Postrenal AKI: Urine osmolality (mOsm/kg) > 500 Feb 22, 2018 · When rupture or obstruction of the urinary tract prevents the normal collection and expulsion of urine from the body, the resulting azotemia is termed postrenal. . This calculation is widely used to help differentiate prerenal disease (decreased kidney perfusion) from acute tubular necrosis (ATN) as the cause of acute kidney injury (AKI, formerly called acute renal failure). Cuando disminuye el volumen o la presión en el flujo sanguíneo a través del riñón, la filtración sanguínea también se reduce e incluso se puede detener del todo. Akibatnya, fungsi ginjal pun terganggu ketika mengeluarkan nitrogen dalam urine. Immediate therapy should be directed at restoring urine flow, correcting extracellular fluid volume deficits, minimizing the cardiac toxicity of hyperkalemia Apr 19, 2021 · Intrarenal azotemia yaitu kelebihan nitrogen dalam darah yang disebabkan oleh kerusakan ginjal. Recognizing postrenal azotemia early is crucial because it is often reversible with prompt intervention. prerenal, intrinsic renal, or postrenal. 2. This is referred to as renal azotemia. Urine osmolality (mOsm/kg) Serum creatinine concentrations must always be interpreted in light of the patient’s muscle mass, urine specific gravity, and physical examination findings in order to rule out pre- and postrenal causes of azotemia. 4 Fe-Na < 1% Suggestive of ATN or postrenal azotemia: Urinary Na+ >40 mEq/L Urine/plasma Creat ratio <20 Renal failure index (RFI) >1 urine/plasma osmolality ratio: 1. The contemporary definition of acute kidney injury is based on the clinical guidelines set forth by 2012 Kidney Apr 1, 2009 · Postrenal azotemia is usually caused by an obstruction to urine outflow or a rupture of the urine outflow tract. The prima facie finding here is anuria, occasionally accompanied by hypertension. Nov 1, 2009 · Postrenal azotemia can coexist with prerenal and/or renal azotemia. Unilateral ureteral occlusion (an example of renal disease) is not associated with azotemia unless generalized disease of the nonobstructed kidney is also present. The clinical utility of these findings is often limited as therapy and disease states, for example, the use of loop diuretics, catabolism, and gastrointestinal bleeds, may influence renal sodium excretion and serum urea concentration. Renal ultrasound revealed bilateral hydronephrosis with hydroureter. Prerenal azotemia can be classically differentiated by biochemical findings in the urine and blood (Table 1). 1 mg/dl that had increased from his baseline of 1. Nov 25, 2023 · Acute kidney injury (AKI), previously called acute renal failure (ARF), denotes a sudden and often reversible reduction in kidney function, as measured by glomerular filtration rate (GFR). Herein, we describe an 80-year-old man with a history of nonmetastatic gastric cancer who presented with postrenal azotemia due to the coincidence of Jan 13, 2024 · Postrenal azotemia is caused by a blockage of urine flow below the kidneys. 2 Although postrenal etiologies of AKI are typically recognized as structural or functional alterations in the urinary tract that prevent urine outflow, the pathophysiologic Mar 16, 2023 · Dialysis disequilibrium syndrome usually occurs following initiation of dialysis, among patients with severe baseline azotemia. Postrenal azotemia results from interference with excretion of urine from the body (e. However, for the purposes of this review, the term ARF, rather than ATN, will be used. 020 can be expected, but it will still be inadequate to prevent azotemia. Aug 23, 2007 · Postrenal azotemia — obstruction of the urinary tract — is initially accompanied by few microscopical changes (early hydronephrosis, with enlargement of the pelvic cavity and minimal Jun 28, 2023 · Azotemia is when the kidneys cannot get rid of the waste product nitrogen, causing it to build up in the blood. Postrenal AKI. 1. UTO can occur at any site in the urinary tract, including the upper (renal pelvis, ureter) and lower urinary tract (bladder, prostate, Azotaemia is the laboratory finding of increased concentrations of non-protein nitrogenous wastes, measured as blood urea or serum creatinine. The central pathophysiology appears to be a rapid reduction in blood urea nitrogen levels, causing osmotic shifts that result in cerebral edema. This results in an elevation of serum blood urea nitrogen (BUN), creatinine, and other metabolic waste products that are normally excreted by the kidney. In such cases, prerenal or postrenal (obstructive etiologies involving ureter, bladder, prostate, or urethra) causes are more likely. 0 mg/dl 2 years earlier. Azotaemia can result from primary renal disease or from prerenal or postrenal processes. Similar to prerenal azotemia, in postrenal azotemia the kidneys are initially normal; however, the urine specific gravity varies, depending on the animal's hydration status. This obstruction can be due to conditions such as kidney stones, tumors, or an enlarged prostate gland. Metastatic ureteral masses are not rare, but isolated ureteral metastasis from the origin of gastric cancer is rare. Apr 28, 2022 · Acute kidney injury was diagnosed based on the International Renal Interest Society (IRIS) guidelines, and included presence of acute onset of clinical signs consistent with AKI (eg, anuria, oliguria, polyuria, vomiting, inappetence) and acute onset of azotemia after exclusion of postrenal causes. The current evidence supports the validity of KDIGO criteria to identify groups of hospitalized patients with increased risk of May 15, 2020 · If postrenal azotemia is not clear, sometimes postrenal AKI can be diagnosed by increasing visibility near the occlusion. Postrenal azotemia is caused by obstruction of the urinary tract, which can result from conditions such as kidney stones, tumors, or an enlarged prostate gland. 18 Gastrointestinal bleeding patients were Conceptually, prerenal azotemia and postrenal etiologies should spare damage to the kidney tissue, but intrarenal causes of AKI, such as ATN, are caused by inflammatory, ischemic or toxic injury Postrenal azotemia can be caused by congenital abnormalities such as vesicoureteral reflux, blockage of the ureters by kidney stones, pregnancy, compression of the ureters by cancer, prostatic hyperplasia, or blockage of the urethra by kidney or bladder stones. (known as ―uremia‖ or ―azotemia‖) due to inability to remove urine from the body (known as ―postrenal azotemia‖) may predominate in rare cases or with urinary tract rupture May contribute to recurrent urinary tract infection; functional urinary retention may be identified because of the recurrent Jul 31, 2023 · Prerenal kidney failure, also known as acute renal failure (ARF), or acute kidney injury (AKI), is an extensively researched concept that has undergone numerous revisions in the diagnosis over the last decade. Symptoms vary from nausea and mild headache to delirium and seizures. Urine specific gravity is variable in animals with postrenal azotemia from obstruction. This Osmosis High-Yield Note provides an overview of Acute and chronic kidney disease essentials. Once prerenal and postrenal causes of ARF were excluded, the diagnosis would focus on postrenal azotemia, complete recovery may be seen 1 to 2 days after relief of the offending lesion, provided that normal perfusion or urinary outflow is reestablished before structural changes occur. Anuria B. Increased serum phosphorus B. Hydronephrosis 가 존재한다면 Postrenal AKI R/O 을 위해서 Urologic evaluation을 시작합니다. Postrenal azotemia is a potentially life-threatening consequence of urinary obstruction. Mar 9, 2023 · Azotemia is an elevation of blood urea nitrogen (BUN) and serum creatinine levels. Extensive renal lesions result in azotaemia when there is a loss of 75% or greater of functioning nephrons. Oct 1, 2013 · Complete urine outflow obstruction (i. 0 Fe-Na > 2-3 Dec 4, 2015 · Nonetheless, in people, hemodynamic azotemia (referred to as transient azotemia) is associated with a higher odds ratio for mortality, similar to persistent azotemia. It can happen due to kidney disease or damage. The reference range for BUN is 8-20 mg/dL, and the normal range for serum creatinine is 0. Nonoliguric, Postrenal failure is a result of A. Jul 1, 2004 · In the clinical setting, the terms ATN and acute renal failure (ARF) are frequently used interchangeably. In anuria, bladder catheterization is mandatory to rule out bladder neck obstruction, whereas in progressive azotemia, catheterization should be done after the patient has voided to determine the postvoid residual volume. One of the kidneys’ key roles is to break down and reabsorb proteins for use in the body. Treatment is supportive. There are at least 30 biochemical definitions that have existed for AKI. Renal azotemia refers to an elevation of nitrogen-containing waste products in blood like urea and creatinine, which are due to renal dysfunction often causing an acute kidney injury (AKI). (See also Overview of Tubulointerstitial Sep 16, 2017 · The time-honored classification of AKI to prerenal azotemia, intrinsic renal diseases, and post-renal urinary obstruction provides a conceptual framework by which pathophysiological mechanisms can be investigated . Postrenal azotemia is a potentially life-threatening consequence of urinary obstruction Its most serious consequences include fluid volume deficits, hyperkalemia, and metabolic acidosis. Postrenal azotemia occurs when there is a Jun 11, 2024 · INTRODUCTION AND DEFINITION. Herein, we describe an 80-year-old man with a history of nonmetastatic gastric cancer who presented with postrenal azotemia due to the coincidence of right distal ureteral metastasis and left distal ureteral stone. Blood loss, Which is a characteristic finding in renal failure? A. Debido a las funciones renales insuficientes, aumenta la cantidad de urea y creatina en la sangre . what urine sg is seen with renal azotemia. Prerenal azotemia is when systemic circulation causes a decrease of the flow to the kidney’s resulting in an increase in both BUN & creatinine levels (Salifu, 2017). Urinary obstruction causes increased tubular pressure, which impairs glomerular filtration, renal blood flow, and tubular function. Aug 3, 2023 · Postrenal azotemia is due to obstruction. 5 non-renal cases were taken. decreased excretion (prerenal, renal, postrenal) what cuases decreased creatinine. A urinary tract obstruction causes postrenal azotemia. Azotemia D. Its most serious consequences include fluid volume deficits, hyperkalemia, and metabolic acidosis. 081 in international unit) is used to distinguish pre-renal azotemia (PRA) and acute tubular necrosis (ATN). Tubular function is often impaired for several days after relief of the obstruction. Penyebab utama penumpukan senyawa kimia ini yaitu penggunaan obat-obatan, seperti antibiotik, kemoterapi, dan obat-obatan NSAID. acute tubular necrosis D. Normalmente, los riñones filtran la sangre. Acute kidney injury (AKI) is an abrupt and usually reversible decline in the glomerular filtration rate (GFR). May 15, 2020 · Postrenal acute kidney injury (AKI) is a condition in which renal function is compromised due to urinary tract obstruction (UTO). Obstruction D. Postrenal azotemia relates to the process after kidney filtration, describing a problem in the ureters or bladder. In addition, he had significant enlargement of his • POSTRENAL AZOTEMIA • Urinary tract obstruction accounts for <5% of cases of acute renal failure but is usually reversible • Since a single kidney is capable of adequate clearance, complete obstructive acute renal failure requires obstruction at the urethra or bladder outlet, bilateral ureteral obstruction, or unilateral obstruction in a Jul 21, 2021 · Azotemia es el nombre que se le da al cuadro médico que se presenta con un aumento del nivel de nitrógeno en la sangre debido a diversas enfermedades . Intrarenal AKI. Azotaemia is the laboratory finding of increased concentrations of non-protein nitrogenous wastes, measured as blood urea or serum creatinine. Jun 1, 2022 · Studies To Assess For Prerenal, Intrarenal, and Postrenal Acute Kidney Injury (AKI) Studies. isosthenuric or minimally concentrated. Prostate gland hyperplasia PRERENAL INTRARENAL is used to distinguish prerenal from renal or postrenal (obstructive) azotemia; a value > 15 is considered abnormal and may occur in prerenal and postrenal azotemia. A density greater than 1. Tubulointerstitial nephritis. La azotemia, según su origen, se puede dividir en azotemia prerrenal (cuando disminuye la perfusión renal), azotemia renal (por daño renal) o azotemia postrenal (alteración en la eliminación de orina del cuerpo). Mar 18, 2021 · Azotemia in dogs is a buildup of nitrogen-based substances, which include waste like urea, creatinine, old cells, and food, in the bloodstream. Azotemia is defined as an increased concentration of nonprotein nitrogenous compounds in blood, usually urea and creatinine. Bartges, DVM, PhD DEFINITION Azotemia is an excess of urea, creatinine, or other nonprotein nitrog enous substances in blood, plasma, or serum. 1 , 6 The maximal documented sCr during Prerenal Azotemia Versus Intrinsic AKI. , obstruction Acute renal failure is divided into its classic parts: prerenal azotemia, postrenal azotemia (obstruction), and renal azotemia (including acute tubular necrosis). The IRIS CKD staging system cannot be applied to patients with: Pre- or postrenal azotemia azotemia Nephrology A higher than normal blood urea–BUN or other nitrogen-containing compounds in the blood; ↑ BUN may be: (1) prerenal, due to ↓ renal blood flow–with ↓ glomerular filtration rate–GFR and/or excess urea production, seen in dehydration, shock, ↓ blood volume, and CHF; (2) renal, with ↓ GFR due to acute or chronic renal failure; (3) postrenal, due to urinary La azotemia prerrenal puede no presentar síntomas. , obstruction in urethra, bladder, or both ureters) for more than 24 hours usually results in postrenal azotemia. , severe dehydration, heart failure). Aug 1, 2011 · Postrenal azotemia is usually caused by an obstruction to urine outflow or a rupture of the urine outflow tract. Azotemia is is a laboratory abnormality and is defined as an increase in urea nitrogen and/or creatinine, due to decreased renal excretion. Immediate therapy should be directed at restoring urine flow, correcting extracellular fluid volume deficits, minimizing the cardiac toxicity of hyperkalemia Inicio » Especialidades » Nefrólogo CDMX » Azotemia Prerrenal. Immediate therapy should be directed at restoring urine flow, correcting extracellular fluid volume deficits, minimizing the cardiac toxicity of hyperkalemia, and ameliorating the cardiovascular effects of Mar 9, 2023 · Postrenal azotemia. La azotemia prerrenal hace referencia a cuando existen niveles altos de sustancias nitrogenadas en la sangre. Urinary indices in postrenal azotemia due to complete bilateral obstruction are usually nondiagnostic. This value is <15:1. In severe cases, it has the potential to adversely affect the kidneys and cause acute renal failure. Pueden presentarse síntomas de deshidratación, e incluir cualquiera de los siguientes: Confusión; Disminución o ausencia de la producción de orina; Boca seca debido a la sed; Pulso rápido; Fatiga; Piel pálida prerenal azotemia is a common occurrence in hospitalized patients and is generally easier to define in clinical practice than in clinical research. The division of acute tubular necrosis into the ischemic and toxic varieties is supplemented by an analysis of toxic varieties into those … Mar 19, 2024 · Postrenal acute kidney injury is caused by an acute obstruction of urinary flow, Azotemia is key laboratory finding in patients with prerenal AKI. Postrenal azotemia. BUN/Creatinine ratio is maintained when BUN and creatinine are raised: This is suggestive of renal diseases like: Intrarenal glomerulonephritis. These waste products act as poisons when they build up. Prerenal AKI . The 2012 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guidelines for Acute Kidney Injury defined AKI as one or more of three criteria []. Etiologies of acute kidney injury are categorized as prerenal, intrinsic renal, and postrenal. Symptoms of azotemia include swelling, abdominal pain, and crackling sounds when breathing. Oct 13, 2020 · Postrenal Azotemia. Prerenal azotemia is the most common form of kidney failure in hospitalized people. Shock Prerenal Intrarenal Postrenal, Choose the classification for each type of renal dysfunction. The fractional excretion of sodium (FENa) measures the percent of filtered sodium that is excreted in the urine. Oct 15, 2011 · A blood urea nitrogen (BUN)/creatinine ratio (BCR) >20 (0. Detection of postrenal azotemia requires attentiveness to the history … Feb 4, 2021 · Azotemia is a type of nephrotoxicity that involves excess nitrogen compounds in the blood. [1][2][3] However, immediately after a renal insult, blood urea nitrogen (BUN) or creatinine (Cr) levels may be within the normal range, and the only sign of AKI may be a decline in urine output. The initial workup includes a patient history to identify the use of nephrotoxic medications or systemic illnesses that might cause poor renal perfusion or Nov 18, 2021 · Abstract. Postrenal azotemia can lead to kidney failure if left untreated. Explore the AMBOSS platform for medical knowledge on Acute Kidney Injury, covering its causes and diagnostic evaluation. Postrenal인지 감별하기 위해서이죠. In postrenal azotemia, renal function and the glomerular filtration rate are completely normal and efficient. This can be caused by dehydration , excessive blood loss, heart failure , or any condition that decreases blood flow to the kidneys. Uremia is the term for the clinical syndrome of renal failure with azotemia […] Sep 7, 2017 · Suggestive of prerenal azotemia or glomerulonephritis: Urinary Na+ <20 mEq/L Urine/plasma Cr ratio >30 Renal failure index (RFI) <1 urine/plasma osmolality ratio: >1. There are multiple classification systems use to define AKI: The RIFLE criteria of 2004, AKIN criteria in 2007, and the KDIGO system in 2012. prerenal azotemia B. He was found to have a serum creatinine of 7. Ureteral metastasis is usually unilateral and does not lead to postrenal azotemia unless in single kidney patients. Feb 4, 2021 · Mild ATN will take over 72 hours (>3 days) to recover, and more severe cases often will take weeks. The diagnosis is suspected when azotemia develops after a hypotensive event, severe sepsis, or medication exposure and is distinguished from prerenal azotemia by laboratory testing and response to volume expansion. Some of the causes are tumors, a urinary catheter, or an enlarged prostate. However, there is little evidence that BCR can distinguish between these two conditions and/or is clinically useful. Acute kidney injury (AKI) is a clinical syndrome that complicates the course and worsens the outcome in a significant number of hospitalised patients. Crystals in the Nov 18, 2021 · Ureteral metastasis is usually unilateral and does not lead to postrenal azotemia unless in single kidney patients. Acute kidney injury (AKI), previously called acute renal failure (ARF), is a common clinical problem []. They damage tissues and reduce the ability of the organs to function. Learn more about its causes, symptoms, and treatment with Osmosis videos, flashcards, and quizzes. Postrenal azotemia can also occur with prerenal azotemia. Dehydration C. Treatment typically Mar 14, 2024 · Postrenal azotemia occurs when there is an obstruction in the urinary tract, preventing the normal flow of urine from the kidneys. This is when there is an obstruction of urine flow after the waste leaves your kidneys. This obstruction or blockage can happen in the urethra, ureters, or even in the passages through your bladder. g. Postrenal causes of AKI are characterized by acute obstruction to urinary flow. BUN /Creatinine ratio is raised; this is suggestive of: Prerenal May 14, 2023 · Azotemia is important when discussing the precipitant syndrome of acute kidney injury (AKI); there are three subtypes, prerenal, intrinsic, and post-renal azotemia. It results from urinary tract obstruction, which prevents the normal flow of urine from the kidneys to the bladder. Monitoring the duration of acute kidney injury Jan 1, 2016 · The history of the patient was clearly taken and the cause of the azotemia whether prerenal, renal or postrenal was noted. Postrenal azotemia Study with Quizlet and memorize flashcards containing terms like Choose the classification for each type of renal dysfunction: Nephrotoxic medications Prerenal Intrarenal Postrenal, Choose the classification for each type of renal dysfunction. This has various causes, the most common of which are probably kidney stones and pregnancy; however, the ureters can be compressed by cancer, prostatic hyperplasia, or bladder stones, and there are various congenital conditions that can also cause it. Mar 9, 2023 · Postrenal azotemia. 일 단 U/A 를 시행하고 renal US 를 시행합니다. AKI can lead Prerenal azotemia Acute renal parenchymal injury Postrenal disease; History: Volume depletion (vomiting, diarrhea, diuretics, burns) or decreased effective circulating volume (CHF, cirrhosis), thirst: Exposure to nephrotoxicants, procedure associated with hypotension, volume depletion: Radiation, surgery, etc Hesitation, weak stream, etc: Symptoms Study with Quizlet and memorize flashcards containing terms like The retention of nitrogenous wastes is referred to as A. 2 It often accompanies vomiting, May 1, 1996 · Postrenal azotemia is a potentially life-threatening consequence of urinary obstruction. Jan 31, 2018 · Postrenal azotemia > 2%: 10-20 < 350 > 40: Normal : Defined as < 400 mL per day of urine output; Causes prerenal azotemia; acute glomerulonephritis 6 days ago · In addition, cats with chronic kidney disease retain the ability to concentrate urine for longer periods than dogs. Accurate diagnosis of the underlying cause is key to successful management and includes a focused Postrenal azotemia, though less common than prerenal or intrinsic renal causes of AKI, is nonetheless significant. Nov 7, 2023 · INTRODUCTION. Nephron damage B. Immediate therapy should be directed at restoring urine flow, correcting extracellular fluid volume deficits, min … A 54-year-old Hispanic man with type 2 diabetes mellitus and hypertension was initially evaluated at another institution for difficulty voiding urine. Any condition that Jun 20, 2024 · Examination reveals a distended bladder but is otherwise unremarkable. Recent advances in clinical and basic research will help with a more accurate definition of this syndrome Mar 9, 2023 · In suspected intrarenal azotemia, look for hypertension and its end-organ effects, such as hypertensive retinopathy and left ventricular hypertrophy (apical impulse displaced lateral to midclavicular line), rash, joint swelling or tenderness, needle tracks, hearing abnormality, palpable kidneys, abdominal bruits, pericardial rub, and asterixis. Azotemia Prerrenal. Prerenal azotemia is a consequence of reduced renal perfusion (e. . Oliguria C. If a patient has AKI that recovers quickly (in less than 3 days), it is unlikely to be ATN. AKI is said when the kidneys aren't functioning at 100%, and it has developed relatively quickly, typically over a few days. Polzin, DVM, PhD, Carl A. Jan 12, 2022 · Postrenal azotemia. One prominent example of postrenal azotemia is kidney stones, which can affect both ureters, causing urine The condition is asymptomatic unless it causes renal failure. Postrenal azotemia can coexist with prerenal and/or renal azotemia. It can result from a variety of disorders including, reduced blood flow to the kidneys with hypovolemia, urinary tract obstruction and renal disease. However, BUN is affected by protein intake and by several nonrenal processes (eg, trauma, infection, gastrointestinal [GI] bleeding, corticosteroid use) and, although suggestive Postrenal ARF or postrenal azotemia can be caused by obstruction at any site along the urinary tract. Even though the kidneys would otherwise be able to function normally, obstruction of urine flow at any point below the level of the kidneys leads to accumulation of metabolic wastes and postrenal azotemia/uremia. vv zl ij ig nb tw mm wh za cv