The presentation depends on the etiology and the stage of the acute kidney failure. Mild forms may be asymptomatic and are identified on laboratory examination. More severe cases may present with lethargy, fatigue, confusion, anorexia, nausea, and weight gain. The patient may be anuric, oliguric, pass normal volumes of urine or may even complain of polyuria.

• Fatigue

  The patient was admitted with acute kidney failure for 3 times and due to a history of proximal weakness, fatigue, and muscular cramps after physical activities a glycogen-storage disease was suspected. [ncbi.nlm.nih.gov]

  We ask about general symptoms (anxious mood, depressed mood, fatigue, pain, and stress) regardless of condition. Last updated: January 30, 2019 [patientslikeme.com]

  Effects may include a metallic taste in the mouth, prolonged nausea and vomiting, incessant hiccuping, itching all over the body, fluid retention, unintended weight loss and an over-all feeling of fatigue and sluggishness. [livestrong.com]

  Again, the increase in fatigue is because of the kidney failure. [diabetes.co.uk]

• Congestive Heart Failure

  insufficiency, arrest (adult) 1,156 1.9 47 9 Other complications of pregnancy 1,062 1.8 271 10 Previous C-section 1,054 1.8 218 11 Acute cerebrovascular disease 1,043 1.7 45 12 Diabetes mellitus with complications 964 1.6 109 13 Congestive heart failure [web.archive.org]

  […] loss or gain Hypovolemia or hypervolemia Mouth Dehydration Jugular veins and axillae (perspiration) Hypovolemia or hypervolemia Pulmonary system Signs of congestive heart failure Heart New murmur of endocarditis or signs of congestive heart failure Abdomen [aafp.org]

  There was a very high prevalence of congestive heart failure in the valve surgery subgroup (48%), and congestive heart failure was independently associated with long-term mortality in the multivariate model. [doi.org]

  Hypovolemia – volume depleted, hemorrhage, intravascular volume depletion from congestive heart failure or cirrhosis. [foamcast.org]

• Weight Gain

  […] loss or weight gain, such as 3 pounds or more in 24 hours or 6 pounds or more in 7 days Fever above 100.4°F (38.0°C) or chills Muscle aches Night sweats Very little or no urine output Swelling of your hands, legs, or feet Back pain Abdominal pain Extreme [mountnittany.org]

  Advantages and disadvantages should be weighed carefully when comparing AAS therapy to other weight-gaining measures. [ncbi.nlm.nih.gov]

  More severe cases may present with lethargy, fatigue, confusion, anorexia, nausea, and weight gain. The patient may be anuric, oliguric, pass normal volumes of urine or may even complain of polyuria. [symptoma.com]

  Symptoms and Signs Initially, weight gain and peripheral edema may be the only findings. Often, predominant symptoms are those of the underlying illness or those caused by the surgical complication that precipitated renal deterioration. [merckmanuals.com]

• Acutely Ill Patient

  Avoidance of nephrotoxic drugs and iodinated contrast agents in these patients reduces the risk of them developing AKI. All acutely ill patients in hospital should be closely monitored for signs of developing AKI. [patient.info]

  In-patients who are severely ill, are most likely to develop AKF. [symptoma.com]

  Patient and kidney survival by dialysis modality in critically ill patients with acute kidney injury. Int. J. Artif. Organs 30, 281–292 (2007). 162. Wald, R. et al. [nature.com]

• Coronary Atherosclerosis

  atherosclerosis 10,400 2.7 605 10 Respiratory failure, insufficiency, arrest (adult) 8,749 2.3 404 11 Acute cerebrovascular disease 8,361 2.2 597 12 Cardiac dysrhythmias 7,624 2.0 795 13 Complications of surgical procedures or medical care 6,850 1.8 [web.archive.org]

• Easy Bruising

  bruising, and pale skin (from anemia); ... [emedicinehealth.com]

  bruising, or blood in the stool Excessive thirst Frequent hiccups Problems with sexual function Menstrual periods stop (amenorrhea) Shortness of breath Sleep problems Vomiting Exams and Tests Most people will have high blood pressure at all stages of [mountsinai.org]

• Tachypnea

  Vital signs are assessed frequently, and fever, tachycardia, tachypnea or bradypnea, and hypotension are reported. The electrocardiogram is monitored for arrhythmias. [medical-dictionary.thefreedictionary.com]

• Nausea

  Wicked Dreams 7 Oregon 18 Nausea and vomiting, abdominal pain pain 6.6 WBCs, protein 30 Increased cortical echogenicity, no hydronephrosis "Synthetic marijuana" 8 New York 33 Nausea and vomiting 3.3 Not available Not performed Spice Gold 9 Oregon 27 [cdc.gov]

  Other symptoms of acute tubular necrosis include tiredness, swelling, lethargy, nausea, vomiting, abdominal pain, kidney pain, loss of appetite, and rash. Sometimes there are no symptoms. [emedicinehealth.com]

  Effects may include a metallic taste in the mouth, prolonged nausea and vomiting, incessant hiccuping, itching all over the body, fluid retention, unintended weight loss and an over-all feeling of fatigue and sluggishness. [livestrong.com]

• Vomiting

  […] and vomiting, flank pain 6.3 WBCs, RBCs, epithelial casts, granular casts Not available Blueberry-flavored 4 Wyoming 18 Nausea and vomiting, flank pain 4.1 Hyaline casts, WBCs No increased cortical echogenicity or hydronephrosis Blueberry-flavored or [cdc.gov]

  Any warning signs of AKI, such as vomiting or producing little urine, require immediate investigation for AKI and treatment. People who are dehydrated or at risk of dehydration may need to be given fluids through a drip. [nhs.uk]

  Other symptoms of acute tubular necrosis include tiredness, swelling, lethargy, nausea, vomiting, abdominal pain, kidney pain, loss of appetite, and rash. Sometimes there are no symptoms. [emedicinehealth.com]

• Loss of Appetite

  You may experience the following: Peeing less than normal Swelling in your legs, ankles, and feet (caused by your body holding on to fluid) Drowsiness or feeling very tired Shortness of breath Itching Joint pain, swelling Loss of appetite Confusion Throwing [webmd.com]

  Some of the symptoms of acute kidney failure are: Urinating less or not at all even when you are drinking fluids Swelling all over the body or swelling of just the legs, feet, or ankles Confusion Drowsiness and tiredness Loss of appetite Nausea and vomiting [summitmedicalgroup.com]

  Other symptoms of acute tubular necrosis include tiredness, swelling, lethargy, nausea, vomiting, abdominal pain, kidney pain, loss of appetite, and rash. Sometimes there are no symptoms. [emedicinehealth.com]

• Hiccup

  Effects may include a metallic taste in the mouth, prolonged nausea and vomiting, incessant hiccuping, itching all over the body, fluid retention, unintended weight loss and an over-all feeling of fatigue and sluggishness. [livestrong.com]

  Decreased appetite Decreased sensation, especially in the hands or feet Fatigue or slow sluggish movements Flank pain (between the ribs and hips) Hand tremor Heart murmur High blood pressure Nausea or vomiting, may last for days Nosebleeds Persistent hiccups [medlineplus.gov]

  […] worse include: Abnormally dark or light skin Bone pain Drowsiness or problems concentrating or thinking Numbness or swelling in the hands and feet Muscle twitching or cramps Breath odor Easy bruising, or blood in the stool Excessive thirst Frequent hiccups [mountsinai.org]

• Asterixis

  Such symptoms include Anorexia Nausea Vomiting Weakness Myoclonic jerks Seizures Confusion Coma Asterixis and hyperreflexia may be present on examination. [merckmanuals.com]

  […] in Patients with Acute Renal Failure and Uremia* Symptoms Anorexia Fatigue Mental status changes Nausea and vomiting Pruritus Seizures (if blood urea nitrogen level is very high) Shortness of breath (if volume overload is present) Physical findings Asterixis [aafp.org]

  Later, as nitrogenous products accumulate, symptoms of uraemia may develop, including anorexia, nausea and vomiting, weakness, myoclonic jerks, seizures, confusion, and coma; asterixis and hyperreflexia may be present on examination. [web.archive.org]

• Metallic Taste

  Effects may include a metallic taste in the mouth, prolonged nausea and vomiting, incessant hiccuping, itching all over the body, fluid retention, unintended weight loss and an over-all feeling of fatigue and sluggishness. [livestrong.com]

  taste in the mouth Bruising easily Changes in mental status or mood Decreased appetite Decreased sensation, especially in the hands or feet Fatigue or slow sluggish movements Flank pain (between the ribs and hips) Hand tremor Heart murmur High blood [medlineplus.gov]

  taste in the mouth. [betterhealth.vic.gov.au]

• Hypertension

  Author information 1 Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Campus Kiel, Georges-Köhler-Haus, Fleckenstr. 4, 24105, Kiel, Germany. 2 Department of Pathology, University of Hannover, 30625, Hannover, Germany. [ncbi.nlm.nih.gov]

  Diseases and conditions that cause chronic kidney failure include: Type 1 or 2 diabetes Hypertension Glomerulonephritis is inflammation of the filtration units in the kidneys (glomeruli) Interstitial nephritis is inflammation of the kidney tubes and surrounding [play.google.com]

  Nitrate therapy may help reverse fluid shifts by reducing hypertension temporarily through vasodilatation. [ems1.com]

  Hypertension is one of the causes of renal failure and there is a clear co-relation between salt intake and hypertension, he says. [qatar-tribune.com]

  Co-founder of http://www.medcram.com MedCram: Medical topics explained clearly including: Asthma, COPD, Acute Renal Failure, Mechanical Ventilation, Oxygen Hemoglobin Dissociation Curve, Hypertension, Shock, Diabetic Ketoacidosis (DKA), Medical Acid Base [youtube.com]

• Hypotension

  Hypotension during intermittent dialysis occurred in more patients randomly assigned to receive intensive therapy, although the frequency of hemodialysis sessions complicated by hypotension was similar in the two groups. [ncbi.nlm.nih.gov]

  and 0 point for not having hypotension; 0 point for ATN-ISI score Table 5 Prognostic score of 90-day mortality in hospitalized patients with acute kidney injury. [doi.org]

  The cause is usually ischemic (from prolonged hypotension) or nephrotoxic (from an agent that is toxic to the tubular cells). [aafp.org]

• Tachycardia

  Tachycardia and hyponatremia are common during attacks. In cases with cardiac arrhythmia and respiratory paralysis (rare), attacks can be fatal. [orpha.net]

  […] cholecystectomy ERCP or cholangiogram previous cholangitis immunocompromise malignancy CLINICAL FEATURES History fever (>80%) abdominal pain (especially RUQ) (>80%) nausea and vomiting, malaise predisposing factors and history of an underlying cause Examination tachycardia [litfl.com]

  On examination, patients may have pyrexia (in 90% of cases), rigors, jaundice, right upper quadrant tenderness, confusion, hypotension, and tachycardia may be present. [teachmesurgery.com]

  Physical signs may include fever, right upper quadrant tenderness, jaundice, mental status changes, hypotension and tachycardia. Peritonism is an unusual sign and should stimulate the search for an alternative diagnosis. [patient.info]

  Other signs and symptoms may include orthostatic hypotension and tachycardia. [todaysgeriatricmedicine.com]

• Back Pain

  pain Abdominal pain Extreme tiredness Date Last Reviewed: 2/1/2017 © 2000-2018 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. [mountnittany.org]

  […] and vomiting, abdominal pain / back pain 7.7 Within normal limits Increased cortical echogenicity Mr. [cdc.gov]

  […] up or feeling like you’re going to Chest pain or pressure Muscle twitching Seizures or coma (in severe cases) Stomach and back pain Fever Rash Nosebleed Causes of Acute Kidney Failure There are three main reasons your kidneys fail all of a sudden: Something [webmd.com]

• Muscle Weakness

  Muscle weakness. When your body's fluids and electrolytes — your body's blood chemistry — are out of balance, muscle weakness can result. Permanent kidney damage. [mayoclinic.org]

  Read the NICE guidelines Complications of acute kidney injury The most serious complications of acute kidney injury are: high levels of potassium in the blood – in severe cases, this can lead to muscle weakness, paralysis and heart rhythm problems fluid [nhs.uk]

• Muscle Twitch

  As AKI progresses, you may have any of the following: Decrease in the amount of urine or no urination Swelling in your arms, legs, or feet Weakness, drowsiness, or no appetite Nausea, flank pain, muscle twitching or muscle cramps Itchy skin, or your breath [drugs.com]

  twitching Seizures or coma (in severe cases) Stomach and back pain Fever Rash Nosebleed Causes of Acute Kidney Failure There are three main reasons your kidneys fail all of a sudden: Something is stopping blood flow to your kidneys. [webmd.com]

  twitching or cramps Breath odor Easy bruising, or blood in the stool Excessive thirst Frequent hiccups Problems with sexual function Menstrual periods stop (amenorrhea) Shortness of breath Sleep problems Vomiting Exams and Tests Most people will have [mountsinai.org]

• Pruritus

  The patient may also complain of pruritus (itching), as a result of bile accumulation, and pale stool with dark urine, from the obstructive jaundice. [teachmesurgery.com]

  Symptoms may include: Appetite loss General ill feeling and fatigue Headaches Itching ( pruritus) and dry skin Nausea Weight loss without trying to lose weight Symptoms that may occur when kidney function has gotten worse include: Abnormally dark or light [mountsinai.org]

  The patient may also report acholic (putty-coloured) stools and pruritus. A history of gallstones, CBD stones, recent cholecystectomy, ERCP or other invasive procedures, HIV or AIDS may assist the diagnosis. [patient.info]

  Later, as acute kidney injury persists and waste products accumulate in the body, people may experience Fatigue Decreased ability to concentrate on mental tasks Loss of appetite Nausea Overall itchiness (pruritus) People with acute kidney injury may develop [merckmanuals.com]

  View/Print Table TABLE 1 Key Symptoms and Physical Findings in Patients with Acute Renal Failure and Uremia* Symptoms Anorexia Fatigue Mental status changes Nausea and vomiting Pruritus Seizures (if blood urea nitrogen level is very high) Shortness of [aafp.org]

• Petechiae

  Pallor, rash, bruising: petechiae, purpura and nosebleeds may suggest inflammatory or vascular disease, emboli or disseminated intravascular coagulation. Pericardial rub. [patient.info]

  Checking the patient for areas of small, purple or red spots (petechiae), hemorrhage beneath the skin (purpura), and bluish discoloration of a fairly large area of the skin (ecchymosis) can lead to a diagnosis of an inflammatory or vascular cause for [encyclopedia.com]

• Oliguria

  Sudden and sustained deterioration of the kidney function characterized by decreased glomerular filtration rate, increased serum creatinine or oliguria. [icd9data.com]

  This patient’s oliguria with acutely elevated BUN and plasma creatinine suggest that he is in acute renal failure (ARF). [foamcast.org]

  Oliguria was observed in 72.2% of the patients. Perinatal asphyxia was present in 29.8% of the neonates, sepsis in 28.5%, respiratory distress syndrome in 25.2%, dehydration in 24.2%, and heart failure in 21.2%. [ncbi.nlm.nih.gov]

• Anuria

  Peritoneal dialysis was started at a mean of 51 hours after transplantation for treatment of anuria (5 patients, 50%), oliguria (3 patients, 30%), fluid overload or hyperkalemia (1 patient each, 10%) and continued for a mean of 101 +/- 90.5 (range, 33 [ncbi.nlm.nih.gov]

  […] the kidneys Kidney stones Kidney tumors malign: hypernephroma benign: e.g. angiomyolipoma Congenital defects Kidney duplication Cystic kidneys Horseshoe kidney Renal insufficiency (liable for hemodialysis if required) Uremia Acute renal failure (ARF), anuria [flexikon.doccheck.com]

  A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition. posttraumatic renal failure ( ICD-10-CM Diagnosis Code T79.5 Traumatic anuria 2016 2017 2018 2019 [icd10data.com]

  […] kidney disease, stage 3 (moderate) N184Chronic kidney disease, stage 4 (severe) N185Chronic kidney disease, stage 5 N186End stage renal disease N189Chronic kidney disease, unspecified N19Unspecified kidney failure R34Anuria and oliguria T795xxATraumatic anuria [cms.gov]

  Clinically, AKI is recognised by decreasing urine volume (oliguria or anuria) and a rise in serum creatinine. [patient.info]

• Confusion

  More than 30 different definitions have been used in the literature, creating much confusion and making comparisons difficult. [ncbi.nlm.nih.gov]

  More severe cases may present with lethargy, fatigue, confusion, anorexia, nausea, and weight gain. The patient may be anuric, oliguric, pass normal volumes of urine or may even complain of polyuria. [symptoma.com]

  Feeling confused, anxious and restless, or sleepy. Some people may not have any symptoms. And for people who are already quite ill, the problem that’s causing the acute kidney failure may be causing other symptoms. [worldkidneyday.org]

  On examination, patients may have pyrexia (in 90% of cases), rigors, jaundice, right upper quadrant tenderness, confusion, hypotension, and tachycardia may be present. [teachmesurgery.com]

• Seizure

  This can cause both neurological and cardiac complications, such as seizures, coma, arrhythmia and hypotension, according to the American Academy of Family Physicians. [livestrong.com]

  Some endogenous toxins that trigger nephrotoxic ARF include the following: Rhabdomyolysis (release of myoglobin in the urine resulting from the destruction of muscle tissue) caused by the following: Intoxication (e.g., alcohol, cocaine) Seizure Traumatic [healthcommunities.com]

  EMS providers will likely consider more common causes of respiratory distress, chest pain or seizures. Pay close attention to the history of the illness and the timing of the physical findings. [ems1.com]

  Additionally, you may have shortness of breath, nausea, fatigue, drowsiness, chest pain, chest pressure, seizures and even coma in severe cases. However, in some cases, the urine output remains in normal levels. [worldpulse.com]

  […] is very dark confusion lower urine output itching skin or skin rashes from waste buildup pressure or pain in the chest shortness of breath swelling in the lower extremities unexplained nausea Some people may experience severe side effects, including seizures [medicalnewstoday.com]

• Headache

  […] but I've had very few headaches. So, they don't know what's causing it yet, I've got to go back on Monday for a scan and biopsy, and they took another arnful of blood from me today. [diabetes.co.uk]

  […] as bleeding, severe diarrhea) Heart attack, heart failure, and other conditions leading to decreased heart function Organ failure (e.g., heart, liver) Overuse of pain medicines called “NSAIDs”, which are used to reduce swelling or relieve pain from headaches [kidney.org]

  Some of its most common side effects include the following: ataxia, nystagmus, drowsiness, headaches, diplopia, fatigue and myoclonic twitches. 1 All of these effects appear quite often in patients with chronic kidney disease, especially if they are undergoing [revistanefrologia.com]

  […] infection Pale skin History of taking certain medications History of trauma Swelling of the tissues Inflammation of the eye Detectable abdominal mass Exposure to heavy metals or toxic solvents Chronic symptoms may include: Poor appetite Vomiting Bone pain Headache [stanfordchildrens.org]

  Symptoms may include: Appetite loss General ill feeling and fatigue Headaches Itching ( pruritus) and dry skin Nausea Weight loss without trying to lose weight Symptoms that may occur when kidney function has gotten worse include: Abnormally dark or light [mountsinai.org]

• Lethargy

  Hughson, MD, of Shorsh General Hospital in Kurdistan, said the patients complained of weakness and lethargy. They presented with serum creatinine levels of 2.6–3.8 mg/dL and estimated glomerular filtration rate (eGFR) of 22–34 mL/min/1.73 m 2. [renalandurologynews.com]

  Other symptoms of acute tubular necrosis include tiredness, swelling, lethargy, nausea, vomiting, abdominal pain, kidney pain, loss of appetite, and rash. Sometimes there are no symptoms. [emedicinehealth.com]

  More severe cases may present with lethargy, fatigue, confusion, anorexia, nausea, and weight gain. The patient may be anuric, oliguric, pass normal volumes of urine or may even complain of polyuria. [symptoma.com]

  […] person’s symptoms may vary, and may be non-specific or severe, including: Pain in the upper right part of your belly (abdomen) Fever Chills Yellowing of the skin and eyes (jaundice) Nausea and vomiting Clay-colored stools Dark urine Low blood pressure Lethargy [hopkinsmedicine.org]

• Altered Mental Status

  Patients can also present with Reynold pentad, which is Charcot triad with shock and altered mental status 1,3,4. Gram-negative enteric bacteria, most commonly Escherichia coli, are the primary pathogens 4. [radiopaedia.org]

  There may be other causes for altered mental status that might be present. Remember to check blood glucose levels and treat as necessary. [ems1.com]

  Alterations in mental status (lethargy or coma) and bleeding caused by coagulopathy may develop. [medical-dictionary.thefreedictionary.com]

  Physical examination may show high temperature, tachycardia, hypotension, jaundice, right upper quadrant or epigastric tenderness and altered mental status. [ncbi.nlm.nih.gov]

Most persons with AKF are asymptomatic; if at all, the symptoms are generalized and physical examination is not conclusive. Oftentimes, the disorder is detected incidentally from the results of blood and urine tests during consultation for some other medical condition or purpose.

Laboratory predictors of AKF:

• Azotemia: Elevated blood urea nitrogen (BUN]) and creatinine.
• Fluctuating electrolyte levels in the blood (may be abnormally high or low): Impaired perfusion.
• Anemia: Severe kidney failure is severe. The red blood cell count is low.

Urine output per unit time or metabolic waste excreted should be measured. Proteins and useful substances are excreted when kidney tissue is damaged. In case of renal retention, urine remaining in the bladder after micturation is measured by inserting a catheter into the bladder. This is done in postrenal failure due to enlarged prostate.

Dark-colored urine is due to the presence of creatinine and other substances in concentrated form. Microscopy will reveal blood, pus cells and casts as indicators of disease. Measurement of electrolyte levels can help identify the cause of AKF.

Ultrasonography of the kidneys and bladder can confirm specific causes of kidney failure [10]. Biopsy can be done for histological assessment, if needed.

• Hyponatremia

  Treatment of hyponatremia is generally free-water restriction. In patients with severe AKI and more profound hyponatremia, renal replacement therapy may be necessary. [renalandurologynews.com]

  //www.medcram.com MedCram: Medical topics explained clearly including: Asthma, COPD, Acute Renal Failure, Mechanical Ventilation, Oxygen Hemoglobin Dissociation Curve, Hypertension, Shock, Diabetic Ketoacidosis (DKA), Medical Acid Base, VQ Mismatch, Hyponatremia [youtube.com]

  Tachycardia and hyponatremia are common during attacks. In cases with cardiac arrhythmia and respiratory paralysis (rare), attacks can be fatal. [orpha.net]

  Hyponatremia usually is moderate (serum sodium, 125 to 135 mmol/L) and correlates with a surplus of dietary or intravenous water intake. Normochromic-normocytic anemia with a hematocrit of 25 to 30% is typical. [merckmanuals.com]

• Creatinine Increased

  The second aim was to remark that this syndrome is characterised by a spectrum of progressive damage, from mild creatinine increase to renal injury to a more severe form, failure: this important concept should increase clinicians awareness to every form [ncbi.nlm.nih.gov]

  AKI and has the same risks as a creatinine increase from a normal baseline). 6. [web.archive.org]

• Creatinine Increased

  The second aim was to remark that this syndrome is characterised by a spectrum of progressive damage, from mild creatinine increase to renal injury to a more severe form, failure: this important concept should increase clinicians awareness to every form [ncbi.nlm.nih.gov]

  AKI and has the same risks as a creatinine increase from a normal baseline). 6. [web.archive.org]

• Hyperuricemia

  Mild hyperuricemia, as a result of decreased renal uric acid excretion, is common in AKI. More severe elevations in serum uric acid develop when AKI develops in the setting of hypercatabolism or cell lysis. [renalandurologynews.com]

  […] kliewi Finnish Akuutti munuaisten vajaatoiminta, hematuria Munuaistulehdus, proteinuria Munuaistiehyiden kuolio Last Update: 2012-04-10 Usage Frequency: 2 Quality: Maltese Ħaġra fil- kliewi, urina mhux normali, albuminerija, hypercalcinuria, nefrite, hyperuricemia [mymemory.translated.net]

• Hypermagnesemia

  Mild asymptomatic hypermagnesemia is common in oliguric AKI as the result of impaired excretion of ingested magnesium. [renalandurologynews.com]

  Attention to electrolyte imbalances (e.g., hyperkalemia, hyperphosphatemia, hypermagnesemia, hyponatremia, hypernatremia, metabolic acidosis) is important. [aafp.org]

Complicated and advanced cases of AKF are confined in the intensive care unit of the hospital and treated as a medical emergency. Catheterization, endoscopy or surgery are indicated in cases of postrenal AKF or obstruction of the renal outflow.

Uncomplicated cases of less than 5 days duration, without infection or malignancy may heal spontaneously with palliative procedures alone. Restoring normal kidney function can be attained by:

• Regulating or restricting the use of certain medications
• Maintaining proper nutrition.
• Restricting fluids, dietary sodium, phosphorus and potassium.
• Regulating blood levels of potassium and phosphate.
• Initiating dialysis.

For anemia, infusion of crystalloid (normal saline or lactated Ringers) or colloid (in cases of significant hypoalbuminemia) fluids with packed RBCs is recommended [2]. Use of semisynthetic hydroxyethyl starch has been linked to higher mortality rates [11]. Blood transfusion is optional if only 1 unit is required. Fluid resuscitation should be managed by an expert in this procedure.

Proper diet, with protein equivalent to 0.8 to 1 grams per kilogram of body weight (0.4 to 0.5 grams per pound) may be prescribed. No foods that are high in phosphorus (e.g., liver, nuts, dairy products, legumes, and soft drinks) to lower the phosphorus concentration in the blood. Calcium salts (calcium carbonate or calcium acetate) or sevelamer may be taken orally to lower phosphate levels in the blood. To reduce potassium level in the blood, sodium polystyrene sulfonate may be given per orem or via the rectum.

Prolonged AKF leads to the accumulation of metabolic wastes and excess fluids in the blood, necessitating removal of these by hemodialysis. Dialysis is initiated as per need or in some cases repeated for several weeks until the kidneys normal function is restored.

Recovery from acute kidney failure is determined by the nature and location of the underlying cause of the disease. Prognosis is good and full recovery may be expected when the disease process does not involve direct damage to the kidney parenchyma itself. Partial recovery is possible in cases where there is residual pathology. Prognosis is poor when the patient is in the advanced stage of disease at the onset of renal failure. Mortality is high in severe cases of acute renal injury [9].

In a longitudinal study of 1-10 years period, about 12.5% of survivors of acute renal failure had to undergo dialysis; 19-31% of these patients had chronic kidney disease. The mortality rate in hospitalized AKF patients is 40- 50%. The mortality rate among ICU patients with acute kidney failure requiring dialysis is 70-to 80%.

The underlying causes of acute kidney failure by location of injury [3]:

• Prerenal: Diminished blood flow to the kidneys and impairment of filtration function resulting from hypovolemia, overdiuresis, hemorrhage, third spacing of fluid (in severe pancreatitis), sepsis, heart failure or hepatorenal syndrome (in severe liver disease).
• Intrinsic: Direct damage to the kidneys, resulting from acute tubular necrosis (ATN), scleroderma renal crisis, rapidly progressive glomerulonephritis, thrombosis, interstitial nephritis, hemolytic uremic syndrome, cortical necrosis from severe ischemic injury, thrombotic thrombocytopenic purpura (TTP), atheromatous embolization or renovascular disease (with the use of Angiotensin-converting enzyme (ACE) inhibitor in bilateral renal artery stenosis).
• Postrenal: Impairment of the excretory function resulting from urinary retention, renal calculi, retroperitoneal fibrosis, prostate hyperplasia, strictures, tumor, lymphoma, orascending urinary infection (including pyelonephritis).

Acute kidney injury is an escalating problem of clinical and public health importance. Two to three cases per 1,000 persons are diagnosed each year [4]. Seven percent of in-patients and 75% of severely ill patients develop the disease in conjunction with multiple organ disorders.

Low blood pressure or slow blood flow to the kidneys diminishes the kidney's filtration function, causing the accumulation of nitrogenous waste products in the blood (prerenal azotemia). Consequently, the kidneys respond to the decrease in glomerular filtration rate by reabsorbing sodium and water back into the blood stream to maintain electrolyte and fluid balance. Baroreceptors in the carotid artery and aortic arch likewise respond by causing vasoconstriction of the glomerular efferent arteriole and dilatation of the afferent arteriole to limit glomerular filtration. The renin/angiotensin/aldosterone system is activated, whereby, angiotensin II, another vasoconstrictor, causes aldosterone to be released and resulting in reabsorption of sodium and water at the renal tubules. Hypovolemia (low blood volume) likewise stimulates the hypothalamus to signal the release of ADH (anitdiurectic hormone or vasopressin), leading to further resorption of water in the tubules thus, concentrating the urine.

After glomerular dysfunction, direct damage to the kidneys is brought about by pathophysiological processes involving the inner wall of small blood vessels and death of epithelial cells in the renal tubules or acute tubular necrosis (ATN), secondary to ischemia (lack of oxygen) of the kidneys. Damage is most severe in the proximal part of the tubule and outer layers of the medulla. Incremental reactive oxygen species, decreased ATP, and death of cells are the results of hypoxemia [5]. Immune-mediated reactions such as, activation of complement, participation of cytokines, chemokines, neutrophils, complement-mediated attack on membranes, and vasoactive hormones all contribute to disrupting the integrity of the renal parenchyma. Exposure to poisons, medications, and contrast dye used for x-ray studies may also cause ATN. Toxicity to cells from the dye  and constriction of blood vessels were observed in animal models. These resulted in increased viscosity, low oxygen tension in the blood and poor circulation in the renal medulla [6].

Renal injury at the level of the ureters is associated with blocked tubules resulting from increased internal pressure causing ischemia and degeneration. Presence of monocytes and macrophages, cytokines, free radicals, proteases, and TNF-beta are linked to direct damage on the tubules and fibrosis [7].

The possible involvement of a genetic component in the etiology of AKI is being considered with apolipoprotein E (APO-E) genes [8]. More genes may be anticipated in future studies.

The National Institute for Health and Care Excellence (NICE/UK) recommends eliminating the causes of acute kidney failure as the best strategy for prevention [12]. NICE guidance of 2013 emphasizes the importance of early detection of patients at risk by monitoring their urinary output and creatinine levels. Risk factors such as nephrotoxic drugs and iodinated contrast agents should be avoided. These guidelines apply to all acutely ill patients in hospital. An alternative to the use of contrast dye is intravenous volume expansion with isotonic sodium bicarbonate or 0.9% sodium chloride [13].

Acute kidney failure (AKF), also referred to as acute kidney injury or acute renal failure, is the sudden disruption of renal filtration function, resulting in the accumulation of metabolic wastes and electrolytes in the blood, which is life-threatening. AKF is known to occur in hospitalized patients, especially those who are in an advanced stage of illness and who are, therefore, the most vulnerable among high risk groups. AKF may develop within hours or, at most, a few days, and as such, it is treated as a medical emergency. Presumably, except in the case of a patient with severe disease or multiorgan dysfunction, it is possible to reverse the damage to the kidneys and to recover from AKF.

The organization Kidney Disease: Improving Global Outcomes (KDIGO) considers a case as acute kidney failure when [1]:

• The urine output is <0.5 mL/kg/hour for 6 hours or
• Serum creatinine level increase by ≥0.3 mg/dL within 48 hours; or
• Serum creatinine is ≥1.5 times of baseline, for 7 days prior to consultation.

The pathophysiology of AKF [2] can be classified into three subgroups:

• Prerenal AKF due to decline in filtration function
• Intrinsic AKF due to direct damage to the kidneys
• Postrenal AKF due to impairment of excretory function

The cause of AKF is multifactorial based on the aforementioned classification. It ranges from impairment of blood flow to the kidneys, to infections and malignancies, and obstruction of the ureters. Symptoms are oftentimes generalized or mimic other diseases. Diagnosis is based on laboratory examinations and confirmatory imaging studies of the underlying causes of AKF. The rationale of treatment is to eliminate the causes and to restore the normal functioning of the kidneys. Prevention depends on a large extent on primary health care and avoidance of the predisposing conditions.

Acute kidney failure (AKF) is the sudden inability of the kidneys to filter off excess salts, fluids, and waste materials from the blood, which, if left untreated, can lead to fatal consequences. In-patients who are severely ill, are most likely to develop AKF. Sudden onset and rapid progression of the disease characterize AKF in contrast to chronic kidney disease in which the loss of kidney function is gradual and lasts over a long period of time. The cause of AKF is diverse which ranges from infection, trauma, pathophysiological processes, autoimmunity, systemic diseases, to malignancy. AKF occurs in three stages:

• Prerenal - impairment of the filtering function.
• Intrinsic - direct damage to the kidney tissue.
• Postrenal - obstruction with excretion of urine via the ureters.

Causes

Conditions that predispose to acute kidney failure are: autoimmune diseases (e.g., acute nephritic syndrome and interstitial nephritis); acute tubular necrosis (ATN); severe or sudden dehydration; urinary tract obstruction; and toxicity from poisons or certain medications.

Reduced blood flow that are associated with the following conditions can impair kidney functions. These are: hemorrhage, septic shock, dehydration, low blood pressure, burns, trauma, serious illness, and surgery.

Conditions that are associated with clotting of blood, leading to AKF include: transfusion reaction; hemolytic uremic syndrome; scleroderma; idiopathic thrombocytopenic thrombotic purpura (ITTP); and malignant hypertension.

Other conditions that can cause complications and damage the kidneys are: infections, such as septicemia and acute pyelonephritis; placenta previa and placenta abruption in pregnancy.

Symptoms

Symptoms that can occur abruptly and progress rapidly in AKF are edema and crackling sound in the lungs (due to fluid retention), nausea and vomiting, confusion, low back pain, dehydration, abdominal pain, and high blood pressure.

Diagnosis

Routine laboratory tests for AKF include serum creatinine, creatinine clearance time, blood urea nitrogen (BUN), serum potassium, serum sodium, urinalysis (microscopy), estimated glomerular filtration rate (eGFR) and certain blood tests (optional). Preferred imaging procedure is ultrasound, others that can be helpful in detecting postrenal dysfunction are X-ray, MRI, and CT scan.

Treatment

Treatment is based on mitigating and if possible, eliminating the conditions which lead to the development of AKF. Complete recovery is not always possible, but repair of the damage to the kidneys should at least restore part of the filtration function and normal physiologic responses. Early detection and prompt intervention can reverse the threat to human life.

Dietary restriction must be observed in terms of kinds and amount of fluids, protein (low), salt (low), carbohydrates (high) and potassium (low) to prevent the accumulation of toxic substances in the kidneys.

Prescriptions of antibiotics, for infection; diuretics, to facilitate excretion of urine; calcium and insulin, to regulate blood potassium levels must be complied with.

Dialysis may be needed to facilitate removal of accumulated nitrogenous waste in the blood. It is mandatory in cases of cessation of micturation, dementia, pericarditis, and high potassium blood level.

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