Acute Kidney Injury In Pregnancy Research Articles

Acute Kidney Injury in Pregnancy: A Prospective Study.

When acute kidney damage occurs during pregnancy, it poses a difficult clinical problem. One of the main causes of maternal and fetal morbidity and death is pregnancy-related acute kidney injury (AKI), a significant obstetric complication characterized by a fast deterioration in renal function and several subsequent clinical problems. The objective of the study is to analyze the etiological factors, clinical manifestations, and maternal and fetal outcomes of AKI during pregnancy. This prospective observational research involved patients hospitalized in the General Medicine and Obstetrics and Gynecology departments at Indira Gandhi Institute of Medical Sciences, Patna, for a year (October 2021 to September 2022) due to obstetric difficulties resulting in acute renal damage. The study included 62 patients with a mean age of 25.08±4.25 years. The majority of patients in our study were aged 18-25 years (38, 61.3%), followed by 26-30 years (19, 30.6%) and >30 years (5, 8.1%). The majority of patients in our study were non-booked (52, 83.9%) and presented as emergency cases, whereas 10 (16.1%) patients had booked. In addition, 34 (54.8%) patients were primigravida, while 28 (45.1%) were multigravida. There were 25 patients in their third trimester (40.3%), 19 who were postpartum (30.6%), 10 who were post-abortion (16.1%), and eight in their second trimester (12.9%). Upon admission, the majority of the patients showed signs of oliguria, accounting for 45 cases (72.6%). This was followed by nine cases of abnormal kidney function (14.5%) and eight cases of anuria (12.9%). Among the other symptoms, fever was observed in 25 cases (40.32%), whereas breathlessness increased to 15 cases (24.19%), edema was present in 14 cases (22.58%), vomiting and altered sensorium were observed in four cases (6.45%), abdominal pain was observed in three cases (4.83%), and burning micturition was observed in two cases (3.22%). The most common causes of AKI in pregnancy in the present study were puerperal sepsis (18 cases, 29.0%), followed by preeclampsia/eclampsia (14 cases, 22.6%), hemorrhagic shock (10 cases, 16.1%), septic abortion (six cases, 9.7%), hyperemesis gravidarum (four cases, 6.5%), acute fatty liver of pregnancy (three cases, 4.8%), disseminated intravascular coagulation (three cases, 4.8%), drug-induced sepsis (two cases, 3.2%), and urosepsis (two cases, 3.2%). Modes of delivery in this study were normal vaginal delivery (32 cases, 51.6%), lower segment cesarean section (21 cases, 33.9%), dilation and evacuation (seven cases, 11.3%), and total hysterectomy (two cases, 3.2%). Hemodialysis was performed in 39 patients (62.9%), and 51 (82.3%) received blood transfusions. The mean systolic and diastolic BP (mmHg) were 111.37±22.60 and 71.40±18.88, respectively. Maternal outcome data revealed that 48 (77.4%) women had fully recovered, eight (12.9%) had not recovered, 43 (69.4%) were lost to follow-up, and two (3.2%) had died. Neonatal outcomes in the present study were as follows: live birth, 43 (69.4%); abortion, eight (12.9%); intrauterine death of the fetus, five (8.1%); and neonatal mortality, six (9.7%). The diagnosis and treatment of AKI during pregnancy is a significant challenge for the treating physician because of the pathophysiological changes that occur during pregnancy, the variability of symptoms, and the fact that clinical and laboratory features may occasionally overlap.

Ethnic disparities in pregnancy-related acute kidney injury in a United Kingdom population.

The incidence of acute kidney injury in pregnancy (P-AKI) is rising and is associated with detrimental maternal and foetal outcomes. Ethnic disparities in pregnancy outcomes are well recognized, with females who identify as Black or Asian being more likely to die during pregnancy compared to females who identify as White ethnicity. This study reports rates of P-AKI and associated risk factors in pregnant females of different ethnicities. All pregnancies were recorded between 2016 and 2020. AKI episodes were identified using electronic alerts. Ethnicity, AKI stage (1-3),obstetric outcomes and risk factors for P-AKI (chronic hypertension, pregnancy-induced hypertension and pre-eclampsia, and haemorrhage) were assessed. There were 649 P-AKI episodes from 16,943 deliveries (3.8%). Black females were more likely to have P-AKI (5.72%) compared to those who were White (3.12%), Asian (3.74%), mixed ethnicity (2.89%) and Other/Not Stated (3.10%). Black females, compared to White females, were at greater risk of developing P-AKI if they had haemorrhage requiring blood transfusion (OR 2.44, 95% CI 1.31,4.54; p < 0.001) or pregnancy-induced hypertension (OR 1.79, 95% CI 1.12, 2.86; p < 0.001). After adjusting for risk factors, Black females had increased risk of developing P-AKI (OR 1.52, 95% CI 1.22, 1.80; p < 0.001) compared to White females. Black females were at increased risk of developing P-AKI compared to White females. Mode of delivery, pregnancy-induced hypertension and haemorrhage are likely to have contributed. The increased risk persists despite accounting for these variables, suggesting that other factors such as socioeconomic disparities need to be considered. The incidence of P-AKI is likely higher than previously stated in the literature. However, caution must be exercised, particularly with AKI stage 1, as the KDIGO system is not validated in pregnancy and gestational changes in renal physiology need to be considered. Pregnancy-specific AKI definitions are needed.

Outcome of Acute Kidney Injury in Pregnancy in N’Djamena, Chad

Outcome of Acute Kidney Injury in Pregnancy in N’Djamena, Chad

An Unusual Cause of Acute Kidney Injury in Pregnancy: Beware of HELLP Look-Alikes

The differential diagnosis between new occurrence or revelation of chronic kidney diseases in pregnancy and hypertensive disorders of pregnancy is not easy, and the presence of a hypertensive disorder superimposed on a glomerular disease is even more challenging, as this case exemplifies. A 29-year-old woman was referred with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome at the end of her pregnancy. Immediately after cesarean delivery, she developed anuria, unexplained by blood loss or hypotension, and in the absence of known nephrotoxic drugs. While the laboratory features of HELLP rapidly resolved, AKI persisted, and the finding of high-level proteinuria was the hint leading to diagnosis of a glomerular disease (focal segmental glomerulosclerosis, FSGS), later proven by kidney biopsy. This case, reporting on the rare association between HELLP and FSGS, offers the opportunity to discuss the role of proteinuria, hypertension, and in the differential diagnosis of pregnancy-related acute kidney injury (pAKI).

Primary hyperparathyroidism, presenting with acute kidney injury in the first trimester of pregnancy; a case report

Primary hyperparathyroidism (PHPT) is the leading cause of hypercalcemia. Total serum calcium level &gt;3.5 mmol/L is associated with a high risk of a hypercalcemic crisis, manifesting with nausea, vomiting, dehydration, myalgia’s, abdominal pain, acute pancreatitis, acute kidney injury (AKI), cardiac rhythm disorders and disturbances of consciousness. We report here a case of PHPT, manifested with hypercalcemic crisis during pregnancy. A 30-year-old woman in the first trimester of pregnancy admitted complaining on loss of appetite, nausea, vomiting, lower abdomen pain, weakness, and leg pain during the last 10 days. She had a history of two uncomplicated pregnancies, and two episodes of renal colic, her kidney function was normal 2 weeks prior to admission. Work-up showed hypochloremia, hypokalemia, hyponatremia, total serum calcium was 5.34 mmol/L, and serum creatinine 226 µmol/L, and she underwent urgent hemodialysis (HD). Her parathyroid hormone (PTH) was 948 pg/mL, and imaging revealed missed miscarriage 9-10 weeks, soft tissue mass 30x20x33mm near the lower pole of the left lobe of the thyroid gland, small stones in renal calices, and polysegmental pneumonia. She received antibiotics, calcimimetics, and every-day hemodiafiltration (HDF), and underwent vacuum aspiration of uterine cavity and surgical removal of the parathyroidoma. Her PTH shortly returned to the reference level, and serum creatinine dropped to 140 µmol/L after kidney replacement therapy (KRT) secession. Pathology confirmed the diagnosis of parathyroid adenoma. PHPT should be included in the diagnostic algorithm of AKI in pregnancy along with vomiting of pregnant, sepsis, pre-eclampsia and other causes. Successful management of PHPT complications in pregnancy demands multidisciplinary team.

Causes and prevalence of acute kidney injury in pregnancy regarding to pregnancy-related problems: single-center study

Causes and prevalence of acute kidney injury in pregnancy regarding to pregnancy-related problems: single-center study

Pr-AKI: Acute Kidney Injury in Pregnancy - Etiology, Diagnostic Workup, Management.

Despite significant improvements in inpatient and outpatient management, pregnancy-related acute kidney injury (Pr-AKI) remains an important risk factor for early and late maternal and fetal morbidity and mortality. There is a discrepancy between the incidence of Pr-AKI in developing and in developed countries, with the former experiencing a decrease and the latter an increase in Pr-AKI in recent decades. Whereas septic and hemorrhagic complications predominated in the past, nowadays hypertensive disorders and thrombotic microangiopathy are the leading causes of Pr-AKI. Modern lifestyles and the availability and widespread use of in-vitro fertilization techniques in industrialized countries have allowed more women of advanced age to become pregnant. This has led to a rise in the percentage of high-risk pregnancies due to the disorders and comorbidities inherent to or accompanying aging, such as diabetes, arterial hypertension and preexisting chronic kidney disease. Last but not least, the heterogeneity of symptoms, the often overlapping clinical and laboratory characteristics and the pathophysiological changes related to pregnancy make the diagnosis and management of Pr-AKI a difficult and challenging task for the treating physician. In addition to general supportive management strategies such as volume substitution, blood pressure control, prevention of seizures or immediate delivery, each disease entity requires a specific therapy to reduce maternal and fetal complications. In this review, we used the current literature to provide a summary of the physiologic and pathophysiologic changes in renal physiology which occur during pregnancy. In the second part, we present common and rare disorders which lead to Pr-AKI and provide an overview of the available treatment options.

Acute Renal Failure in Pregnancy: A Prospective Cohort Study

Introduction: Pregnancy-related acute renal failure is a common occurrence and is associated with substantial maternal morbidity and mortality in developing countries. It may comprise up to 25% of the referrals to dialysis centres in developing countries. Acute kidney injury in pregnancy bears a high risk of bilateral renal cortical necrosis and resultant chronic renal failure. Acute renal failure in pregnancy follows bimodal relation to period of gestation. First peak is seen in early pregnancy between 7-16 weeks of gestation and second peak occurs in later part of pregnancy and puerperium. The incidence and aetiology are changing over time. Socio-economic and environmental factors are accountable for a regional difference in incidence, aetiology and outcome also. Aim: To analyse the current aetiological factors, clinical spectrum of presentation of Acute Renal Failure (ARF) in pregnancy and to assess its maternal and foetal outcome. Materials and Methods: It was a prospective cohort study of 100 patients presenting with acute renal failure during pregnancy and puerperium which was done at SCB Medical College, Odisha, India. Inclusion criteria were previously healthy pregnant females with sudden oliguria anuria, sudden increase in serum creatinine to more than 1.5 mg/dL or increase in serum creatinine of more than 0.5 mg/dL per day from base line if haemodialysis was indicated. Maternal outcomes were recovery with conservative treatment, dialysis, ICU admission and maternal death. Foetal outcomes were gestational age at delivery, birth weight, stillbirth or perinatal death. All these were recorded. Results: During the first trimester of gestation acute renal failure developed most often due to septic abortion (3%). Preclampsia was the most common cause of acute renal failure (50%) in late third trimester and postpartum periods followed by puerperal sepsis (9%) Abruptio placentae (3%) and Postpartum Haemorrhage (PPH) (5%). Oedema and oliguria were the most common presentation in 81% and 30% of cases. Eighty seven percent recovered with i.v. fluids and diuretics (conservative management), 13% required dialysis, 23% required blood and Fresh Frozen Plasma (FFP), 30% needed ICU admission and 11% died during treatment. Foetal outcome were measured in terms of foetal growth restriction (24%), preterm delivery (14%), foetal distress (13%), SNCU admission (23%) and stillbirth (5%). Conclusion: This study concludes that pregnancy related acute renal failure is associated with serious prognosis both for the mother and child. Even though good obstetric care can reduce morbidity and mortality associated with it, these patients require special and intensive care management facility which can bring them better survival rates.

Acute kidney injury in COVID-19: Considerations in pregnancy.

The clinical manifestations of COVID-19 are diverse with the involvement of different organ systems. Renal involvement is particularly noteworthy with acute kidney injury (AKI) being an important disease manifestation, particularly in pregnancy. Pregnancy itself serves as a high-risk condition for COVID-19 disease and a risk factor for deterioration, developing a more severe illness than nonpregnant women, and subsequent higher intensive care unit admission, oxygen therapy, and ventilatory support. There are reports in the literature highlighting the involvement of vital organs in pregnancy; however, data pertaining to AKI in pregnancy during COVID-19 are lacking in terms of risk factors, disease management, and outcomes. The entire spectrum of hormonal changes and adaptive mechanisms in pregnancy can be adversely affected by this viral infection. A literature search regarding AKI in COVID-19 in pregnancy was performed on PubMed, Scopus, Google Scholar, and ScienceDirect, and the relevant articles were selected. Our review highlights key issues pertaining to AKI in COVID-19 in pregnancy in an attempt to overcome, albeit partly, the scarcity of corroborative literature regarding the same.

Acute Kidney Injury in Pregnancy.

Acute kidney injury in pregnancy is a public health problem and a significant cause of maternal and fetal morbidity and mortality. The incidence of pregnancy-related acute kidney injury has increased in the developed countries, theorized to be the result of an increase in pregnancies in advanced maternal age, and continues to remain higher in developing countries owing to inadequate antenatal care. While hyperemesis gravidarum is a common cause of pregnancy-related acute kidney injury during the first trimester, complications such as preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome, acute fatty liver disease of pregnancy, thrombotic thrombocytopenic purpura, and hemolytic uremic syndrome are important causes of acute kidney injury later in the pregnancy. Diagnosis of pregnancy-related acute kidney injury can be difficult owing to lack of diagnostic criteria and overlapping clinical features between various causes. General measures to treat pregnancy-related acute kidney injury include identification of the underlying cause of kidney injury, intravenous fluid resuscitation, timely initiation of dialysis if needed, and prompt fetal delivery, if necessary. Specific treatment includes steroid and immunosuppressive therapy for glomerulonephritis; prompt delivery for severe preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome, and acute fatty liver of pregnancy; and plasmapheresis and eculizumab for thrombotic microangiopathies such as thrombotic thrombocytopenic purpura and atypical hemolytic uremic syndrome.

Effect of HELLP syndrome on acute kidney injury in pregnancy and pregnancy outcomes: a systematic review and meta-analysis

BackgroundHELLP syndrome may increase adverse pregnancy outcomes, though the incidence of it is not high. At present, the impact of HELLP syndrome on P-AKI (acute kidney injury during pregnancy) and maternal and infant outcomes is controversial. Thus, we conducted a meta-analysis to find out more about the relationship between HELLP syndrome and P-AKI and pregnancy outcomes.MethodsWe systematically searched PubMed, Embassy and Cochrane Databases for cohort studies and RCT to assess the effect of HELLP syndrome on P-AKI and maternal and infant outcomes. Study-specific risk estimates were combined by using fixed-effect or random-effect models.ResultsThis meta-analysis included 11 cohort studies with a total of 6333 Participants, including 355 cases of pregnant women with HELLP syndrome and 5979 cases that without. HELLP syndrome was associated with relatively higher risk of P-AKI (OR4.87 95% CI 3.31 ~ 7.17, P<0.001), fetal mortality (OR1.56 95% CI 1.45 ~ 2.11, P<0.001) and Maternal death (OR3.70 95% CI 1.72 ~ 7.99, P<0.001).ConclusionsHELLP syndrome is associated with relatively higher risk of P-AKI, fetal mortality and maternal death.

Acute kidney injury in pregnancy and postpartum

Abnormal Uterine Bleeding is most common complaint during reproductive age group. The woman with AUB were classified according to PALM-COEIN classification. The most of the woman (38%) belongs to AUB(L). The most common histopathological finding was secretary phase of endometrium 44.28%. The most common histopathological finding in AUB(M) was simple hyperplasia without atypia was 77.77%. Therefore the PALM- COEIN classification system is applicable globally and should be followed every health facility.

A study of AKI in pregnancy and puerperium

Pregnancy related acute kidney injury is a common occurrence and is associated with substantial maternal mortality and morbidity in developing countries. The incidence of pregnancy related acute kidney injury in developing countries from 4% to 36%; it varies widely across the world. Acute kidney injury in pregnancy bears a high risk of bilateral cortical necrosis and consequently chronic renal failure. Study aimed to evaluate the preventable causes, contributing factors responsible for pregnancy related acute kidney injury and to assess the outcome of patients with pregnancy related acute kidney injury during pregnancy and puerperium.

Spectrum of Acute Kidney Injury in Pregnancy associated Thrombotic Microangiopathy

Thrombotic microangiopathy (TMA) is characterized by microvascular thrombosis due to endothelial injury or abnormal platelet aggregation. It commonly manifests as microangiopathic hemolytic anaemia, thrombocytopenia and organ injury that may include acute kidney injury (AKI). It has a diverse etiology. Pregnancy associated TMA represents a secondary form that may be caused by complement mediated Hemolytic Uremic Syndrome (HUS), Thrombotic Thrombocytopenic Purpura (TTP) and preeclampsia-eclampsia, Rarely, renal cortical necrosis – a catastrophic event, may be seen in pregnancy-related TMA. We discuss three cases of thrombotic microangiopathy related to pregnancy. TMA is associated with significant fetomaternal morbidity and mortality and hence a rapid diagnosis and prompt disease management is crucial for a favourable patient outcome.

Acute kidney injury in pregnancy.

Pregnancy-related acute kidney injury (Pr-AKI) is associated with increased maternal and fetal morbidity and mortality and remains a large public health problem. Pr-AKI incidence has globally decreased over time for the most part. However, the cause presents a disparity between developing and developed countries, reflecting differences in socioeconomic factors and healthcare infrastructure - with the noteworthy outlier of increased incidence in the United States and Canada. Although Pr-AKI can be secondary to conditions affecting the general population, in most cases it is pregnancy specific. Septic abortion, hyperemesis gravidarum, and hemorrhage have become less prevalent with access to healthcare but are being displaced by thrombotic microangiopathies, such as preeclampsia, hemolysis, elevated liver enzymes, low platelets syndrome, thrombotic thrombocytopenic purpura, and pregnancy-associated hemolytic-uremic syndromes, as well as acute fatty liver of pregnancy. Understanding these conditions plays a pivotal role in the timely diagnosis and enhancement of therapeutic approaches. In this review, we focus on the renal physiology of the pregnancy, epidemiology, and specific conditions known to cause Pr-AKI, summarizing diagnostic definition, insights in pathophysiology, clinical considerations, and novel treatment approaches, thus providing the reader a framework of clinically relevant information for interdisciplinary management.

The Changing Landscape of Acute Kidney Injury in Pregnancy from an Obstetrics Perspective.

Pregnancy-related acute kidney injury (PR-AKI) is a heterogeneous disorder with multiple aetiologies that can occur at any time throughout pregnancy and the post-partum period. PR-AKI is an important obstetric complication that is associated with significant maternal and foetal morbidity and mortality. Although there has been an overall decline in the incidence of PR-AKI worldwide, a recent shift in the occurrence of this disease has been reported. Following improvements in obstetric care, PR-AKI incidence has been reduced in developing countries, whereas an increase in PR-AKI incidence has been reported in developed countries. Awareness of the physiological adaptations of the renal system is essential for the diagnosis and management of kidney impairment in pregnancy. In this review we scrutinize the factors that have contributed to the changing epidemiology of PR-AKI and discuss challenges in the diagnosis and management of acute kidney injury (AKI) in pregnancy from an obstetrics perspective. Thereafter we provide brief discussions on the diagnostic approach of certain PR-AKI aetiologies and summarize key therapeutic measures.

Serious kidney disease in pregnancy: an Australian national cohort study protocol

BackgroundMaternal kidney disease (acute kidney injury (AKI), advanced chronic kidney disease (CKD), dependence on dialysis or a kidney transplant) has a substantial impact on pregnancy, with risks of significant perinatal morbidity. These pregnancies require integrated multidisciplinary care to manage a complex and often challenging clinical situation. The ability to deliver optimal care is currently hindered by a lack of understanding around prevalence, management and outcomes in Australia. This study aims to expand an evidence base to improve clinical care of women with serious kidney impairment in pregnancy.Methods/designThe “Kidney Disease in Pregnancy Study” is a national prospective cohort study of women with stage 3b-5 CKD (including dialysis and transplant) and severe AKI in pregnancy, using the Australasian Maternity Outcomes Surveillance System (AMOSS). AMOSS incorporates Australian maternity units with > 50 births/year (n = 260), capturing approximately 96% of Australian births. We will identify women meeting the inclusion criteria who give birth in Australia between 1st August 2017 and 31st July 2018. Case identification will occur via monthly review of all births in Australian AMOSS sites and prospective notification to AMOSS via renal or obstetric clinics. AMOSS data collectors will capture key clinical data via a web-based data collection tool. The data collected will focus on the prevalence, medical and obstetric clinical care, and maternal and fetal outcomes of these high-risk pregnancies.DiscussionThis study will increase awareness of the issue of serious renal impairment in pregnancy through engagement of 260 maternity units and obstetric and renal healthcare providers across the country. The study results will provide an evidence base for pre-pregnancy counselling and development of models of optimal clinical care, clinical guideline and policy development in Australia. Understanding current practices, gaps in care and areas for intervention will improve the care of women with serious renal impairment, women with high-risk pregnancies, their babies and their families.

Acute Kidney Injury - Part II: Special Situations

Acute renal failure (ARF) has been defined as a syndrome in which an abrupt decrease in renal function produces retention of nitrogenous waste products. Translating this abstract description into a clinically useful, accurate, and widely accepted definition has been challenging, in large part because of the focus on serum creatinine concentration, which is easily obtained but has the inherent limitation of poor detection of rapid or subtle, but clinically important, changes in the glomerular filtration rate (GFR). In recent years, therefore, the term acute kidney injury (AKI) has replaced ARF because AKI denotes the entire clinical spectrum from mild increases in serum creatinine to overt renal failure. AKI is defined by the Risk-Injury-Failure-Loss-ESRD (RIFLE) criteria, based on serum creatinine concentration and urine flow rate. The Acute Kidney Injury Network (AKIN) subsequently modified the definition further and divided AKI into three stages. This part of the AKI review specifically discusses special situations: rhabdomyolysis, aristolochic acid nephropathy, acute urate nephropathy, acute phosphate nephropathy, AKI in multiple myeloma, ehytlene glycol poisoning, contrast-induced nephropathy, AKI in sepsis, hepatorenal syndrome, and AKI in pregnancy. This review contains 10 tables, and 47 references. Keywords:Acute kidney injury, dialysis, contrast, rhabdomyolysis, nephropathy, urinalysis, multiple myeloma, ethylene glycol, sepsis, hepatorenal syndrome

Acute Kidney Injury - Part II: Special Situations

Acute renal failure (ARF) has been defined as a syndrome in which an abrupt decrease in renal function produces retention of nitrogenous waste products. Translating this abstract description into a clinically useful, accurate, and widely accepted definition has been challenging, in large part because of the focus on serum creatinine concentration, which is easily obtained but has the inherent limitation of poor detection of rapid or subtle, but clinically important, changes in the glomerular filtration rate (GFR). In recent years, therefore, the term acute kidney injury (AKI) has replaced ARF because AKI denotes the entire clinical spectrum from mild increases in serum creatinine to overt renal failure. AKI is defined by the Risk-Injury-Failure-Loss-ESRD (RIFLE) criteria, based on serum creatinine concentration and urine flow rate. The Acute Kidney Injury Network (AKIN) subsequently modified the definition further and divided AKI into three stages. This part of the AKI review specifically discusses special situations: rhabdomyolysis, aristolochic acid nephropathy, acute urate nephropathy, acute phosphate nephropathy, AKI in multiple myeloma, ehytlene glycol poisoning, contrast-induced nephropathy, AKI in sepsis, hepatorenal syndrome, and AKI in pregnancy. This review contains 10 tables, and 47 references. Keywords:Acute kidney injury, dialysis, contrast, rhabdomyolysis, nephropathy, urinalysis, multiple myeloma, ethylene glycol, sepsis, hepatorenal syndrome

Acute Kidney Injury - Part II: Special Situations

Acute renal failure (ARF) has been defined as a syndrome in which an abrupt decrease in renal function produces retention of nitrogenous waste products. Translating this abstract description into a clinically useful, accurate, and widely accepted definition has been challenging, in large part because of the focus on serum creatinine concentration, which is easily obtained but has the inherent limitation of poor detection of rapid or subtle, but clinically important, changes in the glomerular filtration rate (GFR). In recent years, therefore, the term acute kidney injury (AKI) has replaced ARF because AKI denotes the entire clinical spectrum from mild increases in serum creatinine to overt renal failure. AKI is defined by the Risk-Injury-Failure-Loss-ESRD (RIFLE) criteria, based on serum creatinine concentration and urine flow rate. The Acute Kidney Injury Network (AKIN) subsequently modified the definition further and divided AKI into three stages. This part of the AKI review specifically discusses special situations: rhabdomyolysis, aristolochic acid nephropathy, acute urate nephropathy, acute phosphate nephropathy, AKI in multiple myeloma, ehytlene glycol poisoning, contrast-induced nephropathy, AKI in sepsis, hepatorenal syndrome, and AKI in pregnancy. This review contains 10 tables, and 47 references. Keywords:Acute kidney injury, dialysis, contrast, rhabdomyolysis, nephropathy, urinalysis, multiple myeloma, ethylene glycol, sepsis, hepatorenal syndrome