acute kidney injury ( aki ) is characterized by rapid ( over hours to days ) decline in glomerular filtration rate , retention of nitrogenous waste products and perturbation of the extracellular fluid volume , electrolytes and acid - base homeostasis . aki constitutes approximately 5% of hospital admissions and up to 30% of admissions to intensive care units . although reliable statistics on the prevalence of aki are not available , statistics on referrals to dialysis units suggest that the condition is more common in india as compared to the west . aki can result from decreased renal perfusion without cellular injury , an ischemic , toxic or obstructive insult to the renal tubule , a tubulointerstitial process with inflammation and edema or primary reduction in the filtering capacity of the glomerulus . the mortality rate among patients with aki approaches 50% and has changed little over the past 15 years . this study was conducted in a tertiary care hospital providing nephrology services in himachal pradesh , india , located in western himalayas to assess clinico - etiological aspects , risk factors , clinical course and outcome of aki . this was a prospective study , done over a period of 1 year in a tertiary care hospital . all one hundred and two patients with clinical ( uremic symptoms or oliguria or anuria of recent onset ) and laboratory evidence of azotemia ( urea and creatinine above 40 mg / dl and 1.5 mg / dl , respectively ) were eligible . adult patients who developed kidney injury after at least 24 hours of admission were referred as hospital - acquired aki . patients with chronic renal failure , acute on chronic renal failure and those not willing to participate were excluded from this study . the patients included in the study were explained in detail about the purpose of the study and an informed consent was taken . each patient was looked for the complications of aki - like fluid overload , hypertension , electrolyte abnormalities , metabolic acidosis , uremic complications , bleeding , neurological abnormalities and infections . kidney injury was listed as a cause of death if patient exhibited evidence of severe uremia , hyperkalemia or volume overload secondary to oliguria . patients were classified as oliguric ( urine output<500 ml / day ) and non oliguric ( urine output>500 ml / day ) during the azotemic phase.the study has been approved by institutional ethics committee . a total of 19,248 admissions were recorded in the hospital during the year of study . community - acquired aki was observed in 86 patients ( 84.3% ) and hospital - acquired kidney injury in 16(15.7% ) patients . the mean age of these patients was 48.9618.3 ( range 18 to 85 ) years . the mean duration of hospital stay was 9.417.3 days with a range from 1 to 34 days . out of the 102 patients , 87 were admitted with medical causes ( 85.3% ) , 10 with surgical causes ( 9.8% ) and 5 with obstetrical causes ( 4.9% ) . the coexisting conditions observed in aki were observed in 87(85.3% ) patients and is shown in table 2 . multiorgan failure was present in 61 ( 59.8% ) patients and single organ failure in 41(40.2% ) patients . active urinary sediment was noted in 54 patients and mortality rate in them was 56% . kidney biopsy was done in nine patients which revealed acute tubular necrosis ( atn ) in 4 : snake bite 2 , wasp bite 1 , drugs 1 ( nsaids+aminoglycoside 1 ) ; allergic interstitial nephritis ( ain ) in 1 ( cephalosporins ) ; atn+ain in 1 ( wasp bite ) ; diffuse proliferative glomerulonephritis ( dpgn ) in 2 and crescentic glomerulonephritis in 1 . in the remaining majority of patients either the consent for kidney biopsy was not available or the patients had improved . the rate of infection was 62% in those who survived and 78% in those who died ( p>0.05 ) . the mortality rate with positive blood culture was 48% as compared to that of 39% where blood culture was negative ( p>0.05 ) . in the study , 64 patients required vasopressor support and 26 ( 40.6% ) died whereas 2 ( 5.3% ) out of 38 patients died who did not receive vasopressor support ( p<0.05 ) . fifty - four patients ( 53% ) received dialysis , were treated with peritoneal dialysis ( pd ) and 50 with hemodialysis ( hd ) . on an average each patient treated with hd received 2.51.5 ( range 1 - 7 ) sessions of hd . 25 ( 46.3% ) of the patients who received dialysis died . in this study , 16 patients had nonoliguric aki and mortality in nonoliguric aki was 11% as compared to 46% in the oliguric patients ( p<0.05 ) . pre - renal aki was present in 21.6 ( 20.6% ) , intrinsic renal in 71(69.6% ) and post - renal in 10(9.8% ) . out of 102 patients 28 died ( 29.2% ) and 68 patients recovered renal function ( 70.8% ) . in 6 patients ( 5.9% ) outcome could not be ascertained as they were either discharged on request or left against medical advice before recovery . the mortality was 6.7% in hospital acquired aki and 22.5% in community acquired aki ( p<0.05 ) . the present study was conducted in a tertiary care hospital a hilly state in western himalayas . out of a total 102 patients with aki , it is due to endemic malnutrition , poor socioeconomic conditions , hot climate ( resulting in peripheral vasodilatation ) , which in conjunction with excessive sweating predisposes to hypovolumic insults . the study revealed that our patients are more than a decade younger than in the west but comparable with most of indian studies . medical causes contributed to aki in 85.3% , surgical causes in 9.8% and obstetric causes in 4.9% of patients . a study from south india showed 87.6% aki in medical patients , 8.9% and 3.4% aki in surgical and obstetrical patients respectively and similar observations have been made previously . the pattern is however changing , surgical causes are increasing due to more trauma and major surgeries and obstetrical causes are decreasing because of better care in obstetrics . the low percentage of aki in surgical patients in our study could be attributed to non performance of open heart and pancreatic surgery in our institution during the study period . among the causes leading to aki , intrinsic renal causes were seen in 69.6% , pre - renal in 20.6% and postrenal causes were present in 9.8% patients . septicemia was observed in 33.3% , acute gastroenteritis(leading to volume depletion ) in 20.6% , toxic causes ( nephrotoxic drugs+biological toxins ) in 25.5% , obstructive uropathy in 9.8% , toxemia of pregnancy in 3.9% , cardiogenic shock in 5.9% , cerebral malaria and visceral leishmaniasis in one patient each . eleven out of 34 patients who died were aged 60 years and above accounting for 32.4% . the literature regarding the development of aki in elderly with septicemia is variable.[79 ] in the present study drugs were responsible for the development of aki in 16 patients ( 15.7% ) . drug - related causation was implicated in 18.3% of aki cases reported in a one year survey . in india a study reported a 20% incidence of drug induced aki with a larger proportion ( 40% ) being secondary to aminoglycoside usage . nsaid 's , acei 's , radiocontrast media and aminoglycosides are labeled as  internists nephrotoxic quartet  as these are common nephrotoxic drugs . the kidney is an organ characterized by a large blood supply which ensures a high level of toxicant delivery over a period of time . the extensive resorptive capacity of the tubule with specialized transporters promotes cellular uptake of the toxicant . concentrating capability of the tubule produces the high concentrations in the medullary lumen and interstitium . in the present study , 9.8% patients had obstructive uropathy . whereas trauma , drugs and cardiovascular surgery are the leading causes of surgical aki in the developed countries , obstructive uropathy constitutes a major cause of surgical aki in certain tropical areas . the obstetrical causes of aki were 5.2% in this study which were comparable with the figure of 6% by an indian study . improvements in obstetrical care have led to a decline in the incidence of obstetric aki from 22% of all aki in 1960s to 8% in 1990s . community acquired aki was associated with increased mortality as compared to hospital - acquired aki ( 22.5% vs 6.7% ) . mortality was high in patients having aki due to medical causes as compared to patients with aki resulting from surgical and obstetrical causes . possible explanation for the lower mortality in surgical and obstetrical patients is that they did not have multiorganfailure which was common among patients with medical aki . presence of cardiovascular diseases , neurological diseases at the time of presentation to the hospital were associated with higher mortality . mortality was high in patients who required vasopressor support and amongst those who required dialysis therapy . vasopressor support as well as dialysis support are considered a prognostic factor for outcome in aki patients . urine output is an established prognosticator in aki.[1517 ] occurrences of infections after the development of aki were associated with a poor outcome . in conclusion , aki is still common in the community and is associated with high mortality . septicemia , volume depletion and nephrotoxins were the leading cause of aki in our study . presence of hypotension , multiorgan failure , oliguria and active urine sediment and complications in the form of severe metabolic acidosis and hyperkalemia and patients with renal category of aki were associated with increased mortality .
acute kidney injury ( aki ) is common in hospitalized patients and is an important cause of mortality . 
 this is a descriptive study of aki in patients from himachal pradesh , india , located in western himalayan region . over a period of 1 year 
 , 102 patients with clinical and laboratory evidence of azotemia were included . out of 102 patients , 84.3% had community acquired aki and 15.7% had hospital acquired aki . 
 medical causes were leading contributors ( 85.3% ) , with septicemia being the main factor ( 33.3% ) . 
 multiorgan failure was present in 59.8% patients . 
 the overall mortality was 29.2% , and community acquired aki was associated with higher mortality as compared to hospital - acquired aki ( 22.5% vs 6.7% ) . 
 aki is still common in community and associated with high mortality . 
 septicemia , volume depletion and nephrotoxins were the leading cause of aki in our study . 
 our study highlights the presence of hypotension , multiorgan failure and oliguria with mortality . 
 community - acquired aki had higher mortality than hospital - acquired aki .