European Journal of Cardiovascular Medicine

Acute kidney injury (AKI) is characterized by reduced kidney function, marked by decreased urine output, elevated serum creatinine levels, and increased blood urea nitrogen, with creatinine levels remaining normal despite kidney damage [1].

AKI is a heterogeneous condition marked by a rapid decrease in glomerular filtration over hours to days, elevating the risk of mortality and morbidity in hospitalised patients [2]. AKI is a multifaceted condition resulting from diverse pathophysiological mechanisms and aetiologies. Early identification of AKI necessitates swift diagnosis for timely reversal. Hypoperfusion of kidney, obstruction of urine outflow, and diminished venous outflow are chiefly attributed to insufficient venous and arterial supply or urinary flow.

Sepsis may serve as a contributing factor in AKI [3]. AKI severity and/or duration increases, risk of intrinsic AKI due to cellular injury, after organ dysfunction, and ultimately, overt organ failure [4]. There by resulting in an increasing risk of morbidity and mortality. The reduction in urine output is simply one indicator of acute renal damage [5].

AKI significantly increases the build-up of metabolic byproducts, water, and sodium [6]. Moreover, it increases the likelihood of electrolyte disturbances, with the majority of patients exhibiting the aforementioned symptoms constituting 7% of all hospital admissions and 30% of ICU admissions [8].

Blood urea nitrogen (BUN) or creatinine levels may be within the normal range very far after a renal injury. However, the decrease in urine flow might be the only indication of acute renal damage. AKI can cause the build-up of salt, water, and other metabolic by-products and also several electrolyte imbalance problems among hospitalized.

Sixty-seven percent of patients who admitted to the intensive care unit (ICU) are having renal impairment . The majority of drugs are excreted by the kidneys, therefore, dosages must be modified to prevent compromising renal function.

KDIGO (Kidney Disease Improving Global Outcome) characterizes AKI by the following criteria:

The Acute Kidney Injury Network (AKIN) was established in 2004 and introduced a set of diagnostic criteria for defining AKI. According to AKIN, AKI is characterized by an abrupt decline in kidney function within 48 hours, which can be identified by one of the following criteria: an absolute increase in serum creatinine of ≥0.3 mg/dl (≥26.4 µmol/l), a percentage rise in serum creatinine of ≥50% (1.5 times the baseline value), or a decrease in urine output, with documented oliguria of <0.5 ml/kg per hour sustained for more than 6 hours.

Recent data suggests that even small increases in serum creatinine levels may be linked to worse outcomes compared to the RIFLE criteria. To address this, the AKIN introduced a new classification and staging system. The objective of this study is to identify the etiological factors of AKI and assess their outcomes.

This hospital based Cross sectional Study was conducted among 150 Patients with Acute Kidney Injury at Government General Hospital, Srikakulam. Duration of Study was June 2023 - December 2024. Ethical approval for the study was secured from the Institutional Ethics Committee of GMC Srikakulam. Written informed consent was obtained from all participants prior to their inclusion in the study.

Sample size calculation

According to Prasanta Kumar Bhattacharya et al.^[7] study, taking the most observed etiology, Infections 56% as prevalence. The sample size required for the given study is 150, with 10% alpha error at 95% confidence level^. Open epi Version 3.01 was used to calculate the sample size.

Inclusion Criteria: -

1.      The patients with an absolute increase in serum creatinine of more than or equal to 0.3mg/dl (> or = 26.4micromoll/ml), a percentage increase in serum creatinine of more than or equal to 50% (1.5-fold from baseline).

2. Age group 18 years and above
3. Both Sexes

Exclusion Criteria:-

1. Patients with chronic kidney
2. Patients with abnormal kidney size and abnormal cortico-medullary differentiation on imaging.
3. Patients who didn't consent for the
4. Age below 18

METHODOLOGY

A comprehensive diagnostic evaluation of 150 patients is carried out to determine the reason for AKI. This evaluation includes a detailed history, a physical examination, a complete urine examination, renal function tests, renal ultrasound, a smear for the malarial parasite, serology for dengue fever and enteric fever, and other pertinent investigations.

After the diagnosis has been made, the proper treatment is administered, etiological factors are treated. If they can be treated, the agents causing the problem are removed.

There were a total of 150 patients who participated in the research study. The average age of the patients was 43.97 years, and their ages ranged from 18 to 75 years old. There were a total of 150 patients, consisting of 99 men and 51 females.

Out of a total of 150 patients, there were 18 patients who were between the ages of 18 and 25 years old, 30 patients who were between the ages of 26 and 35 years old, 33 patients who were between the ages of 36 and 45 years old, 36 patients who were between the ages of 46 and 55 years old, 29 patients who were between the ages of 56 and 65 years old, and those who were over the age of 66 years old. Within the scope of our research, the most often seen clinical manifestations included fever, oliguria, anuria, vomiting, jaundice, and abnormal sensorium patterns.

The most common clinical feature in our study was oliguria. It accounted for about 72.6%. 20.7% of the patients normal urine output (non-oliguric) and only 6.7% of the patients had anuria.

In our investigation, the predominant causes of AKI were sepsis (30.6%), followed by poisoning (21.3%), snake bite (19.3%), diarrheal disease (12.7%), dengue (8%), pancreatitis (3.3%), scrub typhus (1.3%), and post-renal causes (0.6%), with wasp bite accounting for (0.6%).

TABLE: 1 ETIOLOGICAL PROFILE OF AKI IN OUR STUDY

TABLE 2: TYPE OF AKI

In our research, the most common cause of AKI include poisoning and snake bites, but sepsis can induce both pre renal and renal AKI.

According to our study utilizing AKIN standards, 15 patients (10%) were classified as AKIN stage 1, 37 patients (24.7%) as AKIN stage 2, and 98 patients(65.3%) as AKIN stage 3.

Fifteen patients with AKIN stage 1 were treated conservatively, and all patients exhibited satisfactory recovery.

In AKIN stage 2, of the 37 patients, 4 patients (10.8%) required hemodialysis, while the remaining 33 patients (89.2%) were treated conservatively. All patients in AKIN stage 2 exhibited satisfactory recovery.

Among 98 patients in AKIN stage 3, 76 patients (77.6%) received dialysis, whereas 22 patients (22.4%) were treated conservatively. Forty-two patients out of ninety-eight (42.9%) succumbed.

TABLE 3: CLASSIFICATION BASED ON AKIN CRITERIA

In our study, 80 patients (53.3%) underwent dialysis

• In AKIN stage 1, out of 15 patients, all are recovered with conservative
• In AKIN stage 2, out of 37 patients, 33 patients were managed conservatively and 4 patients underwent hemodialysis.
• In AKIN stage 3, out of 98 patients, 22 patients were managed conservatively and 76 patients underwent dialysis.

TABLE 4: TREATMENT GIVEN

TABLE 5: ACUTE KIDNEY INJURY OUTCOME

In our study, 80 patients (53.3%) received dialysis, 38 patients recovered successfully, and 42 patients succumbed. Of the deceased patients, 22 succumbed to poisoning, predominantly from paraquat exposure.

In AKIN stage 1, all 15 patients exhibited favourable recovery through conservative care.

In AKIN stage 2, of the 37 patients, 33 were treated conservatively while 4 required haemodialysis. All patients have fully recuperated.

In AKIN stage 3, of the 98 patients, 22 were treated conservatively while 76 underwent dialysis. Among the patients at AKIN stage 3, 38 survived while 42 succumbed. Out of the 42 patients, 22 were diagnosed with poisoning. In this study, poisoning was the predominant cause of mortality, succeeded by sepsis.

The average patient age in this study was 43.96 years, significantly younger than the demographic most commonly affected by AKI in high-income countries, where the incidence peaks in individuals aged 65 years and older. This discrepancy may reflect region-specific occupational and environmental exposures, such as widespread agricultural labor and contact with nephrotoxic substances like pesticides and herbicides. These findings emphasize a need to reassess risk profiles for AKI in rural Indian settings, where younger populations may face heightened exposure to preventable hazards. Similar trends were observed in a study from rural South India by Rajapurkar et al., (2016) [8], where a substantial proportion of AKI cases occurred in the working-age group due to occupational exposures.

Male predominance was marked, with 66% of patients being male. This trend mirrors findings from several international and Indian studies and may be attributable to occupational factors, healthcare-seeking behavior, or the prevalence of comorbid conditions like hypertension and diabetes mellitus, which predispose to renal compromise. The skewed gender ratio may also reflect cultural influences on healthcare access, where males are more likely to receive hospital-based care.

Oliguria, noted in 72.6% of cases, was the most common presenting symptom, followed by anuria in 6.7%. These findings align with classical AKI symptomatology and validate the utility of urine output as a critical and accessible diagnostic tool, especially in low-resource settings where serum creatinine testing may not be immediately available. The reliance on clinical signs such as oliguria underlines the importance of bedside skills in initial AKI detection.

Our study studied 150 consecutive AKI patients 99 were males and 51 were females. The minimum age group in our study was 18 years and the maximum age was 75 years, with a mean age of 43.96 years. The mean age is lower than that in Ravindra L Mehta et al.,(2007) [9] study (59.5yrs) and Bernich B et al.,[10] study (56.2 years).

In the present study, 72.6% of patients presented with oliguria and 6.7% patients presented with anuria. Hence, decreased urine output was a symptom in 79.3% of patients. In comparison to Bernich B et al., study, decreased urine output was a symptom in 80% of patients.

Oliguria was the most common presenting symptom, followed by anuria . These findings align with classical AKI symptomatology and validate the utility of urine output as a critical and accessible diagnostic tool, especially in low-resource settings where serum creatinine testing may not be immediately available. The reliance on clinical signs such as oliguria underlines the importance of bedside skills in initial AKI detection.

Sepsis was the leading cause of AKI in our study, accounting for 30.6% of cases. This is consistent with global data, particularly from intensive care settings, where sepsis-induced renal hypoperfusion and systemic inflammation play pivotal roles in AKI pathogenesis. Sepsis-related AKI often reflects a complex interplay of factors including microcirculatory dysfunction, cytokine release, and tubular injury. Similar findings were reported by Bagshaw et al., (2008) [11], who emphasized sepsis as a key contributor to AKI in critically ill patients.

Of particular interest in this study was the high incidence of poisoning (21.3%) and snakebite (19.3%) as primary causes of AKI. These etiologies are relatively rare in urban or high-income contexts, highlighting unique environmental and occupational risks in rural India. Paraquat poisoning emerged as a particularly lethal contributor, responsible for the majority of AKI-related deaths in the cohort. Paraquat is a potent herbicide with no known antidote, its ingestion leads to oxidative damage and direct tubular necrosis, often resulting in irreversible renal failure and multiorgan dysfunction. The continued availability of paraquat in rural communities represents a significant public health concern. The nephrotoxicity of paraquat was also reported in a case series by Afshin Asl et al., (2016) [12], reinforcing its high mortality and urgent need for regulatory measures.

Snake bite-induced AKI, largely resulting from hemotoxic or myotoxic venom, contributes to acute tubular necrosis and disseminated intravascular coagulation (DIC). The high prevalence of such cases in this region reflects the occupational risks associated with agriculture and highlights a persistent burden of envenomation in tropical, rural environments. Management of snakebite AKI is time- sensitive, requiring prompt antivenom administration and renal support, which may be delayed due to logistical or healthcare access issues. A study by Habib et al., (2017) [13] similarly emphasized the burden of snakebite-induced AKI in rural communities.

According to studies , diarrhea-associated AKI has significantly decreased from 36.83% in 1983-1995 to 19% in 1996-2008. Sepsis-related AKI has increased

from 1.57% in 1983-1995 to 11.43% in 1996-2008 [14].

In the current investigation, sepsis was found to be the most common cause of AKI at a rate of 30.6%. This finding is comparable to findings from other studies such as Nagabhushana S et al., [15], Kapadia MP et al., [16].

In the current investigation, poisoning was shown to be the second most common cause, accounting for 21.3% of all cases. In comparison to the findings of earlier investigations, the findings of our study by Nagabhushan S et al., were significantly greater. The reason may be the excessive usage of the pesticide paraquat in the areas close to the study location.

Similar to the findings of Nagabhushana S et al., and Kapadia M et al., the current our study found that approximately 19.3% of patients experienced AKI as a result of a snake bite. Because the patients who had been bitten by snakes were from rural areas, the study produced more positive outcomes.

In our study, diarrhoea was a cause of AKI in 12.7% of the patients. In contrast, diarrhoea was the cause of AKI in 10% of the cases in Nagabhushana S et al. and 11% of the cases in Kapadia MP et al. In our study, poisoning accounted for 21.3% of cases, higher than the other studies.

Obstructive uropathy accounted for 0.6% of cases in our study, whereas 6% were in Nagabhushana S et al.

Our study found that:

• 10% of patients were in the first stage of AKIN
• 7% were in the second stage
• 3% were in the third stage of AKIN.

Some of the studies that were conducted in the past were based on the AKIN criteria and the RIFLE criteria for classifying individuals who had AKI.

Utilizing the AKIN classification, a large proportion of patients (65.3%) were categorized as Stage 3 at the time of presentation the most advanced form of AKI. Only 10% of patients were identified in Stage 1, indicating a predominance of late-stage diagnosis. This distribution contrasts sharply with trends in high-income countries, where routine biochemical monitoring often leads to earlier detection and intervention. Delayed presentation in this cohort may be attributed to limited access to primary care, lack of awareness of early AKI symptoms, or financial and logistical barriers to seeking timely medical help. A multicenter study by Hoste et al. (2015)[17] highlighted the significance of early-stage AKI detection in improving outcomes.

Prognostic outcomes correlated strongly with the AKIN stage at presentation. All patients in Stage 1 and Stage 2 recovered, with only four Stage 2 patients requiring dialysis. In contrast, Stage 3 patients had a mortality rate of 42.9%, with 77.6% requiring dialysis. These statistics underscore the importance of early detection and intervention in AKI. Conservative management in early stages appears highly effective, while late-stage AKI carries a grave prognosis despite aggressive therapeutic measures, including dialysis

By applying the AKIN criteria to 320 patients, Bosen et al., 2016 were able to identify 31.3% of patients who were in the first stage of AKIN, 10.6% of patients who were in the second stage, and 58.10% of patients who were in the third stage.

Each of the fifteen patients in our study who were diagnosed with AKIN stage 1 was treated with conservative measures and made a full recovery. Thirty- seven patients in the current study were diagnosed with AKIN stage 2, and four of them received haemodialysis. In our study, the mortality was 28% and the results were similar to Gammelager et al.[18] and Joannidis et al.[19].

Of the total 150 patients, 53.3% required dialysis, underscoring the severe nature of renal impairment at the time of hospital admission. This high rate of dialysis highlights the strain on tertiary care infrastructure in regions with limited nephrology services. Dialysis availability, machine-to-patient ratios, trained personnel, and cost barriers remain significant challenges. Expanding dialysis services and ensuring equitable access are critical for improving AKI outcomes in resource-limited settings. An audit by Amino K Bello et al. (2015) [20] on dialysis delivery in Indian public hospitals revealed similar limitations.

The overall in-hospital mortality rate was 28%. Paraquat poisoning alone accounted for over 52% of these deaths, followed by complications from sepsis. The lethality of paraquat is well-documented in literature and serves as a compelling argument for policy-level intervention to ban or restrict its use. Similarly, the mortality burden from septic AKI could potentially be mitigated through better infection control, early sepsis recognition, and timely referral. A global perspective by Susantitaphong et al., (2013)[21] emphasized that mortality from AKI remains unacceptably high in low and middle income countries, primarily due to preventable factors.

According to our research findings, patients treated with conservative care and those treated with dialysis were more similar to those treated by Bernieh et al.2017.

In our study, patients who were classified as having AKIN stage 1 were treated with conservative methods, whereas patients who were classified as having AKIN stage 2 or stage 3 were treated with conservative methods and dialysis. Dialysis was only required for four patients who were at stage 2 of AKIN.

In contrast, the majority of patients who were at stage-3 of AKIN required dialysis—patients who were diagnosed with AKIN stage 3 also experienced mortality. The study found that poisoning was the most common cause of death, accounting for 52% of all deaths that occurred throughout the course of the research. It was shown that sepsis was the second most common cause of death in this study.

According to Ostermann M et al., 2007 [22].The following RIFLE class F have a death rate of 57%, while the RIFLE class R has a mortality rate of 21%, It was found that there was a correlation between acute renal damage and the result of hospitalisation. However, the severity of the AKI had a bigger influence on the prognosis than the related organ failure.

The research conducted by Hoste et al., 2008 was a retrospective study that involved 5383 patients. It was performed at a single centre with a mortality percentage of 8.8% for males and 11.4% for females. Hospital mortality was the time point that served as the endpoint for the investigation.

It was a retrospective multicentered study that was conducted by Uchino et al., and it involved the investigation of 20,126 patients hospitalised in the intensive care unit. Sr. Creatinine and GFR were the criteria that were utilized in the study. The mortality rates were R-15.1%, I-29.25, and F-41.1%, respectively

In the current single-centered study was conducted on inpatients who were admitted to the hospital. The study involved a prospective study comprising 150 patients. In patients with AKIN stage 1 and stage 2, the mortality rates were 0%, while in patients with AKIN stage 3, the mortality rate was 42.9%.

Most common etiology in our study is sepsis, followed by poisoning and snake bite. The patients are categorized based on AKIN criteria and classified into three stages. All the patients in AKIN stage 1 recovered with conservative management. All the patients in AKIN stage 2 recovered, although 10.8% required dialysis.89.2% of AKIN stage 2 patients recovered with conservative management. In AKIN stage 3, 81.6% of patients were treated with dialysis, while 18.4% of patients recovered with conservative management. In present study, 42 patients (42.85 %) died, all of them were in the third stage of AKIN. In this study, Out of 42 patients, 22 patients died due to poisoning. Poisoning was the       predominant cause     of mortality, succeeded by sepsis.

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