| Abstract|| |
To determine the incidence, etiology and outcome of acute kidney injury (AKI) at a teaching hospital in Oman, we studied all adult cases that developed AKI at our hospital from July 2006 to June 2007. Data from the hospital information system (HIS) for all adult admissions in the wards and intensive care units for the study period were obtained, and included baseline serum creatinine, serum creatinine on the day of diagnosis, peak serum creatinine, urine output in the last six and 12 hours at the time of diagnosis, etiology of acute renal failure, presence of any co-morbid conditions, and renal replacement therapy and outcome. Of the 19,738 adult admissions, there were 108 episodes of AKI in 100 patients. The incidence of acute renal failure was 0.54%. The etiology of AKI was pre-renal in 55 (50.9%), obstructive in 5 (4.6%) and acute tubular necrosis (ATN) in the remaining 48 (44.4%) patients. Renal replacement therapy (RRT) was required in 24.1% of cases. Of the patients who developed AKI, 36 (33.33%) died during same hospital admission, 37 (34.26%) recovered to discharge with no renal impairment, 32 (29.63%) recovered with residual renal impairment and 2 (1.85%) recovered with dialysis dependence.
|How to cite this article:|
Balushi F, Khan S, Riyami D, Ghilaini M, Farooqui M. Acute kidney injury in a teaching hospital in Oman. Saudi J Kidney Dis Transpl 2011;22:825-8
|How to cite this URL:|
Balushi F, Khan S, Riyami D, Ghilaini M, Farooqui M. Acute kidney injury in a teaching hospital in Oman. Saudi J Kidney Dis Transpl [serial online] 2011 [cited 2020 Jun 3];22:825-8. Available from: http://www.sjkdt.org/text.asp?2011/22/4/825/82732
| Introduction|| |
Acute kidney injury (AKI) is an important clinical complication of many diseases, procedures and treatment. There are several population-and hospital-based studies originating from different parts of the world on this issue.  However, there are only a few studies reported from the Arabian Gulf countries. , There are a few case reports of unusual etiologies of acute renal failure, but there is no published data on the incidence, etiology and outcome of AKI in Oman.
In this study, we aim to determine the incidence, etiology and outcome of AKI at a teaching hospital in Oman.
| Patients and Methods|| |
The study was designed as a retrospective, observational, descriptive study of all adults who developed AKI at the Sultan Qaboos University Hospital from July 1, 2006 to June 30, 2007. Data from the Hospital Information System (HIS) for all cases admitted to adult inpatient services with the ICD-10 diagnosis codes of acute renal failure (N17, N17.0, N17.8, N17.9), and total number of adult admissions in the wards and Intensive Care Units (ICU = Medical/Surgical Intensive Care Unit + Coronary Care Unit) for the study period were obtained. Electronic Patient Records of the identified patients were reviewed and demographic data such as age, gender, and co-morbid conditions (diabetes mellitus, hypertension and heart disease) were recorded for all patients. All repeated episodes of AKI in the same patient were studied as separate events. Patients with chronic renal impairment, who developed superimposed AKI, were also included. The diagnostic criteria of acute renal failure were set as following:
Data pertaining to AKI, such as baseline serum creatinine, serum creatinine on the day of diagnosis, peak serum creatinine, urine output in the last six and 12 hours at the time of diagnosis, etiology of acute renal failure (as recorded by treating nephrologists) and presence of sepsis, hypotension, medications-including inotropes, renal replacement therapy and outcome, were also recorded.
- Urine output less than 500 mL per 24 hours.
- Increase in serum creatinine by more than 50 ΅moles during admission.
- 50% increase in serum creatinine with documented reduction in urine output.
- Serum creatinine more than the upper limit of normal (when baseline serum creatinine was not known) and improved to within normal range or more than 50 ΅mol/L.
| Results|| |
There were 19,738 adult admissions (n=1,373 in ICU) during the study period. There were 110 episodes of acute renal failure recorded in 100 patients. Two episodes were excluded due to incomplete data. The characteristics of the patients with acute renal failure are shown in [Table 1]. Of the total studied cases, there were 79 episodes of AKI in the general hospitalized patients and 29 in the patients in the ICU. The mean age of the patients with AKI was 61.4 years; 60.2% (n=65) were males. The majority of patients had significant co-morbid conditions such as, diabetes mellitus (n=55; 50.9%), hypertension (n=58; 53.7%) and heart disease (n=55; 50.9%). The incidence of AKI was 0.54% of all the patients and 2.11% of ICU admissions. The etiology of AKI, as determined by the treating nephrologists, was pre-renal (n=55; 50.9%), obstructive (n=5; 4.6%) and acute tubular necrosis (ATN) in the remaining (n=48; 44.4%) patients. The etiology of ATN in these patients was sepsis, hypotension, medications, and multi-factorial.
The urine output was not recorded in 65 (60.2%) of the cases. However, 20 (18.5%) cases were non-oliguric (urine output more than 500 mL/24 hours), 19 (17.6%) were oliguric (urine output less than 500 mL/24 hours) and four (3.7%) were anuric (less than 100 mL/24 hours).
Renal replacement therapy (RRT) was required in 26 (24.1%) of cases. Two cases required dialysis but were not included in the RRT group as one patient died after the decision to initiate dialysis was made and before RRT was started. The family of a second patient refused RRT and the patient was considered not for resuscitation or RRT. The duration of dialysis required before recovery of renal function or death was less than seven days in 18.5% of AKI [20 (74.1%) of all patients requiring dialysis], 8-14 days in 2.8% (three (11.1%) of all patients requiring dialysis], and 15-20 days in 0.9% (n=1 or 3.7% of all patients requiring dialysis); only 1.9% of the cases [two (7.4%) of all patients requiring dialysis] remained dialysis dependent.
Of the patients who developed AKI, 36 (33.3%) died during the same hospital admission, 37 (34.3%) recovered to discharge with no renal impairment, 32 (29.6%) recovered with residual renal impairment, 2 (1.85%) recovered with dialysis dependence until discharge, and one (0.93%) patient left against medical advice.
The incidence of AKI in the ICU in our study was 2.11% (n=28). Renal replacement therapy was required for 60.7% (n=17) in those developing acute renal failure in the ICU compared to 11.2% (n=9) in the wards. There were no cases of obstructive acute renal failure in the ICU settings. The incidence of pre-renal AKI was 53.6% in ICU versus 50.0% in wards, and ATN was 46.4% in ICU versus 43.8% in wards with no statistical difference. Mortality was much higher in the ICU patients (n=22; 78.6%) compared to those in the wards (n=13; 16.2%). Septic ATN was much common in the ICU patients (n=18; 64.3%) compared to the patients in ward (n=12; 15%).
| Discussion|| |
The incidence of acute renal failure in hospitalized patients in our institution was 0.54% in all patients and 2.11% of ICU admissions. The incidence and outcome of patients with AKI has varied significantly in the different studies. Liangos et al recently described the epidemiology and outcomes of acute renal failure in a national survey of hospitalized patients in the United States. They found an incidence of 19.2 per 1,000 hospitalizations.  Furthermore, they found that AKI was more commonly coded for in older patients, male gender, black race, and in the setting of chronic kidney disease, congestive heart failure, chronic lung disease, sepsis, and cardiac surgery. Rashed et al, in their six-month pilot study at a hospital from Qatar, reported an incidence of 0.49% (55 cases out of 11,216 admissions).  Abraham et al reported an incidence of 1.3% and Al-Homrany reported an incidence of 5.7% in hospitalized patients from Kuwait and southern Saudi Arabia, respectively. , While describing the changing epidemiology of acute renal failure around the globe in their review article, Lamiere and colleagues have observed an incidence of acute renal failure ranging from 1.3/1,000 admissions to 91/1,000 admissions per year in hospitalized patients.  There are several factors which may determine the incidence of AKI in the hospital settings. These factors include the population served by the hospital ("catchment area"), number of hospital beds per million population, demographics of the population (age, race, etc.) and the definition of AKI. The etiology of AKI varies in the different parts of the world. Obstetric complications, , diarrhea,  snake bite ,,, and infections such as malaria , are still the common causes of AKI in the developing countries.
AKI develops more commonly in the critical care setting. It is well known to be associated with sepsis, hypotension and use of medications in critically ill patients. ,, Bagshaw et al studied the incidence and outcome for early AKI in a cohort of Australian intensive care units and reported an estimated crude cumulative incidence of 5.2%.  They also reported increasing incidence of AKI during the study period. The crude hospital mortality for patients with AKI was 42.7% versus 13.4% in those who did not develop it. Cruz et al studied the incidence and outcome of acute renal failure in the intensive care unit in a multicenter study using the RIFLE criteria. In their study, 10.8% of the ICU patients developed AKI (19% were classified as risk, 35% as injury and 46% as failure). ICU mortality was 20% in the risk, 29.3% in the injury, and 49.5% in the failure class. Similarities in the observed figures in our study population and those reported from Saudi Arabia and Qatar are possibly due to similar population demographics and health care services. Inpatient and hospital-based studies do not reveal the true burden of the disease for the given community. The population-based studies from the region may define the disease burden more accurately. Such studies, however, do aid in resource planning for individual hospitals.
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Consultant Nephrologist, Department of Medicine, Sultan Qaboos University, P. O. Box 35, Al-Khoud 123