Abstract
In literature, there was little data about frequency and outcomeof ARF with two or more causes in etiology. Therefore, the aim of this studywas to search this issue.
This series included 339 patients with ARF from Jan 1,1987 to Jan 1,1999.Fourty-six (30 males) of all patients (13.5%) had two or more causes in etiologyof ARF. Of these patients, causes were prerenal and renal in 26 (56%), prerenal,renal and postrenal in 12 (26%), renal and postrenal in 4 (9%), and prerenaland postrenal in 4 (9%). The most frequent cause is diarrhea and vomitingin prerenal, gentamycin usage in renal and prostat hypertrophy in postrenal.Of these patients, there was oliguria in 32 (70%), anuria in 8 (17%) and non-oliguriain 6 (13%). Treatment modalities of patients was only medical in 19 (41%),dialysis in addition to medical therapy in 27 (59%). In spite of treatment,5 (10.8) of patients with two or more causes in etiology died. Causes of deathwere uremic coma in 2, cardiac disorders in 2 and septic shock in 1. Three(11.2%) of other patients with one cause died. Mortality rates were not different(χ2: 0.0298, p> 0.5). Cortical necrosis was diagnosed in one patient with multiplee etiologyand 2 of other patients.
Finally, frequency of ARF with two or more etiologic causes was 13.5%,and most frequent causes were hypovolemia and nephrotoxic drugs. Outcome ofthese patients was similar to other patients with one cause.
INTRODUCTION
In etiology of acute renal failure (ARF), there is whichever renal ischemia(prerenal), renal parenchimal disorder (renal), or urinary tract obstruction(postrenal) Citation[[1]]. To facilitate diagnosis andexpedite intervention it is divided the differential diagnosis into prerenal,postrenal and intrinsic renal failure Citation[[2]].In addition, one factor predictive of outcome in ARF is the nature of theunderlying illness that precipitated the renal failure. As the support thisresult, it was noted that mortality was lowest obstetric patients (5% to 10%),highest in acute tubular necrosis associated with surgery or trauma (50% to60%) and intermediate (35% to 40%) in patients with nephrotoxic ARF Citation[[3]]. There is little literature knowledge about frequencyand outcome of patients with several of these different causes. In recentdata, explaining etiology of acute tubular necrosis, the present of multipleecauses has been emphasized Citation[[4]]. Also, it wasreported that hospital-acquired ARF occured usually due to multiplee etiologicalcauses Citation[[5]].
The aim of study is to establish frequency and outcome in patients withARF, have causes more than one.
PATIENTS AND METHODS
This study included 339 patients with ARF admitted to our clinic betweenJan 1, 1987 and Jan 1, 1999. ARF was diagnosed by medical history, physicalexamination and laboratory findings.
Fourty-six (30 males, 16 females) of all patients (13.5%) had more causesthan one. That is, they had multiplee etiology. However, other patients (n= 293) had one of etiologic cause.
The patients with multiplee etiology applied directly our clinic (n= 12, 25%), or they were sent to our clinic after treated by short-time hospitalizedor outpatient in other medical centers (n = 34, 75%). Etiologic causes ofthese patients were hypovolemia, obstetric, intraoperative and post-renaldisorders. Their etiologic causes were separated as prerenal, renal and postrenalby based on classical data Citation[[6]]. Mean age was55 ± 18 years in these patients and 40 ± 17 years in other patients(n = 293). Of the patients with multiplee etiology, oliguria in 32 (70%),anuria in 8 (17%) and non-oliguria in 6 (13%) were established. In addition,mean fractional sodium excretion and renal failure index of these patientswere 2.5% and 3.4, respectively. That is, they had renal tubular damage. Nineteenpatients (41%) were treated only medically, whereas 27 patients (59%) weretreated by dialysis together with medical therapy. Dialysis procedure washemodialysis in 23 patients (85%) and peritoneal dialysis in 4 patients (15%).In medical therapy, iso-osmolar fluid infusion to replace fluid to dehydratedpatients, 2 microgram/kg. body weight/min. infusion of Dopamin to increaseblood coming to renal tubules and 120 mg to 240 mg infusion of Furosemid and15 g to 20 g infusion of Mannitol to force diuresis in oliguric patients weredone; in addition, solutions included essential aminoacids, 10% to 20% Glucoseand 10% to 20% Lipid were given to catabolic patients. In patients with post-renaldisorders, urethra or ureter cathater were placed, or nephrostomy was percutaneouslydone.
Findings were statistically interpreted by student's t-test (unpaired)and chi-square test corrected by Yates in SPSS (5.0.1).
RESULTS
Mean age of the patients with multiplee etiology was higher than thoseof other patients (p > 0.001). Causes leadingto ARF in patients with multiplee etiology were prerenal and renal in 26 patients(56%), prerenal, renal and postrenal in 12 patients (26%), renal and postrenalin 4 patients (9%), and prerenal and postrenal in 4 patients (9%). However,some patients had more than one of prerenal or renal or postrenal causes.Number of causes in etiology was 2 in 33%, 3 in 50%, 4 in 2% and 5 in 4% ofthe patients. They are seen following .
Table 1. Causes in ARF with multiplee etiology
In the patients with multiplee etiology, oliguria or anuria replacedpoliuria after mean 7 ± 5 days (range:3–26). Thus, BUN and serumcreatinin levels decreased normal levels in mean 13 ± 6 days (range:7–34)after they hospitalized.
5 (10.8%) of these patients died in spite of treatment. However, 3 (11.2%)of other patients with one cause in etiology died. Mortality rates of thesegroups were not different (χ2 = 0.0298, p > 0.5). Etiology of died patients with multipleeetiology was prerenal and renal in 4 and prerenal, renal and postrenal in1. Causes leading to death in these patients were uremic coma in 2, cardiacdisorders in 2, septic shock in 1.
Irreversibl renal failure due to cortical necrosis was diagnosed in1 of patients with multiplee etiology and 2 of other patients.
DISCUSSION
Frequency of ARF with multiplee etiology was reported 47% by Davidmanet al., 65% by Rasmussen and Ibels and 12% by Hou et al. (5,7,8). It was pointedout as 13.5% in the present study. Difference of these rates may be dependingon age, etiology and co-morbid conditions of the patients.
Rasmussen et al. and Davidman et al. were investigated patients withhospital-acquired ARF. Multiplee causes in etiology were hypovolemia, nephrotoxicdrug usage and chronic renal failure in study of Davidman et al., and weredehydration, sepsis, aminoglycoside, or radiocontrast usage, pigmentüriand hepatic disorders in study of Rasmussen et al. That is, causes were prerenaland renal, and nephrotoxic drugs are seen as significant cause in two groups.In addition, in 57% of these patients, ARF had been occured at a surgicalprocedure. However, Hou et al. did not explain in detail multiplee causes.As seen previous studies, the most frequent multiplee etiology was prerenaland renal in the present series.
The patients with multiplee etiology were older than other patientsin both Davidman et al. series and the present study. In ARF with multipleeetiology, it was suggested in a study that age was a significant factor Citation[[9]], but another study defended that age was a non-significantfactor Citation[[7]]. That is, there was not agreementof opinions.
In the present series, 95% of the patients had oliguria or anuria. However,this rate was reported as 20% by Hou et al., 13% by Davidman et al. and 55%by Rasmussen and Ibels Citation[[5]], Citation[7-8].In these series, nephrotoxic drugs plays an important role in etiology ofARF. Therefore, oliguria or anuria rate may be lower than those in the presentseries, because nonoliguric ARF is common after aminoglycoside nephrotoxicityand administration of radiocontrast dye Citation[[3]].Furthermore, number of causes leading to ARF was important in formation ofoliguria, because there is additive interaction among causes Citation[[7]]. Rasmussen and Ibels noted that number of causes inetiology was 2 in 45%, 3 in 17% and 4 in 3% of patients Citation[[7]].In the present series, these numbers were higher. For example, three causesin etiology were 50% of the patients. Therefore, patients of the present seriesmay possess high frequency of oliguria.
In the present series, 63% of the patients were treated by dialysis.This rate was reported 49.6% by Rasmussen and Ibels and 13.5% by Davidman.Discordance of these rates may be due to difference of frequency of oliguria,because patients with oliguria need more dialysis treatment than patientswith non-oliguria Citation[[7]].
In patients with ARF, has multipleee etiology, mortality rate was reported29% by Hou et al., 53% by Rasmussen and Ibels and 12% by Davidman et al.This rate was 13.5% in the present series. If all of patients with ARF investigate,mortality rate was between 7% and 80% Citation[[1]].These differences of mortality rates may be depending on causes in etiology,severity of illness and added other diseases. For example, in Davidman etal. series, most frequent etiologic causes were dehydration and drugs, leadingto low mortality rate. In addition, the greater part of patients had nonoliguria.In general, nonoliguric ARF has a better prognosis, possibly because it inducemilder degrees of renal injury Citation[[3]]. On thecontrary, in Rasmussen et al. series, most frequent etiologic cause was surgicalevents, leading to high mortality. Dehydration and drugs were significantetiologic causes in the present series. Therefore, mortality rate was similarto that of Davidman et al. series.
Finally, patients with ARF due to multiplee etiology were older andtheir the most frequent etiologic causes were established as hypovolemia andnephrotoxic drug. Outcome of these patients was similar to other patientswith one cause.
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