Influência do diabete melito na morbidade e mortalidade da insuficiência renal aguda em unidade de terapia intensiva

Abstract

Acute Renal Failure can be defined as an abrupt and sustained reduction in the glomerular filtration rate with a consequent retention of nitrogenous waste products. Despite the development in treatment, mortality remains high, varying beetween 50 and 70%. In hospitalised patients the incidence is about 5% but in respect to intensive care units it varies from 10 to 30%. In the last three decades, the characteristics of patients who suffer from acute renal failure changed dramatically. Before the advent of dialytic treatment, the main causes of mortality were uraemia, hyperkalaemia and the cardiac complications arising from volume overload. Nowadays, the causes are sepsis, cardiopulmonary failure, nephrotoxic drugs, and post renal transplantation complications. Multiple organ dysfunction, disseminated intravascular coagulation and diabetes mellitus are morbid conditions that can aggravate the prognosis of acute renal failure in intensive care units. Due to the high prevalence of diabetes mellitus in the population, this study intends to evaluate its influence in the morbidity and mortality of patients suffering from acute renal failure in the intensive care unit of Hospital de Base of São José do Rio Preto, Brazil was made in the period from January 1997 to December 2000. A total of 255 (25%) of the patients were diabetic and 765 (75%) were not. Demographic data, the presence of underlying diseases, aetiology, types, the clinical features and complications of acute renal failure were evaluated. Besides these, the presence of multiple organ failure syndrome was observed. In the study population 64% were male, 46% were more than 60 years old and 85% had one or more concomitant diseases. The ischaemic aetiology predominated in 53% of cases and a clinical cause was the most common type seen at 57%. The means and standard deviations of the Apache II score and creatinine levels (mg/dL) were 20.5 + 6.7 and 3.7 + 2.0 respectively. The prevalence of disseminated intravascular coagulation, shock, liver failure and respiratory failure were 32%, 69%, 15% and 79% respectively. Among the observed complications hyperkalaemia was seen in 35%, acidosis in 70%, sepsis in 61%, systemic arterial hypertension in 14%, bleeding in 22%, central nervous system disfunction in 44% and mortality in 71% of the cases. The demographic data, clinical features, morbidity and mortality due to acute renal failure of diabetic and non-diabetic individuals were compared. The hyperkalaemia, acidosis, respiratory failure, shock, central nervous system dysfunction, hypervolaemia and the bleeding were similar in both groups. A logistic regression analysis did not demonstrate a significant association between diabetes mellitus and mortality. An ischaemic aetiology, the failure of three or more organs, hyponatraemia and acidosis exhibited significant association between mortality and acute renal failure. In conclusion, the diabetic patients were older involving fewer men, with less oliguria, disseminated intravascular coagulation, hyponatraemia and liver failure than the non-diabetic individuals. Diabetes mellitus had no influence on the mortality due to acute renal failure in the intensive care unit.