Protein-calorie malnutrition and lymphocytopenia as predictors of hospitalinfection in the elderly

BACKGROUND: Clinical and epidemiological studies have established that maln utrition is a risk factor for infection in patients being submitted to surg ery. To date no study has been carried out to establish the association bet ween the nutritional condition and the incidence of hospital-acquired infec tions in patients in the medical area. We study the incidence of hospital-a cquired infections in the elderly in an attempt to determine the rate of th is infection and its association with protein-calorie malnutrition. Another aim of this study has been to determine the predictive value of the parame ters used to evaluate the patient's state of nutrition and immunity. PATIENTS AND METHOD: We included 240 patients over 64 years old, 118 males and 122 females, admitted to the medical area of a general hospital. The nu tritional and immunity condition of the patients was evaluated through dete rminations of weight, height, body mass index, hypoalbuminemia and total ly mphocyte count. The psichophisical degree of dependence was evaluated throu gh of Norton scale. The details on the hospital infections came from a clin ical and microbiological follow-up of patients, in accordance with the crit eria of the Centers for Disease Control of Atlanta. RESULTS: The frequency of protein-calorie malnutrition was 12.5% and the ac cumulated incidence of hospital-acquired infections was 19.6%. Functional i ncapacity of the elderly prior to hospitalization (odds ratio, 4.70; 95% CI : 1.1-19.0) as well as the presence of certain extrinsic risk factors (odds ratio, 2.35; 95% CI: 1.1-5.1) were, in addition to hypoalbuminemia (odds r atio, 3.60; 95% CI: 1.3-10.2) and lymphocytopenia (odds ratio, 2.67; 95% CI : 1.3-5.7), the independent variables that showed the most significant asso ciation with the incidence of hospital-acquired infections. CONCLUSIONS: The nutritional parameters associated with the immune system d etermined greater risk of hospital-acquired infections among elderly patien ts admitted to the medical area of a hospital. The initial evaluation of el derly patients hospitalitzed in accordance whit the psychophysical degree o f dependence based on the Norton scale is useful to evaluate those patients who were at greater risk for hospital infections.