Objective: Actual fluid intake in the institutionalized elderly was compared with three established standards to determine adequacy of fluid intake.
Design: Consecutive 3-day food and fluid intake was observed directly and analyzed by computer for water content. Number and frequency of medications and Minimum Data Set (MDS) information about cognitive skills, physical locomotion, and ability to understand were obtained from medical records. Recommended fluid intake was determined using three established standards for two age groups: 65 through 85 years and 86 through 100 years. The standards were 30 mL/kg body weight (standard 1); 1 mL/kcal energy consumed (standard 2); and 100 mL/kg for first 10 kg, 50 mL/kg for next 10 kg, and 15 mL for remaining kg (standard 3).
Subjects/setting: Data were collected in one nursing home. Subjects were 40 residents who were free from acute illness and infection and/or were not receiving enteral feedings.
Main outcome measures: Fluid intake and MDS data were collected. Data about medications were obtained after preliminary data collection observations.
Statistical analysis performed: A two-tailed t test was used to compare actual fluid intake with recommended fluid intake. Interaction effect of age on fluid intake was analyzed using multiple analysis of variance. Correlations were used to evaluate relationships among fluid intake, number and frequency of medications, age, weight, and MDS data.
Results: This population received adequate or more than adequate fluid according to the standards of 30 mL/kg body weight or 1 mL/kcal energy consumed, but inadequate fluid according to standard 3, which adjusted for extremes of underweight or overweight. Age was not a factor in adequacy of fluid intake. Positive correlations existed between fluid obtained from nonmeal feedings and number and frequency of medications.
Applications: When the standard of 30 mL/kg body weight is used, underweight residents have unrealistically low fluid recommendations. Standard 3, which adjusts for extremes in body weight, is more reasonable for patients whether they are of normal weight, underweight, or overweight. This standard more closely supports other recommendations of 1,500 to 2,000 mL fluid intake per day. Number and frequency of medications influences the amount of fluid residents obtain during nonmeal feedings.