Energy Balance in Elderly Patients after Surgery for a Femoral Neck Fracture

Abstract

To study energy and protein balances in elderly patients after surgery, spontaneous energy and protein intake and resting energy expenditure (REE) were measured in 20 elderly female patients with a femoral neck fracture (mean age 81 ± 4, SD, range 74-87 years; weight 53 ± 8, range 42-68 kg) during a 5-6 day period following surgery. REE, measured over 20-40 min by indirect calorimetry using a ventilated canopy, averaged 0.98 ± 0.15 kcal/min on day 3 and decreased to 0.93 ± 0.15 kcal/min on day 8-9 postsurgery (p < 0.02). REE was positively correlated with body weight (r = 0.69, p < 0.005). Mean REE extrapolated to 24 hr (24-REE) was 1283 ± 194 kcal/day. Mean daily food energy intake measured over the 5-day follow-up period was 1097 ± 333 kcal/day and was positively correlated with 24-REE (r = 0.50, p < 0.05). Daily energy balance was -235 ± 351 kcal/day on day 3 (p < 0.01 us zero) and —13 ± 392 kcal/day on day 8-9 postsurgery (NS us zero) with a mean over the study period of -185 ± 289 kcal/day (p < 0.01 us zero). When an extra 100 kcal/day was allowed for the energy cost of physical activity, mean daily energy balance over the 5-day study period was calculated to be -285 ± 289 kcal/day (p < 0.01 us zero). Measurements of total 24-hr urinary nitrogen (N) excretion were obtained in a subgroup of 14 patients. Calculated net protein oxidation was 56.0 ± 19.5 and 61.7 ± 25.6 g/day on day 3 and on day 8-9, respectively. Spontaneous protein intake on the other hand was only 38.1 ± 16.6 on day 3 and 36.9 ± 15.2 g/day on day 8-9 ( p < 0.01 and p < 0.001 us protein oxidation for the two periods, respectively). Net protein balance averaged -17.3 ± 22.9 g/day on day 3 and -24.3 ± 16.5 g/day on day 8-9. It is concluded that elderly patients with a femoral neck fracture do not adequately adjust their spontaneous food intake to meet their energy and protein needs. The results support the view that such patients would benefit from an oral supplementation above their spontaneous food intake providing an extra 200-300 kcal/day containing 20 g of protein/day. (Journal of Parenteral and Enteral Nutrition 14:563-568, 1990)