Preoperative nutritional evaluation of elderly patients: the Mini Nutritional Assessment as a practical tool

Abstract

Background and goal: Age and malnutrition are each surgical risk factors. Because the Mini Nutritional Assessment (MNA) has been specifically designed for assessing the nutritional status of elderly patients, it can be used for preoperative nutritional evaluation. Therefore, the MNA was included in the preoperative clinical evaluation of patients over 60 years of age to describe their nutritional status.

Methods: Every patient over 60 years of age, scheduled for elective surgery, was seen in anaesthesiology consultation and was submitted to the MNA. The MNA is a clinical score consisting of four additive items: 'Anthropometric assessment' based on BMI, mid-arm and calf circumferences, weight loss; global evaluation; dietetic assessment, and subjective assessment - these last three items being obtained through a specific questionnaire. It requires no biological marker. Awarding to the obtained score, the MNA stratifies patients in the following categories: well-nourished (24 </= MNA </= 30), at risk of malnutrition (17 </= MNA < 23.5), and undernutrition (MNA < 17). Also recorded were: age, gender, type of scheduled operation, and the American Society of Anesthesiologists (ASA) physical status score. Results are given as median (extremes).

Results: Four hundred and nineteen patients (50.4% women) were seen between January and October 1996. The mean age was 72 years (range, 60-98 years); BMI: 25.2 (12.8-40.4) kg m(-2). The MNA score was recorded in 408 patients, ranging from 1.5 to 30 (median: 26). According to the score, the patients were stratified in: well-nourished, 276 patients (67.6%), at risk, 104 patients (25. 5%) and suffering from overt malnutrition, 28 patients (6.9%). According to the ASA score, 290 patients were found to be at low or mild risk for anaesthesia and surgery (ASA 1 and 2), and 72 patients (24.8%) were stratified as being at least at risk of malnutrition. One hundred and eighteen other patients were found to be at a higher risk (ASA 3 and 4), and 58 (49.2%) were not well-nourished (MNA < 24).

Conclusion: The MNA was found to be well-suited for the preoperative assessment during anaesthesia consultation because it required no biological marker. It showed that approximately one-third of all the examined patients, and half of the ASA 3-4 patients, were not well-nourished. The ASA score could not predict poor nutritional status. The results suggested that nutritional assessment should be routinely performed in ASA 3-4 patients over 60 years of age.