If a patient is screened for malnutrition at hospital admission, a dietetic consult might not be necessary at that time. However, later on, based on clinical signs of malnutrition, the patient can be send to a dietician to perform a nutrional assessment. The dietician decides wether a full nutritional assessment is needed. If the patient is screened on the ward by using a validated screening tool, this extra screening is just a formality.
To assess the risk of malnutrition, the following objective parameters are used: Body Mass Index (BMI), weight loss percentage, intake and losses and biochemical parameters.
Body Mass Index
The Body Mass Index (BMI) is calculated on the basis of a measured length and weight. One uses the following formula: weight in kg / (Height in meters) ². The BMI is influenced by age, gender, race and the amount of muscle mass.
Weight loss percentage
Desired and undesired weight loss can lead to malnutrition, f.e. in anorexia and after a gastric reduction surgery. For the calculating the percentage of weight loss, one uses the following formula: (current Weight - start weight) / usual weight * 100%. The lute standard as follows: More than 5% weight loss within one month or more than 10% weight loss within 6 months are an indicator of malnutrition. If the patient can not be weighed on a normale scale, a weighing chair, or bed can be used. The weight loss percentage is not a usefull tool in patients with edema, ascites or dehydration.
Percentage weight loss
Intake and losses
More than 5 days of no or minimal food intake may indicate (a risk for) malnutrition. Read more about intake and losses on this page.
Think about inflammatory parameters in regular care, such as albumin. The albumin level can be used to estimate how ill a patient is, and/or to determine the visceral protein reserves. The normal value the Maastricht UMC + uses for adults, is 35.0 - 45.0 g / l. If a patient has a lot of inflammatory markers in the blood, this isn't necessary caused by a decreased food intake; an infection can also be the cause of the loss of body cell mass. Therefore, several parameters of inflammation are used, like lymphocytes, pre-albumin, transferrin, CRP, HB and erythrocyte sedimentation rate. Read more about biochemical parameters on this page.
Subjective Global Assessment
A Subjective Global Assessment (SGA) can also be used to assess the nutritional status. With the help of a patient's medical anamnesis, a diet amnamnesis and a few simple observations, the general nutritional status can be assessed. This method is not used by dieticians of the Maastricht UMC +. Criteria are:
- (estimated) weight loss in the last six months;
- certain diseases and therapies that provide a reduced intake of nutrients;
- increased losses;
- metabolic stress;
- a combination of these risk factors.
A number of studies show that by means of this SGA method, (para) medics and even less experienced persons can reproduce these results. Here is an example of a SGA.
The dietician does not undertake any action if the following conditions are met:
- The patient has no risk-disease and/or will get a big surgery or risky therapy in the near future;
- The patient has no malabsorption or long lasting diarrhea;
- The patient has a normal bodyweight: a BMI >20;
- The patient did not loose more than 5% of his bodyweight in one month or 10% in 6 months;
- The patient has a sufficient food-intake;
- The patient does not have elevated inflammation parameters in his/her blood.
Oedema or dehydration
Be alert to oedema or dehydration:
- By pressing a finger the skin of arm or leg, it is possible to check oedema. The skin stays in the pushed down position.
- By taking the skin between thumb and finger, it's possible to check whether the patient is dehydrated. The skin stays in the upright position.