Severe undernutrition nearly always leads to marked changes in body spaces (e.g., alterations of intra-extracellular water) and in body masses and composition (e.g., overall and compartmental stores phosphate potassium, magnesium). Hemodynamic instability, severe volume derangement, electrolytic disturbances, hypoglycaemia, hypothermia and bone marrow depression are common in severe undernutrition [1
]. If the caloric deficiency is severe and enough prolonged adults can lose up to half of their body weight, and body mass index decreases to 13 kg/m2
or less. Severe undernutrition affects every body area: digestive system, cardiovascular and respiratory systems, reproductive system, nervous system, muscle, blood, metabolism and immune system [2
Nutritional support can be regarded as a graded process developing through different levels which are not necessarily to be considered mutually exclusive: (1) improving energy and nutrient intake from ordinary food; (2) oral nutritional support (sip feed); (3) artificial nutrition choosing enteral nutrition (EN) as preferred route of feeding if there is a functional, accessible gastrointestinal tract [8
Refeeding of severely malnourished patients represents two very complex and conflicting tasks:
- avoid “refeeding syndrome” caused by a too fast correction of malnutrition [13,14,15];
- avoid “underfeeding” caused by a too cautions rate of refeeding.
These patients suffer from poor myocardial contractility and circulatory volume should be evaluated with care. Electrolyte disturbances and vitamin deficiencies are quite frequent, and during refeeding these derangements can actually arisen or aggravate.
Nutritional support in severely undernourished patients has main objectives: (1) to restore lean body mass; (2) to preserve or restore immune function; (3) to contrast or avert metabolic complications; (4) to attenuate oxidative cellular injury and metabolic response to stress or starvation; (5) to prevent heart failure and respiratory failure.
Caring for severely starved patients and re-starting nutrition requires close monitoring seeking for early signs or symptoms of refeeding syndrome and a specialized care plan.
In the more complicated cases, i.e., patients with extreme undernutrition and life threatening weight loss or patients unable or unwilling to consume an adequate oral diet, there is the indication to start artificial nutrition.
To avoid “refeeding syndrome” and to avoid “underfeeding” of these critical and severely undernourished patients, the caloric intake should be planned starting with indirect calorimetric measurements, because resting energy expenditure (REE) is the main component of daily expenditure particularly in severely undernourished patients [16
If this measurement is not possible, we should estimate energy needs with the Harris Benedicts formula considering that in patients without inflammatory complications the energy need is 70–80 percent in respect to the estimated value [18
Although there is a general consent regarding crucial nutritional rehabilitation, there are only few studies that report artificial nutrition in severe undernutrition. Given the recognized difficulties in conducting randomized clinical trials in these critical patients, evidence-based guidelines for use of enteral or parenteral nutrition are lacking.
In order to make a choice, we should consider the two following points:
- The international guidelines on the use of artificial nutrition state that “if the gut works you must use it”.
- In the majority of critically ill patients the preferred way of feeding is EN, because it is safer compared to parenteral nutrition as it is well documented in numerous prospective randomized controlled trials involving the effects of critical illness on mortality. The most consistent outcome effect of EN is a reduction in infectious morbidity, a positive impact on the duration of treatment and a normalization of the endocrine and metabolic status .
The aim of this paper is to discuss the modality of refeeding severe undernourished patients by EN and to present our experience with the use of enteral tube feeding for the gradual correction of very severe undernutrition while avoiding the refeeding syndrome.