|Protein-Energy Interactions (IDECG, 1991, 437 p.)|
|Effects of disease on desirable protein/energy ratios|
Most acute infections are self-limiting, and specific antimicrobial therapy now exists for most infectious illnesses. For some diseases, however, clinical recovery may be delayed and nutritional support becomes a significant consideration. Persistant diarrhea, i.e., episodes lasting longer than 15 days, follows from 10 to 20% of acute episodes depending on the location (WHO, 1980).
The majority of these episodes do not have a dramatic symptomatology but are nevertheless associated with severe weight loss and malnutrition. Such individuals have considerable limitation in their capacity to digest and absorb nutrients, and some may require parenteral nutrition to stabilize and improve their nutritional status. However, it is important to feed them as much as possible by mouth, if necessary using predigested formulas or continuous tube feeding. The aim is to provide adequate nourishment to facilitate prompt recovery of the intestinal mucosa.
A certain proportion of children with acute diarrhea! disease of nonspecific cause have persistent carbohydrate intolerance and develop a much more severe and prolonged nutritional deficit (ROSENBERG and SCRIMSHAW, 1972).
There are some infections for which specific therapy is not effective and which have long-term and sometimes severe consequences for nutritional status. Most prominent of these is the current pandemic of Acquired Immunodeficiency Syndrome (AIDS). The malnutrition of AIDS has multiple etiologies. AIDS is a viral infection producing a systemic response that includes anorexia, fever and weight loss that initially responds to specific retroviral therapy with azothymidine (AZT) or dideoxyinosine (DDI). In addition to the adverse impact of the systemic response on nutritional status, involvement of the gastrointestinal mucosa with the virus may contribute further to the malnutrition (HUANG et al., 1988).
Patients with AIDS develop superimposed infections that do not normally produce symptoms in immunocompetent hosts. Gastrointestinal infections such as with Isospora Microsporidia, Mycobacterium avium intracellulare or cryptosporidia produce severe diarrhea and malnutrition in AIDS for which antimicrobial therapy is of limited effectiveness. A limited number of such patients (usually less than 10%) may benefit from home enteral or parenteral feeding (KOTLER et al., 1989; 1991).
There are a number of illnesses commonly seen in AIDS patients for which chemotherapy is more effective such as Pneumocystis carini, toxoplasmosis, cytomegalovirus, herpes simplex and tuberculosis. In these diseases the treatment in the hospital may be sufficiently long and difficult that enteral or parenteral alimentation may become necessary. This is especially likely in the patient who has an altered state of consciousness or requires mechanical ventilation.
A second common clinical syndrome is that of nosocomial pneumonias or intra-abdominal infections that develop in critically ill patients following surgery or other critical conditions such as pneumonia, major gastrointestinal bleeding, trauma, acute inflammatory disease of the intestine and pancreas or chronic organ insufficiency (liver, heart, lung, kidney). The organisms often found in these situations are or become resistant to multiple antibiotics. In such patients the clinical course may be quite prolonged and the septic syndrome can be profoundly catabolic. This general category of patient is the most common indicator for parenteral and enteral nutrition in the hospital setting.