Hyperalimentation solutions

Phosphorus, 12 to 15 mmol/L, should be routinely added to hyperalimentation solutions to prevent hypophosphatemia. 

In 1978, on the basis of a few measurements of urine calcium and phosphate excretion as well as an awareness of the previously mentioned work regarding the amounts of calcium and phosphate normally accreted in utero and postnatally, it became apparent that the demineralization, fractures and rickets we were seeing in our infants were caused by calcium deficiency. Consequently we increased the amount of calcium added to the parenteral alimentation solutions. If more than 12.5 mM of the calcium were added to a liter of hyperalimentation solution, gross precipitation would occur in the feeding solution. If 10 mM of calcium were added per liter, crystalline precipitated began to build up on the inside of our barium-impregnated silicone rubber central venous catheters. This crystalline precipitate resulted in gradual occlusion and functional loss of these lines. After several false starts and six lost catheters, chemical and crystal analysis showed that the precipitate inside these catheters was CaHPO. ... 

Figure 3. Interaction among pH, calcium, and phosphate in hyperalimentation solutions. The pH, calcium values to the right of phosphate isoconcentration curves are associated with precipitation of dibasic calcium phosphate, while pH, calcium values to the left of phosphate isoconcentration curves are associated with solubility of calcium and phosphates in hyperalimentation solution.

The intravenous route is used to deliver larger volumes (e.g. replacement and hyperalimentation solutions). Positioning catheters in a central vein s blood flow avoids multiple injections in seriously ill patients. Rapid dilution occurs compared to injection in peripheral veins. In the latter, infiltration, phlebitis due to osmolarity, pH and the characteristic of the drug and excipients can damage the vessels and lead to the loss of veins for therapy. Other common risks encountered with intravenous administration include activity restriction, impact of normal fluctuations in feeding, activity and sleeping patterns, the pulling out of intravenous lines by the patient, infection and extravasion. 

Figueredo, J. V., and Kaminski, M, V., 1979, Iron dextran in intravenous hyperalimentation solutions in the treatment of iron deficient anemia, J. Parent. Enter. Nutr. 3 509. 

A unit of pediatric hyperalimentation solution capable of providing the daily nutrient requirements for the average newborn infant can be formulated readily in the United States from commercially available products. The combination of 400 ml of 5% protein hydrolysate or crystalline amino acids with 250 ml of 50% dextrose produces a solution which contains approximately one calorie per ml. 

Fig. 5. Hyperalimentation solution is delivered to the infant continuously and accurately by means of a constant infusion pump. A 0.22 micron membrane filter is inserted between the central venous feeding catheter and the intravenous administration tubing. The infant is maintained on a metabolic bed in order to provide accurate collection of all urine and other wastes.

Severe negative nitrogen balance may occasionally have to be corrected by hyperalimentation or total parenteral nutrition (TPN). Intravenous solutions used in TPN contain essential and nonessential amino acids, plus a source of calories in the form of fat and carbohydrate. They "spare" the administered amino acids and allow them to be used for tissue repair. The TPN fluid must also contain all other nutritional factors required for life, including essential fatty acids, vitamins, and minerals. Severe metal and essential fatty acid deficiencies have been observed in situations in which such inclusions had not been made. 

The arguments offered above call for caution and the careful, however scientifically sound, evaluation of the safety of food items for human consumption. Close toxicological and pharmacological surveillance of nutritional products with additives and/or the history of chemical or physical processing is of paramount importance. The importance of this surveillance is demonstrated most convincingly by observations made recently in the field of hyperalimentation. Here the patient, deprived of the ability of oral food intake, is dependent on the intravenous infusion of solutions of essential amino acids. For solution stabilization sodium bisulfite was added. This presumed preservative, however, reacts with tryptophan (20) with the formation of products which affect liver tissue adversely (21). 

In order to insure maximum safety to the patient, it is strongly recommended that any institution in which intravenous hyperalimentation is practiced should have a designated and qualified hyperalimentation or total parenteral nutrition team. The minimum team should consist of an attending physician who is well versed in nutrition and metabolism, a conscientious and interested house officer or research fellow, a pharmacist trained in aseptic solution formulation, and a technician or nurse. Other members of a complete hyperalimentation team include a nutritionist, clinical pathologist or biochemist, physical therapist, sociologist, and psychiatrist. 

It had been demonstrated all too often in the literature (Ashcraft et al., 1970 Bernard t al., 1971 Curry et al., 1971) that failure to comply with the principles and procedures outlined by our team for the execution of safe and effective intravenous hyperalimentation will result in an inordinately high rate of metabolic, mechanical and infectious complications. In order to minimize the development of inflammation and infection at the catheter-skin exit site, the dressing is changed at least three times a week the skin around the catheter is treated with tincture of iodine or other antiseptic solutions and fresh antimicrobial ointment is applied. 

A two year old girl with 90% third degree burns survived. She had received central hyperalimentation for a period of two months. When catheter sepsis continued to be a major problem, she was treated by peripheral alimentation using 10% Intralipid, Aminofusin 600 and the hypertonic carbohydrate solution for a period of four weeks. This allowed intravenous provision of calories to 2,500 calories per square meter body surface per day. Her infection was controlled with the change from central to peripheral venous alimentation. Three other patients who were treated only with peripheral alimentation showed no evidence of infection that could be related to the intravenous therapy. 

---