Colloid Osmotic Pressure of Parenteral Nutrition Components and Intravenous Fluids

Objective: Parenteral nutrition is an important part of therapy for critically ill animals that cannot tolerate enteral feedings. It has been hypothesized that parenteral nutrition might also play a role in increasing colloid osmotic pressure (COP). The purpose of this study was to measure COP of various parenteral nutrition components and compare them to the COP of commonly used intravenous solutions.
Design: Membrane colloid osmometry was used to measure the COP of parenteral nutrition components (lipids, Abstractamino acids, dextrose solutions) and of synthetic colloids, crystalloids, and blood products.
Main Results: Parenteral nutrition components and all crystalloid solutions had COP measurements < 1 mm Hg. Great variation in COP was found in the different artificial colloids and blood products. The COP of the artificial colloids tested ranged from 32.7 ± 0.2 mm Hg for hetastarch to 61.7 ± 0.5 mm Hg for dextran 70.
Conclusions: The results of this in vitro study suggest that parenteral nutrition does not directly contribute to an increase in oncotic pressure. Further studies are needed to determine whether parenteral nutrition may indirectly influence COP in vivo. Knowing the COP of a fluid, along with its other properties, is useful in making appropriate therapeutic decisions.     

Prospective evaluation of a peripherally administered three-in-one parenteral nutrition product in dogs

OBJECTIVES: Peripheral parenteral nutrition is an option for short-term nutritional support in dogs which cannot be supported with enteral nutrition. The objective of this study was to examine the use of a three-in-one, 840 mOsmol/l peripheral parenteral nutrition product containing amino acids, lipids and glucose in separate compartments in dogs. METHODS: Nine dogs were administered the three-in-one product, and two dogs were administered the amino acid part of the product, via a peripheral vein. Dogs were monitored for mechanical and metabolic complications. RESULTS: Mechanical complications (apparent thrombus or thrombophlebitis) caused failure of infusion at a median of 36 hours. None of the dogs appeared to develop catheter-related sepsis. Using a 10-hour infusion period appeared to decrease the incidence of line failure. Mild and clinically non-significant hyperglycaemia was the only metabolic complication. In four of the dogs, serum folate, cobalamin and homocysteine concentrations were determined before and after peripheral parenteral nutrition administration. Oral and parenteral administration of methionine has been previously associated with lowered serum folate concentrations. Low serum folates and the subsequent hyperhomocysteinaemia have been associated with venous endothelial damage and venous thrombus in other species. Serum cobalamin also affects homocysteine metabolism. Median serum folate, cobalamin and homocysteine concentrations were not affected by the short-term administration of this three-in-one product. CLINICAL SIGNIFICANCE: Using the product for 24 hours/day may require catheter replacement due to line failure. Other than line failure, which may be improved by 10- to 12-hour infusion times, this product was found to be safe and practical for short-term peripheral parenteral nutrition in dogs.     

Study of the clinical effects of postoperative parenteral nutrition in 15 horses

Several clinical variables were compared in two groups of 15 horses recovering from resection and anastomosis of a strangulated small intestine; 15 were treated with parenteral nutrition and 15 were starved routinely. There was some evidence that parenteral nutrition had a short-lived adverse effect on both the catheter sites and gastric emptying, but there were no marked adverse clinical effects and no evidence of any improvement in the horses' condition.     

Nutritional management of the foal with diarrhoea

Diarrhoea is a common problem in the neonatal and suckling foal. In certain circumstances supplemental nutrition is necessary depending on the age of foal, severity of diarrhoea and presence of other systemic manifestations. Nutritional supplementation can be provided either enterally or parenterally. Enteral nutrition is superior to parenteral nutrition because it is the most natural and physiologically sound means to provide nutritional support. Parenteral nutrition may be warranted if the foal is unable to receive or tolerate enteral nutrition. Dextrose alone or with amino acids and lipids can provide appropriate nutrition when enteral feeding is not tolerated. As soon as the foal stabilises enteral feeding can be reintroduced.     

Immunodeficiency associated with lymphosarcoma in a horse.

Immune system dysfunction and immunoglobulin deficiency was diagnosed in a 2-year-old horse with disseminated lymphosarcoma. Prolonged (35 days) parenteral nutrition was delivered to support the horse during a period in which immune function studies could be performed. Correction of nutritional compromise by use of parenteral nutrition did not correct the immunoglobulin deficiency, and results of lymphocyte phenotype testing did not indicate abnormal proportions of leukocytes. Lymphoblast transformation studies were suggestive of a circulating immunosuppressive factor in the horse's serum. Normal cell function was detected when the cells were stimulated in precolostral equine serum.     

Parenteral nutrition in the mature horse

Parenteral nutrition is an important component of the management of critically ill horses unable or unwilling to eat. It provides dextrose, amino acids, vitamins and minerals and, in some cases, lipids for nutritional support until enteral nutrition can be reinstituted. It can also be used as a supplement to enteral nutrition, where horses are not ingesting at least 80% of digestible energy (resting) requirements for more than 2–3 days. This review discusses the indications, applications, monitoring and complications of parenteral nutrition in mature horses.     

Early enteral nutrition in young dogs suffering from haemorrhagic gastroenteritis

The purpose of this study was to investigate clinical and metabolic effects of combined parenteral and oral nutrition compared with parenteral nutrition in young dogs with haemorrhagic gastroenteritis in a prospective clinical study. Dogs with acute gastroenteritis received either parenteral nutrition (group PN, n = 9) or combined parenteral and early enteral nutrition (group EN, n = 10). Infusions were compounded from amino acids, lipids, glucose and electrolyte/glucose solutions [149 g/l glucose, 20 g/l triglycerides, 40 g/l amino acids and 4009 kJ metabolizable energy/l (957 kcal ME/l)], and supplemented with potassium, phosphate and trace elements. Group EN received additionally a hydrolysed diet (74 kJ/kg BW(0.75) on day 2 and 148 kJ/kg BW(0.75) on days 3 and 4). Glucose, triglycerides, protein, albumin, fibrinogen, urea, creatinine, alkaline phosphatase, glutamate dehydrogenase and glutamate pyruvate transaminase were measured before and during the infusions, haematological traits only before the infusions. Statistics included two-factorial anova and subsequent t-test or Wilcoxon test (P < 0.05). All dogs of group EN survived compared with seven of nine patients in group PN. Most dogs in the EN group vomited within half an hour after introduction of oral feeding on day 2 but tolerance for food increased on days 3 and 4. The general health status and faecal and blood parameters of the surviving dogs were similar (P > 0.05) between the groups. In all dogs leucocytes increased during the treatment period, haematocrit and haemoglobin levels declined. Infusions increased blood glucose and triglycerides (P < 0.05); however, no adverse signs were observed. Early enteral nutrition was possible after a short period of adaptation, however, vomiting can be a severe problem. The evaluation of clinical benefits of early enteral nutrition in young dogs with haemorrhagic gastroenteritis requires further investigations.     

Nutritional support for treatment of hepatic lipidosis in a llama

A 3-year-old female llama that was 3 months into her first lactation and 10 weeks pregnant was evaluated for anorexia of 24 hours' duration. On physical examination, the llama was in lateral recumbency, bradycardic, tachypneic, and hyperthermic. Palpation per rectum confirmed the presence of a possible dry fecal mass in the spiral colon. A tissue biopsy specimen of the liver was obtained, and histologic examination revealed moderate diffuse lipid accumulation within the hepatocytes. Lactated Ringer's solution was administered for rehydration, and partial parenteral nutrition was then initiated. Hepatic lipidosis is a disease characterized by abnormal accumulation of lipid in the liver and is associated with high mortality in camelids. Anorexia associated with hepatic lipidosis promotes further lipid mobilization and fatty infiltration of the liver. Partial parenteral nutrition with enteral supplementation may be used to maintain adequate energy intake and minimize further lipid mobilization. The distinctive metabolism of camelids may require higher amino acid supplementation relative to nonprotein calories in parenteral solutions than those traditionally provided to other species. Treatment with insulin may be effective     

Nutritional support of the foal during intensive care

Provision of adequate nutritional support to the sick neonatal foal is a vital part of intensive care; frequently, however, it is very difficult to accomplish. In this article, current recommendations concerning both enteral and parenteral nutrition are discussed.     

Clinical application of parenteral nutrition in the treatment of five ponies and one donkey with hyperlipaemia

Five ponies and one donkey with hyperlipaemia that occurred secondarily to a variety of primary clinical conditions were treated with lipid-free partial parenteral nutrition comprising equal volumes of 50 per cent glucose and 15 per cent amino acids. The infusion supplied energy and protein at rates of 2.6 kJ/kg per hour and 34.3 mg/kg per hour, respectively. In all six cases there was a prompt and sustained decrease in serum concentrations of triglyceride. In four of the six cases a good response to treatment of the primary condition was also seen and the subjects were discharged successfully. In the remaining two cases, poor clinical response of the primary condition resulted in euthanasia, although hyperlipaemia was nevertheless resolved. The main complication of parenteral nutrition was hyperglycaemia.     

Esophageal patch grafting as a treatment for esophageal stricture in a horse.

Esophageal patch grafting, using the sternocephalicus muscle, was used for treatment of cervical esophageal stricture in a mare. The mare was maintained during the initial healing phase by total parenteral nutrition.     

Total parenteral nutrition in a neonatal llama

Total parenteral nutrition reversed cachexia, dehydration, and electrolyte abnormalities in a neonatal llama suffering from prolonged diarrhea. Complications were not observed during the 8 days that IV-administered fluids and nutritional support were provided.     

Parenteral nutritional support in the small animal patient

Malnutrition has a direct relationship to complications associated with ineffective wound and fracture healing, inadequate immune responses, decreased tolerance to cancer therapy, muscle weakness, and certain organ dysfunctions (heart and liver). Malnutrition combined with disease, injury, or stress increases the metabolic rate in patients above that of resting. These patients are undergoing an accelerated form of starvation, which is more common than presently recognized in veterinary medicine and may be responsible for the less than optimal responses to proper therapies. Diseased or injured patients unable to digest or absorb nutrients from the gastrointestinal tract require additional medical support in the form of parenteral nutrition. Advances in parenteral solutions, products, and delivery systems make parenteral nutritional support possible in veterinary medicine, although not possible in all small animal practices. Proper patient selection, well-informed clients, dedicated technicians, and knowledgeable veterinarians are all essential in the successful implementation of parenteral nutritional support.     

Refeeding syndrome in a cat with hepatic lipidosis

Refeeding syndrome is characterized by severe hypophosphatemia occurring in patients given enteral or parenteral nutrition after severe weight loss. There are few veterinary reports that describe this syndrome but it is well documented in human medicine. This report describes a case of a domestic shorthair cat diagnosed with hepatic lipidosis following a 4-week history of decreased appetite and weight loss and in whom refeeding syndrome was documented after initiation of enteral nutrition. Clinical findings, blood work abnormalities and disease progression in this patient are described from the time of diagnosis through to recovery. A review of the current literature pertinent to this clinical syndrome is included.     

Nutritional Support In Pancreatitis: A Retrospective Study

The medical records of animals with pancreatitis that received nutritional support were evaluated. Over a five year period (1989–1994), 16 patients with pancreatitis (14 dogs and 2 cats) received nutritional support. Affected animals commonly exhibited vomiting, diarrhea, and weight loss, as well as multiple clinicopathological abnormalities.
Total parenteral nutrition (TPN) was used in 13 of the cases, while two animals received partial parenteral nutrition (PPN), and one was fed through a jejunostomy tube. The duration of nutritional support ranged from one to 13 days, with a mean of 6.6 days. Three of the animals receiving TPN had complications resulting from the nutritional support, including hyperglycemia, hyperammonemia, and hyperlipidemia. The survival rate for all 16 cases was 56% (9 of 16).
A variety of nutritional support techniques can be successfully used in animals with pancreatitis and are associated with few complications, most of which can be managed with adjustments in treatment regimen.     

Total parenteral nutrition in four healthy adult horses

Total parenteral nutrition was accomplished in 4 healthy adult horses. During the 10-day study, the horses were not permitted to ingest food or water. Body weight was maintained at 94% of initial values without clinical evidence of dehydration. Serum urea nitrogen and triacylglycerol concentrations decreased during the study, without other significant hematologic or biochemical changes. Horses adapted without problems to the routine of IV feeding and confinement. All horses were healthy at the conclusion of the study. It was concluded that intravenous feeding with a lipid-glucose-amino acid-electrolyte solution was an acceptable method of maintaining nutrition in the healthy adult horse.     

Severe hypophosphataemia associated with the management of hyperlipaemia in a miniature pony

This report describes a case of severe hypophosphataemia associated with the management of hyperlipaemia in a miniature pony following colic surgery. Clinical signs attributed to hypophosphataemia included obtundation, anorexia, tachycardia, tachypnoea and generalised muscle fasciculations. Hyperlipaemia was managed with enteral and partial parenteral nutrition; insulin was also administered to control hyperglycaemia after the initiation of caloric support. Specific therapy for hypophosphataemia consisted of parenteral potassium phosphate at 0.03 mmol/kg bwt/h (i.v.). The pony made a full recovery without further complications. Hypophosphataemia may be an under‐recognised clinical problem in certain populations of critically ill equids, such as those with hyperlipaemia and receiving insulin as part of their management. The routine measurement of phosphate concentration in these cases is recommended.     

Nutritional and clinicopathological effects of post operative parenteral nutrition following small intestinal resection and anastomosis in the mature horse

REASONS FOR PERFORMING STUDY: There is an absence of data describing the nutritional requirements and nutritional status of horses following surgery for colic; furthermore, the potential effect of parenteral nutrition (PN) on improving nutritional status in such cases is unknown. HYPOTHESIS: Post operative colic cases suffer from a potentially detrimental negative energy balance and the PN formulation developed in this study would lead to clinicopathologically detectable improvements in the subjects' nutritional status. METHODS: Several clinicopathological variables, some known to be associated with nutritional status, were compared in 2 groups of horses in the post operative period following colic surgery; Group N (n = 15) were treated with PN and Group C (n = 15) were starved routinely. RESULTS: Group N had significantly lower serum concentrations of triglycerides, total bilirubin, albumin and urea and significantly higher serum concentrations of glucose and insulin compared with Group C in the post operative period. CONCLUSIONS: The control group of horses demonstrated significant clinicopathological evidence of starvation and the described PN protocol resulted in a demonstrably improved nutritional status in the treated horses. POTENTIAL RELEVANCE: Further study is required to investigate clinical benefits and possible harmful side effects of post operative parenteral nutrition before the technique can be advocated for widespread use in practice.     

Enteral nutrition by tube

When oral intake is unsatisfactory or contraindicated, maintenance of nutrition by tube feeding is an alternative to the parenteral route. A large volume of research data supports the decision to use the enteral route whenever possible. Entry of food into the alimentary tract is a stimulus to structural and functional maintenance of that tract. Enteral nutrition can be given via indwelling nasoesophageal, pharyngostomy, esophagostomy, percutaneous or surgical gastrostomy, or enterostomy tube. Use of an appropriate catheter, familiarity with the technique used, and careful patient selection and monitoring are important factors in successful tube feeding. Blenderized pet food diets should be fed whenever possible; commercially available liquid diets provide an alternative when tube caliber or patient factors preclude the use of blenderized foods.     

Nutritional support for patients

A good intake of fluids and essential nutrients in the first fourteen days is of vital importance to recuperating animals. Moreover, it is important to encourage cats and dogs to eat after illness or surgery, in order to promote optimal functioning of the gut and the immune system. Enteral nutrition is to be preferred to nasogastric feeding or parenteral nutrition. In the first stage of recovery, during the first 24 to 48 hours, it is important to feed the gut' with nutrients, and thereafter, in the second stage of recovery (after day 3), the calorie intake can be increased. Timely nutritional support with nutraceuticals, such as arginine, glutamine, taurine, long-chain polyunsaturated omega-3 fatty acids, and prebiotic fibres, can considerably shorten the recovery period of cats and dogs after illness or surgery