Case #1 Answers:

Answer 1
When a hospitalized patient is unable to take in appropriate calories to meet his needs, a decision needs to be made whether to institute nutritional supplementation and if so, the route of supplementation. In deciding whether or not to institute nutritional supplementation, the patient's pre-injury nutritional status needs to be taken into consideration. Other important factors include the severity of the injury for which the nutritional supplementation is needed and the anticipated time until the patient is able to resume adequate intake.

Assessment of this patient should include evaluation of the nutritional status. The subjective global assessment (SGA) has gained prominence as an alternative method for assessing the nutritional status of hospitalized patients. SGA combines information gathered from the patient's history with features of a clinical examination. A review of the history would highlight factors such as: unintentional loss of body weight (less than 5% is considered small and loss of >10% is considered definitely significant), dietary intake, gastrointestinal symptoms, functional capacity, and metabolic demands of the current stress state.

This patient Hx: recent wt gain of 10#, with increased intake & decreased activity level, no GI intolerance or supplement use, but a risk for deficiencies due to alcohol abuse. Given the current stress state early nutrition support and avoidance of lean body mass losses may improve survival, reduce infections and wound healing, and decrease length of stay.

The physical examination of the patient should be reviewed for indices of nutritional status. Four features are key: loss of subcutaneous fat measured in the triceps region and the mid-axillary line at the lower ribs, muscle wasting in the quadriceps and deltoid region, presence of edema in ankle or sacral region, and presence of ascites.

Examination of this patient does not reveal any signs of muscle or fat wasting.

An observation of the patient's skin, hair, eye, tongue, and mouth can reveal changes associated with vitamin and mineral deficiencies.

For this patient, the initial examination did not reveal a changes in the color of the tongue; scarlet (niacin deficiency) or magenta (riboflavin deficiency); the tongue was not inflamed (riboflavin, B12, folate, pyridoxine, iron); and stomatitis was not present (riboflavin and other B-vitamins).

For an initial nutrition assessment of patient's with traumatic injury the SGA may be more reliable than laboratory measures of nutrition assessment.

The team should assess the functional capacity of this patient's gastrointestinal system and also they should make an estimate of when the patient will be able to resume oral feeding (within 7 - 10 days of injury?).

Without intraluminal fuels intestinal integrity may deteriorate and allow translocation of gut bacteria. One means to combat nutrient deprivation and simultaneously keep the local defense barrier of the intestine intact is through tube feeding. Indications for tube feeding include an anticipated period without adequate oral intake of 1-2 weeks. The situations, which preclude enteral feeding and use of the GI tract, are: bowel obstruction or perforation, bowel ischemia, pancreatitis, and occasionally the preoperative bowel. When gastric emptying is delayed, putting the patient at increased risk for aspiration, enteral access may be placed beyond the pylorus.

This patient meets the criteria for enteral tube feedings with the anticipated duration of NPO status and high stress needs with adequate GI function.

Answer 2
The results of Indirect Calorimetry reveal a measure of energy expenditure or 24-hour requirements as reflected by the REE (for this patient on day #5 REE = 2040) and a measure of the substrate utilization with the respiratory quotient (RQ = 1.00).

REE most closely correlates with fat-free, lean body mass. Most disease states increase REE: for example an increase from 20- 50% with surgery and trauma. This is proposed to be an effect of the release of neurotransmitters and inflammatory mediators, futile substrate cycling, elevated core temperature, and increased protein turnover.

The REE accounts for 75% to 90% of the total energy expenditure (TEE), the remainder of which is accounted for by thermogenesis resulting from nutritional intake, environment, and physical activity. Besides being fed and temperature control, activity accounts for much of the variability in TEE. In the awake and alert state, energy needs are increased by 10%. Agitation and restlessness in the critically ill patient can contribute up to 10% of TEE. While paralysis can decrease energy needs, routine nursing procedures will increase energy expenditure. Spontaneous activity, some medications, hyperventilation, and pain can increase TEE. The patient's stage of recovery will contribute to changes in REE, necessitating repeat measures to assess the adequacy of the nutrition therapy & estimated needs.

The RQ is derived from actual measures of VCO2 /VO2 (carbon dioxide produced and oxygen consumed). In comparing the metabolism of the three substrates, glucose oxidation is associated with the highest RQ at 1.0 (the level of this patient). Fat oxidation is lowest at 0.7, and protein metabolism in between with an RQ of 0.8. Hyperventilation, metabolic acidosis (with buffering of acid in generating carbon dioxide), and overfeeding (leading to lipogenesis) may all increase RQ.

In this patient with normal nutritional status a high CHO infusion or intake exceeding energy requirements may cause a rise in RQ..

The RQ of 1.0, in light of the feeding at full goal, may indicate overfeeding with the subsequent increased CO2 generation. Other metabolic aberrations may be occurring. The patient should be assessed for hyperglycemia and hypertriglyceridemia. It is usually prudent to decrease the amount of calories being delivered to this patient until the metabolic or respiratory aberrations are corrected.

Answer 3
IV solutions should be evaluated when considering the energy intake and tolerance of a patient's feeding regimen. Dextrose provides 3.4 kcal/gram. For example, 250 cc of a 5% Dextrose solution will supply 43 kcals. As volume and concentration are adjusted the amount of glucose infused also changes. With 1 liter of D10 the patient receives 340 kcals. Medications often supply dextrose or fat with the solution. Propofol is a medication that is delivered in a 10% lipid solution. The energy yield of 10% IV lipids is 1.1 kcal/ml.

This patient is receiving 20 cc per hour Propofol in a 10% lipid solution, which supplies 480 cc per day and an additional 528 kcals from fat.

Answer 4
The composition of the enteral formula delivered to patients will vary depending on the clinical situation. Unless a patient is fluid restricted or has significant malabsorption, a product that basically supplies 1 kcal/ml in an isotonic, polymeric, lactose-free solution can be selected. The macronutrient distribution typically falls as 12-20% of the calories from protein, 45-60% from carbohydrate, and 30-40% of its calories from fat.

Protein needs are increased with severe burns, large wounds, or voluminous diarrhea. Values up to and greater than 1.5 gm protein/kg/day may be used to target intake, rather than the more typical 0.8 to 1.2 gms/kg/day. Conversely, in renal failure or acute hepatocellular disease values from 0.6 to 0.8 gms/kg are used to help prevent uremia or encephalopathy. Once the clinical status has stabilized, increases in protein can be made as tolerated by the patient.

This patient's REE is measured at 2040 kcal per day. With a rate 115 cc per hour of Osmolite HN, he was receiving about 2.7 liters of this product per day (a total of 3,390 kcals with the Propofol) and 119 gm protein per day or 1.4 gm protein/kg/day. In light of the elevated RQ and total energy intake more than 50% greater than estimated needs by Indirect Calorimetry, less calories should be supplied from the enteral formula. Given the severity of his traumatic injuries and would healing requirements, an increase in protein intake is indicated.

The feeding recommendation would be to change to a higher protein product, decrease the feeding rate to a lower level of energy intake, and add a modular protein supplement.

FS Replete at 60 cc per hour supplies about 1.4 liters per day for 1440 kcals and 89 gm protein. Plus 2 scoops of Promod TID add 30 gms of protein for a total of 119 gms protein (1.4 gm/kg/d). Total energy intake with the enteral formula, Promod, and Propofol would be 2100 calories.

Answer 5
The CO2 production would decline as the energy intake more closely matches the patient's ability to utilize calories and lipogenisis is avoided. The arterial blood gas results should be reviewed for the patient response to feeding changes.

Answer 6
In addition to the standard multi-vitamin preparation, supplementation with Thiamin and Folate is suggested. These specific B-vitamins are primarily supplemented with alcohol consumption to prevent anemia and Wernicke's encephalopathy.

Answer 7
The debilitated patient with poor gastric emptying and impairment of the swallowing and cough mechanism is at risk for aspiration. Especially for the patients on respirators because tracheal suctioning induces coughing and gastric regurgitation. For patients with diabetes and high gastric residuals an evaluation for gastroparesis may be indicated. There is a high incidence of gastric emptying dysfunction associated with head trauma.

To lessen the risk of aspiration, gastric residuals are monitored and the volume of the residual left in the stomach used as a monitor of enteral feeding tolerance. Generally, gastric residuals are considered high based on the estimated gastric capacity and anticipated rate of stomach emptying for that rate of feeding infusion. For example for an adult patient receiving 75 cc per hour with a residual of 170 cc is higher than desired as it is greater than an acceptable 150 cc and it is also more than 2 hours worth of infused feeding volume.

Continuous gastric infusion, rather than intermittent bolus feeding, may be better tolerated in the sick patient. The head of the bed can be raised 30-45 degrees during feeding and for 1 hour after feeding. An isotonic formula should be emptied from the stomach in a reasonable time frame. If these adjustments are not sufficient to decrease gastric residuals a jejunal feeding tube can be used. The main indications for a tube placed in the small bowel are: tracheal aspiration, reflux esophagitis, gastroparesis, insufficient gastric size from prior resection, postoperative feeding from major procedures, and occasionally access.

Answer 8
The patient's tolerance of tube feeding should include functional as well as biochemical indices. Monitors include gastric residuals, abdominal distention and cramping, stool output, fluid and electrolyte status. The volume of the feeding that the patient has actually received should compared to the feedings orders and nutrition goals. Metabolic complications, such as fluid overload, hyperglycemia, hypophosphatemia, hypokalemia can also occur with enterally fed patients.

Answer 9
A review of the patient's response to feedings provided, current clinical status, estimated nutritional needs, levels of rapid turnover protein indices, and available anthropometrics will indicate nutritional status. A repeat indirect calorimetry for the present MEE and RQ will help establish energy needs and substrate utilization during this phase of recovery. The factors for physical activity and stress should be re-assigned. The patient's recent level of intake and feeding tolerance will support current nutrition targets. A prealbumin level, with its half-life of 1-2 days will better reflect the current anabolic response, than the 21-day half-life of albumin. A 24-hour urine urea nitrogen collection (when accurate collection is feasible) can be used for a nitrogen balance study. Nitrogen balance =nitrogen (protein/6.25) in diet B (nitrogen in urine + nitrogen in stool (usually given as 2 gm N unless there is voluminous diarrhea).