Conflicts
y No convincing evidence that colloids are better than crystalloids.
y No convincing evidence that one colloid is better than other colloid.
Adverse events
y Decreases immunoglobulin response y Decreases albumin production y Decreases ionised calcium level y Decreases response to tetanus toxoid y Increases ECF volume deficit
y Dextran interferes with cross matching and it causes coagulopathy y Hetastarch decreases vWF and factor 8c levels and causes coagulopathy y Hetastarch also causes macroamylesemia.
25% albumin has been found to have some advantages over other colloids in new studies y It has proven anti-inflammatory effect, volume requirement is 5 times less and it has no
coagulopathic side effects
y However, 25% albumin causes only fluid shift in body. Therefore, it should not be used in cases of acute volume loss unless some volume is restored
Hetastarch: It is a starch polymer (6%) in isotonic saline y High molecular weight—4.5 lacs
y Medium molecular weight—2 lacs y Low molecular weight—70,000 daltons
y Hextend—6% hetastarch solution with a buffered multi-electrolyte solution Dextran 70 has a longer duration of action than dextran 40
y None of these fluids have definite preferential advantages over others y All of them have minimal risk of allergic/anaphylactic reactions.
y Ebb phase—first 24 hours of stress when all metabolic activities slow down – Given by Cuthbertson
– Main role is to conserve volume and energy y Flow phase—has two divisions
Catabolic phase during the first 3 to 10 days as followed by anabolic phase from 10 to 60 days after stress.
y During this phase, insulin/glucagon ratio is a better predictor of survival than either of them alone.
y Mineral response to stress—increase in copper levels and decrease in iron and zinc levels.
Endocrine response to stress is as shown in the flow chart given below:
Metabolic response to stress is as shown in the charts below:
Factors affecting these responses to stress are as follows:
Q18. Write a note on nutritional assessment of surgical patient and estimation of his calorie needs.
Ans.
Nutritional assessment of a patient y History
– Duration and amount of weight loss—weight loss > 10% in less than 6 months is significant
– Decreased dietary intake
– Gastrointestinal symptoms such as vomiting, diarrhea, anorexia
– Other diseases, comorbid conditions and its relation to decreased nutrition.
y Physical examination – Subcutaneous fat – Pedal edema – Ascites – Muscle wasting
– General physical examination from head to toe to look for nutritional deficiencies y Anthropometry
– Body mass index
– Mid arm muscle circumference – Triceps skin fold thickness.
y Laboratory analysis
– Serum protein and albumin—an albumin value between 3.5 to 5 mg/dL is adequate – Hemoglobin
– Indirect calorimetry.
Nutritional needs
y Basal energy expenditure is given by Harris-Benedict equation and gives an estimate of calorie needs at basal metabolism level in an individual
y Resting energy expenditure is 10% greater than basal energy expenditure as it takes into account the work of breathing in addition to BEE. The resting energy expenditure is calculated using Weir equation
3 REE values at 10% variation or 3 respiratory quotient values within 5% of each other is the REE of the patient
y Total energy expenditure is product of REE and stress factor. This stress factor is calculated using different stresses that a person is going on such as illness, shivering, food, physical activity and injury
Total energy expenditure is the amount to be met by nutritional supplementation.
y Normal protein requirement is 0.8 to 1 g/kg/day and
y Normal calorie requirement is 25 to 30 kcal/kg/day for a person with moderate work and healthy state.
Other estimated calorie protein and stress factors are available for calculation of a specific patient.
For example, a patient with burns needs 35 to 40 kcal/kg/day calories and 2 to 2.5 g/kg/day of protein. The stress factor is 2.0 in these patients and so on for other patients with moderate or severe stress, trauma or surgery, the values linger between the above mentioned two extremes.
Q19. Write a note on indications and methods of administering total parenteral nutrition.
Write a note on total parenteral nutrition therapy.
Ans.
Fundamental goals of nutritional support are
y Meet the energy requirements for metabolic purposes y Tissue repair
y Maintenance of core temperature
y Minimize the protein breakdown and preserve the lean body mass Indications of total parenteral nutrition
y Seriously ill patients with severe malnutrition/sepsis/trauma when enteral feeding cannot be given
y Newborn with tracheoesophageal fistula, omphalocele, gastroschisis y Infants with meconium ileus, short bowel syndrome
y High output enterocutaneous fistula
y Radiation enteritis/acute chemotherapy toxicity/postoperative ileus y Weight loss preliminary to major surgery
y Cancer cachexia y Ileus for > 10 days
y Patients with sprue, hypoproteinemia, pancreatic insufficiency
y Patients with esophageal dyskinesia after anorexia nervosa, cerebrovascular accident or psychogenic vomiting
y Patients with ulcerative colitis, regional enteritis or tuberculous enteritis
y Exacerbation of pancreatitis after enteral nutrition or pancreatitis with prolonged ileus.
Contraindications
y Hemodynamic instability y Electrolyte imbalance
y When the prognosis does not support parenteral nutrition.
Types of access
y Peripheral parenteral nutrition can be used for < 2 weeks at a stretch and osmolality
< 900 mosm/L through peripheral line.
y Central parenteral nutrition through central line.
Constituents
y Carbohydrate as 15 to 25% dextrose solution to provide 50 to 70% of the calorie requirements of the patient
y 3 to 5% crystalline amino acid solution. It is always to be administered after the glucose up to about 100 mg has been administered to avoid the utilization of the protein as an energy source
y Fat emulsion from soyabean or safflower oil to provide 15% of the total calories required by the patient
y Vitamin K is to be added as TPN formulations are deficient in vitamin K
y All other essential minerals and electrolytes are present in TPN
y Insulin is administered separately from the TPN bag as infusion or on sliding scale as per 6 hours glucose determinations.
Complications
y Complications related to the access site – Cardiac dysrrythmias
– Pneumothorax – Catheter line infection – Inadvertent arterial puncture – Nerve or lymphatic injury – Air embolism
– Venous perforation and hemothorax – Venous thrombosis
– Catheter occlusion
– Catheter line infection or abscess y Metabolic complications
– Hyperglycemia (most common) or hypoglycemia – Hypertriglyceridemia
– Azotemia – Osteoporosis
– Trace metal deficiency (Zinc deficiency most common) – Refeeding syndrome
- Patients with low BMI, increased unintentional weight loss and very low nutrient intake in recent past are at maximum risk
- Occurs due to restitution of feeding at a very rapid rate after prolonged malnutrition which results in rapid working of the cellular pumps and resultant internalization of potassium, phosphorus and magnesium
- This produces hypokalemia, hypomagnesemia and hypophosphatemia
- Additional fluid load administered can result in congestive cardiac failure, cardiac arrhythmias and sudden death
– Liver dysfunction, fatty infiltration and steatosis – Gallstones.
Q20. Write a note on enteral nutrition.
Ans. Fundamental goals of nutritional support are
y Meet the energy requirements for metabolic purposes y Tissue repair
y Maintenance of core temperature
y Minimize the protein breakdown and preserve the lean body mass Indications of enteral nutrition
y Distal, low output, entrocutaneous fistula y Dysphagia except to liquids
y Patients after major trauma or surgery
y Protein energy malnutrition with poor oral intake
y To enhance adaptation after enterectomy y Inflammatory bowel disease
Contraindications y Severe pancreatitis y Severe diarrhea
y Proximal or high output small intestinal fistula y Small bowel obstruction or ileus
Access
y Nasogastric (Increased risk of aspiration) y Nasoduodenal/nasojejunal route
y Percutaneous endoscopic gastrostomy/jejunostomy y Surgical gastrostomy/jejunostomy
Methods
y Bolus or gravity method—250 to 500 mL 4–6 hourly y Intermittent—some calculated amount hourly
y Continuous infusion—infusion at 20–40 mL/hour of full strength formula.
Enteral nutrition formulas
y Low residue isotonic formula with 1 kcal/mL is the first line formula
y Isotonic formula with dietary fiber (digestible dietary pectins)—delay intestinal transit and decrease the incidence of diarrhea.
y Immune enhancing formula—formulas containing branched chain amino acids, omega 3 fatty acids, glutamine, beta carotene or arginine
y Calorie dense formulas—2 kcal/mL for intragastric feeding y High protein formulas—suitable for trauma/critically ill patients
y Elemental formuals—predigested nutrients with high osmolality. Need dilution before administration. Used in patients with malnutrition and pancreatitis
y Renal failure formula—contain essential amino acids and low volume y Pulmonary failure formula—high fat content (50%) and low in carbohydrates y Hepatic failure formula—increased branched chain amino acids.
Complications Metabolic complications
y Hyperglycemia or hypoglycemia y Hypertriglyceridemia
y Azotemia y Osteoporosis
y Refeeding syndrome
– Patients with low BMI, increased unintentional weight loss and very low nutrient intake in recent past are at maximum risk
– Occurs due to restitution of feeding at a very rapid rate after prolonged malnutrition which results in rapid working of the cellular pumps and resultant internalisation of potassium, phosphorus and magnesium
– This produces hypokalemia, hypomagnesemia and hypophosphatemia
– Additional fluid load administered can result in congestive cardiac failure, cardiac arrhythmias and sudden death
y Liver dysfunction, fatty infiltration and steatosis y Gallstones.
Gastrointestinal complications y Abdominal cramps y Abdominal distension
y Pneumatosis intestinalis and small bowel necrosis especially in the critically ill patients.
Tube related complications y Displacement
y Blockage y Perforation y Infection y Malposition.