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Interventions for Addressing Medical Complications Related to Outpatient Refeeding and Intake Regulation October 14, 2016 St. Joseph Mercy Health System Eating Disorder Conference Allison Laurie, PMHNP-BC Overview/Objectives • • • • Define refeeding syndrome (RFS) Identify patients at risk for RFS Describe the pathophysiology of starvation Identify the main pathophysiologic features/clinical manifestations of RFS • Discuss prevention of RFS • Identify recommended treatment & standards of care • Case review 2 Background • Refeeding is the cornerstone of treatment for patients with anorexia nervosa • Essential to prevent serious or even fatal medical complications of starvation • Starvation induced cognitive deficits can preclude efficacy of psychotherapies • Weight restoration is not without risk for the patient; must be balanced against the potentially fatal complications of the refeeding syndrome. 3 Refeeding Syndrome Overview • Clinical complications that occur as a result of fluid and electrolyte shifts during nutritional rehabilitation of malnourished patients • May result in cardiac arrhythmia, cardiac failure or arrest, hemolytic anemia, delirium, seizures, coma, and sudden death Garber, A. K., Sawyer, S. M., Golden, N. H., Guarda, A. S., Katzman, D. K., Kohn, M. R., Le Grange, D., Madden, S., Whitelaw, M. & Redgrave, G. W. (2016). A systematic review of approaches to refeeding in patients with anorexia nervosa. International Journal of Eating Disorders. 4 Risk Factors • • • • • Directly related to the amount of weight loss during the current episode, and the rate of weight restoration. Patients at <70 percent of IBW, or those who have lost weight most rapidly, are at greatest risk for the syndrome. Inpatient hospitalization recommended if patient has <70 percent of IBW for initial stage of nutritional replenishment. Other risk factors: low phosphate, potassium, or magnesium prior to refeeding; little to no nutritional intake for previous 5 to 10 days. Highest risk within first 2 weeks of refeeding. Risk progressively dissipates over the next few weeks. Mehanna, H. M., Moledina, J., & Travis, J. (2008). Refeeding syndrome: what it is, and how to prevent and treat it. Bmj, 336(7659), 1495-1498. 5 Pathogenesis of Starvation Starvation/malnutrition Insulin concentrations decrease, glucagon increases Gluconeogenesis, protein and fat catabolism (for glucose synthesis) Weight loss Water, vitamin, and mineral depletion 6 Consequences of Starvation • Decreased insulin and increased glucagon secretion. • Switch from glucose toward ketone bodies as a source of energy. • Glycogen stores used • BMR decreases • Brain adapts to using ketones • Atrophy of all organs • Reduced lean body mass • Abnormal liver function 7 Refeeding Syndrome 8 Clinical Manifestations • Symptoms of RFS are variable and may be unpredictable. • Nausea/vomiting • Lethargy • Respiratory insufficiency • Cardiac failure • Hypotension • Arrhythmias • Delirium • Coma • Fatality Mehanna, H. M., Moledina, J., & Travis, J. (2008). Refeeding syndrome: what it is, and how to prevent and treat it. Bmj, 336(7659), 1495-1498. 9 Clinical Manifestations of Electrolyte Abnormalities Associated with RFS • • • • • Phosphate Potassium Magnesium Sodium Vitamins/Thiamine Mehanna, H. M., Moledina, J., & Travis, J. (2008). Refeeding syndrome: what it is, and how to prevent and treat it. Bmj, 336(7659), 1495-1498. 10 Phosphate • Pathogenesis: • Begins with depletion of stores during starvation • Upon intake of glucose with refeeding, release of insulin triggers cellular uptake of phosphate • Insulin additionally causes cells to produce a variety of depleted molecules that require phosphate (ATP), which further deplete body’s stores of phosphate. • Lack of phosphate results in tissue hypoxia and resultant myocardial dysfunction, respiratory failure, etc. 11 Clinical Manifestations of Hypophosphatemia - Normal range: 0.8-1.45 mmol/l - Cardiovascular: heart failure, arrhythmia, hypotension, cardiomyopathy, shock, death. - Renal: acute tubular necrosis, metabolic acidosis - Skeletal: rhabdomyolysis, weakness, myalgia, diaphragm weakness. - Neurologic: delirium, coma, seizures, tetany - Endocrine: hyperglycemia, insulin resistance, osteomalacia - Hematologic: hemolysis, thrombocytopenia, leukocyte dysfunction 12 Potassium • Pathogenesis: • Also depleted in starvation • Serum concentration may be normal • With the change to anabolism upon refeeding, potassium is taken up into cells as they increase in volume and number, and as a direct result of insulin secretion • Result is hypokalemia • Causes derangements in the electrochemical membrane potential. 13 Clinical Manifestations of Hypokalemia - Normal Range 3.5-5.1 mmol/l - Cardiovascular: hypotension, ventricular arrhythmias, cardiac arrest, bradycardia, or tachycardia - Respiratory: hypoventilation, respiratory distress, respiratory failure - Skeletal: weakness, fatigue, muscle twitching - GI: diarrhea, nausea, vomiting, anorexia, paralytic ileus, constipation - Metabolic: metabolic acidosis 14 Magnesium • Another predominantly intracellular cation • Important cofactor for must enzyme systems including oxidative phosphorylation and ATP • production • Necessary for structural integrity of DNA, RNA, and ribosomes. • Affects membrane potential, deficiency can lead to cardiac dysfunction & neuromuscular complications. 15 Clinical Manifestations of Hypomagnesemia - Normal Range: 0.77-1.33mmol/l - Cardiovascular: arrhythmias, T wave alternans - Respiratory: hypoventilation, respiratory distress, respiratory failure - Neuromuscular: weakness, fatigue, muscle cramps, ataxia, vertigo, paresthesia, hallucinations, depression, convulsions - GI: abdominal pain, diarrhea, vomiting, loss of appetite, constipation - Hypocalcemia - *Many cases of hypomagnesemia do not manifest until late 16 Sodium • Pathogenesis: • Changes in carbohydrate metabolism have a profound effect on sodium and water balance • Introduction of carbohydrate to a diet leads to a rapid decrease in renal excretion of sodium and water. • If fluid repletion is instituted to maintain a normal urine output, pts may rapidly develop fluid overload. 17 Clinical Manifestations of Hyponatremia • • • • • Normal Range: 136-145 mmol/l Cardiovascular: heart failure, arrhythmia Respiratory: respiratory failure, pulmonary edema Renal: renal failure Skeletal: muscle cramps, fatigue, fluid retention, swelling (edema). ©2015 18 Vitamins/Thiamine • Thiamine is an essential coenzyme in carbohydrate metabolism. • Deficiencies can result in • Korsakoff’s syndrome: • Retrograde and anterograde amnesia, confabulation • Wernicke’s encephalopathy: • Ocular abnormalities, ataxia, confusion, hypothermia, coma • Particular concern in alcoholism * Vitamin deficiencies may also result in • CHF, lactic acidosis, beriberi disease, and muscle weakness. ©2015 19 Cardiovascular Complications Most fatalities occur due to cardiac complications • • Impaired contractility, decreased stroke volume, heart failure, and arrhythmias Atrophy of the heart during starvation results in heightened vulnerability for fluid overload and heart failure. • Sodium and fluid retention can lead to volume overload • Echo, ECG, and cardiology consult as indicated by pt’s clinical status • ©2015 20 Preventing RFS Identification of high risk patients • One or more of the following (NICE guidelines): • • Little to no intake for >10 days • Body mass index (kg/m2) <16 • Weight loss of >15% in the past three to six months • Low levels of potassium, phosphate, or magnesium before feeding Mehanna, H. M., Moledina, J., & Travis, J. (2008). Refeeding syndrome: what it is, and how to prevent and treat it. Bmj, 336(7659), 1495-1498. ©2015 21 Preventing RFS Identification of high risk patients: • Or the patient has two or more of the following: • • Body mass index <18.5 • Unintentional weight loss >10% in the past 3 to 6 months • Little or no nutritional intake for >5 days • History of alcohol misuse or drugs including insulin, chemotherapy, antacids or diuretics. Mehanna, H. M., Moledina, J., & Travis, J. (2008). Refeeding syndrome: what it is, and how to prevent and treat it. Bmj, 336(7659), 1495-1498. ©2015 22 Preventing RFS Patients are at highest risk for RFS in the first two weeks of nutritional replenishment and weight gain. • Historically, the standard of care for refeeding patients with AN is to initiate at low caloric levels, and advance slowly. • Example: Start at 1,200 calories per day (kcal/day) and advance by about 200 calories every other day. • ©2015 23 When to Hospitalize? Criteria for admission vary by region, age, and the type of treatment facility. • Some published positions and guidelines have suggested that hospital admission is warranted in the presence of: • • Vital sign abnormalities (bradycardia, hypotension, orthostatic HR/BP, and hypothermia) • Failure to respond to lower levels of care, suicidality, or other severe psychiatric symptoms • Severe malnourishment (BMI<15kg/m2) ©2015 24 Preventing RFS Monitoring the patient clinically and biochemically during the refeeding process. • Proactive correction of electrolyte abnormalities (particularly phosphorus levels) • Monitoring for and treating cardiovascular complications. • ©2015 25 When Not to Hospitalize For some patients, weight restoration can be achieved successfully outside of the hospital. • Alternative treatment settings include partial hospitalization, residential programs, intensive outpatient programs. • Non-inpatient settings are cost-effective for long-term nutritional rehabilitation. • ©2015 26 How to Refeed In mild and moderately malnourished patients, lower calorie refeeding is too conservative. • In severely malnourished patients, there is insufficient evidence to support changing the current standard of care for refeeding. • Standard recommendations for the macronutrient composition of refeeding is 2535% fat, 15-20% protein, 50-60% carbohydrate. • Garber, A. K., Sawyer, S. M., Golden, N. H., Guarda, A. S., Katzman, D. K., Kohn, M. R., Le Grange, D., Madden, S., Whitelaw, M. & Redgrave, G. W. (2016). A systematic review of approaches to refeeding in patients with anorexia nervosa. International Journal of Eating Disorders. ©2015 27 Treating RFS Reduce nutritional support • Correct hypophosphatemia, hypokalemia, and hypomagnesemia. • Patients with marked edema, or a serum phosphorus <2mg/dL should be hospitalized to intravenously correct electrolyte deficiencies, and for close monitoring. • Continuous telemetry may be needed to monitor cardiopulmonary physiology. • Garber, A. K., Sawyer, S. M., Golden, N. H., Guarda, A. S., Katzman, D. K., Kohn, M. R., Le Grange, D., Madden, S., Whitelaw, M. & Redgrave, G. W. (2016). A systematic review of approaches to refeeding in patients with anorexia nervosa. International Journal of Eating Disorders. ©2015 28 Case Review A 40-year-old woman with a history of anorexia had suffered several complications of the condition in the past, including electrolyte disorders, arrhythmias, amenorrhea, osteoporosis, depression and progressive social isolation. Before admission, she had lost further weight to 40 kg (BMI 13.5 kg/m2). Prior to admission, she resumed eating several large meals a day. On admission, she had ankle edema and hypotension (95/70 mm Hg). Serum concentrations of phosphate, magnesium and potassium were low and the ECG showed sinus bradycardia (51 b.p.m.) and a prolonged QT interval (490 ms). Within 4 h of admission and continuation of oral nutrition and, despite oral supplements of vitamins and electrolytes, she developed muscle weakness and drowsiness. The ECG showed short runs of ventricular tachycardia. i.v. supplementation of electrolytes and minerals was started and the serum electrolyte concentrations returned to normal within 2 days, with resolution of the muscle weakness and the ventricular tachycardia. However, the QT interval remained prolonged at 460 ms. ©2015 29 Key Points Severe anorexia nervosa with a very low BMI is a common cause of the refeeding syndrome in hospital practice. In this case, refeeding was begun by the patient herself and was continued after hospital admission. In severe and prolonged malnutrition, there may be cardiac atrophy as well as electrolyte abnormalities, including sinus bradycardia and a prolonged QT interval (Heymsfield et al., 1978; Powers, 1982). These changes make the heart more vulnerable to hypophosphatemia and hypokalemia with ventricular arrhythmias and sudden death (Isner et al., 1985; Beumont and Large, 1991), especially, if the QT interval exceeds 470 ms (Cooke et al., 1994). It should also be remembered that the concomitant abuse of diuretics, laxatives and alcohol by anorectic patients may exacerbate electrolyte and vitamin deficiencies. It is, therefore, important to be alert to the danger of the refeeding syndrome in patients with these problems. ©2015 30 Questions? ©2015 31