Anorexia nervosa: refeeding and hypophosphatemia

Prophylactic Phosphate Supplementation for the Inpatient Treatment of Restrictive Eating Disorders

PURPOSE

The medical stabilization of adolescent patients with restrictive eating disorders can be associated with refeeding syndrome, a potentially fatal complication preceded by refeeding hypophosphatemia (RH). Whether RH can be prevented by routine prophylactic phosphate supplementation has not been previously examined. This study sought to determine the safety and efficacy of a refeeding strategy that incorporates prophylactic phosphate supplementation to prevent RH.

METHODS

Retrospective chart data were collected for patients aged younger than 18 years with restrictive eating disorders admitted to a tertiary pediatric inpatient ward between January 2011 and December 2014. All patients were refed with a standardized protocol that included prophylactic oral phosphate supplementation (1.0 ± .2 mmol/kg/day).

RESULTS

During the 4-year study period, 75 admissions (70 patients) were included for analysis. The mean age and percent median body mass index of included patients were 15.3 years and 83.5%, respectively. Seven out of 75 (9%) had percent median body mass index of <70% and 26 out of 75 (35%) had percent body weight loss >20%. All patients were normophosphatemic at the time of admission (mean serum phosphate 1.24 ± .2 mmol/L). Serial laboratory evaluation revealed that all supplemented patients maintained serum phosphate levels >1.0 mmol/L during the initial 7 days of refeeding. Eleven patients became mildly hyperphosphatemic (range 1.81-2.17 mmol/L) with no associated clinical consequences. Additional analysis of 11 patients presenting with hypophosphatemia before refeeding revealed that with supplementation, phosphate values normalized by Day 1, and this group experienced no further RH episodes during initial refeeding.

CONCLUSIONS

Prophylactic oral phosphate supplementation appears safe, and no episodes of RH occurred in patients with restrictive eating disorders undergoing inpatient refeeding.

Cardiac changes in anorexia nervosa

Introduction Anorexia nervosa is an eating disorder, which is associated with many different medical complications as a result of the weight loss and malnutrition that characterise this illness. It has the highest mortality rate of any psychiatric disorder. A large portion of deaths are attributable to the cardiac abnormalities that ensue as a result of the malnutrition associated with anorexia nervosa. In this review, the cardiac complications of anorexia nervosa will be discussed.

METHODS

A comprehensive literature review on cardiac changes in anorexia nervosa was carried out.

RESULTS

There are structural, functional, and rhythm-type changes that occur in patients with anorexia nervosa. These become progressively significant as ongoing weight loss occurs.

CONCLUSION

Cardiac changes are inherent to anorexia nervosa and they become more life-threatening and serious as the anorexia nervosa becomes increasingly severe. Weight restoration and attention to these cardiac changes are crucial for a successful treatment outcome.

Predictors of hypophosphatemia during refeeding of patients with severe anorexia nervosa

OBJECTIVE

Hypophosphatemia of refeeding is one of the most dangerous complications seen during the treatment of patients with anorexia nervosa. Although easily detectable and treatable, hypophosphatemia is under-recognized as a complication of refeeding. Specific risk factors for the development of hypophosphatemia are likely to exist among patients with severe anorexia nervosa. The purpose of this study was to identify clinically useful markers that may predict the development of or protection from hypophosphatemia during refeeding.

METHODS

We conducted a retrospective case-control study of 123 patients with severe anorexia nervosa admitted for medical stabilization at the ACUTE Center for Eating Disorders between October 1, 2008 and December 31, 2013. Risk factors for refeeding hypophosphatemia were determined by multivariate logistic regression from clinical parameters and laboratory values measured at the time of admission.

RESULTS

The prevalence of hypophosphatemia was 33.3% (41 of 123 patients). Higher hemoglobin was the only risk factor associated with a higher odds of developing hypophosphatemia (adjusted odds ratio [aOR], 1.56 [95% confidence interval [CI], 1.12-2.18]). Statistically significant protective factors against the development of hypophosphatemia were observed with higher body mass index (aOR, 0.54 [95% CI, 0.39-0.75]), higher serum potassium (aOR, 0.29 [95% CI, 0.14-0.62]), and higher serum prealbumin (aOR, 0.91 [95% CI, 0.84-0.99]).

DISCUSSION

Four independent factors associated with refeeding hypophosphatemia were identified. Identification of findings which correlate with hypophosphatemia, or the lack thereof, has the potential to facilitate appropriate triage of patients with anorexia nervosa for closer monitoring during refeeding.

Refeeding hypophosphatemia in hospitalized adolescents with anorexia nervosa: a position statement of the Society for Adolescent Health and Medicine

Refeeding hypophosphatemia in hospitalized adolescents with anorexia nervosa is correlated with degree of malnutrition. Therefore, when initiating nutritional rehabilitation, clinicians should have a heightened awareness of the possibility of refeeding hypophosphatemia in severely malnourished patients (<70% median body mass index).

Higher caloric intake in hospitalized adolescents with anorexia nervosa is associated with reduced length of stay and no increased rate of refeeding syndrome

PURPOSE

To determine the effect of higher caloric intake on weight gain, length of stay (LOS), and incidence of hypophosphatemia, hypomagnesemia, and hypokalemia in adolescents hospitalized with anorexia nervosa.

METHODS

Electronic medical records of all subjects 10-21 years of age with anorexia nervosa, first admitted to a tertiary children's hospital from Jan 2007 to Dec 2011, were retrospectively reviewed. Demographic factors, anthropometric measures, incidence of hypophosphatemia (≤3.0 mg/dL), hypomagnesemia (≤1.7 mg/dL), and hypokalemia (≤3.5 mEq/L), and daily change in percent median body mass index (BMI) (%mBMI) from baseline were recorded. Subjects started on higher-calorie diets (≥1,400 kcal/d) were compared with those started on lower-calorie diets (<1,400 kcal/d).

RESULTS

A total of 310 subjects met eligibility criteria (age, 16.1 ± 2.3 years; 88.4% female, 78.5 ± 8.3 %mBMI), including 88 in the lower-calorie group (1,163 ± 107 kcal/d; range, 720-1,320 kcal/d) and 222 in the higher-calorie group (1,557 ± 265 kcal/d; range, 1,400-2,800 kcal/d). Neither group had initial weight loss. The %mBMI increased significantly (p < .001) from baseline by day 1 in the higher-calorie group and day 2 in the lower-calorie group. Compared with the lower-calorie group, the higher-calorie group had reduced LOS (13.0 ± 7.3 days versus 16.6 ± 9.0 days; p < .0001), but the groups did not differ in rate of change in %mBMI (p = .50) or rates of hypophosphatemia (p = .49), hypomagnesemia (p = 1.0), or hypokalemia (p = .35). Hypophosphatemia was associated with %mBMI on admission (p = .004) but not caloric intake (p = .14).

CONCLUSIONS

A higher caloric diet on admission is associated with reduced LOS, but not increased rate of weight gain or rates of hypophosphatemia, hypomagnesemia, or hypokalemia. Refeeding hypophosphatemia depends on the degree of malnutrition but not prescribed caloric intake, within the range studied.

The clinical biochemistry of anorexia nervosa

In anorexia nervosa, under-nutrition and weight regulatory behaviours such as vomiting and laxative abuse can lead to a range of biochemical problems. Hypokalaemia is the most common electrolyte abnormality. Metabolic alkalosis occurs in patients who vomit or abuse diuretics and acidosis in those misusing laxatives. Hyponatraemia is often due to excessive water ingestion, but may also occur in chronic energy deprivation or diuretic misuse. Urea and creatinine are generally low and normal concentrations may mask dehydration or renal dysfunction. Abnormalities of liver enzymes are predominantly characterized by elevation of aminotransferases, which may occur before or during refeeding. The serum albumin is usually normal, even in severely malnourished patients. Amenorrhoea is due to hypogonadotrophic hypogonadism. Reduced concentrations of free T4 and free T3 are frequently reported and T4 is preferentially converted to reverse T3. Cortisol is elevated but the response to adrenocorticotrophic hormone is normal. Hypoglycaemia is common. Hypercholesterolaemia is a common finding but its significance for cardiovascular risk is uncertain. A number of micronutrient deficiencies can occur. Other abnormalities include hyperamylasaemia, hypercarotenaemia and elevated creatine kinase. There is an increased prevalence of eating disorders in type 1 diabetes and the intentional omission of insulin is associated with impaired metabolic control. Refeeding may produce electrolyte abnormalities, hyper- and hypoglycaemia, acute thiamin depletion and fluid balance disturbance; careful biochemical monitoring and thiamin replacement are therefore essential during refeeding. Future research should address the management of electrolyte problems, the role of leptin and micronutrients, and the possible use of biochemical markers in risk stratification.

Identification and management of eating disorders in children and adolescents

The incidence and prevalence of eating disorders in children and adolescents has increased significantly in recent decades, making it essential for pediatricians to consider these disorders in appropriate clinical settings, to evaluate patients suspected of having these disorders, and to manage (or refer) patients in whom eating disorders are diagnosed. This clinical report includes a discussion of diagnostic criteria and outlines the initial evaluation of the patient with disordered eating. Medical complications of eating disorders may affect any organ system, and careful monitoring for these complications is required. The range of treatment options, including pharmacotherapy, is described in this report. Pediatricians are encouraged to advocate for legislation and policies that ensure appropriate services for patients with eating disorders, including medical care, nutritional intervention, mental health treatment, and care coordination.

Does aggressive refeeding in hospitalized adolescents with anorexia nervosa result in increased hypophosphatemia?

PURPOSE

Concerns about refeeding syndrome have led to relatively conservative nutritional rehabilitation in malnourished inpatients with anorexia nervosa (AN), which delays weight gain. Compared to other programs, we aggressively refed hospitalized adolescents. We sought to determine the incidence of hypophosphatemia (HP) in 12-18-year-old inpatients in order to inform nutritional guidelines in this group.

METHODS

A 1-year retrospective chart review was undertaken of 46 admissions (29 adolescents) with AN admitted to the adolescent ward of a tertiary children's hospital. Data collected over the initial 2 weeks included number of past admissions, nutritional intake, weight, height, body mass index, and weight change at 2 weeks. Serum phosphorus levels and oral phosphate supplementation was recorded.

RESULTS

The mean (SD) age was 15.7 years (1.4). The mean (SD) ideal body weight was 72.9% (9.1). Sixty-one percent of admissions were commenced on 1,900 kcal (8,000 kJ), and 28% on 2,200 kcal (9,300 kJ). Four patients were deemed at high risk of refeeding syndrome; of these patients, three were commenced on rehydration therapy and one on 1,400 kcal (6,000 kJ). All patients were graded up to 2,700 kcal (11,400 kJ) with further increments of 300 kcal (1,260 kJ) as required. Thirty-seven percent developed mild HP; no patient developed moderate or severe HP. Percent ideal body weight at admission was significantly associated with the subsequent development of HP (p = .007).

CONCLUSIONS

These data support more aggressive approaches to nutritional rehabilitation for hospitalized adolescents with AN compared to current recommendations and practice.

Refeeding syndrome: treatment considerations based on collective analysis of literature case reports

Refeeding syndrome (RFS) represents a group of clinical findings that occur in severely malnourished individuals undergoing nutritional support. Cardiac arrhythmias, multisystem organ dysfunction, and death are the most severe symptoms observed. As the cachectic body attempts to reverse its adaptation to the starved state in response to the nutritional load, symptoms result from fluid and electrolyte imbalances, with hypophosphatemia playing a central role. Because guidelines for feeding the malnourished patient at risk for refeeding syndrome is scarce, we have provided management recommendations based on the knowledge derived from a collection of reported English literature cases of the RFS. A MEDLINE search using keywords including "refeeding syndrome," "RFS," and "refeeding hypophosphatemia" was performed. References from initial cases were utilized for more literature on the subject. We have emphasized the continued importance of managing patients at risk for RFS, compared how management of the severely malnourished patients have evolved over time, and provided comprehensive clinical guidelines based on the sum of experience documented in the case reports for the purpose of supplementing the guidelines available. Based on our review, the most effective means of preventing or treating RFS were the following: recognizing the patients at risk; providing adequate electrolyte, vitamin, and micronutrient supplementation; careful fluid resuscitation; cautious and gradual energy restoration; and monitoring of critical laboratory indices.

Nutrition in clinical practice—the refeeding syndrome: illustrative cases and guidelines for prevention and treatment

The refeeding syndrome is a potentially lethal complication of refeeding in patients who are severely malnourished from whatever cause. Too rapid refeeding, particularly with carbohydrate may precipitate a number of metabolic and pathophysiological complications, which may adversely affect the cardiac, respiratory, haematological, hepatic and neuromuscular systems leading to clinical complications and even death. We aimed to review the development of the refeeding syndrome in a variety of situations and, from this and the literature, devise guidelines to prevent and treat the condition. We report seven cases illustrating different aspects of the refeeding syndrome and the measures used to treat it. The specific complications encountered, their physiological mechanisms, identification of patients at risk, and prevention and treatment are discussed. Each case developed one or more of the features of the refeeding syndrome including deficiencies and low plasma levels of potassium, phosphate, magnesium and thiamine combined with salt and water retention. These responded to specific interventions. In most cases, these abnormalities could have been anticipated and prevented. The main features of the refeeding syndrome are described with a protocol to anticipate, prevent and treat the condition in adults.

Heart failure in anorexia nervosa: case report and review of the literature

OBJECTIVE

To report the presentation and causes of heart failure complicating anorexia nervosa (AN).

METHOD

Report of a case of heart failure occurring in a patient with AN and a review of the literature.

RESULTS

A 56 year old woman with a 25 year history of AN binge-purge subtype experienced increasing shortness of breath on exertion, orthopnea, and swelling of the ankles. Investigations revealed a reduced left ventricular ejection fraction. A diagnosis of heart failure caused by severe prolonged protein-calorie malnutrition was made. She was treated with a diuretic, a beta adrenergic blocker and an angiotension enzyme inhibitor. Her cardiac function returned to normal after a year of refeeding. Protein-calorie malnutrition, ipecac toxicity, and deficiencies of thiamine, phosphorus, magnesium, and selenium have been reported to cause heart failure in patients with AN.

DISCUSSION

If shortness of breath occurs in AN it may be a symptom of heart failure. The diagnosis is further suggested by increased jugular venous pressure, increasing shortness of breath on exertion, and pulmonary crepitations at the bases of the lungs on physical examination. The chest x-ray usually shows pulmonary venous redistribution, the electrocardiogram may be normal, and the echocardiogram should document a reduced left ventricular ejection fraction. Standard medical therapy for heart failure should be started. In addition, a history of ipecac use should be taken, deficiencies should be corrected, and weight restoration can reverse cardiac abnormalities.

Pericardial effusion requiring pericardiocentesis in a girl with anorexia nervosa

OBJECTIVE

Silent pericardial effusion is frequently observed in patients with anorexia nervosa. The nature of the pericardial fluid could never be established, as pericardiocentesis was ethically unfeasible.

METHOD

We describe the case of a girl with anorexia nervosa in whom an initial, clinically irrelevant pericardial effusion increased rapidly, making pericardiocentesis necessary to prevent cardiac tamponade.

RESULTS

It was thus possible to exclude the inflammatory or infectious nature of the pericardial fluid, although the pathogenesis of this cardiac alteration remains obscure.

CONCLUSION

Echocardiographic examination appears to be strongly advisable in patients with anorexia nervosa.

Severe hypophosphatemia in a patient with anorexia nervosa during enteral refeeding

Hypophosphatemia is a seldom but potentially fatal complication of the nutritional recovery or refeeding syndrome in patients with protein-calorie malnutrition or starvation. We report here the case of a 35-year-old anorexic patient who presented a severe but uncomplicated hypophosphatemia during enteral refeeding, despite phosphorus supplementation. Serum phosphorus monitoring is recommended in severely malnourished anorexic patients, particularly during the first week of refeeding, be it parenteral or enteral.

Nutritional strategy in the management of heart failure in adults

The incidence of congestive heart failure (CHF) is increasing in Westernized countries, and patients with CHF experience poor quality of life (functional impairment, high hospitalization rate and high mortality). Malnutrition occurring during the course of CHF is referred to as cardiac cachexia and is associated with higher mortality independent of the severity of CHF. Cardiac cachexia involving a loss of more than 10% of lean body mass can clinically be defined as a bodyweight loss of 7.5% of previous dry bodyweight in a period longer than 6 months. The energy requirements of patients with CHF, whether cachectic or not, are not noticeably modified since the increase in resting energy expenditure is compensated by a decrease in physical activity energy expenditure. Malnutrition in CHF has been ascribed to neurohormonal alterations, i.e. anabolic/catabolic imbalance and increased cytokine release. Anorexia may occur, particularly during acute decompensation of CHF. Function is impaired in CHF, because of exertional dyspnea and changes in skeletal muscle. Decreased exercise endurance seems to be related to decreased mitochondrial oxidative capacities and atrophy of type 1 fibers, which are attributed to alteration in muscle perfusion and are partially reversible by training. Malnutrition could also impair muscle function, because of decreased muscle mass and strength associated with decreased glycolytic capacities and atrophy of type 2a and 2b fibres. With respect to the putative mechanisms of cardiac cachexia, anabolic therapy (hormones or nutrients) and anticytokine therapy have been proposed, but trials are scarce and often inconclusive. In surgical patients with CHF, perioperative (pre- and postoperative) nutritional support has been shown to be effective in reducing the mortality rate. Long term nutritional supplementation trials in patients with CHF and cachexia are thus required to establish recommendations for the nutritional management of patients with CHF.

Anorexia nervosa medical issues

Anorexia nervosa is an increasingly common chronic psychiatric disorder with a multitude of medical complications. Most of these complications are reversible if there is timely restoration of body weight. A few of them, particularly osteoporosis, refeeding complications, and cardiac arrhythmia, are potentially much more serious. In the end, a multidisciplinary team approach with input from a primary care provider who is familiar with these medical sequelae, together with psychiatric and dietary expertise, can effectuate a successful outcome.

Identifying and treating eating disorders

Pediatricians are called on to become involved in the identification and management of eating disorders in several settings and at several critical points in the illness. In the primary care pediatrician's practice, early detection, initial evaluation, and ongoing management can play a significant role in preventing the illness from progressing to a more severe or chronic state. In the subspecialty setting, management of medical complications, provision of nutritional rehabilitation, and coordination with the psychosocial and psychiatric aspects of care are often handled by pediatricians, especially those who have experience or expertise in the care of adolescents with eating disorders. In hospital and day program settings, pediatricians are involved in program development, determining appropriate admission and discharge criteria, and provision and coordination of care. Lastly, primary care pediatricians need to be involved at local, state, and national levels in preventive efforts and in providing advocacy for patients and families. The roles of pediatricians in the management of eating disorders in the pediatric practice, subspecialty, hospital, day program, and community settings are reviewed in this statement.

Hypophosphatemia following self-treatment for anorexia nervosa

Hypophosphatemia is recognized as a serious complication of hospital treatment for patients with anorexia nervosa but may also occur prior to medical intervention.

METHOD

This paper reports a case of severe hypophosphatemia in a patient who consumed large quantities of carbohydrates following a period of dietary restraint.

DISCUSSION

The possible mechanisms underlying the hypophosphatemia in this case are discussed and its management is described.

Haemolytic anaemia in a patient with anorexia nervosa

We report on a 17-year-old female patient with severe anorexia nervosa (AN) (body mass index of 9.8 kg/m(2)) who developed hypophosphataemia (serum phosphate 0.4 nmol/l) and subsequent haemolytic anaemia during oral refeeding. Hypophosphataemia due to an increased phosphate uptake may lead to a reduction of erythrocyte adenosine triphosphate. This mechanism is important for the differential diagnosis of haemolytic anaemia in patients with AN. To prevent this complication, phosphate supplementation should be considered in the refeeding of severely malnourished patients.

Hypophosphatemia secondary to oral refeeding in anorexia nervosa

OBJECTIVE

Hypophosphatemia is a well-known complication of the refeeding syndrome in severe cases of anorexia nervosa, described mostly as a result of refeeding with total parenteral nutrition. Few cases have been reported secondary to either nasogastric or oral refeeding.

METHOD

The authors present three cases in which hypophosphatemia developed secondary to oral refeeding in severe anorexia nervosa.

RESULTS

All 3 patients developed significant hypophosphatemia, to a low of 0.9 mg/dl in two cases and a low of 1. 7 mg/dl in the third. The first patient received close to 3,000 calories per day, along with intravenous fluids, in the hospital; the other 2 patients ate large amounts for several days at home. Caloric restriction and replenishment with phosphorous resulted in a rapid return of phosphorous values to normal levels.

DISCUSSION

Those who treat severely malnourished patients with eating disorders, whether as inpatients or outpatients, need to be vigilant for the development of the refeeding syndrome, even in patients receiving oral refeeding alone.

Review article: recognition and treatment of eating disorders in primary and secondary care

Eating disorders are serious illnesses affecting 1-2% of young women. Patients may present to any doctor, sometimes atypically (e.g. unexplained weight loss, food allergy, infertility, diarrhoea), delaying diagnosis and leading to needless investigation. The cardinal signs are weight loss, amenorrhoea, bingeing with vomiting and other compensatory behaviours, and disturbances in body image with an exaggeration of the importance of slimness. When other causes have been excluded, useful investigations are serum potassium, bone mineral density scanning and pelvic ultrasound. In emaciated patients multiple systems may fail with pancytopaenia, neuromyopathy and heart failure. Clinical assessment of muscle power is used to monitor physical risk. Treatment may involve individual, group or family sessions, using cognitive-behavioural, psychodynamic and family approaches. More severe or intractable illness is treated with day care, with in-patient care in a medical or specialist psychiatric unit reserved for the most severely ill patients. Antidepressants have a place in the treatment of bulimia nervosa unresponsive to psychological approaches, and when severe depressive symptoms develop. The children of people with eating disorders may have an increased risk of difficulties. Support for the patient and family, and effective liaison between professionals, are essential in the treatment of severe eating disorders.

Severe hypophosphatemia. Pathophysiologic implications, clinical presentations, and treatment

We conducted this review to heighten the awareness and describe pathologic manifestations of hypophosphatemia. We present 3 cases of varied manifestations of hypophosphatemia where recognition was delayed. In certain settings, severe hypophosphatemia has significant morbidity and potential mortality. Appreciation of the pathophysiologic basis for organ dysfunction in severe hypophosphatemia should result in early recognition and treatment. We reviewed the English-language literature for reported cases and research studies dealing with pathophysiologic mechanisms subserving clinical manifestations. We observed that depletion of adenosine triphosphate (ATP) would explain most of the derangement noted in cellular functions. Phosphate plays a key role in the delivery of oxygen to the tissue. Lack of phosphate, therefore, leads to tissue hypoxia and hence disruption of cellular function. Severe hypophosphatemia becomes clinically significant when there is underlying phosphate depletion. Otherwise, short-term acute hypophosphatemia is not usually associated with any specific disorder. Chronic hypophosphatemia, on the other hand, results in hematologic, neuromuscular, and cardiovascular dysfunction, and unless corrected, the consequences can be grave. Most of the time hypophosphatemia results from renal loss of phosphate, diagnosed by a fractional secretion of phosphate > 5%. It is hard to provide precise estimates of how many patients are seen with hypophosphatemia annually at academic medical centers. This is complicated by use of chemistry panels that do not measure inorganic phosphate unless specifically ordered. This often leads to delay in correct diagnosis, and, therefore, additional delay in providing appropriate management. A high index of suspicion alone avoids the unnecessary withholding of treatment that can be life saving.

Rapid recovery from anorexia nervosa after a life-threatening episode with severe thrombocytopenia: report of three cases

We report the cases of three patients with anorexia nervosa (AN) who each recovered rapidly after experiencing a life-threatening episode with severe thrombocytopenia. All three cases were the typical restricting-type of AN, occurring in adolescence. They refused to be admitted to a hospital until their general condition had been severely deteriorated. Their lowest platelet counts were 2.9, 4.6, and 2.3 x 10(4)/mm3, respectively. Apparent hemorrhagic tendencies, such as purpura, gingival and nasal bleeding, and gastrointestinal bleeding were observed. The bone marrow examination showed apparent hypoplasia in two patients. No evidence of disseminated intravascular coagulation or autoantibody to platelets was detected. The platelet counts recovered rapidly by water and nutritional supplementation. The recovery from the AN itself was excellent in all three patients without specific psychotherapy.