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Case 37 

Case 37
Chapter:
Case 37
Author(s):

Alissa J. Walsh

, Otto C. Buchel

, Jane Collier

, and Simon P.L. Travis

DOI:
10.1093/med/9780199557899.003.37
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Subscriber: null; date: 09 July 2020

A 19-year-old first-year university student was transferred to the emergency department shortly after the start of her second term, bedridden for a week, and with a history of anorexia nervosa.

On examination, she weighed 28.8kg (BMI 10.9kg/m2), had a bradycardia (pulse 46bpm), a temperature of 35.6°C, and blood pressure 94/57mmHg.

Investigations showed:

  • Hb 17.5g/L, WCC 9.0 × 109/L, platelets 79 × 109/L

  • Na 140mmol/L, K 3.6mmol/L, creatinine 84μ‎mol/L

  • Phosphate 0.33mmol/L, magnesium 0.92mmol/L

  • Bilirubin 58μ‎mol/L, ALT 540 IU, ALP 570 IU, albumin 39g/dL

  • CRP normal

Over the next 2 days, her blood results changed (Table 37.1).

Table 37.1 Change in blood results

Day

Na

K

Cr

Ca

P

Mg

Bil

ALT

ALP

Alb

Hb

Pl

1

140

2.8

73

2.35

0.72

0.83

67

586

628

35

14.3

45

2

139

3.6

70

2.25

0.65

0.84

68

601

681

36

15.2

33

Questions

  1. 37a) What is the most likely cause of hypothermia, bradycardia, and thrombocytopenia with abnormal liver function tests in this patient?

  2. 37b) What other diagnoses should be considered in a patient with anorexia nervosa?

  3. 37c) How is the patient’s condition best treated?

  4. 37d) What is the legal context in which treatment is conducted?

  5. 37e) What is the short-term and long-term prognosis?

Answers

  1. 37a) What is the most likely cause of hypothermia, bradycardia, and thrombocytopenia with abnormal liver function tests in this patient?

    Anorexia nervosa is the likely cause of all of this patient’s medical problems. Virtually all organ systems are disrupted through starvation, characterized by anorexia nervosa. This patient is critically ill and needs admission for emergency medical care. The most striking feature is the BMI of 10.9kg/m2. Thrombocytopenia and abnormal liver function tests occur at a very late, pre-terminal stage of starvation.

    Anorexia nervosa is a complex psychiatric illness with potentially severe medical consequences. Patients in the pre-terminal phase commonly have bradycardia, hypotension, and dehydration; amenorrhoea and leucopenia occur at an earlier stage. Delayed gastric emptying, hair loss, and the presence of lanugo (a fine hair pattern on the face, neck, and trunk) are also associated with severe anorexia nervosa. Anaemia should not be attributed to anorexia nervosa without further investigation (below). Of particular concern for adolescents is the potential for delayed onset of puberty and growth. Malnutrition and hormonal dysfunction may contribute to bone loss.

    Functional and structural brain abnormalities may also occur in individuals with anorexia nervosa, including enlarged ventricles and decreased grey matter or cognitive deficits in problem solving, attention, memory, and verbal or visuospatial processing. This leads to disorders of executive functioning, so that rational decision making is impaired. This needs to be understood by the general medical team, who are otherwise inclined to dismiss such patients as ‘mad’. The attitude that such patients have a self-inflicted injury and must accept the consequences, because they ‘do not know what is good for them’ is a complete failure to understand the cognitive consequences of starvation.

    Electrolyte disturbances may be exacerbated by purging or induced vomiting. Elevated hepatic transaminases and renal insufficiency are warning signs of impending death. Cardiac arrhythmias (including a prolonged QT interval) with sudden death are the consequence of hypokalaemia, hypomagnesaemia, or hypophosphataemia.

  2. 37b) What other diagnoses should be considered in a patient with anorexia nervosa?

    Other diagnoses that should be considered include:

    • Coeliac disease: an anti-endomysial antibody should be checked as part of this patient’s workup

    • Crohn’s disease: a high CRP, anaemia, or thrombocytosis should always raise the possibility of Crohn’s disease, which can present with anorexia, weight loss, and no pain or diarrhoea. Sadly there is a substantial literature on Crohn’s disease misdiagnosed as anorexia nervosa

    • Addison’s disease (or pituitary failure) should be considered if there is a low Na with a normal or relatively high K. Very readily overlooked

    • Paracetamol (or other drug) overdose may account for the abnormal liver function tests and needs to be considered in the context of acute deterioration in any patient with anorexia nervosa

    • Always beware a diagnosis of anorexia nervosa if the individual does not have the disturbed body image that characterizes the condition.

  3. 37c) How is the patient’s condition best treated?

    The metabolic mayhem must be recognized as an emergency, but careful re-feeding will reverse the abnormalities. The major adverse consequence of medical treatment of patients with anorexia nervosa is the refeeding syndrome (see Case 49), which is potentially life threatening. The principal biochemical features of this syndrome are hypophosphataemia, hypomagnesaemia, hypokalaemia, fluid retention, and thiamine deficiency. This causes peripheral oedema (a useful clinical sign of pre-terminal anorexia), congestive heart failure, cardiac dysrrhythmias, skeletal muscle weakness, respiratory failure, metabolic acidosis, ataxia, seizures, or encephalopathy and death.

    When a patient with anorexia nervosa has hypokalaemia, hypophosphataemia, elevated transaminases, bradycardia, or thrombocytopenia, urgent intravenous treatment is necessary.

Initial management

Intravenous fluids are required to correct dehydration.

Electrolyte (K, Mg and P) replacement: the patient should be monitored twice daily until stable, which is usually within 72–76 hours (refeeding guidelines: see Case 49).

Intravenous vitamins are required, including thiamine (e.g. Pabrinex 2 vials, for 3 days).

Monitoring: pulse rate, blood pressure and temperature should be monitored every 6 hours. Patients with heart rates <50 beats/min or orthostatic hypotension should be on bed rest.

Psychiatric asessment (see below), almost invariably requiring detention under the Mental Health Act or equivalent, is required to ensure compliance with controlled refeeding.

Controlled refeeding: oral refeeding is the best approach to weight restoration, but patients who are critically ill with electrolyte disturbance require controlled nasogastric feeding. Such patients are archetypal manipulators, encouraging doctors and nurses to believe that such an invasive approach is unnecessary, that they have learned a lesson, and that oral refeeding is possible. When life is threatened by transaminitis, electrolyte disturbance, or bradycardia, do not believe it. It is important to liaise with the consultant psychiatrist, but the cognitive impairment associated with starvation precludes rational behaviour. Such patients create havoc on a general ward, preventing controlled refeeding and calling on staff out of hours to change their treatment. Although nasogastric feeding can be viewed as coercive by patients, in retrospect, most patients and families consider nasogastric feeding to have been helpful in recovery. It helps to have defined protocols for management and (as importantly) to stick to agreed treatment plans.

Dietitian: a weight gain of 0.2kg/day is a reasonable goal. The dietitian is best placed to be the single person who governs the refeeding regimen, and without whose sanction no treatment is ever changed. This appears unduly dogmatic, but without a single person responsible for controlled refeeding, the regimen is always manipulated and changed, usually by appeal to doctors on call or nurses unfamiliar with the treatment plan. It should be emphasized that the dogmatic approach to controlled refeeding only applies to the stage of biochemical disturbance, since this is a life-threatening event. Once refeeding has been accomplished, a cooperative consensual approach is (inevitably) more productive.

Continuous supervision: a framework for managing patients with life-threatening anorexia nervosa is best established in advance. In practice, patients with biochemical disturbance requiring nasogastric refeeding should have 1:1 care with a psychiatric nurse or assistant. This may seem an impossible goal, but without continuous attention, the patient will interrupt feeding (pull out the tube, tip the feed down the sink), march up and down the ward to burn energy, or binge on carbohydrates rather than follow a controlled eating schedule. This then defeats the object. Since the mortality of severe anorexia nervosa is 30%, any other condition with this mortality would merit special nursing care.

Consistent nursing instructions: so challenging to general medical and nursing staff are these patients that a protocol agreed in advance (between general physician, psychiatrist and appropriate specialist colleagues) is the only way to ensure consistent care.

Distinguish between the medical emergency of the refeeding phase for biochemical disturbance, and the psychiatric phase for addressing the psychological disturbance that has lead to anorexia nervosa.

Long-term management

Medical hospitalization is often brief and does not allow adequate time for psychiatric intervention. Liaison with a psychiatrist with a special interest in eating disorders is a crucial part of continuing management and care.

  1. 37d) What is the legal context in which treatment is conducted?

    A key concept in the ethical and legal analysis relating to compulsory treatment is that of the capacity to consent to, or refuse, treatment. An adult patient with such capacity has the right to refuse any, even life-saving, treatment. On this account, compulsory treatment is only justified if the patient lacks capacity. Most mental health statutes internationally allow mental health professionals to detain and treat patients with a psychiatric disorder who are at risk to themselves or others, without consideration of whether or not the patient lacks capacity. There are exceptions to this, since the question of capacity is the key factor in the compulsory treatment of anorexia nervosa.

    Treatment without consent and the management of treatment refusal is particularly contentious in the context of anorexia nervosa. The dilemma is that it is very difficult to engage patients in psychological therapies if treatment is compulsory. Furthermore, refeeding unwilling patients may lead to short-term weight gain, but be ineffective in the long run.

    Outcome studies suggest that the long-term prognosis following compulsory treatment is poor. Even if compulsory treatment were shown to be effective, there remains an ethical debate about the circumstances in which compulsory treatment is justifiable. Anorexia nervosa at a pre-terminal phase often involves implementing a refeeding programme that requires the use of strict supervision, enforcement of specific dietary plans, prevention of exercising or purging, and nasogastric feeding. Recommendations will vary according to the jurisdiction, but it behoves any doctor or carer to make themselves aware of the legal constraints that govern practice.

  2. 37e) What is the short-term and long-term prognosis?

    Although weight-restoration therapy is reliably helpful in the short-term management of anorexia nervosa, the long-term benefit remains unclear. Even after successful completion of structured behavioural programmes, attitudes about weight and eating behaviour remain abnormal. As a result, relapse rates are high. For inpatient treatment programmes, nearly 50% with anorexia nervosa who undergo weight-restoration therapy have a relapse during the first year after hospitalization.

    After weight restoration, outpatient treatment specifically aims to prevent relapse. Patients and families are informed about the need for vigilance regarding eating behaviour and weight. The specific type of relapse prevention is selected on the basis of the patient’s previous therapy and success with initial attempts at weight maintenance.

    Estimates of long-term full recovery for adolescents with anorexia nervosa range from 33% to 57%, so relapse is common. There are few controlled studies on the efficacy of relapse-prevention strategies. Antidepressant medication appears to be of limited value, although cognitive behavioral therapy may help some patients. Additional studies are needed to identify the essential components of care for patients with anorexia nervosa, as well as relapse-prevention strategies.

    People with anorexia nervosa have a 6–7-fold increase in mortality (including natural and unnatural causes of death). Anorexia nervosa itself has a standardized mortality ratio of 650. Suicide accounts for 20–30% of deaths in anorexia nervosa. Factors associated with an increase in fatal outcome include:

    • Older age at first admission (>20 years of age)

    • Repeated admissions

    • Hospitalization for other psychiatric and somatic disorders.

Further reading

Attia E, Walsh BT (2008). Behavioral management for anorexia nervosa. New Engl J Med; 360: 500–6.Find this resource:

Papadopoulos FC, Ekbom A, Brandt L, Ekelius L (2009). Excess mortality, cause of death and prognostic factors in anorexia nervosa. Br J Psychiatry; 194: 10–17.Find this resource:

Sylvester C, Forman S (2008). Clinical practice guidelines for treating restrictive eating disorder patients during medical hospitalisation. Curr Opin Paed; 20: 390–97.Find this resource:

Tan JOA, Hope T, Stewart A, Fitzpatrick R (2006). Competence to make treatment decisions in anorexia nervosa: thinking processes and values. Philos Psychiatry Psychol; 13: 267–82.Find this resource: