Anorexia Nervosa

Get a preoperative ECG and read the QT against the electrolytes - An ECG is recommended in these patients specifically to find life-threatening arrhythmias, and bradycardia, arrhythmia, and sudden death are documented cardiovascular complications. Hypokalemia and hypomagnesemia both contribute to torsades de pointes on a prolonged QT, so read the interval alongside the potassium and magnesium rather than in isolation.

Echo when the BMI is very low or the heart is symptomatic - Echocardiography is indicated when BMI is under 14 kg/m2 or there is hemodynamic compromise: dyspnea, a murmur, or syncope. Mitral valve prolapse and echo abnormalities are part of the disease, so an unexplained murmur here earns imaging before an elective case.

Bradycardia and hypotension are the baseline, not the event - Resting bradycardia and low pressures are the expected starved state. Get the ward numbers before induction so you are treating a real change rather than chasing the patient's normal, and remember there is very little reserve left for a further fall in cardiac output.

Send potassium, magnesium, and phosphate - Purging drives hypokalemia and a hypochloremic metabolic alkalosis, and starvation adds magnesium and phosphate depletion. Correct them before an elective anesthetic; hypokalemia on its own produces weakness, hypoventilation, respiratory distress, and arrhythmia.

Refeeding syndrome is a perioperative event, not just a ward one - Any glucose load restarts the shift, and a dextrose infusion and TPN both count. Hypophosphatemia is the hallmark; phosphate under 1.0 mg/dL brings hemolytic anemia, heart failure, tachypnea, seizures, and death, and it impairs myocardial contractility to the point of cardiovascular collapse. Replete phosphate, potassium, and magnesium before parenteral nutrition is started, and advance the regimen slowly.

Check a glucose and do not fast them longer than the case needs - Hypoglycemia is a listed metabolic complication and glycogen stores are gone. Get a point-of-care glucose on arrival and again through a long case.

The respiratory muscles are part of the weakness - Hypokalemia produces weakness, fatigue, paralysis, hypoventilation, and respiratory distress, and hypophosphatemia adds respiratory failure and rhabdomyolysis. Titrate neuromuscular blockade to effect and expect a patient with less to spend on the work of breathing at emergence.

Warm them from the start - Cold intolerance is one of the presenting complaints, and there is very little subcutaneous fat or muscle bulk holding heat. Forced-air warming and warmed fluids from induction, not as a rescue in PACU.

Pad and position for fragile bone - Osteoporosis is a standard endocrine complication, and DEXA is indicated once amenorrhea has run beyond nine months. Position as you would an elderly osteoporotic patient: generous padding, gentle transfers, and no forced range of motion under anesthesia.

Read the psychiatric medication list for cardiac risk - Olanzapine is first-line for the acutely ill, with SSRIs and second-generation antipsychotics used for comorbid depression and anxiety. Tricyclics are avoided because of cardiotoxicity in malnourished patients, and bupropion is avoided in eating disorders because of seizure risk. Several of these stack QT effects onto an already abnormal ECG.

Check the blood count - Pancytopenia from starvation is described, along with a low ESR, and a CBC and coagulation panel are part of the standard workup. Have a hemoglobin and a platelet count in hand before any case with expected blood loss.

Do not write off postoperative vomiting as PONV - Superior mesenteric artery syndrome is specifically looked for with abdominal CT in low-BMI patients, and refeeding pancreatitis and hepatitis are described complications. Persistent vomiting in a very low-weight patient deserves a look rather than another dose of ondansetron.

Anorexia nervosa is restriction of energy intake relative to requirements, producing significantly low body weight alongside an intense fear of gaining weight and a distorted body image. What reaches the operating room is starvation physiology, not a psychiatric diagnosis. Chronic caloric deficit, and in the purging subtype self-induced vomiting, laxatives, and diuretics, give bradycardia and hypotension, mitral valve prolapse, echocardiographic changes, arrhythmia and sudden death, hypoglycemia, thyroid and cortisol derangement, osteoporosis, and pancytopenia from marrow starvation. Cold intolerance, fatigue, and constipation are the everyday complaints. The trap on the other side is refeeding: reintroduced glucose drives an insulin surge that shifts phosphate and potassium into cells, and the resulting hypophosphatemia and hypokalemia produce cardiac and respiratory compromise. Anorexia nervosa carries the highest mortality rate of any psychiatric disorder.