Define Biochemical and Metabolic Problems and their Management?
Hypokalaemia (low concentration of potassium ion in the blood), we learnt earlier, is a problem caused due to self-induced vomiting and/or laxative misuse. For this potasium supplementation is often required. Hyponatraemia (deficiency of sodium) may result from diarrhoea and vomiting, misuse of diuretics or excessive intake of water. Rapid correction of hyponatraemia and the use of hypertonic fluids are hazardous. Hence, medical treatment becomes important. Further, in patients with eating disorder, iron, folic acid deficiency may occur and those who have been avoiding animal foods may be deficient in vitamin B,, as well. However, supplemental iron may be dangerous in the early stages of refeeding. Some people with eating disorders are also deficient in zinc. Zinc deficiency may cause altered taste, smell, appetite, as well as, a variety of neuropsychiatric symptoms. Taking zinc supplements may help. Recent studies with bulimia patients indicate that zinc supplements seem to reduce their obsession with weight and concern with body image. A significant proportion of patients are deficient in thiamin and the increase in carbohydrate metabolism which occurs during refeeding may exhaust inadequate thiamin reserves. The early stages of refeeding are a high-risk period for biochemical, fluid balance and cardiovascular abnormalities and patients should be monitored closely. Patients at particular risk include those whose weight is very low, those who have had previous biochemical abnormalities or purge, and those with concurrent medical conditions such as diabetes, infection and major organ failure. Electrolyte disturbances are most likely to occur during the first 1-2 weeks of refeeding. There is a risk of hypophosphataemia (deficiency of phosphate) and acute thiamin deficiency when beginning refeeding. Abnormal liver function tests can occur at presentation or during refeeding. This appears to be self-limiting but other causes of liver dysfunction should be excluded. Delayed gastric emptying results in early satiety and sensations of abdominal fullness or bloating. Use of frequent small meals may help with this; metoclopramide may be used (usually in a reduced dosage of 5 mg three times daily), but is often of only limited effectiveness.