We have not printed information on the need for medical letters for quite a few years. Dr. Rebecca S. Wappner is Professor and Section Director of Pediatric Metabolism and Genetics at Riley Hospital for Children in Indianapolis, Indiana. She kindly consented to write about the steps to take in times of sickness including the need for a medical (help) letter.

Sick Days

Everyone with a child who has a metabolic disorder needs to be prepared for those days when the child experiences the flu or a cold and changes need to be made in nutrient intake. With the increased fluid and caloric requirement associated with fever, children with metabolic disorders are at risk of having their disorder become uncontrolled. The best way to prevent this is to increase calories and fluids and reduce the amount of natural protein that is usually taken. Every patient should have a sick day plan and a sick day diet individualized for them by their metabolic staff.

The sick day diet should be started when the individual develops the flu, cold, or other illnesses which decrease appetite. The metabolic doctor should be contacted to see what other measures need to be taken. If you haven't received a return phone call from the metabolic clinic, and you know the sick day plan needs to start, do not hesitate to start it. (An extra batch of formula can always be discarded if not needed.)

For MSUD, the sick day diet is usually 110% to 150% of the usual amount of special medical food (supplement devoid of the branched-chain amino acids) plus additional isoleucine and valine. The isoleucine and valine are calculated at the usual daily dietary intake of the branched-chain amino acids (BCAAs) when milk, regular formula, and/or food is included. If any table foods are taken, they should contain minimal or no leucine so leucine intake is lowered to near zero. The goal is to keep the caloric intake high enough to prevent catabolism or breakdown of the body stores of protein. Urine DNPH testing should be done at least twice a day and a blood test taken to check the level of the BCAAs.

A relatively new drug, Zofran (ondansetron), is now available in a tablet/pill form, in addition to the previously available (expensive) IV form, and can be used to prevent vomiting, especially if the vomiting is related to a gastroenteritis (stomach flu). Phenergan can also be used, but may cause sleepiness. Kaopectate and Imodium-AD can be taken for diarrhea. Check with the doctor for appropriate doses for the age of the child. Also check about any other cold remedies or medications.

As the individual improves, go back to the usual daily formula, and slowly increase the leucine from natural foods over a few days. Be sure to continue to monitor urine DNPH during the time of increasing leucine intake in case a rebound occurs.

Help Letters

Despite early planning and starting sick day formulas, sometimes we are unable to stop an episode of metabolic decompensation - or, vomiting and/or diarrhea continue. It is now time to go to the hospital before things get worse. Every child with MSUD or an organic acidemia should have a "Help Letter" written by their clinic which the family carries with them at all times. This "Help Letter" should contain:

  • Patient's name and date of birth.
  • Diagnosis and a brief explanation of the diagnosis - short, clear, and just enough of the "scary" information to make the ER staff move into action. Example: MSUD is a disorder of BCAA metabolism that results in elevated blood levels of the BCAAs - leucine, isoleucine, and valine. Untreated the disorder can result in vomiting, abnormal neurologic findings, an odor of maple syrup (from abnormal BCAA metabolites), hypoglycemia, acidosis, hyperammonemia, lethargy, coma, and death. MSUD is treated with a special diet, low in leucine, using special medical foods and a limited amount of natural protein foods. Persons with MSUD are at risk for metabolic decompensation at times of decreased caloric intake, i.e., with flu, colds, fasting, or vomiting.
  • Specific directions for the ER staff. Example: If patient's name presents to you for emergency care, it is most important that you see her/him immediately. Blood should be taken for a Dextrostix, electrolytes with CO2 level, serum osmolality, and quantitative amino acids. Urine should be sent for urinalysis and osmolality. If she/he is symptomatic (vomiting, lethargic) do not wait for the results of the studies, but proceed with an IV with D5/W , normal saline and run it at a maintenance rate. Give 2 mEq/Kg sodium bicarbonate as a slow bolus over 20-30 minutes (dilute 1:1 with IV fluids). Watch carefully for signs of increased intracranial pressure; give Mannitol if pressure is present. If you call us when patient's name is in your ER, we would be most willing to assist you in her/his care and give additional instructions.
  • Specific instructions for contacting the metabolic staff in charge of the patient. Example: We can be reached by calling Clinic's number during working hours, or by calling emergency number after hours and weekends, and asking for name(s) of person(s).

Families should plan ahead when traveling in case an episode of metabolic decompensation occurs. Prior to a trip, you should:

  • Make sure you have extra copies of the "Help Letter."
  • Make sure you have supplies you might need if an episode of decompensation starts: Zofran tablets and Kaopectate, extra isoleucine and valine for MSUD, and a supply of IV L-carnitine and protein-free powder for organic acidemias.

Ask your metabolic clinic for a list of the children's hospitals and other metabolic staff along your route. You may even considering driving a certain way, just to be closer to a metabolic clinic in case you need help.


The MSUD Family Support Group is currently funding several research projects and we are proactively looking for researchers interested in developing new treatments or finding a cure for MSUD. Significant funding is necessary if we are to accomplish this goal.
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