Clinical Puzzles in Parenteral Nutrition & Micronutrient Deficiencies

Short Bowel Syndrome and Parenteral Nutrition

• Short Bowel Syndrome: A condition where the small intestine is shortened or damaged, leading to malabsorption of nutrients.
• Home Parenteral Nutrition (HPN): Essential for individuals with short bowel syndrome to meet nutritional needs, even if they consume food orally.

Water-Soluble Vitamins

• Water-soluble vitamins must be regularly replenished because the body does not store them.

Case Study: Biotin Deficiency (Vitamin B7)

• Patient History: A 54-year-old woman admitted to the University of Michigan Hospital in January 1980 after experiencing a sudden loss of blood flow to her intestines.
  • Removal of the right colon, entire ileum, and most of the jejunum.
  • Remaining small intestine: approximately 21 centimeters reconnected to the colon.
  • Initially maintained weight on a regular diet, but by August, she returned with dehydration and malnourishment.
• Initial Symptoms:
  • Depression
  • Partial memory loss
  • Waxy pallor (pale, piqued, and somewhat shiny skin)
  • Body hair loss
  • Anorexia (medical anorexia, not psychological).
• Treatment and Diagnosis:
  • Oral supplementation of biotin (10 mg/day) – a high dosage.
  • After three weeks, hair regrowth started, but symptoms persisted.
  • Switched to IV supplementation (5 mg/day).
  • One month later, serum and urine levels returned to normal.
  • Maintenance IV dose via HPN: 60 micrograms/day.
• Deficiency Identification: Identified as Biotin (B7) deficiency due to the patient's symptoms and treatment response.

Biotin (Vitamin B7) Details

• Function:
  • Cofactor for carboxylase enzymes.
  • Important for metabolic reactions: gluconeogenesis, fatty acid synthesis, and amino acid metabolism.
  • Supports energy production by converting food into usable energy.
  • Regulates gene expression.
  • Plays a role in DNA replication.
  • Important for fetal development, especially in the nervous system.
• RDA for Pregnant Women: 30-35 micrograms.
• Importance: Maintenance of hair, skin, and nails.
• Deficiency Symptoms: Relate to malabsorption and other vitamin deficiencies.
• Historical Context: Biotin was not routinely included in TPN solutions in 1980, contributing to the oversight in this case.
• Identification and Prevention: Regular vitamin and nutrient panels are crucial, especially for patients on parenteral nutrition, to prevent deficiencies often overlooked in favor of macronutrient needs.

Differential Diagnosis: Similar Symptoms

• Other Nutrient Deficiencies Mimicking Biotin Deficiency: Niacin and B12 deficiencies can cause dermatitis and neurological changes similar to biotin deficiency.
• Biotinidase Deficiency: A rare disorder where the body has trouble absorbing biotin due to the deficiency in the biotinidase enzyme and can be caused by consuming raw egg whites (raw egg white disease).
• Biotin Recommendations: 30 micrograms for the general population and 35 micrograms for pregnant women.
• Food sources of biotin include liver, avocado, nuts, and seeds.

Case Study 2: Potassium Imbalance and Other Complications

• Patient Profile: 72-year-old male with heart failure, type 2 diabetes (managed with diet), osteoarthritis, and hypertension.
• Initial Labs: Low blood pressure and slightly acidic pH.
• Medications:
  • Enalapril (ACE inhibitor) for hypertension.
  • Spironolactone (Potassium-sparing diuretic).
  • Metoprolol for heart failure.

Potassium Physiology and Hyperkalemia

Normal serum potassium levels are 3.5 - 5
ormal{mM/L}. Hyperkalemia is when the potassium levels are above 5.5
ormal{mM/L}. It can be potentially life-threatening. It's typically due to the kidney's inability to excrete potassium.

• Causes of Hyperkalemia:
  • Excessive potassium intake (e.g., salt substitutes).
  • Increased potassium production (e.g., burns, hemolysis, intense physical activity).
  • Decreased excretion (kidney issues/drugs).
• Signs and Symptoms: Often general symptoms:
  • Muscle weakness.
  • Flaccid paralysis (weak, floppy, unresponsive muscles).
  • Lethargy.
  • Confusion.
• Diagnosis: ECGs are a diagnostic tool. ECG changes indicate issues, though lab values showing potassium weren't initially provided.

Case Study 3: Magnesium Deficiency & Patient Counseling

• Patient Background:
  • The patient drinks more alcohol than normal (amount unspecified) and has switched to pre-packaged foods for convenience.
  • Takes a calcium supplement without specific guidance.
  • Smokes 5-10 cigarettes daily.
  • Spends hours in the backyard gardening.
  • Reports occasional numbness and tingling in her hand.
• Diet Recall Concerns: Likely vitamin C deficiency and no vegetables.
• Calcium Supplementation:
  • Evaluate calcium intake from fortified orange juice.
  • Discuss the necessity of calcium supplementation given her diet, rather than abruptly telling her to stop.
  • Counsel in a way that educates about dietary sources of calcium.

Magnesium Deficiency

• Relevance to Case: Magnesium deficiency is a key issue.
• Causes: Increased alcohol intake and antibiotic use.
• Role of Magnesium:
  • Essential for bone health.
  • Required for vitamin D conversion into its active form.
  • Helps in calcium regulation for bone health.
• Leads to poor bone health and an increased risk of fractures.
• Treatment: Magnesium supplementation.
• In severe cases, intravenous magnesium might be required. The patient had experienced three fractures in a short period.

Scope of Practice and Patient Care

• Addressing Alcohol Use and Smoking:
  • Consider addressing alcohol use and smoking in follow-up appointments.
  • These could be coping mechanisms, so the approach should be sensitive.
• Referral to Social Work:
  • Important to refer the patient to a social worker for substance use and other psychosocial issues.
  • Additionally, for caretaker support and financial concerns.
  • For help accessing resources and nutrition.