Geriatric Clinical Pearls: Cases, Nutrition, and PK/PD Changes

Clinical Case Scenarios

• 85 YO Patient: DM/Osteoporosis (B) → Insufficient physical activity. Recommendation: Calcium supplementation.
• 68 YO Patient: (C) → Nitro 100mg x2, T 4mg. (B) → J/UC/CRP/US (Interpretation unclear, likely lab/imaging tests).
• 82 YO Patient: Pneumonia (Pn) + Pyelonephritis (B) → Ceftriaxone 750 mg once.
• 86 YO Patient: C. difficile Treatment (Tx) (D) → Discontinue Ceftriaxone; initiate Vancomycin.
• 84 YO Patient: Fall Prevention in Elderly → Shortest option (Focus on factors other than fatigue or agility).
• Women with Depression → Treatment: CITALOPRAM.

Key Clinical Concepts and Questions

• Gastrointestinal (GI) Changes with Age (D): Decreased salivary gland function, decreased liver size, decreased detoxification potential.
• Constipation Definition (B): Stool frequency of 2–3 days (Longest option).
• Dementia and Urinary Incontinence (UI) (D): Management involves reminders and adaptation strategies.
• GI Malabsorption Exacerbation (C): Longest option (e.g., NSAID interaction with Warfarin).
• Hypothyroidism (A): TSH 5.5 (2–5% range); associated with decreased cognitive function.
• Microcytic Anemia (B): MCV 85, MCH 26.
• Anemia in the Elderly (C): Associated with Congestive Heart Failure (CHF).
• Chronic Disease (CD) Management in Elderly:
  1. Treatment (A): Focus on glycemic control, avoiding hypoglycemia.
  2. Features (B): Asymptomatic (Asx), classic symptoms, and CD complications.
• Diverticulosis (B): Associated with motor dysfunction in the Large Intestine (LI).
• Menopause (A): Lipid profile changes include increased LDL and Triglycerides (TG), and decreased HDL.
• Osteoporosis and DEXA Scan (B): Defined by 2 clinical fractures or osteoporosis fracture diagnosis.
• Inflammatory Bowel Disease (IBD) (C): Associated with Urinary Tract Infections (UTI) and neurological issues.
• Bone Marrow (BM) Changes with Age (B): Decreased stem cells in blood, decreased granulocytes.
• Most Common Condition in Elderly: Shortest option (e.g., Stroke or Dry Mouth).
• Malnutrition Consequences: Increased morbidity and increased mortality.
• Hypothyroidism Symptoms (Sx) (A): Impaired function.
• Anemia (C): Associated with CHF.

Geriatric Physiological Changes

Changes commonly observed in the elderly:

Hematology: Anemia Calculations and Types

Iron Deficit Formula

Iron Deficit Calculation: Body weight (kg) × (78 × 0.35 × Hb [g/L])

Megaloblastic Anemia

Causes:

• Gastritis
• Malnutrition/Malabsorption
• Gastrectomy

Symptoms (Sx):

• Weakness
• Pallor
• "Brushed" tongue (Glossitis)
• Dementia
• Paresthesia
• Psychosis

Note: Vitamin B12 deficiency often leads to Pernicious Anemia.

Nutrition and Recommended Daily Intake

General recommendations for elderly patients:

• Protein: 1.0–1.25 g/kg/day (or 1.5 g/kg based on initial note)
• Water: 30 ml/kg/day

Specific Micronutrient Recommendations

• Vitamin D: 800–1000 IU (International Units)
• Vitamin B12: 1 mg (1000 μg)
• Folic Acid: 800 μg
• Vitamin C: 75–90 mg
• Potassium: 3500–4700 mg
• Magnesium: 300–350 mg
• Calcium: 1200 mg
• Iron: 8.7–10 mg
• Zinc: 8.7–15 mg
• Selenium: 55 μg

Criteria for Malnutrition and Nutritional Deficiency

1. BMI: 20–22
2. Mid Upper Arm Circumference (MUAC): < 23.5 cm
3. Skinfold Measurement: Men 12.5 mm, Female 16.5 mm, or < 10% decrease by age and sex.
4. Laboratory Tests:
   • Lymphopenia Indexes:
     • < 1.5 × 10⁹ cells/L – Malnutrition
     • < 0.9 × 10⁹ cells/L – Severe Malnutrition
   • Albumin: < 35 (or 30) g/L
   • Pre-albumin: < 100 mg/L
   • Transferrin: < 2 g/L
   • Other Decreasing Indices: Cholesterol, Magnesium (Mg), Iron (Fe), Glucose (Glu), Zinc (Zn), Creatinine.

Rome Criteria for Functional Constipation

Diagnostic criteria often include:

• Less than 3 spontaneous bowel movements per week.
• Feeling of anorectal obstruction in more than 25% of cases.
• Straining with bowel movements in more than 25% of defecation cases.
• Hard stool (Bristol Stool Scale 1 or 2) in more than 25% of cases.
• Sensation of incomplete bowel evacuation in more than 25% of cases.
• Manual maneuvers required during defecation in more than 25% of cases.
• Insufficient criteria to diagnose Irritable Bowel Syndrome (IBS).
• Rare occurrence of normal (soft) stool without the use of laxatives.

Thyroid Disorders in the Elderly

Hyperthyroidism

Treatment (Tx):

• Thioamides (e.g., Methimazole 20–40 mg/day)
• Propylthiouracil 50 mg or Methimazole 5 mg + 10 mg tablets

Symptoms (Sx):

• Affects 25% of people over 65.
• Presentations often involve: Cardiovascular (CVS), Gastrointestinal (GI), Neuropsychiatric, and Neuromuscular systems.

Hypothyroidism

Treatment (Tx):

• Thyroxine 75 μg

Symptoms (Sx):

Symptoms can be subtle or atypical in the elderly:

• Bradycardia
• Dementia
• Depression
• Weight loss/Loss of appetite (Anorexia)
• Myxedema face
• Syncope

Neurology and Sleep Management

Chaos Theory in Health

Management involves physical and mental exercise, and intermittent drug (X) use.

Sleep Treatment (Tx) Options

• Hypnotics
• Melatonin
• Benzodiazepines (BDZ) (consider mean duration)
• Muscle relaxants (e.g., specific drug class)
• Dopamine agonists
• Surgical options
• CPAP (Continuous Positive Airway Pressure)

Vascular Dementia (VaD) vs. Alzheimer's Disease (AD)

Basal Energy Expenditure (BEE) Calculation

I. WHO Formula

• Men: 13.5 × Weight (kg) + 487
• Women: 10.5 × Weight (kg) + 596

II. Harris-Benedict (H-B) Formula

• Men: 66 + (13.7 × Weight) + (5 × Height) - (6.8 × Age)
• Women: 665 + (9.6 × Weight) + (1.8 × Height) - (4.7 × Age)

Pharmacokinetic (PK) and Pharmacodynamic (PD) Changes

Atypical Presentation of Thyrotoxicosis

Thyrotoxicosis (Hyperthyroidism) often presents atypically in the elderly:

1. Cardiovascular (CVD): Atrial Arrhythmia, Heart Failure (HF), Angina.
2. Gastrointestinal (GI): Failure to thrive, Anorexia, Dyspepsia, Abdominal distress, Rapid weight loss.
3. Neuromuscular: Proximal and distal myopathy.

Diagnostic Testing for Severe Pneumonia (Pn)

1. Chest X-ray: Infiltrate may appear 24 hours following symptom onset.
2. Sputum specific tests are often unreliable.
3. Gram staining is often prioritized over culture initially.
4. Blood cultures are not mandatory in all febrile patients.