What is the diagnosis and treatment of protein calorie malnutrition?

Diagnosis and Treatment of Protein Calorie Malnutrition

Protein calorie malnutrition (PCM) is diagnosed through a combination of weight loss assessment, BMI calculation, muscle mass evaluation, reduced food intake measurement, and inflammatory markers, with treatment focusing on adequate protein-calorie supplementation based on severity.

Diagnostic Criteria for PCM

Definition and Classification

• PCM is defined as a condition of decreased body stores of protein and energy fuel that can occur regardless of cause and is associated with diminished functional capacity related to metabolic stresses 1
• Severity classification:
  • Moderate PCM: Non-volitional weight loss of 5-10% within past 6 months or 10-20% beyond 6 months 2
  • Severe PCM: Weight loss of >10% within past 6 months or >20% beyond 6 months 1, 2

Key Diagnostic Parameters

• BMI thresholds:
  • Moderate: <20 kg/m² if <70 years old and <22 kg/m² if ≥70 years old 2
  • Severe: <18.5 kg/m² if <70 years old and <20 kg/m² if ≥70 years old 2
• Reduced muscle mass (sarcopenia) assessed through validated methods 1, 2
• Reduced food intake:
  • Moderate: Any reduction below energy requirements for >2 weeks 2
  • Severe: ≤50% of energy requirements for >1 week 2
• Disease burden/inflammation from acute illness or chronic disease 2

Assessment Methods

Screening Tools

• Use validated screening tools within 24 hours of hospital admission 3:
  • Nutritional Risk Screening 2002 (NRS-2002) - recommended by ESPEN for surgical and critically ill patients 4
  • Subjective Global Assessment (SGA) - effective for geriatric patients 4
  • Mini Nutritional Assessment Short-Form (MNA-SF) - suitable for polymorbid patients including those with cognitive dysfunction 4
  • Global Leadership Initiative on Malnutrition (GLIM) criteria - two-step approach with screening followed by assessment 4

Physical and Anthropometric Assessment

• Measure weight and height to calculate BMI, correcting for fluid retention when applicable 5, 2
• Assess for visible signs of muscle wasting (sarcopenia) 5
• Measure mid-upper arm circumference and derived midarm muscle circumference to evaluate muscle mass 5
• Evaluate handgrip strength as a functional measure of nutritional status 1, 5
• Document functional status using validated scales such as WHO or Karnofsky scale 4, 5

Laboratory Assessment

• Measure serum proteins including albumin and prealbumin (noting these are also affected by inflammation) 1, 5
• Check inflammatory markers like C-reactive protein to correctly interpret albumin levels 5
• Assess total lymphocyte count as an indicator of immune function 1
• Evaluate electrolytes, minerals, and triglycerides 2

Dietary Intake Assessment

• Monitor dietary intake for several days using semi-quantitative methods 4
• Food intake equal to or less than 50% of energy requirements over 3 days should trigger nutritional intervention 4
• Compare actual intake to estimated requirements 5
• Assess for appetite loss, which has high prognostic power in predicting malnutrition risk 5

Treatment Approach

Nutritional Requirements

• Protein needs: 1.0-2.0 g/kg of body weight per day 3
• Caloric needs: 25-30 kcal/kg of body weight per day 3
• Higher protein intake of 1.2-1.5 g/kg/day is recommended for treatment 2

Intervention Strategies

• Oral nutritional supplements for mild cases of malnutrition in patients who can consume food orally 3
• Enteral tube feedings when oral intake is insufficient but gastrointestinal tract is functional 3
• Parenteral nutrition for patients with non-functional gastrointestinal tract 3
• Early nutritional support, within 48 hours of hospital admission, to prevent further muscle wasting 2

Special Considerations

• In liver disease, PCM is found in 65-90% of patients with end-stage disease 1, 2
• Weight loss should not be recommended in patients with decompensated end-stage liver disease 1, 2
• Accurate estimation of nutritional status is complicated by fluid retention in liver disease 1, 5
• In kidney disease, BMI may underestimate malnutrition in overhydrated patients 2

Monitoring and Follow-up

• Regular reassessment of nutritional status and adjustment of interventions according to the patient's changing condition 5
• Regular weight measurement and examination for edema or ascites 4
• Determination of calorie-nitrogen ratio intake regularly 4
• Assessment of any improvement in functional capacity 4

Common Pitfalls and Caveats

• Fluid retention in conditions like liver or kidney disease may mask the severity of weight loss 1, 2
• Restrictive diets should be avoided due to the risk of worsening malnutrition 4
• Multiple dietary restrictions can lead to reduced food choices and increased risk of malnutrition 4
• Serum proteins like albumin are affected by inflammation and may not accurately reflect nutritional status alone 5, 2