What is the best way to manage an infection in an adult, including nutrition and medication?

Managing Infection in Adults: Nutrition and Medication

For adult infections requiring hospitalization, initiate early nutrition screening and provide high-protein nutritional support (targeting 20-25% above normal protein requirements) alongside appropriate antibiotic therapy, as malnutrition significantly increases mortality and hospital length of stay. 1

Immediate Assessment and Antibiotic Initiation

Severity Assessment

• Screen for malnutrition risk immediately upon presentation using validated tools, as 37% of general medical inpatients with infection are malnourished, rising to 53% in elderly patients 1
• Assess for high-risk features including older age, polymorbidity, immunocompromised status, pre-existing malnutrition, and ICU-level illness 1
• Monitor vital signs at least twice daily: temperature, respiratory rate, pulse, blood pressure, mental status, and oxygen saturation 1, 2

Antibiotic Selection

• For community-acquired pneumonia, initiate amoxicillin 500-875 mg every 12 hours or 250-500 mg every 8 hours as first-line therapy, taken at the start of meals to minimize gastrointestinal intolerance 3
• For severe infections or hospital-acquired pneumonia, use piperacillin-tazobactam 3.375g IV every 6 hours plus azithromycin for broad-spectrum coverage including resistant organisms 4, 5
• Do not delay antibiotic therapy while awaiting diagnostic results, as this consistently increases mortality 5
• Continue treatment for minimum 48-72 hours beyond symptom resolution, with at least 10 days for streptococcal infections 3

Nutritional Management Strategy

During Acute Infection Phase

• Optimize oral intake as first-line intervention through dietary counseling and individualized nutrition from experienced professionals 1
• Provide high-protein, volume-restricted formulas when oral intake is inadequate 1
• Target protein intake 20-25% above normal requirements (approximately 1.2-1.5 g/kg/day) during acute infection to minimize protein loss 6
• Consider oral nutritional supplements (ONS) early, as 6-74% of hospitalized infection patients require supplementation 1
• Progress to enteral nutrition (nasogastric feeding) if oral intake remains insufficient, which improves nutritional status and reduces hospital length of stay compared to parenteral nutrition 1

Micronutrient Support

• Ensure adequate intake of immune-supporting micronutrients including vitamins A, C, D, E, B6, B12, folic acid, iron, selenium, and zinc through balanced diet 7, 8
• Avoid single-nutrient supplementation unless documented deficiency exists 9
• Consider multinutrient supplementation only in patients with pre-existing deficiencies, not in those with adequate dietary intake 9

Monitoring Nutritional Status

• Measure weight and food intake routinely during hospitalization 1
• Monitor C-reactive protein on days 1 and 3-4 in patients with unfavorable clinical parameters 5
• Reassess nutritional risk if patient fails to improve by 72 hours 5

Supportive Care Measures

Hydration and Symptom Management

• Ensure adequate hydration with IV fluids if oral intake is poor, but avoid fluid overload 1, 2
• Advise patients to drink plenty of fluids and rest 1
• Provide simple analgesia (paracetamol) for pleuritic pain 1
• Address infection-specific symptoms: breathlessness, dry mouth, loss of taste/smell, and gastrointestinal issues with targeted advice 1

Oxygen Therapy

• Titrate oxygen to maintain SpO2 >92% and PaO2 >8 kPa (60 mmHg) 1, 4
• High concentrations can be safely given in uncomplicated pneumonia 1
• In patients with COPD, guide oxygen therapy by repeated arterial blood gas measurements to avoid hypercapnic respiratory failure 1, 5

Post-Discharge and Recovery Phase

Continued Nutritional Support

• Provide individualized dietetic-led care during and after hospitalization, which significantly improves nutritional and clinical outcomes 1
• Continue nutrition support for 6 months post-discharge in older adults, which improves daily energy and protein intake, malnutrition risk scores, and reduces readmission rates 1
• Combine nutritional support with multidisciplinary rehabilitation for optimal functional recovery 1

Follow-Up Planning

• Review patients 48 hours after initiating treatment, or earlier if clinically indicated 1
• Repeat chest radiograph in patients not progressing satisfactorily 1
• Consider further investigations including bronchoscopy if signs, symptoms, and radiological abnormalities persist 6 weeks after completing treatment 1

Critical Pitfalls to Avoid

• Do not withhold nutritional support during acute infection based on outdated concerns about "feeding the infection" - the evidence shows nutritional support improves outcomes 1
• Avoid aminoglycosides as monotherapy due to poor respiratory secretion penetration 5
• Do not continue escalating ineffective therapies (e.g., bronchodilators for unresponsive wheezing) while delaying appropriate treatment 4
• Recognize that bilateral infiltrates carry high mortality risk requiring aggressive early management 4
• Do not assume adequate nutrition post-discharge - up to 78% of post-ICU patients require dietetic input during rehabilitation 1

Special Considerations

Renal Impairment

• For GFR 10-30 mL/min: reduce amoxicillin to 250-500 mg every 12 hours 3
• For GFR <10 mL/min: reduce to 250-500 mg every 24 hours 3
• Hemodialysis patients: administer additional dose during and at end of dialysis 3

Dysphagia Management

• Screen for dysphagia, present in up to 52% of hospitalized infection patients 1
• Provide texture-modified diets as needed (required in 55-89% of patients with dysphagia) 1
• Address post-extubation dysphagia specifically in ICU patients 1