CBRN Infection Prevention & Critical Care Monitoring 5 — Questions and Answers
Question 1: In a burn unit, which surface is considered the highest-risk vector for cross-contamination between patients?
- Patient bedding
- Healthcare worker hands (Correct answer)
- Air vents in the room
- IV tubing
Correct answer: Healthcare worker hands
Healthcare worker hands are the most common vehicle for pathogen transmission between patients, making hand hygiene the single most important infection control measure.
Question 2: A burn patient receiving mafenide acetate (Sulfamylon) develops tachypnea and a decreasing serum bicarbonate. What is the most likely cause?
- Pulmonary embolism
- Carbonic anhydrase inhibition causing metabolic acidosis (Correct answer)
- Hyperchloremic alkalosis
- Narcotic-induced respiratory depression
Correct answer: Carbonic anhydrase inhibition causing metabolic acidosis
Mafenide acetate inhibits carbonic anhydrase, impairing bicarbonate reabsorption and causing a metabolic acidosis with compensatory hyperventilation.
Question 3: What is the primary goal of early enteral nutrition in the critically burned patient from an infection prevention perspective?
- Preventing hypoglycemia
- Maintaining gut mucosal integrity to prevent bacterial translocation (Correct answer)
- Reducing the need for TPN
- Increasing serum albumin levels rapidly
Correct answer: Maintaining gut mucosal integrity to prevent bacterial translocation
Early enteral nutrition preserves intestinal mucosal integrity, preventing bacterial translocation across the gut wall, which can lead to systemic infection and sepsis.
Question 4: Which factor most increases a burn patient's risk for developing a catheter-associated urinary tract infection (CAUTI)?
- High fluid intake
- Prolonged indwelling urinary catheter use (Correct answer)
- Frequent dressing changes
- Hyperglycemia alone
Correct answer: Prolonged indwelling urinary catheter use
Duration of catheterization is the strongest modifiable risk factor for CAUTI; daily reassessment and early removal are key prevention strategies.
Question 5: A burn patient's arterial blood gas shows pH 7.30, PaCO2 28 mmHg, HCO3 13 mEq/L. How should this be interpreted?
- Respiratory alkalosis with metabolic compensation
- Metabolic acidosis with respiratory compensation (Correct answer)
- Mixed respiratory and metabolic alkalosis
- Uncompensated respiratory acidosis
Correct answer: Metabolic acidosis with respiratory compensation
The low pH with low bicarbonate indicates a primary metabolic acidosis; the low PaCO2 reflects appropriate respiratory compensation (hyperventilation).
Question 6: When should prophylactic systemic antibiotics routinely be administered in burn patients without clinical signs of infection?
- Immediately after admission for all burns >20% TBSA
- Perioperatively for surgical excision and grafting only (Correct answer)
- Daily throughout the hospital stay
- Whenever a fever >38°C is detected
Correct answer: Perioperatively for surgical excision and grafting only
Current guidelines recommend against routine prophylactic antibiotics in burn patients; perioperative prophylaxis for surgical procedures is the accepted exception.
Question 7: A burn patient on continuous renal replacement therapy (CRRT) requires vancomycin for MRSA infection. Which pharmacokinetic consideration is most important?
- CRRT has no effect on vancomycin clearance
- Vancomycin is significantly cleared by CRRT, requiring dosing adjustments and level monitoring (Correct answer)
- Higher doses must always be avoided due to nephrotoxicity risk in CRRT
- Vancomycin should be replaced with oral linezolid automatically
Correct answer: Vancomycin is significantly cleared by CRRT, requiring dosing adjustments and level monitoring
CRRT significantly removes vancomycin, altering standard pharmacokinetics; frequent level monitoring and dose adjustment are essential to maintain therapeutic concentrations.
CBRN Infection Prevention & Critical Care Monitoring 5
In a burn unit, which surface is considered the highest-risk vector for cross-contamination between patients?