Ventilator-associated pneumonia: monotherapy is optimal if chosen wisely.

Traditionally, ventilator-associated pneumonia (VAP) has been treated either with double drug therapy or with monotherapy. Double drug therapy has been used to increase spectrum, for possible synergy, and to decrease the emergence of resistance. VAP therapy should be directed primarily against Pseudomonas aeruginosa, which also provides aerobic Gram-negative coverage, the usual pathogens in VAP. The potent anti-P. aeruginosa antibiotics available today have sufficient activity that double drug coverage is unnecessary. Double drug therapy does not decrease resistance if a 'high resistance potential' antibiotic is used in the combination. The study by Damas and colleagues in this issue of Critical Care supports monotherapy for VAP. Optimal therapy for VAP involves selecting a potent anti-P. aeruginosa antibiotic with a 'low resistance potential' that minimizes drug-drug interactions, minimizes resistance, and is cost effective. Monotherapy of VAP should be the standard of care.