Initial treatment of ventilator-associated pneumonia with an appropriate antibiotic regimen has been found to reduce hospital mortality in these patients. Appropriate antimicrobial treatment would be antibiotics with in vitro activity against an identified bacterial species. The result of delaying administration of appropriate antibiotics for this infection has not been studied nor has the effect of delay on patient outcomes. Iregui and associates determined the impact of initially delayed appropriate antibiotic treatment on outcome in patients with ventilator-associated pneumonia.

The trial was a prospective surveillance and data collection of consecutive patients receiving mechanical ventilation and antibiotic treatment for ventilator-associated pneumonia. Patients in an intensive care unit (ICU) at a university-affiliated urban teaching hospital were enrolled. Patients with community-acquired pneumonia were enrolled if a new infiltrate developed after they had received mechanical ventilation for at least 48 hours while empiric antibiotic treatment was ongoing. Appropriate empiric antibiotic therapy for this pneumonia was based on previous experience in identifying the most common bacterial infections in that ICU. Delay in appropriate antibiotic treatment was defined as starting therapy at least 24 hours after the diagnosis of ventilator-associated pneumonia was established. The primary outcome measure was hospital mortality. Secondary outcomes included the duration of mechanical ventilation, hospital and ICU lengths of stay, mortality attributed to ventilator-associated pneumonia, and disposition following hospitalization.

Of the 107 patients who met the inclusion criteria, 33 received delayed antibiotic therapy. The most common reason for postponing antibiotic therapy was delay in writing antibiotic orders. Patients who had a delay in receiving antibiotics had an average interval of 29 hours from meeting diagnostic criteria to first antibiotic administration, while the average interval for the entire group was 12 and one-half hours. Forty-four patients died as a result of ventilator-associated pneumonia during the study. Patients in which initiation of appropriate antibiotic treatment was delayed had a substantially higher risk for mortality than those who received antibiotics within 24 hours.

The authors conclude that patients with ventilator-associated pneumonia who had delayed initiation of appropriate antibiotic therapy were at greater risk for hospital mortality than those who received antibiotics within 24 hours of diagnosis. To eliminate this delay, the authors suggest that physicians initiate antibiotic therapy based on the pathogens most commonly occur in the local clinical setting and modify therapy if necessary after appropriate cultures and stains are obtained.