ObjectiveTo determine whether the institution of a methicillin-resistant Staphylococcus aureus prevention protocol was associated with a decrease in methicillin-resistant S. aureus ventilator-associated pneumonia in long-term, acute care ventilator patients.DesignA retrospective chart review comparing the number of episodes of clinical pneumonia per patient ventilator day in the 12 months preceding and 24 months following the introduction of the protocol.SettingUniversity affiliated, long-term, acute care ventilator hospital.PatientsLong-term, acute care ventilated patients who presented with clinical pneumonia.InterventionsAddition of a methicillin-resistant S. aureus prevention protocol. In addition to universal precautions, the protocol consisted of mupirocin 2% ointment applied to the anterior nares, and whole body washing with chlorhexidine. All patients were given mupirocin and chlorhexidine twice weekly. Patients were cohorted in the same room if they were, or had been, infected or colonized with methicillin-resistant S. aureus in any anatomical location or at any time. This procedure replaced strict isolation of methicillin-resistant S. aureus-infected or colonized individuals.Measurements and Main ResultsClinical pneumonia was diagnosed when a patient developed fever, bronchorrhea, increased white blood cell count, methicillin-resistant S. aureus isolated from the tracheal aspirate, and new or increasing infiltrate on chest roentgenograph.During the 12 months preceding the protocol, there were 0.2% episodes of methicillin-resistant S. aureus ventilator-associated pneumonia per ventilated patient day compared with 0.026% in the 24 months after the protocol (p < .001). The relative and absolute risk reductions associated with the introduction of the protocol were 87% and 6, respectively.ConclusionsThe period following the institution of the protocol showed a significant reduction in episodes of clinical pneumonia compared with the 12-month period preceding the use of the protocol (p < .001). Thus, we conclude that the introduction of this protocol is associated with a significant decrease in methicillin-resistant S. aureus ventilator-associated pneumonia.(Crit Care Med 1995; 23:1200-1203)