Single center, retrospective chart review. Patients admitted to MDMC ICU from 4/1/2017 to 6/30/2020 will be identified through the electronic medical record utilizing ICD codes for HAP and VAP.

Single center, retrospective chart review. Patients admitted to MDMC ICU from 4/1/2017 to 6/30/2020 will be identified through the electronic medical record utilizing ICD codes for HAP and VAP. Patients with respiratory culture data signifying a Gram-negative organism as the cause of HAP/VAP will be analyzed as described below if study inclusion criteria is met. Minimum inhibitory concentration (MIC) data will interpreted per Clinical & Laboratory Standards Institute (CLSI) standards to determine local patterns of resistance. Multivariable logistic regression will be performed to determine risk factors for piperacillin-tazobactam, cefepime or meropenem resistant Gram-negative isolates. Project target date of completion and close-out is May 2021.

Inclusion Criteria:

• ICU, Neuro critical care unit admission
• Diagnosis of HAP or VAP
• Respiratory culture positive for Gram-negative organism

Exclusion Criteria:

• ICU length of stay <48 hours prior to HAP/VAP
• Culture or MIC data unavailable
• Pregnant

Patients admitted to MDMC ICU from 4/1/2017 to 6/30/2020 will be identified through the electronic medical record utilizing ICD codes for HAP and VAP.