From the Guidelines
Elevated white blood cell (WBC) count in the setting of resolving pneumonia is significant and requires careful evaluation for potential complications or underlying conditions, such as leukemoid reaction, leukemia, or extrapulmonary infection, as stated in the guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia 1. In the context of pneumonia, an elevated WBC count is a common finding, but its significance depends on various factors, including the patient's clinical response to treatment, the presence of other symptoms, and the results of diagnostic tests. According to the guidelines, a reliable tracheal aspirate Gram stain can be used to direct initial empiric antimicrobial therapy and may increase the diagnostic value of the clinical pulmonary infection score (CPIS) 1. Key points to consider when evaluating an elevated WBC count in a patient with resolving pneumonia include:
- The presence of a new or progressive radiographic infiltrate plus at least two of three clinical features (fever greater than 38 C, leukocytosis or leukopenia, and purulent secretions) represent the most accurate clinical criteria for starting empiric antibiotic therapy 1
- A negative tracheal aspirate (absence of bacteria or inflammatory cells) in a patient without a recent (within 72 hours) change in antibiotics has a strong negative predictive value (94%) for VAP and should lead to a search for alternative sources of fever 1
- If a clinical strategy is used, reevaluation of the decision to use antibiotics based on the results of semiquantitative lower respiratory tract cultures and serial clinical evaluations, by Day 3 or sooner, is necessary 1 A modified CPIS of 6 or less for 3 days is an objective criterion to select patients at low risk for early discontinuation of empiric treatment of HAP, but still requires validation in patients with more severe forms of VAP 1. In patients with an elevated WBC count and resolving pneumonia, it is essential to monitor their clinical response to treatment and adjust the antibiotic therapy as needed. Additionally, consideration should be given to searching for other complications or underlying conditions that may be contributing to the elevated WBC count.