CRP and ventilator-associated pneumonia: However, Goerens et al. provided a recommendation for suspected VAP and length of treatment based on clinical status and laboratory findings of (1) worsening clinical and ventilation conditions, (2) abnormal laboratory findings (CRP > 20 mg/l), leukopenia (≤4000 WBC/mm3) or leukocytosis (>15,000 WBC/mm3) and left shift (>10% band forms), (3) and positive cultures from tracheal secretions.