Patients often present with elevated white blood cell count with a left shift, meaning that there is an increase in immature white cells suggestive of an acute infection. Blood cultures may be positive and thoracentesis will display findings consistent with an exudate. Pleural fluid commonly contains neutrophils with bacterial disease and lymphocytes in tuberculosis effusions. Pleural fluid pH and glucose are often low in bacterial disease and a pH of less than 7.2 suggests active bacterial infection. Gram stain, cultures, and counterimmunoelectrophoresis often indicate the offending organism (Hay, Levin, Sondheimer, & Deterding, 2011).