(1) Hemogram: The white blood cell count is mostly (10 ~ 20) × 109/L, the neutrophils are more than 80%, and the nucleus moves to the left or there are toxic particles in the cytoplasm. The white blood cell count of the elderly, infirm, alcoholics and immunocompromised people may be low, but the percentage of neutrophils is still high.
(2) Sputum smear or culture: Gram staining showed a large number of neutrophils and Gram-positive cocci with capsules; The diagnosis can be made by sputum culture for 24 ~ 48h.
(3) Blood culture and drug sensitivity test should be done in severe cases, and pleural effusion should be taken for bacterial culture in those complicated with pleural effusion.
2. X-ray inspection
(1) Early stage: the lung texture became thicker, and the involved lung segments and lobes were slightly blurred.
(2) Stagnation and hepatoid stage: Bronchial airway sign can be seen in lung consolidation shadow; The costal diaphragm angle can be slightly blunted.
(3) Dissipation period: "false cavity" sign. Inflammation in elderly patients dissipates slowly, and may become organic pneumonia due to incomplete absorption.