Postoperative Pulmonary Complications: Pneumonia and Acute Respiratory Failure Differences between Nosocomial or Hospital and Community Acquired Pneumonia Hospital Acquired and Ventilator Associated Pneumonia Oncohema Key CAP (Community Acquired Pneumonia), HAP (Hospital Acquired Pneumonia), VAP (Ventilator Associated Pneumonia), and HCAP (Health Care Associated Pneumonia) are types of pneumonia differing by where sumaya Gholami