Diagnosis and treatment of pneumonia in the surgical intensive care unit [published erratum appears in Surg Gynecol Obstet 1991 Apr;172(4):324] It is often difficult to detect the onset of parenchymal pulmonary infection (pneumonia) in a surgical intensive care unit (SICU) setting. Clinical and laboratory parameters that usually indicate the presence of pneumonia, such as fever, elevated white blood cell count and abnormal sputum culture, may also be present in patients with nonpneumonic infection. Prompt diagnosis is particularly important for patients in SICU because the mortality rate associated with pneumonia in these patients may be as high as 50 per cent. In the SICU setting, pneumonia is best diagnosed using well-defined roentgenologic criteria. Treatment should consist of a broad-spectrum antibiotic regimen to which all sputum pathogens are sensitive. Such a regimen significantly reduces the mortality rate for patients with pneumonia in an SICU setting. Aztreonam has been found to be as effective against susceptible gram-negative bacilli as traditional agents, such as the aminoglycosides, and to have a significantly milder side effect profile. 