Lower respiratory tract infections after abdominal operations: epidemiology and risk factors.

Objective: To find out the incidence and aetiology of lower respiratory tract infections after abdominal operations and identify predisposing factors.

Design: Prospective open study.

Setting: Department of General Surgery, Hospital Germans Trias i Pujol, Barcelona, Spain.

Subjects: 2,083 patients having abdominal operations between March 1985 and June 1987 excluding splenectomies, and those requiring thoracoabdominal incisions.

Main Outcome Measures: The presence of three or more of the following: temperature of 38 degrees C or more, cough with mucopurulent sputum, raised white cell count, or changes on the chest radiograph or bronchogram.

Results: 50 patients (2.4%) developed lower respiratory tract infections. Micro-organisms were isolated from 15 (30%), the most common being Haemophilus influenzae. The most important risk factors were American Society of Anesthesiologist's grade, duration of anaesthesia, age, and operations on the upper gastrointestinal tract.

Conclusion: Further work is needed to investigate other possible predisposing factors and develop a predictive score.