Nosocomial infections after aneurysmal subarachnoid hemorrhage: time course and causative pathogens

Nosocomial infections after aneurysmal subarachnoid hemorrhage (aSAH) are associated with prolonged length of stay and poor functional outcome. It remains unclear if infections result in prolonged length of stay or, vice versa, if prolonged length of stay results in more infections. Before strategies can be designed to reduce infections after aneurysmal subarachnoid hemorrhage, more data are needed on time course and causative pathogens of infections.

To investigate the time course of infection onset and bacterial microorganisms that cause nosocomial infections after aSAH.

In consecutive patients with aneurysmal subarachnoid hemorrhage admitted to the University Medical Center Utrecht between 2009 and 2011, we analyzed the proportion of patients with infections, day of infection onset, and culture results.

Of the 291 included patients, 107 (37%) patients developed 115 nosocomial infections. Fifty-six patients (19%) developed an infection within the first week. Median day of infection onset was for pneumonia (n = 49; 17%) day 4 (interquartile range 3-9), respiratory tract infection (n = 16; 6%) day 4 (interquartile range 1-7), urinary tract infection (n = 27; 9%) day 11 (interquartile range 7-14), and meningitis/ventriculitis (n = 10; 3%) day 19 (interquartile range 9-33). Cultures of infections mostly yielded Staphylococcus aureus (20%), Haemophilus influenzae (15%), and Escherichia coli (14%),

Nosocomial infections after subarachnoid hemorrhage are common and mostly occur in the first week after ictus. Future studies should investigate if general hygienic measures, infection awareness, minimizing the duration of mechanical ventilation and use of catheters/drains, or prophylactic antibiotics reduce infections and improve functional outcome.