Nosocomial sinusitis in an ICU population

The diagnosis of sinusitis is often entertained in febrile critically ill patients. Some investigators have proposed sinusitis as a source of more serious systemic infections. We sought to determine the incidence rate and risk factors for nosocomial sinusitis. We retrospectively analyzed data from 312 ICU patients who had at least one CT scan of the head while in the ICU. We recorded the presence of sinusitis (denned as an air fluid level or opacification of at least one sinus), and presence and duration of orotracheal and nasogastric (NG) intubation. Patients with more than one CT were evaluated for the interval development of sinusitis. 32 of 113 (28%) orotracheally intubated patients had sinusitis on initial CT, compared with 19 of 199 (10%) unintubated patients (p<0.0001). The prevalence of sinusitis among intubated patients was 18% when the CT was done on the day of ICU admission, 24% on days 1-2, 22% on days 3-6, and 41% after day 6. The prevalence among unintubated patients was 7%, 7%, 23%, and 11% respectively (p<0.01 for effect of intubation, p<0.0001 for effect of time by test of trend). The risk of sinusitis increased with the duration of intubation (p=0.05). 78% of intubated patients and 13% of unintubated patients had an NG tube. Among unintubated patients, an NG tube was not associated with sinusitis (p=0.6). 21 (34%) of 61 patients with a negative initial CT who had subsequent scanning developed sinusitis. Only 5 of these scans were done to rule out sinusitis. Sinusitis developed more often in intubated patients than unintubated patients (51% versus 12%, p<0.002). The time between the first CT and the CT that showed sinusitis was similar (median 7 days, 1-67 days for intubated patients, 6.5 days, 1-37 days for unintubated patients, p>0.7). The length of stay in the ICU was also similar among patients who developed sinusitis and patients who did not (7 days, range 2-28 and 7 days, range 1-67 respectively, p>0.4). Sinusitis is frequent in our ICU population and is associated with orotracheal intubation and with length of ICU stay. A significant number of patients have sinusitis at the time of ICU admission. Approximately 1/3 of patients without initial evidence of sinusitis developed sinusitis on a follow-up CT.