HSC Section 8_April 2017

Hobson et al

Table 1. Pathogens and Clinical Features.

All Patients

Pseudomonas

MRSA

Other (n = 5)

Negative

Clinical Feature

(n = 20)

(n = 9)

(n = 3)

(n = 3)

Percentage of patients

100 64.9

45

15

25

15

Average age (y) Age range (y) Diabetes mellitus Facial nerve palsy

62.3

63.0

65.0

74.3

42-100

42-77

44-100 33.3%

52-79 80.0%

61-84 33.3% 33.3% 66.7% 100%

75% 25% 95% 80%

100.0%

33.3% 100% 66.7%

0%

20%

Bony erosion (on CT scan) Failed local treatment Definitive therapy (wk)

100% 100%

100%

80% 11.8 12.0

7.8 9.2

6.1 7.9

8.5

6.7 6.7

Total therapy (wk)

12.6

Abbreviations: CT, computed tomographic; MRSA, methicillin-resistant Staphylococcus aureus .

more recent reports have documented Pseudomonas infection less frequently, with Pseudomonas cultured in as few as 27% to 54% of cases. 5-7 Given the increasing frequency of nonpseudomonal MOE, we decided to retrospectively review our clinical experience with MOE and specifically compare clinical pre- sentations, management, and outcomes of this infection between cases caused by Pseudomonas and MRSA. We hypothesized that the clinical presentation would be similar, regardless of the causative organism, and that treatment might be prolonged when caused by MRSA or other non- Pseudomonas organisms. Methods Institutional review board approval was obtained for this retro- spective study (University of Pittsburgh institutional review board approval #PRO12010268, principal investigator Andrew A. McCall). The University of Pittsburgh Medical Center Department of Otolaryngology clinical record database was searched for all patients diagnosed with MOE between 1995 and 2012. Diagnosis was confirmed by the documented pres- ence of the all of the obligatory Cohen criteria with 2 modifi- cations. 10 First, it is generally our practice to obtain computed tomographic (CT) scans in lieu of nuclear medicine studies to confirm the presence of MOE. 11 We therefore included patients with documented evidence of bony erosion on CT scans in place of the obligatory Cohen criterion of either posi- tive results on a technetium-99 scan or failure of local therapy. Second, because of the retrospective nature of the study, in some cases, not all of the obligatory clinical criteria were documented for each patient. We accepted patients into the present cohort who were missing documentation of no more than 1 of the clinical signs or symptoms of the obligatory Cohen criteria, as has been done by others. 12 Resolution of infection was based on the absence of clinical signs or symp- toms of disease and the absence of radiographic progression of disease after a minimum follow-up period of 1 month after the completion of antibiotic therapy. Microsoft Excel 2011 (Microsoft Corporation, Redmond, Washington) and GraphPad Prism 6 (GraphPad Software, San Diego, California) were

used for data management and statistical analysis. Statistical comparisons between groups were performed using Fisher’s exact test and Student’s t test as appropriate, and statistical sig- nificance was set at P \ .05. Results Demographics Twenty patients were identified from the database with sup- porting documentation that permitted confirmation of the diagnosis of MOE. The mean age at diagnosis was 65 years for all patients, 62 years for Pseudomonas -infected patients, and 63 years for MRSA-infected patients. There were 12 men and 8 women ( Table 1 ). Culture Data Culture and sensitivity data were documented for all 20 patients. The means of obtaining culture data and therapy prior to culture are documented in Table 2 . There were 9 patients (45%) whose cultures grew P aeruginosa . There was no documented ciprofloxacin resistance in any of the Pseudomonas specimens; 1 Pseudomonas isolate was resis- tant to levofloxacin. Two patients had cultures that grew methicillin-sensitive S aureus in addition to Pseudomonas . Three patients (15%) had cultures that grew MRSA in the absence of Pseudomonas . One patient infected with MRSA also grew Klebsiella and another grew pan-resistant Acinetobacter spp. One MRSA isolate was resistant to clin- damycin; there was no documented resistance to doxycy- cline, trimethoprim-sulfamethoxazole, or vancomycin. In the 5 remaining patients with positive cultures, the fol- lowing organisms were documented (often in a polymicro- bial fashion): Enterococcus spp (n = 2), methicillin- sensitive S aureus (n = 1), Candida spp (n = 1), Aspergillus (n = 1), Staphylococcus lugdunensis (n = 1), Lactobacillus (n = 1), Peptostreptococcus (n = 1), and Alcaligenes faecalis (n = 1). Three patients had negative cultures. Cranial Neuropathies Thirty-three percent of the Pseudomonas -infected patients presented with facial nerve palsies, compared with none of

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