Results:
Eighty-nine patients were included in the study, accounting for 91 affected ears. The study group included 53 males (59.5%) and 36 females (40.5%), with a mean age of 69.8 years. Eighty-three (94.3%) patients had DM at time of admission. Table-1 depicts patient’s characteristics.
The most common complaints at admission were otalgia (n=79, 86.8%) and aural discharge (n= 43, 47.2%). Edema of the external ear canal (n=67, 73.6%) was the most common finding on physical examination, followed by Granulation tissue (n=66, 72.5%) and aural discharge (n=44, 48.3%). Six patients (6.5%) had facial palsy.
Swab cultures were taken from all patients at admission. PA-NOE was the most common pathogen (n=41, 45.0%), followed by sterile-NOE (n=19, 20.8%), and candida species (n=11, 12.0%). For statistical analysis we excluded those with missing data, and grouped the results into 4 main categories:1) PA-NOE (n=41) 2)sterile-NOE (n=19) 3)Fungal-NOE (n=14) 4) other bacteria’s (n=4).
Mean duration of DM at time of hospitalization was 136.6 months, ranging from 6–396 months. The most common DM associated complications were retinopathy (n=26, 30.9%), nephropathy (n=24, 28.5%) and peripheral neuropathy (n=16, 19.0%). Mean HbA1c, which wasretrieved from 28 patients, was 8.13% (5.8%-12.6%). Mean urine microalbumin, collected from 40 patients was 195.5 mcg. Blood glucose measurement during hospitalization was collected from 75 effected ears. Forty-nine patients (53.8%) had mean blood glucose measurements of ≥140mg\dL and 26 patients (28.5%) had ≤ 140mg/dL. Table-2 depicts DM related patient characteristics.
Average duration of hospitalization was 22.3 days. Twenty five patients (27.4%) required surgical intervention. At time of data collection 55 patients died, among them 3 died during hospitalization.
Tables 3 and 4 evaluate the relationship between DM characteristics and NOE outcomes. Mean duration of diabetes was 157.88 months among NOE patients who required surgery in comparison to 127.6 months among patients who were treated conservatively (p-value 0.25). Thirty six patients (54.5%) had mean glucose levels ≥140 mg\dLin the non-surgical group, as opposed to 13 patients (52.0%) in the surgical group (p-value 0.69). No statistical difference was seen between the two groups in regards to HbA1c levels (p-value 0.59) and microalbuminuria (p-value 1.0).Fifty one patients were hospitalized less than 20 days (56.0%) and 40 patients (44%) were hospitalized longer than 20 days. Average age was 68.3 years among patients hospitalized less than 20 days in comparison to 71.7 years among people hospitalized more than 20 days (p-value 0.15). Mean HbA1camong NOE patients hospitalized less than 20 days was 7.6% in comparison to 8.7% among patients hospitalized ≥20 days (p-value 0.027). Duration of diabetes (p-value 0.65), long term complications of diabetes (p-value 0.45) and mean glucose measurements during hospitalization (p-value 0.16) were not statistically significant between the two groups.
In order to further evaluate the effects of glycemic control during hospitalization on NOE, we compared patients with mean blood glucose measurements above and below 140 mg\dL (Table-5), regardless of disease outcome. Among patients with blood glucose measurements of ≤140mg\dL, 11 patients had long term complications of DM (42.3%) in comparison to 30 patients (61.2%) with mean blood glucose measurements of≥140mg\dL (p=0.11). Duration of DM was associated with higher mean glucose measurements during hospitalization (p=0.005). Similarly,higher levels of HbA1C were associated with higher mean glucose measurements during hospitalization (p=0.001). Sevenpatients with glucose measurements ≤140mg\dL had PA-NOE (26.7%), in comparison to 25 patients (51.0%) among those with glucose measurements≥140mg\dL (p=0.045). Figure -1 presents the incidence of isolated pathogen based on mean glucose measurements during hospitalization.