NOE Cohort and antibiotic therapy
Our results have shown that in our cohort of 63 patients, they have received, on average, two different intravenous antibiotic regimes (mean=2.1 courses). Over one third of patients (35%) receive three or more intravenous courses. 63% of these changes are attributed to significant adverse effects from high-dose intravenous antibiotics. This does not include milder reactions or blood derangements that also occurred but did not necessitate a change in antibiotic. There were 10 hospital admissions directly related to adverse effects from treatment. 4 due to severe acute kidney infection (AKI), 2 due to deranged LFTs, 2 due to progression of NOE, and 1 for adverse reaction and clostridium difficile infection.
Recognised risk factors were prevalent in our cohort; with a mean age of 77, predominantly male (44 male, 19 female). 70% had diabetes with half of this group taking insulin. These characteristics are similar to other population studies (1)(13)(14). A Charlson Comorbidity Index score of 5 is significantly higher than the average population (15) and reflects the general susceptibility this typical patient cohort has to developing NOE.
The intravenous antibiotics used most were tazocin (45%) and ceftazidime (25%). This is in line with other UK trusts; a survey on NOE antibiotic selection showed comparable figures, where Tazocin was used first-line in 41% of cases and ceftazidime in 7% (8). Similarly, treatment duration was 80.1 days on average, or a median of 65 days which better accounts for outliers. Although there is no agreed exact duration within the literature, this length of treatment appears consistent with other centres (9)(16). Therefore, both our cohort attributes and antimicrobial management appear representative of the UK NOE population.
We know that more medically complicated, multimorbid patients are likely to require longer treatment (13). 6 of the 8 patients requiring 4 or 5 intravenous antibiotic regimes were admitted as an inpatient and/or were treated with meropenem. The duration of treatment for those requiring multiple different antibiotic regimes (mean= 97.7 days) was significantly longer (p=0.024) than those treated successfully with one course (61.1 days). Diabetes was statistically more prevalent in those requiring multiple regimes. This may suggest that adverse effects of treatment may more frequently affect those with comorbidities and contribute to prolonged duration of treatment.