629 Improving Gentamicin Prescribing for Intra-Abdominal Sepsis on a General Surgical Firm

Aim

Gentamicin is recommended by local guidelines for the empirical treatment of intra-abdominal sepsis. However, severe side effects that can occur through prolonged raised through levels requires its use through a specific dosing protocol. Challenges of this means it often “falls off” the drug chart, leading to suboptimal drug-levels. The aim of this quality improvement project was to improve the process of gentamicin prescription.

Method

A two-week retrospective analysis of all patients admitted was performed to obtain baseline data. Information was collected on gentamicin use, if levels were taken at 6–14 hours post-dose, and if subsequently correctly re-prescribed. PDSA 1 involved placing posters in the surgical office, reminding the clerking doctor of the gentamicin protocol. PDSA 2 involved a departmental teaching session to reiterate the above intervention.

Results

At baseline, only 7% (1/15) of patients prescribed gentamicin had a correct post-dose level taken and subsequently received a correct second dose. After PDSA 1, this rose to 67% (2/3). After PDSA 2, this level was similar at 60% (3/5). Furthermore, at baseline 47% (15/32) of patients deemed to have intra-abdominal sepsis received gentamicin. After PDSA 1, this proportion fell to 11% (3/28) and after PDSA 2 this was 38% (5/13).

Conclusions

Education sessions and posters were effective at increasing the proportion of patients that received a safely prescribed second dose of gentamicin, as a result of correctly taken trough levels. However, a reduction in the percentage of patients receiving gentamicin for intra-abdominal sepsis possibly suggests further education on the role of gentamicin is required.

Bacteroides thetaiotaomicron-derived outer membrane vesicles promote regulatory dendritic cell responses in health but not in inflammatory bowel disease

BACKGROUND

Bacteroides thetaiotaomicron (Bt) is a prominent member of the human intestinal microbiota that, like all gram-negative bacteria, naturally generates nanosized outer membrane vesicles (OMVs) which bud off from the cell surface. Importantly, OMVs can cross the intestinal epithelial barrier to mediate microbe-host cell crosstalk involving both epithelial and immune cells to help maintain intestinal homeostasis. Here, we have examined the interaction between Bt OMVs and blood or colonic mucosa-derived dendritic cells (DC) from healthy individuals and patients with Crohn's disease (CD) or ulcerative colitis (UC).

RESULTS

In healthy individuals, Bt OMVs stimulated significant (p < 0.05) IL-10 expression by colonic DC, whereas in peripheral blood-derived DC they also stimulated significant (p < 0.001 and p < 0.01, respectively) expression of IL-6 and the activation marker CD80. Conversely, in UC Bt OMVs were unable to elicit IL-10 expression by colonic DC. There were also reduced numbers of CD103⁺ DC in the colon of both UC and CD patients compared to controls, supporting a loss of regulatory DC in both diseases. Furthermore, in CD and UC, Bt OMVs elicited a significantly lower proportion of DC which expressed IL-10 (p < 0.01 and p < 0.001, respectively) in blood compared to controls. These alterations in DC responses to Bt OMVs were seen in patients with inactive disease, and thus are indicative of intrinsic defects in immune responses to this commensal in inflammatory bowel disease (IBD).

CONCLUSIONS

Overall, our findings suggest a key role for OMVs generated by the commensal gut bacterium Bt in directing a balanced immune response to constituents of the microbiota locally and systemically during health which is altered in IBD patients. Video Abstract.