Clinical Impact of Accelerate Pheno Rapid Blood Culture Detection System in Bacteremic Patients.

BACKGROUND: Accelerate Pheno blood culture detection system (AXDX) provides rapid identification and antimicrobial susceptibility testing results. Limited data exist regarding its clinical impact. Other rapid platforms coupled with antimicrobial stewardship program (ASP) real-time notification (RTN) have shown improved length of stay (LOS) in bacteremia. METHODS: A single-center, quasi-experimental study of bacteremic inpatients before and after AXDX implementation was conducted comparing clinical outcomes from 1 historical and 2 intervention cohorts (AXDX and AXDX + RTN). RESULTS: Of 830 bacteremic episodes, 188 of 245 (77%) historical and 308 (155 AXDX, 153 AXDX + RTN) of 585 (65%) intervention episodes were included. Median LOS was shorter with AXDX (6.3 days) and AXDX + RTN (6.7 days) compared to historical (8.1 days) (P = .001). In the AXDX and AXDX + RTN cohorts, achievement of optimal therapy (AOT) was more frequent (93.6% and 95.4%, respectively) and median time to optimal therapy (TTOT) was faster (1.3 days and 1.4 days, respectively) compared to historical (84.6%, P ≤ .001 and 2.4 days, P ≤ .001, respectively). Median antimicrobial days of therapy (DOT) was shorter in both intervention arms compared to historical (6 days each vs 7 days; P = .011). Median LOS benefit during intervention was most pronounced in coagulase-negative Staphylococcus bacteremia (P = .003). CONCLUSIONS: LOS, AOT, TTOT, and total DOT significantly improved after AXDX implementation. Addition of RTN did not show further improvement over AXDX and an already active ASP. These results suggest that AXDX can be integrated into healthcare systems with an active ASP even without the resources to include RTN.

Dantrolene Prevents the Lymphostasis Caused by Doxorubicin in the Rat Mesenteric Circulation.

Background and Purpose: Doxorubicin (DOX) is a risk factor for arm lymphedema in breast cancer patients. We reported that DOX opens ryanodine receptors (RYRs) to enact "calcium leak," which disrupts the rhythmic contractions of lymph vessels (LVs) to attenuate lymph flow. Here, we evaluated whether dantrolene, a clinically available RYR1 subtype antagonist, prevents the detrimental effects of DOX on lymphatic function. Experimental Approach: Isolated rat mesenteric LVs were cannulated, pressurized (4-5 mm Hg) and equilibrated in physiological salt solution and Fura-2AM. Video microscopy recorded changes in diameter and Fura-2AM fluorescence tracked cytosolic free calcium ([Ca2+ i]). High-speed in vivo microscopy assessed mesenteric lymph flow in anesthetized rats. Flow cytometry evaluated RYR1 expression in freshly isolated mesenteric lymphatic muscle cells (LMCs). Key Results: DOX (10 µmol/L) increased resting [Ca2+ i] by 17.5 ± 3.7% in isolated LVs (n = 11). The rise in [Ca2+ i] was prevented by dantrolene (3 µmol/L; n = 10). A single rapid infusion of DOX (10 mg/kg i.v.) reduced positive volumetric lymph flow to 29.7 ± 10.8% (n = 7) of baseline in mesenteric LVs in vivo. In contrast, flow in LVs superfused with dantrolene (10 µmol/L) only decreased to 76.3 ± 14.0% (n = 7) of baseline in response to DOX infusion. Subsequently, expression of the RYR1 subtype protein as the presumed dantrolene binding site was confirm in isolated mesenteric LMCs by flow cytometry. Conclusion and Implications: We conclude that dantrolene attenuates the acute impairment of lymph flow by DOX and suggest that its prophylactic use in patients subjected to DOX chemotherapy may lower lymphedema risk.