MICROBIOLOGY
The blood culture results turnaround times can be seen in Figure 1. There was a high level of agreement between the two methods (175/183; 95.63%) (Table 1). In terms of appropriate and efficient antibiotics treatment, 125/183 patients (68.3%) were impacted by the early receipt of the identification of the pathogen; 58/183 (31.7%) were unchanged. “As we were able to get the result on time, our microbiologist could advise the medical team on what to do in terms of source control (Fig 2). The top three sources were urinary, biliary and skin,” commented Olubunmi. “Because of the improved process, we were able to carry out 49 investigations following the use of BioFire, which was really important.” The type of interventions included
echocardiogram, removal of line, removal of urinary catheter, CT (abdominal pelvis/ KUB), MRI and a variety of others. The pilot also established the impact on the duration of antibiotics and length of stay. Length of stay corresponded with the duration on antibiotics – one day less on antibiotics results in a two-day reduction in length of stay, Olubunmi explained. The hospital also found it was able to de-escalate and stop antibiotics in patients where appropriate, based on the findings from the BioFire tests. This saved money and achieved better antibiotic stewardship (Fig 3). In addition, the technology assisted escalation of patient care – 27/183 (14.8%) bacteraemic patients were escalated and required level 2/3 care. In terms of the impact on patient outcomes, 31/183 passed away – which represented a mortality rate of 16.9%.
Olubunmi stated that while all those involved with patient care would wish for mortality to be zero, this result was lower than it would have been if they hadn’t received the results on time. The pilot findings showed that 120/183 patients were discharged (66.5%); 18 were readmitted within 30 days (15%), but only seven (5.8%) were due to infection. The pilot also looked at three primary metrics for measuring performance, and the results were as follows: n Reduction in time to identify pathogen compared to routine care: The study showed a significant reduction in time to pathogen identification, with an average time saving of 17 hours per patient sample compared to sending sample to the main laboratory.
n Reduction in time to antibiotic therapy (improved management and outcome): Patients were on targeted treatment within 13 hours, but this improved significantly to approximately three
Change
Commence De-escalated Escalated Stopped
Fig 3. Antibiotics decision following BioFire results. Date 09.07.23 Event
Severe sepsis from septic arthritis of left knee joint: immunocompromised due to Alpha-1 antitrypsin deficiency (an inherited disorder that may cause lung disease and liver disease). Unwell for 3 weeks, sore throat, thigh cellulitis, swollen elbow. Acutely unwell for 2-3 days (nausea, drowsy, shivers, swelling of left knee, not responding to Co-Amox. Two sets of blood cultures and knee aspirate sent to laboratory. Blind Abx treatment with IV Flucloxacillin +IV Clindamycin; joint washout for source control of sepsis. Remained critically ill in septic shock; transferred to ICU.
10.07.23 Blood cultures flagged positive, BioFire identified GAS.
Targeted antibiotics started within 10 hours of admission; IV immunoglobulin started for confirmed case of invasive GAS; UKHSA notified for tracing close family and institution of antibiotic prophylaxis. Patient clinically stable in ICU.
BioFire identification within 9 hours and 30 mins (1hr of delay in scanning result on EPR). MALDI-ToF identification within 15 hours 30 mins (6 hours later than BioFire identification).
Table 2. GAS case; 44-year-old male, brought in by ambulance to ED. Date
30.01.22 30.01.22 31.01.22 31.01.22
Time 11.10
12.09 05.11 06.10
Event
Blood culture collected from PICC line Blood loaded onto blood culture incubator Sample bottle flagged positive
BioFire – Enteroccocus faecium AND detected marker of resistance to an antibiotic group (VRE)
Antibiotic changes – IV meropenem stopped; VRE targeted antibiotic commenced – linezolid
Source of infection identified – perianal abscess 31.01.22 16.08
Conventional result became available – matches BioFire but resistance/sensitivities of antibiotics not available until 02.02.22
Table 3. VRE case; 58-year-old male, with leukaemia, fever, and neutrophils 0.0.
hours for April and May (as the BioFire process became embedded within blood sciences).
n Contamination rate of <3% (reduced wastage): This was not completely achieved. The ambitious target of <3% was met in two out of six months of the pilot giving an overall median of 3.45% and a mean of 3.63%. (For context, the overall Berkshire and Surrey Pathology Services contamination rate was >4%.)
“This was an ambitious contamination rate target. We are part of a network and we looked at the other hospital
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sites; we are actually doing very well in comparison. It was met in some months but not others, due to a slow start for funding and some staffing issues… However, our CEO and executives are happy with what has been achieved,” Olubunmi commented.
Success stories She concluded her presentation with three success stories – including the rapid detection of invasive group A Streptococcus (GAS) in a patient with severe sepsis; the rapid detection of antibiotic resistance in a patient with
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