(555) Effectiveness of a Dedicated Pseuodomonas aeruginosa Eradication Care Process Model

Background: Pseudomonas aeruginosa (Pa) lung infections are common in people with cystic fibrosis (PwCF) and are associated with increased morbidity and mortality.[1,2] While early and aggressive antibiotic therapy is the standard of care in PwCF, regimens of choice vary by institution. In this analysis, we assessed the effectiveness of our Pa eradication care process model at Primary Children’s CF Center (Figure 1) by comparing the incidence of Pa eradication before and after its implementation.

Methods: This IRB exempt study was a retrospective cohort analysis of individual patient data from the Intermountain Healthcare electronic medical records (EMR). We examined the EMR of all CF patients with respiratory cultures positive for Pa during the study period (January 2006-May 2021). These records were then reviewed for eligibility based on predefined criteria. The control group included patients who met the inclusion criteria and whose initial Pa infection occurred before the protocol implementation (January 2006-December 2015). Qualifying patients who first cultured Pa from January 2016-May 2021 and followed the treatment model without deviation were included in the intervention cohort. Treatment success was determined by the results of the respiratory cultures collected in the two years following the first Pa positive culture. We assessed the success of each arm of the protocol, including regimens for patients who were symptomatic, asymptomatic/newly symptomatic, and those infected with mucoid Pa.

Results: In total 244 records of PwCF were reviewed for eligibility and 130 met the inclusion criteria. 22 patients were included in the intervention cohort, while 108 patients were included in the control group. The total rates of eradication for the intervention and control groups were 46.7% and 47.2%, respectively. In the intervention cohort 36.6% (n=26) of cultures were Pa+ vs. 33.3% (n=156) among the control group.
The incidence of mucoid Pa was 4.5% in the post care process model implementation period vs. 7.4% prior to implementation. 1.4% (n=1) of intervention cohort cultures were mucoid Pa+, compared to 7.4% (n=35) of control cultures.
Further results are pending.

Conclusions: Our institutional Pa eradication care process model may have contributed to the marked decrease in mucoid Pa infections, though the care process model impact on Pa eradication rates overall remains unclear. More data are needed to elucidate the best treatment strategies for Pa infections in PwCF.

Acknowledgements:

References: [1] Emerson J, Rosenfeld M, McNamara S, Ramsey B, Gibson RL. Pseudomonas aeruginosa and other predictors of mortality and morbidity in young children with cystic fibrosis. Pediatric Pulmonology. 2002;34(2):91–100.
[2] Robinson TE, Leung AN, Chen X, Moss RB, Emond MJ. Cystic fibrosis HRCT scores correlate strongly with pseudomonas infection. Pediatric Pulmonology. 2009;44(11):1107–17.