Procalcitonin in management of COVID19 infection

Introduction: Procalcitonin (PCT) has emerged as a tool to guide antibiotic (ABx) therapy in bacterial pneumonia, but PCT's role in distinguishing between bacterial & viral pneumonia is uncertain(1) With the novel SARS-CoV-2 pandemic there's emerging interest in the role of this biomarker for assessing COVID-19 disease severity & progress(2) In COVID-19 pts, bacterial or fungal coinfection incidence is 8%, whilst 72% of the pts have been reported to receive antimicrobial therapy(3) In the UK a recent guideline from NICE suggests early review of need for antibiotic treatment in COVID-19 on basis other than PCT(4) We have reviewed our institutional data in order to assess current practice & usefulness of using PCT as a tool for assessing disease severity, progress & for guiding ABx therapy Objectives: 1) Compare PCT between COVID-19 pts admitted to ICU and not 2) Describe how concurrent bacterial infection in ICU pts influenced PCT 3) Describe how PCT was associated with duration of ABx therapy Methods: Contemporaneous eMR records were reviewed retrospectively for 70 COVID-19 pts admitted to ICU vs 70 who were not Evidence of concurrent bacterial infection was sought;defined as bacteraemia, positive sputum/tracheal aspirate culture or molecular testing Duration of ABx therapy was also collected Student's t-test was used to compare mean PCT values, whilst diagnostic performance of PCT >0 5 μg/mL in bacterial co-infection was assessed Duration of ABx was assessed in pts with PCT> & 0 5 to indicate bacterial co-infection was found to be 21%, but on the contrary the NPV of PCT 0 5 & of 2mg/ml there was a trend towards longer therapy (9 vs 11 days) Conclusion: It's not clear from this data that PCT on presentation discriminates between pts with severe & non-severe COVID-19 Although the usual threshold PCT <0 5mg/mL was able to effectively rule out bacterial co-infection, its PPV was modest This reflects limited impact that PCT had on duration & intensity of ABx therapy In pts with severe respiratory failure clinicians may be reluctant to stop ABx, given the non-trivial rate of bacterial co-infection The combination of PCT & a rapid, sensitive molecular test may improve antimicrobial stewardship