Managing post-analytical phase of procalcitonin testing in intensive care unit improves the request appropriateness

Background-aim The available scientific evidence supports the use of procalcitonin (PCT) measurement in serum for antibiotic stewardship in septic patients hospitalized in intensive care unit (ICU). PCT should be tested daily until its concentrations decrease by ε80% from the peak value or to absolute values δ0.5 ⎧g/L, at which time both antibiotic therapy and PCT monitoring should be stopped. In our hospital, PCT can be ordered without restrictions by ICU clinicians, who should use the test according to the algorithms described above. However, we noticed a tendency to continue PCT monitoring for most patients well past the ‘80% decrease from peak value’ threshold. To avoid this drawback, we decided to introduce a comment in the PCT report to Abstracts / Clinica Chimica Acta 493 (2019) S673–S710 alert clinicians when the 80% decrease was reached, with the hope of improving request appropriateness. Methods Since October 2017, a comment indicating “a decrease ε80% from peak value” was added, whenever relevant, to PCT reports of ICU patients as a clinical validation rule. The number of PCT requests was audited from January to September 2018 (P2) and compared with the same period of 2017 (P1), before the rule implementation. Results 1103 PCT determinations for 181 ICU patients (mean, 6.1 tests per patient; range 1-60) and 991 PCT determinations for 185 patients (mean, 5.4 tests per patient; range 1-38) were ordered during P1 and P2, respectively. During P2, 258 comments were added to PCT reports of 47 patients (mean, 5.5 comments per patient; range 1-25). This resulted in a 10% decrease in total PCT requests and an average reduction of 0.7 in requests per patient. This corresponded to a yearly saving of ~6,000 €. Conclusions The post-analytical phase is the most overlooked phase of the total examination process. However, its proper management is crucial for patient safety and clinical governance of laboratory tasks, including appropriate test utilization. We showed that adding a standard comment to the PCT report for highlighting the clinical information given by the biomarker behaviour in ICU patients undergoing antibiotics can increase the appropriateness for this critical, expensive and often misused test.