Automated erythrocyte sedimentation rate (ESR) analysers are based on different methodology than Westergren method. It is questionable whether ESR values obtained from those analysers are comparable with determined values with Westergren method. The aim was verification of the precision, method comparison and accuracy of automated ESR analysers: Roller 20PN (Alifax S.p.A., Polverara, Italy) and iSED (Alcor Scientific, Smithfield, USA). Blood samples (N = 752 for Roller 20PN and N = 213 for iSED) were sampled into K2EDTA (Kima, Italy) tubes for automated and 3.8% Na-citrate tubes (Kima, Italy) for Westergren method. The data was divided into three groups according to the ESR values obtained with the Westergren method: Group Low (L) (ESR ≤ 20 mm), Group Medium (M) (ESR 21-60 mm), and Group High (H) (ESR ≥ 61 mm). Method agreement was assessed by Bland-Altman analysis and Passing-Bablok regression. Analyser iSED has shown better comparability with Westergren method (bias 0.0 (95%Cl -1.4 to 1.5) range than Roller 20 PN (bias = - 6.4 (95%Cl - 7.1 to -5.7) in the whole measuring. For Roller 20 PN, Passing-Bablok regression has shown constant and proportional difference for Groups L and M, and for iSED only for Group H. Roller 20 PN had lower sensitivity (0.51 (95%Cl: 0.45-0.57) than iSED (0.72 (95%Cl: 0.59-0.80) while they had comparable specificity (> 0.90) and accuracy (≥ 0.80) in comparison with the Westergren method. Both analysers are not comparable with the Westergren method and should not be used interchangeably.

Objectives The aim was to evaluate the stability of serum bicarbonate at room temperature, depending on time to centrifugation and air exposure. Methods Stability study was conducted in the laboratory of Clinical Hospital Centre Rijeka, Croatia in January-February 2022. Nine samples from 10 volunteers were collected in clot activator gel tubes (Greiner Bio-One). Bicarbonate was measured on Beckman Coulter AU480 (Beckman Coulter, Brea, USA). Three tubes were left at room temperature for 30 min, three tubes for 2 h, three tubes for 4 h until centrifugation. First tube from first group (baseline) was measured immediately after centrifugation. Other measurements were expressed as percentage deviation (PD%) from baseline. First tube was remeasured after 1 and 2 h (OT_0h_1h; OT_0h_2h). Second and third tubes were opened 1 and 2 h after centrifugation (C_0h_1h; C_0h_2h). Second group of tubes was processed the same way with 2-hour centrifugation delay (WB_2h; OT_2h_1h; OT_2h_2h; C_2h_1h; C_2h_2h), and third group with 4-hour delay (WB_4h; OT_4h_1h; OT_4h_2h; C_4h_1h; C_4h_2h). PD% was compared to Maximum Permissible Difference (MPD=5.69%). MedCalc statistical software was used (MedCalc, Ostend, Belgium). Results Bicarbonate baseline mean value (range) was 27.3 (23.4–29.6) mmol/L. Obtained PD% (95%CI) were: C_0h_1h 0.46 (−1.21, 2.12); C_0h_2h 0.18 (−2.22, 2.57); OT_0h_1h −6.46 (−7.57, −5.36); OT_0h_2h −10.67 (−12.13, −9.21); WB_2h −0.15 (−2.04, 1.74); C_2h_1h 0.01 (−1.52, 1.54); C_2h_2h −0.40 (−2.65, 1.85); OT_2h_1h −5.43 (−7.30, −3.55); OT_2h_2h −11.32 (−13.57, −9.07); WB_4h −0.85 (−3.28, 1.58); C_4h_1h −2.52 (−4.93, 0.11); C_4h_2h −3.02 (−5.62, 0.43); OT_4h_1h −7.34 (−9.64, −5.05); OT_4h_2h −11.85 (−14.38, −9.33). Conclusions Serum bicarbonate is stable for 4 h in closed uncentrifuged tubes, another 2 h in closed tubes after centrifugation, and is unstable within 1 h in opened tube.

Introduction: It has been recommended that each laboratory modify their critical result reporting practices to reflect the clinical needs of their patient populations. The aim of this survey was to assess how well critical laboratory values defined by the Croatian Chamber of Medical Biochemists (CCMB) correspond to the needs of the physicians at University hospital “Sveti Duh” (Zagreb, Croatia). Materials and methods: We conducted a survey among physicians from five departments in our hospital. Physicians were asked general questions about critical risk results (if and how they want to be informed). A list of critical risk results defined by the CCMB was offered and physicians were asked to revise the existing critical risk results and suggest adding new parameters. Obtained data were presented as numbers. Where the number of observations was low, ratios were used. Results: Survey response rate was 43% (52/121). Majority (48/52) wants to be informed of critical risk results, either personally (31/48) or through a colleague (32/48). They prefer to be informed about critical risk results of prothrombin time, platelet count, haemoglobin, glucose, creatinine, sodium and potassium. Revisions in the CCMB critical risk result list are proposed by 13 out of 48 physicians. Neonatologists approved the CCMB’s list. Conclusions: Although most critical risk results defined by the CCMB correspond well to the needs of the physicians in our hospital, some revisions are necessary to meet the particular needs of individual departments. Communication of critical risk results to those who have requested laboratory testing is highly appreciated practice.