Laboratory risk management for INR alert values

The International Normalized Ratio (INR) is a laboratory test used to monitor and adjust medication with vitamin K antagonists. The alert values of the INR obtained in the laboratory must be managed efficiently to provide the best management for the patient. The aim of the study was to evaluate the risk levels associated with INR alert values for the laboratory in a tertiary care hospital and compare the findings with the established benchmarks. The study was conducted from September 2023 to August 2024 at the Clinical Laboratory from Emergency County Clinical Hospital of Targu Mures. Both risk levels associated with the occurrence of alert values for INR > 4.5 and underlying causes of these values were assessed. Plasma samples collected in all wards were analyzed using Sysmex CS-2500 instrument. The sample's journey through the laboratory was analyzed. The risk was assessed and a daily probability of alert value occurrence for INR was calculated. A total number of 42,799 plasma samples were analyzed, out of which 347 (0.81%) had INR alert values and were collected from 246 patients, some having more than one sample collected. This study showed that INR alert values > 4.5 represent an Unacceptable risk level, with an expected daily occurrence of λ = 0.95 (61% probability of ≥ 1 event per day). The consequence is critical in the risk assessment matrix that corresponds to a frequent probability. The laboratory considered the risk of INR values > 4.5 to be unacceptable both as frequency and consequences. Incomplete documentations of phone communications and resampling delays (> 6 h in 30% of the samples) were identified as potential failure modes. Therefore, laboratories are expected to implement strict control measures to effectively mitigate this risk.