Blood Inventory Management During COVID-19 Pandemic Using a Simple Mathematical Tool: A Two-Year Study from a Tertiary Care Hospital in North India

Multiple recurrent waves of the coronavirus disease 2019 (COVID-19) resulted in major fluctuations in blood supply and demand, which presented a major challenge for the blood centres to maintain adequate blood inventory. Hence, the primary aim of the present study was to determine whether safety stock as a simple mathematical tool can be used to maintain optimum blood inventory to meet all blood demands. The secondary aim of the study was to test whether daily blood stock index (DBSI), which was a novel index developed by the authors and derived from the calculated safety stock, can be used to minimize blood wastage due to the outdating of packed red blood cells (PRBC)/whole blood (WB) units. The present study was a descriptive, cross-sectional study conducted from 1st October 2019 to 31st December 2021 at a blood centre of a tertiary care hospital. For the purpose of data analysis, the time period of study was divided into 7 periods signifying different phases during the COVID-19 outbreak. Data of PRBC/WB (referred to as red cell) collection, red cell issue and the daily red cell stock were collected for these 7 time periods. Safety stock, percentage of out-dated whole blood/packed red blood cell units (OB) and DBSI were calculated based on the data extracted. Red cell collection as well as red cell utilization decreased during the 1st as well as the 2nd wave of the COVID-19 outbreak. The blood centre was able to meet the blood demand of the hospital at all times, as the daily average red cell stock remained above the calculated safety stock during all periods. OB (12.4%) and DBSI (2.3) were highest during the lockdown period of second wave of COVID-19 outbreak (period E). A strong direct relationship was seen between OB (dependent variable) and DBSI (predictor variable) [R = 0.79; p = 0.03]. Firstly, safety stock is a simple, user-friendly mathematic tool which can be used for efficient blood inventory management not only at times of a pandemic/disaster but also during routine times. Secondly, DBSI is a logical and empirical tool to reduce OB units and consequently reduce blood wastage.