Clots in Blood Bags in Northwest Nigeria: Incidence, Correlation with Donor ABO Blood Groups, and Implications on Blood Transfusion in a Low Resource Tropical Setting

Abstract

Like in other developing tropical countries quality control, haemovigilance and root-cause analysis for clotted blood in bags are inadequate or lacking in Nigerian transfusion service. We hypothesized that incidence of clotting would be high and risk of clotting would be affected  by ABO groups due to their natural influence on coagulability. We determined the incidence of clotting in blood bags, evaluate relationship between ABO groups and risk of clotting, and highlight implications of clotted blood in bags on transfusion practice in low-resource Nigerian setting. We retrospectively (2018-2019) analyzed total donations and number of bags with clotted blood in two Nigerian hospitals. Incidence of clotting during the study period was calculated as percentage of bags with clotted blood relative to total donations. Donor age, sex and frequencies of ABO groups of clotted and control (un-clotted) bags were compared by Student-t and X²-tests. Risks of clotting for ABO-O and non-O bags were expressed as Odds ratios (OR) by case-control logistic regression. Results showed incidence of clots in bags was 2.81%. No significant differences between clotted and control bags with respect to donors mean age (29.1 vs. 28.8, p>0.05), proportions of male (98.5% vs. 98.9%, p>0.05) and female (1.5% vs. 1.1%, p>0.05) donors. However, frequency of non-O groups was higher in clotted than in control bags (60.3% vs. 43.9%; OR=1.92[95% CI:1.63-2.54], p=0.015). Conversely, frequency of group-O was lower in clotted than in control bags (39.7% vs. 56.1%; OR=0.52[95% CI:0.26-0.72], p=0.023). In conclusion, incidence of clot was high as hypothesized. Group-O and non-O groups were associated with reduced and increased risks of clotting respectively. Clotting in bags has adverse economic and clinical implications in low-resource country like Nigeria, where health budget is inadequate and donors are scarce. Hence, the need to improve quality control and haemovigilance, and introduce root-cause analysis for clotted bags in Nigerian transfusion service.

Key Words: Clots; Blood Bags; ABO Groups; Transfusion; Donation; Developing Country; Nigeria.