Transfusion-associated circulatory overload in adult, medical emergency patients with perspectives on early warning practice: a single-centre, clinical study

Background. Transfusion-associated circulatory overload is characterised by acute respiratory distress, tachycardia, increased blood pressure, acute pulmonary oedema and/or evidence of positive fluid balance occurring within 6 hours after transfusion. Transfusion-associated circulatory overload is a serious, underreported reaction, which makes this iatrogenic condition difficult to prevent. We present an audit of patients admitted to a medical emergency unit, aiming to investigate: (i) the incidence of transfusion-associated circulatory overload; and (ii) whether cases were reported to the haemovigilance system. The clinical implications are discussed within the frame of the Early Warning Score. Methods. We conducted a retrospective audit of electronic hospital medical records of patients receiving blood transfusion in a single medical emergency unit. Patients were admitted during a 6-month period and data on symptoms and vital signs were extracted from the records. Results. Of 4,353 consecutively admitted patients, 156 patients were transfused with a total of 411 blood components. The audit identified five cases of transfusion-associated circulatory overload (incidence 3.2%) and four cases of transfusion-associated dyspnoea. Vital signs and changes in dyspnoea and blood pressure were registered within the frame of the Early Warning Score, and one case was documented as being transfusion-related in the medical record. No cases were reported to the haemovigilance system. Discussion. The incidence of transfusion-associated circulatory overload in acute emergency patients was similar to that in other clinical studies. Lack of recognition and reporting was marked, even though changes in vital signs were monitored in the context of the Early Warning Score. This study points to a missing link in the transfusion chain, namely recognising the vital signs of circulatory overload during or shortly after transfusion as being a serious adverse transfusion reaction.