Risk Factors For Post-Donation Syncope Among Blood Donors In Nigeria

Abstract

The world health organization recommends that blood donation should in all cases be absolutely voluntary with an altruistic motive of helping the unknown recipients.1 However, only persons in good health should be accepted as donors of blood for therapeutic use.2 The suitability of prospective donors should be determined by a pre-donation assessment of his/her health status. A significant part of the assessment procedure usually takes the form of verbal screening with reliance on answers to simple standard questions relating to general health, past medical history, medications and simple general physical examination including the measurements of weight and blood pressure of the prospective donor.2 Persons who are between the ages of 18 and 65 years and have passed the pre-donation medical assessment with haemoglobin levels of more than 13.5 g/dl in males or 12.5 g/dl in females are acceptable as donors.2, 3 However, pregnant and lactating women are not accepted for homologous blood donation.2, 3 Healthy persons can donate up to 450ml of blood without any deleterious effect on their body, and with only a temporary effect on their circulatory system from which recovery is rapid.2, 3 Nonetheless, syncopal episodes do occur among blood donors with an incidence of between 2% to 5% of all donors in the United Kingdom, being especially common in first-time donors due to nervousness and vasovagal reactions resulting from anxiety.3 The risk of vasovagal attacks is higher among donors who weigh less than 50kg, since the standard donation of a pint of blood represents a greater proportion of their total blood volume. 3 In this report we evaluated the incidence and pattern of risk factors for post-donation syncope as seen in Nigerian blood donors at the blood bank of the University of Maiduguri Teaching Hospital, Maiduguri, North East Nigeria. All cases of post-donations syncope at the blood bank of University of Maiduguri Teaching Hospital were routinely investigated. The investigation usually took the form of a medical examination and re-assessment of the donor medical and drug history with the aim of determining the cause of the syncope in each case. This study is conducted by retrospective appraisal of the result of such investigations carried out during a 5-year period from 2002 to 2006. During the period under review, a total of 10, 124 donors were bled at the blood bank. Out of these 10, 124 donors only 51 had post-donation syncope. Therefore the incidence rate of syncope among our donors was 0.5%. All cases of syncope were seen in first-time donors and occurred immediately within fifteen to thirty minutes after the completion of blood donation as they get out of the donation coach getting ready to go home. The weight of the affected donors ranged from 5976kg. The documented risk factors for syncope included donor medication with alpha methyldopa in 22 (43%) cases, propranolol in 8 (16%) cases and amitriptyline 8 (16%) cases. Anxiety was identified as the risk factor for syncope in 13 (25%) cases as shown on Table 1.