A total of 37,896 units of whole blood were collected from 22,587 (59.6%) voluntary and 15,309 (40.4%) replacement donors. As compared to RDs, all of whom donated in the department, majority of VDs, 20,671 out of 22,587 (92%), donated in the blood donation camps (BDC) outside hospital premises, as per convenience of donors. Proportion of female donors was significantly higher in VDs (13.1%) as compared to RDs; 219 out of 15,309 (1.4%) (P<0.001) .
Blood donation in and outside hospital premises
Mean age of the donors was 31±9 years, with a range of 18–60 years. Mean age of male VDs was 31.4±10.2 (range 18–60) years and female VDs 30.7±10.3 (range 18–59) years. Mean age of male RDs was 30.6±8.2 (range 18–60) and female RDs 33.2±9.1 (range 18–55) years . However, 54.7% donors (20,744) were in the 18–30 years group, 36.5% (13,841) in the 31–45 years group, and only 8.7% (3311) were in the 46–60 years of age group. Mean weight of the donors was 69.5±11.6 kg, with donors weighing in the range of 45 to 130 kg. Mean weight of male VDs was 70±11.3 (range 45–130) kg and female VDs 60.0±9.8 (range 45–110) kg. Mean weight for male RDs was 69.9±11.8 (range 45–120) kg and female RDs 65.2±10.2 (range 48–92) kg .
Mean age of blood donors in voluntary and replacement group
Mean weight of blood donors in voluntary and replacement group
Significantly higher numbers of VDs were repeat donors, i.e., 11,286 (49.97%) as compared to only 5028 (32.84%) repeat RDs (P<0.0001).
Out of 37,896 donors, AEs were observed in 948 donors, giving an overall incidence of 2.5%. Overall AE frequency in RDs and VDs was not significantly different; 562 out of 22,587 for VDs (2.49%) and 386 out of 15,309 for RDs (2.52%) (2.52% vs 2.49%; P=0.87). Out of these 948 AEs, 425 (44.8%) were observed in the department, and 523 (55.2%) in the blood donation camps (BDC), the difference was not found to be statistically significant. (P=0.72). The AEs in female donors were significantly higher as compared to male donors (4.8% vs 2.3%) (P<0.001) . There was no significant difference in the frequency of AEs between voluntary and replacement female donors (4.9% vs 4.6%) (P=0.97); however, voluntary male donors had significantly less AEs rate (2.1%) as compared to replacement male donors (2.5%) (P=0.03).
Comparison of adverse events between voluntary and replacement donors
Out of 948 adverse events observed, majority, i.e., 602 (63.5%) were vasovagal in nature. Next common type of reaction was hematoma formation, 332 (35.0%). Other reactions formed a minority of total reaction. These were: nerve injury 2 (0.2%), thrombophlebitis 1 (0.1%), local allergy 1 (0.1%), and delayed vasovagal reactions, 10 (1.1%) .
Out of 602 vasovagal reactions majority, i.e., 507 (84.2%) were mild in degree; 72 (12%) were moderate, and 23 (3.8%) were severe in degree. Donors experiencing a vasovagal reaction complained of different symptoms. In order of frequency, these were: perspiration 393 (65.3%), dizziness 336 (55.8%), pallor 333 (55.3%), anxiety 312 (51.8%), loss of consciousness 87 (14.5), nausea 61 (10%), vomiting 37 (6.1%), tonic–clonic convulsions 19 (3.2%), palpitations 13 (2.2%), weakness 10 (1.7%), feeling of warmth 9 (1.5%), feeling of cold 5 (0.8%), thirst 4 (0.7%), chest tightness 4 (0.7%), tetany 3 (0.5%), headache 3 (0.5%), twitching 3 (0.5%), dimness of vision with strain on eyes 2 (0.3%), incontinence 2 (0.3%), voice fadeout 2 (0.3%), tremors of hand 1 (0.2%), and cramps 1 (0.2%). In addition, one donor informed that she had started her menstruation after she got a reaction. Those having generalized convulsions had it for a mean duration of 5.3 seconds, ranging from 3 to 10 seconds. Systolic blood pressure ranged from un-recordable to 160 mmHg. Most of the donors had a reaction during or immediately after donation, while the donor was still lying on the donor couch, 389/602 (63.7%). No incidence of donor injury as a result of reaction occurred during the study period.
Factors affecting frequency of vasovagal reactions
Site of donation: There was no significant difference in the overall vasovagal reaction rate amongst donors donating in hospital premises or BDC (1.58% vs. 1.59%). However, male VDs donating in BDC had significantly more reactions 1.59% vs. 0.94% (P=0.03) as compared with those donating in the department. On analyzing the frequency of reactions at voluntary BDCs, donors at educational institutions and industrial sites had higher number of reactions; least number were observed in camps organized by the defense services (P<0.0001) .
Nature of camp and vasovagal reactions
Donation status: First-time male VDs had a reaction rate of 1.84%, which decreased to 0.79% with repeat donations (P<0.001). Similarly, first-time female VDs had a reaction rate of 4.33%, which declined to 1.41% (P<0.0001) on subsequent donations. Although similar trend was seen in RDs male and female, but the difference was not statistically significant.
Donor demographic factors: Overall reaction rate in female donors was significantly higher than males (4.8% vs. 2.3%) (P<0.001). Between female VDs and RDs, the reaction rates were similar (4.9% and 4.6% respectively). Male VDs had significantly lesser reactions (2.1%) as compared to RDs (2.5%) (P=0.03). A continuous decrease in the rate of vasovagal reaction was seen with increasing age of the donor (P<0.0001). Mean age of the donors who had a vasovagal reaction was 26±7 years, with a range of 18–54 years. Highest rate of reaction was seen in the donors within the age group 18–24 years (2.71%), which was significantly higher than the overall reaction rate (1.59%) (P<0.0001), and lowest rate of reaction was 0.33% in the age group 46–60 years, which was significantly lower than the overall reaction rate (P<0.0001).
Reaction rate in donors decreased as weight of the donor increased. Reaction rate in donors weighing less than 60 kg was significantly higher as compared with those weighing more than 60 kg (2.52% Vs. 1.25%; P<0.0001).
First time versus repeat donors: 21,584 (56.95%) of total 37,896 blood donors were first-time blood donors; 50.03% VDs and 67.15% RDs were first-time donors. Of the total 602 vasovagal reactions, most, i.e., 250 were seen in first-time VDs with a reaction rate of 2.21%. In case of repeat voluntary donors, this number was 97 with a reaction rate of 0.85%. Rate of reaction in VDs dropped significantly after first donation (2.21% to 0.85%; P<0.0001), but this decrease was not significant in case of RDs (1.76% to 1.47%; P=0.21) .
Trend in reaction rates in first time and repeat replacement and voluntary donors
Volume of blood collected: According to the donor weight either 350±3 mL (for donors weighing less than 55 kg) or 450±45 mL (donors weighing ≥55 kg) blood was collected. Accordingly, donors weighing less than 55 kg donated ≤7.78±0.78 mL/kg (11.11% of total blood volume), whereas donors weighing more than 55 kg donated ≤8.04±0.80 mL/kg (or 11.48% of total blood volume). Out of all the donors who had a vasovagal reaction, in 123 donors (20.4%) desired amount of blood could not be collected, resulting in under collection and wastage of the unit collected. Overall reaction frequency was significantly higher in donors (replacement as well as voluntary) donating 350±35 mL of blood (3.97%) as compared to those donating 450±45 mL blood (0.67%) (P<0.0001).
Since blood volume collected was adjusted as per weight of the donor, weight seemed to significantly affect the occurrence of reactions.
Psychological factors: After recovery from the reaction, the donors were interviewed regarding any predisposing psychological factors. 84.6% of the donors acknowledged one or more of the following conditions prior to or during donation: general apprehension about safety of blood donation (75.9%), painful phlebotomy (31.6%), knowledge of a friend's reaction to donation (19.9%), prolonged wait before donation (20.6%), and fear of needle and/or blood (15.6%). RDs in addition also expressed anxiety regarding the health status of their patients.
Other factors: There seemed to be no relationship with the time of last meal taken. 136 (22.3) donors had a vasovagal reaction during donation, 253 (41.4) immediately post donation, 124 (20.3) while taking refreshments, and 97 (15.8%) just before leaving the donation site. Only one donor (0.2%) had a reaction prior to phlebotomy.
A total of 332 hematoma formations occurred out of 37,896 donations (0.88%). These occurred at donation site and resulted into under collection; no hematoma formation was reported by the donor after leaving the donation site. Of all the phlebotomies performed during the study period, 24,879 (65.61%) were performed by phlebotomists having an experience of more than 5 years. Comparison of experience of phlebotomist vs. frequency of hematomas revealed that significantly higher number of hematomas were formed by less experienced phlebotomists, 4.7 per 1000 donations vs. 16.5 per 1000 donations (P<0.0001).