Table 1 Details of the proposed interventions
Type of intervention | Mechanism and rationale | Content | Timing | Delivery | Key differences with current practice |
|---|---|---|---|---|---|
Isotonic drink | Suggested to prevent both immediate and late-onset VVRs due to its additional effect of decreasing relative hypovolemia and increasing orthostatic tolerance through electrolyte replacement | Isotonic drink (500 ml): ~350 mg sodium, ~0.03g sugar | Before donation | Cup given to all donors with information posters advertised (isotonic drinks prepared prior to donor arrival/tablet given to donor to add to water) | Sodium content to help restore electrolytes lost during donation |
Applied muscle tension | Physical manoeuvres including tensing/releasing of skeletal muscles to combat orthostatic intolerance Static contractions of the skeletal muscles result in the emptying of large capacitance veins and increased venous return, blood pressure, and ultimately greater cerebral perfusion Other suggested mechanisms include anxiety reduction and distraction | Keeping legs crossed throughout exercise Tensing legs and buttocks and including the abdomen Instructions to “breathe normally” 5-s contractions and release To exercise AMT following donation chair and leaving site, if symptoms | Immediately upon arrival at donation chair | Information handout with instructions given to all donors | Keeping legs crossed throughout exercise (current practice: crossing and uncrossing) Tensing legs and buttocks and including the abdomen (current practice: no abdomen) Instructions to breathe normally (current practice: no breathing instructions) 5-s contractions and release (current practice: 10-s release) To exercise AMT following donation chair or leaving site, if symptoms (current practice; no such recommendation) |
Psychosocial | Fear, pain, blood-related stimuli, lack of social support, and lack of a sense of control are associated with autonomic regulation, hemodynamic changes, blood pressure changes, and VVRs Preparation materials have been suggested to reduce VVRs | Providing information on the donation process, coping strategies, and various areas of possible apprehension (e.g. fear, pain, physical reactions) | Upon arrival and registration | Information handout given to all donors immediately following registration | Providing relevant information and coping strategies to blood donors directly, including related strategies such as distraction (not currently provided in usual practice) |
Chair | Following the donation, the hypovolemic state combined with the orthostatic stress of suddenly standing leads to an increased risk of VVRs Recovery time in the donation chair in the upright position after removal of the donation needle has been suggested to attenuate orthostatic stress, reducing the amount of sudden blood pooling and consequent VVRs | Two minutes in donate/recovery position followed by 1 min in the final rest position | Immediately following needle-withdrawal | Chair inclined by staff manually | Duration of time in chair following donation (i.e. a total of 3 min vs. 2 min in current practice) |