Intervention description {11a}
orthostatic stress, hypovolemic, anxiety, pain
CONTRACTIONS
As noted above, our trial is evaluating different interventions: (1) 500ml of isotonic drink before donation; (2) 3-min rest on donation chair after donation; (3) modified applied muscle tension (AMT); and (4) a psychosocial intervention using preparatory materials. Table Details of the proposed interventions
Physical manoeuvres including tensing/releasing of skeletal muscles to combat orthostatic intoleranceStatic contractions of the skeletal muscles result in the emptying of large capacitance veins and increased venous return, blood pressure, and ultimately greater cerebral perfusionOther suggested mechanisms include anxiety reduction and distractionKeeping legs crossed throughout exerciseTensing legs and buttocks and including the abdomenInstructions to “breathe normally”5-s contractions and releaseTo exercise AMT following donation chair and leaving site, if symptomsKeeping 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)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 VVRsPreparation materials have been suggested to reduce VVRsFollowing the donation, the hypovolemic state combined with the orthostatic stress of suddenly standing leads to an increased risk of VVRsRecovery 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