1/3. Recurrent asystoles associated with vasovagal reaction during venipuncture.A 17-year-old high school student presented with a history of habitual faintings. On 24-hour Holter monitoring, cardiac asystoles were recorded, the longest lasting approximately 7 or 8 seconds during venipuncture procedures. The asystole associated with venipuncture demonstrated the cardioinhibitory effects of vasovagal reaction with blood-injury phobia. He also had a positive response during head-up tilt test showing hypotension and relative bradycardia after intravenous isoproterenol injection. After administration of oral beta blocker, he did not show further or recurrent cardiac asystole during blood injury procedure on electrocardiographic examination. Venipuncture is the most common invasive medical procedure performed in hospital settings. While venipuncture is considered to be reasonably safe, serious complication may occur even when only a small volume of blood is withdrawn. Therefore, medical personnel should be prepared to provide appropriate care.- - - - - - - - - - ranking = 1keywords = venipuncture (Clic here for more details about this article) |
2/3. Fainting induces an acute increase in the concentration of plasma factor viii and von willebrand factor.BACKGROUND AND OBJECTIVES: von willebrand factor (VWF) is stored in the weibel-palade bodies of endothelial cells and may be released in response to different secretion stimuli such as stress, physical exercise, adrenaline, DDAVP and thrombin. DESIGN AND methods: We found that fainting can also induce an acute increase in plasma VWF and factor FVIII (FVIII) concentrations, following observations in two patients with von Willebrand's disease (VWD) who experienced a fainting episode during venipuncture for blood collection. RESULTS: One patient was classified as having type Vicenza VWD, the other as type 1 VWD; both had normal platelet VWF content. After the fainting episode, FVIII and VWF levels were significantly higher than the levels in blood samples collected without stress; mean increases were 4.35-fold for FVIII, 4-fold for VWF:Ag and 5.3-fold for VWF:RCo, with values overshooting the upper limit of the normal range. Moreover, the post-fainting plasma VWF multimer pattern was characterized by a significant increase in all oligomers with the appearance of unusually large VWF multimers, similar to those observed following DDAVP infusion. INTERPRETATION AND CONCLUSIONS: These findings demonstrate that fainting acts as a stimulus capable of inducing the release of VWF from endothelial cells, and further highlight the role of stress in determining hemostatic states potentially favorable to the development of thrombotic complications.- - - - - - - - - - ranking = 0.14285714285714keywords = venipuncture (Clic here for more details about this article) |
3/3. Recurrent asystole associated with vasovagal reaction during venipuncture.A patient with a documented history of 2 asystolic episodes associated with venipuncture demonstrates the profound cardioinhibitory effects that vasovagal reactions to blood and injury ("blood-injury phobia") can produce. In approaching a patient with blood-injury phobia, the clinician should place the patient in the Trendelenburg position, apply a cardiac monitor, administer oxygen, and consider the need for atropine, transcutaneous pacing, and cough cardiopulmonary resuscitation (CPR) prior to venipuncture. diagnosis of vasovagal syncope is discussed. Long-term prophylactic interventions may be beneficial for certain patients.- - - - - - - - - - ranking = 0.85714285714286keywords = venipuncture (Clic here for more details about this article) |