1.01 Vasovagal Syncope (Faint, swoon)
=======================================

agk's Library of Common Simple Emergencies

Presentation
------------
The patient experiences a brief loss of consc- 
iousness, preceded by a sense of anticipation. 
First, there is a period of sympathetic tone, 
with increased pulse and blood pressure, in 
anticipation of some stressful incident, such 
as bad news, an upsetting sight, or a painful 
procedure. Immediately following the stressful 
occurrence, there is a precipitous drop in 
sympathetic tone, pulse and blood pressure, 
causing the victim to fall down or lose 
consciousness. Transient bradycardia and a few 
clonic limb jerks may accompany vasovagal 
syncope, but there are usually no sustained 
palpitations, arrhythmias or seizures, 
incontinence, tongue biting, or injuries beyond 
a contusion or laceration from the fall. 
Ordinarily, the victim spontaneously revives 
after spending a few minutes supine, suffers no 
sequelae, and can recall the events leading up 
to the faint. The whole process may transpire 
in the ED, or a patient may have fainted 
elsewhere, in which case the diagnostic 
challenge is to reconstruct what happened and 
rule out other causes of syncope.

What to do:
-----------
- Arrange for patients, family, and friends 
   anticipating unpleasant experiences in the 
   ED to sit or lie down and be constantly 
   attended.
- If someone faints in the ED, catch him so he 
   is not injured in the fall, lie him supine 
   on the floor for 5-10 minutes, protect his 
   airway, record several sets of vital signs, 
   and be ready to proceed with resuscitation 
   if the episode turns out to be more than a 
   simple vasovagal syncope.
- If a patient is brought to the ED following a 
   faint elsewhere, ask about the setting, 
   precipitating factors, descriptions of 
   several eyewitnesses, and sequence of 
   recovery. Be alert for evidence of seizures, 
   hysteria, and hyperventilation (see sections 
   below). Record several sets of vital signs, 
   including orthostatic changes, and examine 
   carefully for signs of trauma and neurologic 
   residua.
- After full recovery, explain to the patient 
   that this is a common physiological reaction 
   and how, in future recurrences, he can 
   recognize the early lightheadedness and 
   prevent a full swoon by lying down or 
   putting his head between his knees.

What not to do:
---------------
- Do not let families stand for bad news, let 
   parents stand while watching their children 
   being sutured, or let patients stand for 
   shots or venipunctures.
- Do not traumatize the faint victim with 
   ammonia capsules, slapping, or dousing with 
   cold water.

Discussion
----------
Vasovagal syncope is a common occurrence in the 
ED. Observation of the sequence of stress, 
relief, faint makes the diagnosis, but, better 
yet, the whole reaction can usually be 
prevented. It should be noted that although 
most patients suffer no sequelae, vasovagal 
syncope with prolonged asystole can produce 
seizures as well as rare incidents of death. 
The differential diagnosis of a loss of 
consciousness is extensive and therefore loss 
of consciousness should not immediately be 
assumed to be due to vasovagal syncope.

References:
-----------
- Graham DT, Kabler JD, Lunsford L: Vasovagal 
   fainting: a diphasic response. 
   *Psychosomatic Medicine* 1961;6:493-507.
- Lin JTY, Ziegler DK, Lai CW, Bayer W: 
   Convulsive syncope in blood donors. *Ann 
   Neurol* 1982;11:525-528.

 ----------------------------------------------------
 from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES
 Longwood Information LLC 4822 Quebec St NW Wash DC
 1.202.237.0971 fax 1.202.244.8393 electra@clark.net
 ----------------------------------------------------