Syncope

Syncope is an abrupt loss of consciousness with loss of postural tone. It has a very short duration and has a rapid recovery. Presyncope is the sensation of dizziness or lightheadedness, but that does not lead to syncope. Both syncope and presyncope are managed in the same way.

Causes
Most syncopal episodes are benign. There are many causes, such as prolonged standing, fear or intense pain, crowded or warm places. Having a low blood volume (such as from dehydration) is another potential cause. Medications that affect the blood pressure or heart rate can also cause syncope. Often the cause is never identified.

However, syncope occasionally may be a symptom of a serious underlying disease, for example cardiac disease (such as cardiac arrhythmia or valve disease). Other examples of serious underlying disease are hemorrhage (such as gastrointestinal bleeding, ruptured ectopic pregnancy or ruptured spleen), pulmonary embolism and subarachnoid hemorrhage.

A single syncopal episode is likely to have a benign cause. However if there are multiple syncopal episodes occurring over a short period of time then a more serious underlying disease must be suspected.

Signs and Symptoms
The patient may or may not have preceding dizziness or lightheadedness. There will be an abrupt loss of consciousness, as well as a loss of postural tone, causing the patient to fall to the floor or slouch in the chair. The duration of unconsciousness is short.  The recovery is also rapid, with the patient returning to their baseline neurologic function rapidly.

Investigations
Most syncopal episodes are benign. However, occasionally syncope may be a symptom of a serious underlying disease. For this reason it may be necessary to investigate. 

A detailed history and thorough physical examination is required. This will include a neurologic examination, and auscultation of the heart.

The blood sugar level must be checked at the patient’s bedside.

An electrocardiogram (ECG) enables identification rhythm abnormalities, if present. It also enables identification of any myocardial ischemia or infarction, if present.

Routine blood tests may or may not be required, depending on the circumstances. Checking the hemoglobin level is required if internal bleeding or anemia is suspected.

Women of child bearing age must have a urine pregnancy check done. Echocardiography may be required if cardiac disease is suspected.

Treatment
Initial management of syncope includes helping the patient to the ground and positioning them supine, as this position encourages blood flow to the brain. Raising the legs also helps to facilitate this. The patient’s pulse should be palpated and breathing observed, and an open airway must be maintained.

Oxygen should be given if the loss of consciousness is prolonged (for example, over 2 minutes), and the patient put into the recovery position. However, since the majority of syncopal episodes have a very short duration, full recovery almost always occurs prior to presentation at the hospital.

Patients that present following syncope may require treatment of the underlying cause. Whether treatment is required depends on the results of the investigations. If investigations reveal an underlying disease, then appropriate treatment shall be required.

Patients who suffer from recurrent syncope should impose driving restrictions on themselves to protect themselves and others.

Complications
Injuries may be sustained during the syncope, especially if the patient fell from standing, or fell from a height. Common injuries associated with falls include facial fractures, hip fractures, wrist fractures and head injuries. A careful physical examination needs to be performed so that any injuries are identified and treated as required.