As discussed in a previous post, there are a number of significant causes that we need to be aware of. For a quick review, there are 3 main types of syncope:
Reflex-mediated Syncope: In this case, there is increased vagal nerve stimulation, during activities such as prolonged standing in a hot environment, valsalva maneuver (bearing down), or exposure to intense pain, or fear. The result is a drop in SBP, sudden LOC, and then return to GCS 15 in 10-15 seconds.
Orthostatic Syncope:When we change position from sitting/lying to standing, gravity does what it is good at and causes the blood to move toward the lower extremities. This causes a sudden, transient drop in systolic blood pressure. In a healthy individual, baroreceptors in the carotid arch pick up this drop and activate compensatory vasoconstriction and tachycardia. This means that SPB is restored to baseline in seconds. However, in patients with pre-existing hypotension, dehydration, or those on beta-blockers, these compensatory mechanisms may not be active; at least not sufficiently to correct rapid changes in SBP. The result is a brief drop in cerebral perfusion pressure, and loss of consciousness. This lasts anywhere from 10-15 seconds, with a spontaneous return to GCS 15.
Cardiac Syncope: In this case, a cardiac problem causes decreased perfusion of the brain, and a transient LOC, and postural tone. As stated in my earlier post, the common causes include: -Arrhythmia -Ischemia -Brugada syndrome -Hypertrophic cardiomyopathy -WPW -Long QT syndrome
Now that we have reviewed syncope types, lets talk about assessment of the patient, post-syncopal episode. This is a pretty common call. You will be dispatched to a residence or business for a patient who was responding normally, had a sudden LOC for 10-20 seconds, accompanied by a fall or loss of postural tone. These patients will spontaneously return to GCS 15. By the time we arrive, they are usually alert, oriented and wondering what all the fuss is about. So how do we want to approach this assessment?
Well the answer is, we will use the same basic format as we would any other medical complaint:
ABCDE
HPI
PMHx
Meds
Allergies
Last oral intake
HPI: If these patients are truly syncopal, they will have had a spontaneous return to baseline GCS, and your ABCs won't likely need intervention. Our main tool then is our history. We want to know the following:
What happened: “Hello _______ my name is ________ can you tell me what happened?”
Has this ever happened before? If so, have you ever seen a doctor about it, and did they determine a cause?
Onset: We want to know if there was a syncopal prodrome, or if the event occurred without warning. “Did you feel anything unusual before the episode, or did you suddenly wake up on the floor?”. A typical prodrome includes: -Dizziness, lightheadedness. -Blurred vision, tunnel vision, or “seeing stars” -Feeling suddenly warm, flushed, or diaphoretic.
Provocation: “What were you doing immediately before you passed out?” We want to know if the patient was sitting, standing, or suddenly changing position. Any syncope that occurs with an exertional component should be concerning for possible cardiac causes.
Associated symptoms: Is the patient currently experiencing any of the following: -Dizziness, weakness, or drowsiness. Was there any seizure activity. -Chest pain, pressure, or discomfort. -Dyspnea -Nausea, fever/chills -Any recent infections -Pallor or diaphoresis -Has the patient had any recent hospitalizations or changes to his/her medications.
PMHx: We want to pay attention for:
Cardiovascular history or risk factors (MI, HTN, CAD, CHF, CVA, A-fib, PE, aneurism, valvular defects, etc).
DM
Renal problems
Cancer
Pregnancy
Any prior similar episodes
Epilepsy
Medications: A number of medications can potentially lead to syncopal episodes. Cardiac medications such as Digoxin, CCB, Beta-blockers, and Alpha-blockers can all inhibit the body's ability to compensate during orthostatic changes in blood pressure. These drugs interfere with the ability of the heart to increase rate, and interfere with compensatory vasoconstriction. Diuretics such as Furosimide (Lasix), aldactone, hydralazine, etc can cause fluid depletion if there is insufficient oral intake to match losses. This causes a hypotensive state. Improper use of insulin leads to hypoglycemia, but the presence of insulin (or oral diabetic meds) on a med list can also indicate potential for a hyperglycemic hyperosmolar state which also pre-disposes patients to hypovolemia.
Allergies: Our primary concern as allergies are related to syncope, would be anaphylaxis. Syncope may occur in the case of sudden drop in SPB related to anaphylactic exposure.
Last oral intake: This is one of the cases where this line of questioning is useful. If a patient hasn't been eating or drinking properly, we could be looking at anything from dehydration, to electrolyte or glucose imbalances.
Physical assessment and vital signs:
The syncopal patient should receive the works. What I mean by this is that we need to cast a wide net to narrow our differential. Fortunately all of our standard pre-hospital tests help us well in this respect. We want to assess:
Pupils for PERRL, and nystagmus
Chest for air entry and evidence of adventitious sounds
Temperature
Pulse for rate, rhythm, and strength
Cap refill
Respirations for rate rhythm and depth
Blood pressure. Orthostatic pressures are recommended
SPO2 to rule out hypoxia
Blood glucose level
3 lead ECG for obvious abnormalities
12-lead ECG for the high risk causes discussed in the intro.
FAST stroke exam
This physical allows us to assess all the potential angles, and form a reasonable working diagnosis. It seems like a lot to do, however, it only takes 2-3 minutes, and you can have your partner do most of it while you gather your history.
Treatment depends on causes found during assessment. Hypotensive patients should receive a fluid bolus. Hypoglycemia can be corrected with oral glucose in most patients. Cardiac causes can be treated using your local protocols for ischemia, arrhythmia, and hypotension. Many cases of syncope are relatively benign, but vigilance can save a life.
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