Lecture Notes
When approaching an undifferentiated patient, it is important to create a differential of critical or can’t miss conditions off of the chief complaint. The critical differential guides what questions to ask in your HPI, what physical exam findings to focus on, what labs/imaging to order in your workup, and skeletonizes the medical decision-making portion of your note. This organized approach is especially helpful initially when there is diagnostic uncertainty or when patients present with vague or multiple complaints. In the undifferentiated patient, it is often easier to figure out what is NOT going on, than it is to figure out the final diagnosis. Think of it as trying to solve a case with limited clues or leads, it is hard initially but once you obtain more data you begin to get a better idea of what is going on. Sometimes the uncertainty can be paralyzing and you will not know where to start your workup. This is why we advocate focusing on the acute chief complaint and using that to build a critical differential of diseases you can’t miss (patients with multiple chief complaints may have many chronic complaints and only one acute complaint that caused them to come to the ER). Once you have initiated the workup, you then methodically rule out life-threatening conditions using an evidence-based approach. After you have convinced yourself that you have ruled out a life-threatening process, you can focus on building a differential of common diseases from the chief complaint, focusing now on what most likely is going on.
Doctors don’t get to use the words dizziness or lightheaded as they do not convey any medical information. If someone presents with the chief complaint of dizziness you must determine if they mean:
- Syncope/Presyncope
- Vertigo/disequilibrium
The initial part of your encounter should focus on helping the patient define what they mean by dizziness or lightheaded. Ask them to describe what they feel without using the words dizzy or lightheaded. If they cannot describe it to you in an open-ended manner, then provide them with multiple choice options.
Patients usually present in the following 3 scenarios:
- Clear-cut symptoms of syncope/presyncope.
- Clear-cut symptoms of vertigo/disequilibrium.
- A mixture of both syncope and vertigo.
If your patient reports both, try to determine if what they feel is more likely syncope or more likely vertigo.
For these patients, you may have to work up both entities simultaneously, but early on you should develop a feel for which one of the two is more likely.
Syncope/Presyncope
Patients will report “passing out”, “falling out”, fainting, losing consciousness, or feeling like they are going to pass out, tunnel vision, etc. Patients that report these symptoms require the same workup regardless of whether or not they actually lost consciousness. The disposition of the patients will be different depending on what you think caused the syncopal episode.
Syncope is divided into 3 main categories:
- Cardiovascular mediated syncope
- Hypovolemic syncope
- Neurally mediated syncope
Cardiovascular Mediated Syncope
When patients present to the ED with syncope, our evaluation is focused on determining if the loss of consciousness resulted from a cardiovascularly mediated process. This is the life-threatening condition that we cannot miss. It is also the hardest to determine and capture since cardiac arrhythmias may be unpredictable, intermittent, and sometimes self-limited. The whole encounter is structured around risk stratifying your patient for cardiovascular mediated syncope (CMS) and to see if you can build a story for something other than CMS as a diagnosis. This is one of the few times in Emergency Medicine where we really focus on obtaining a family history. It is important to know if there is a family history of sudden cardiac death at a young age, or of family members who have had exertional syncope. This helps us understand if we are dealing with a patient that may have a channelopathy, hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia, etc. The main diagnoses we are looking for are the following:
- Dysrhythmia (significant tachycardia or bradycardia)
- Wolff-Parkinson-White (WPW)
- Brugada Syndrome
- Long QT Syndrome
- Heart Block (2nd-degree Mobitz II/3rd degree)
- Hypertrophic Cardiomyopathy
- Arrhythmogenic Right Ventricular Dysplasia (ARVD)
- Stenotic Valvular disease (Aortic stenosis or Mitral stenosis)
- CHF
These patients will often have loss of consciousness without any prodromal (no warning) symptoms OR they will have exertional syncope.
Hypovolemic (Orthostatic) Syncope
All of my patients that present with dizziness, that is described as syncope/presyncope, are investigated for the following disease processes:
- Volume depletion from:
- Increased output: nausea, vomiting, or diarrhea.
- Decreased input: PO intolerance or decreased PO intake
- Upper/lower GI bleeding or other clinically significant bleeding
- Infection with occult shock
These patients will present with a prodrome of symptoms prior to losing consciousness or may only feel presyncopal without a history of loss of consciousness.
Neurally Mediated Syncope
These patients will also present with prodromal symptoms and have either a vasovagal (fear, pain, Valsalva) or a predictably situational process (coughing, micturition, defecation prior to loss of consciousness.
The Basic Work-up
The most basic workup for these patients includes a thorough history and examination PLUS an ECG. The history will help guide what else to add to you work-up. History and exam can help you determine:
- Patients volume status.
- Hypovolemic.
- Hypervolemic and in decompensated heart failure.
- Assess for carotid bruits.
- Assess for any murmurs (specifically AS/MS).
- HOCM.
- Assess for clinically significant anemia by looking at the patient’s conjunctiva.
- Assess for a GI hemorrhage by performing a rectal exam.
You can then add labs to help you look for electrolyte abnormalities, anemia, infection.
Do Not Routinely Order The Following:
Most patients will only require a basic workup with ECG, CBC, and Chemistry as they are usually asymptomatic by the time they are in the ER. Additional testing is directed by the patient’s HPI and if there are any symptoms present after the syncopal event.
Troponin: is not routinely warranted unless you are concerned for ACS. Remember the patient we are talking about is the patient who had a syncopal or pre-syncopal episode and is now largely asymptomatic. The likelihood of ACS in a patient with an episode of isolated syncope is very low. We are not talking about a patient who reports chest pain concerning for ACS prior to or after the syncopal event.
Chest X-Ray: is not routinely warranted unless you are concerned for aortic dissection or ACS.
Head CT: is not routinely warranted unless you are concerned for a subarachnoid hemorrhage or traumatic intracerebral hemorrhage.
What To Look For On ECG
The ECG will help you determine:
- Electrolyte abnormality
- U-wave in hypokalemia
- Peaked T-wave in hyperkalemia
- Long QT in hypocalcemia or hypomagnesemia
- WPW – Delta wave
- Brugada Syndrome – RBBB in leads V1-V3, Saddle-back STE (google it)
- Long QT Syndrome – QT interval is > ½ the R-R interval
- Heart Block (2nd degree Mobitz II/3rd degree)
- Hypertrophic Cardiomyopathy – Dagger q-waves pathognomonic
- Arrhythmogenic Right Ventricular Dysplasia (ARVD) – epsilon wave (google it)
- Tachycardia or bradycardia
Disposition
Patients without a clearly identifiable cause of syncope and without a prodrome may have cardiovascular mediated syncope. These patients require admission for continued monitoring and work-up. Discharging someone with cardiovascular mediated syncope could be catastrophic. These are characteristically frustrating admissions because patients will often get “million dollar” work-ups that are usually negative. At minimum an admission helps us observe the patient under monitoring to determine if they are clinically stable. If the patient has a malignant arrhythmia you would expect to capture it within the first 24-48 hours. If not, then you at least have compelling evidence to state that the patient is clinically stable after being monitored continuously for 24-48 hours and is a candidate for outpatient Holter/Ziopatch.
Consider admission in the following patients (ACEP Clinical Policy on Syncope):
- Abnormal ECG
- Acute decompensated CHF plus syncope
- If you suspect structural heart disease
- Low hematocrit
- Initial hypotension
- Dyspnea
- Family history of sudden cardiac death
- Elderly
May use San Francisco Syncope Rule to help guide decision making. Consider discharging patients that are younger (<45 years old) that are considered low risk by SF Syncope Rule.
If patients have a clear-cut story for hypovolemic then you resuscitate and disposition based on the primary process (i.e. give blood to GI bleeding and scope as necessary, treat for sepsis, etc).
This is the first part of a two part series on dizziness. Part two can be found at http://www.blog.numose.com/emed-cc/dizziness-2
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