UBC Objectives: Mental Health & Priority Topic: Anxiety

Key Feature 1: Do not attribute acute symptoms of panic (ex: shortness of breath, palpitations, hyperventilation) to anxiety without first excluding serious medical pathology (ex: pulmonary embolism, myocardial infarction) from the differential diagnosis (especially in patients with established anxiety disorder).
Skill: Selectivity, Clinical Reasoning
Phase: Diagnosis, Hypothesis generation

Key Feature 2a: When working up a patient with symptoms of anxiety, and before making the diagnosis of an anxiety disorder: Exclude serious medical pathology.
Skill: Selectivity, Clinical Reasoning 
Phase: Hypothesis generation, Diagnosis

Key Feature 3: In patients with known anxiety disorders, do not assume all new symptoms are attributable to the anxiety disorder.
Skill: Clinical Reasoning
Phase: Diagnosis, Hypothesis generation

Next week, I start my much-anticipated St Paul's Hospital Emergency Department rotation. Having spent some time in emergency departments in clerkship and doing consultations in the emergency department throughout residency thus far, I have a fair sense of what I may expect. Although the emergency department is THE place where people go when there is a real emergency, much of providing care in the emergency department is really weeding through the many more not-so-urgent concerns, and stratifying risk accordingly so as to not miss anything urgent. If I am worried that a patient appears unwell when working in an outpatient clinic, I send them to a nearby ED, as I have twice during my past week working at a clinic in the Downtown Eastside (these patients tend to be sicker than most people who present to clinic). I am looking forward to the challenge of seeing those patients who are indeed sicker, and of getting a better sense of which ones really are well enough to be sent home for ongoing care in an outpatient setting.

An example of a situation in which patients present to the emergency department with a possible emergency is those patients who present with signs and symptoms in keeping with a panic attack. Panic attacks in general are characterized as sudden onset panic/fear, with associated physical signs such as a racing heart, difficulty breathing, chest pain, and a sensation of doom. On the flipside, if a patient has a very real reason to have difficulty breathing or chest pain, such as a massive pulmonary embolism or a heart attack, they too will have a racing heart and probably a sensation of fear as well. Consider that even patients with a history of anxiety or panic attacks would also likely experience these sensations with underlying medical precipitants, so a history of these diagnoses doesn't mean these alternative medical etiologies are off the table as causing this particular presentation. It is the role of the emergency physician to look for and hopefully rule out the possibility that a medical reason is actually underlying the panic. 

So, when a patient presents to the emergency department with what seems to be a panic attack, what are the medical reasons for this presentation that need to be ruled out? My differential diagnosis is as follow: 

1. Cardiovascular diagnoses: Acute coronary syndrome/angina or arrhythmia
2. Respiratory diagnoses: Pulmonary embolism or an exacerbation of asthma or COPD
3. Endocrine diagnoses: Pheochromocytoma or hyperthyroidism
4. Neurological diagnoses: Temporal lobe epilepsy
5. Substance use: Stimulant use, excess caffeine

While I won't get into the details of how to rule-in or rule-out the above DDX, which would be a long post, it's important to perform a clinical assessment that gathers information regarding the possibility that such diagnoses could be present. If there is more than a minimal suspicion, perform investigations to look for the possibility that they are present. And then, if they are not, you can confidently diagnose the patient's presentation as a panic attack, which is also serious, but that can likely be treated sufficiently with outpatient care alone.

Note that for the patient who presents with a complaint of anxiety without an episode of acute panic,  it is reasonable to look for precipitating medical reasons, especially if the anxiety is new for them and without an obvious psychosocial trigger. Consider screening for organic etiology with investigations that may include: CBC, electrolytes, TSH, urinalysis, ECG, urine toxicology screen. Abnormalities in these investigations warrant a workup for illness as indicated (ex: anemia, electrolyte abnormality, hyperthyroidism, etc.)