9 free Paramedic practice questions: Advanced Differential Diagnosis

The vomiting that began yesterday: Vomiting is on the list for thyroid storm and for sepsis. A finding that fits both conditions cannot tell them apart.

The temperature of 103.6°F: A temperature of 103.6°F is the most abnormal number in the question. Fever is the reason both thyroid storm and sepsis are on your list in the first place. Since both conditions cause fever, the temperature cannot narrow the list down.

The confusion and agitation at home: Confusion and agitation are the most alarming things on this call. Both thyroid storm and sepsis cause an altered mental status. The confusion does not separate them.

Establishing intravenous access and applying the pads: Starting an IV and putting the pads on are prep steps for a fast rhythm. Neither one changes conduction or how hard the heart squeezes, so neither one can drop this patient's pressure.

Obtaining a 12-lead ECG before choosing a treatment: A 12-lead looks like a delay on a patient at 170. The 12-lead is the step that tells you whether the rhythm is truly narrow or is VT before you pick a drug. The patient is alert with a pressure of 116/72, and getting a 12-lead carries no risk.

Consulting medical control about the rhythm interpretation: Calling medical control is a good use of backup when the rhythm is hard to read. A phone call does not touch the patient's blood pressure or conduction, so calling medical control is not what risks collapse.

Prolonged expiration with diffuse wheezing: points to an airflow obstruction, like COPD or asthma. Wheezing does not tell you fluid is backing up behind a failing left ventricle.

Absent breath sounds over one side of the chest: a pleural space problem, like a pneumothorax. Cardiogenic pulmonary edema gives you crackles at both bases and distended neck veins, not silence on one side.

Deep, rapid respirations with clear lung sounds: Deep, rapid breathing with clear lungs fits a metabolic problem like diabetic ketoacidosis. Clear lungs do not fit pulmonary edema. Fluid in the alveoli is what makes the crackles in cardiogenic pulmonary edema.

Hypoglycemia: causes an altered mental status because the brain is short on glucose. Those patients are usually sweaty, tachycardic, and agitated. This patient's blood glucose is 96 mg/dL, which is normal.

Postictal state: A postictal state follows a seizure, with confusion and a slow return of consciousness. Breathing and pupils are usually close to normal. A respiratory rate of 6 with pupils at 2 mm goes far beyond a postictal state and points to a drug that slows breathing.

Acute ischemic stroke: A stroke in the pons can damage the pupil centers and the breathing centers at the same time. That gives you pinpoint pupils and very slow breathing too. A stroke that severe usually has a clear focal onset or known vascular risk factors. Nothing like that is described here, and a reversible toxic cause fits better.

Acute viral illness: A viral illness can cause headache and nausea. A virus would not start the same symptoms at about the same time in three people who share only the same home. The shared exposure here is the fuel-burning furnace.

Food-borne illness: would fit if the family shared a meal that made them sick. Nothing here points to a shared meal. The headache and nausea are tied to the furnace during heating season.

Simple asphyxiant exposure: A simple asphyxiant exposure does not explain this symptom pattern the way carbon monoxide does. A fuel-burning furnace in winter, with the whole household sick, points to carbon monoxide until proven otherwise.

Loss of sensation over the affected cheek: One-sided numbness is a stroke warning sign, the same as one-sided weakness. A numb cheek on the drooping side adds a second stroke finding to the droop. A second stroke finding points you toward a stroke, not Bell palsy.

Drooping that spares the forehead: A droop that spares the forehead is the stroke pattern. The forehead still moves because it gets nerve supply from both sides of the brain. Forehead sparing supports a stroke, not Bell palsy.

Tongue deviation toward the affected side: Tongue deviation is a stroke finding, the same as facial droop and trouble swallowing. Bell palsy is a problem with the nerve to the face. A deviated tongue adds a finding outside the face, and that points toward a stroke, not Bell palsy.

Weakness confined to one side of the body: Weakness on one side matches this child's left arm and leg findings. One-sided weakness shows up in Todd paralysis and in a stroke on one side of the brain. One-sided weakness cannot tell you which one caused this child's weakness.

Deficits that were maximal at the onset: Deficits that are worst at onset describe an acute ischemic stroke. The deficit is worst the moment the vessel blocks, and then the deficit stays the same instead of improving. Todd paralysis appears after the seizure and eases over time. A deficit that was worst at onset points toward stroke.

A blood glucose level within normal limits: A normal blood glucose rules out hypoglycemia as the cause of the altered mental status and the weakness. This child's glucose is already 88 mg/dL. A normal glucose says nothing about whether the weakness is getting better or whether a stroke caused it.

Progression of the underlying dementia: Dementia gets worse slowly, over months to years. This patient was forgetful but conversational until yesterday. A jump overnight into hallucinations and drifting off mid-sentence is too fast for dementia.

A new primary psychiatric disorder: A new psychiatric disorder can cause hallucinations. A psychiatric patient usually keeps a steady level of consciousness and can pay attention. This patient drifts in and out, and no psychiatric history is given. Psychiatric causes are only considered after medical causes are ruled out.

Normal age-related memory decline: Normal aging causes mild forgetfulness that stays the same, with no hallucinations and no change in level of consciousness. This patient has new hallucinations and drifts off to sleep mid-sentence. Those findings come from a new illness, not from aging.

Loss of circulating volume from internal bleeding: Internal bleeding causes shock from lost blood volume. With blood loss, the vessels clamp down, and the skin turns pale, cool, and clammy. This patient's skin is warm, dry, and flushed.

Reduced ventricular contractility lowering cardiac output: Reduced contractility is a weak heart muscle, the cause of cardiogenic shock. A weak pump gives cool, clammy skin and signs of fluid backing up behind the heart. This patient has warm, flushed skin, flat neck veins, and clear breath sounds.

Obstruction of blood flow leaving the heart: An obstruction to blood leaving the heart would give you distended neck veins. This patient's neck veins are flat, and the skin is warm and flushed.