The following cases and commentary, which involve evaluation of patients in the emergency department, are excerpted from ACP's Medical Knowledge Self-Assessment Program (MKSAP 15).
Case 1: Fever, cough and chest pain
A 70-year-old man is evaluated in the emergency department for the acute onset of fever, cough productive of yellow sputum, right-sided pleuritic chest pain, and dizziness. He has a history of diabetes mellitus and hypertension treated with hydrochlorothiazide, lisinopril, glyburide, and metformin.
On physical examination, temperature is 35.0o C (95.0o F), blood pressure is 110/70 mm Hg, pulse rate is 120/min, and respiration rate is 36/min. He appears to be in acute respiratory distress. Pulmonary examination reveals dullness to percussion, increased fremitus, and crackles at the right lung base. He is oriented only to person.
Laboratory studies show hematocrit 42%, leukocyte count 23,000/µL (23 × 109/L) with 40% band forms, platelet count 150,000/µL (150 × 109/L), blood urea nitrogen 46 mg/dL (16.4 mmol/L) and creatinine 1.4 mg/dL (123.8 µmol/L).
Arterial blood gas studies on ambient air show PO2 50 mm Hg, PCO2 30 mm Hg and pH 7.48. Chest radiograph shows a right lower lobe infiltrate.
Which of the following is the most appropriate management of this patient?
A. Admit to general medical floor
B. Admit to the intensive care unit
C. Observe in the emergency department for 12 hours
D. Treat as an outpatient
Case 2: Chest pressure in older woman
A 67-year-old woman is evaluated in the emergency department for substernal chest pressure that has lasted for just over three hours. The pressure has not remitted despite administration of one dose of sublingual nitroglycerin on the way to the hospital. The emergency department is in a community hospital that does not have percutaneous coronary intervention (PCI) capability. The nearest hospital with PCI capability is 45 minutes away.
The patient has a history of hypertension and hyperlipidemia. There is no history of recent surgery or bleeding diathesis. Current medications include lisinopril, hydrochlorothiazide, and simvastatin. She has no known drug allergies. Aspirin and sublingual nitroglycerin are administered upon arrival.
On physical examination, her temperature is 37.2° C (99.0° F), blood pressure is 146/92 mm Hg, pulse is 104/min and regular, and respiration rate is 18/min. The patient appears uncomfortable. Crackles are heard at the bases of both lung fields. The S1 is normal; the S2 is paradoxically split. No murmur or gallop is present. Results of a complete blood count, basic metabolic profile, and clotting studies are normal. Initial serum troponin I level is 0.5 ng/mL (0.5 µg/L). A stool sample tests negative for occult blood. An electrocardiogram demonstrates normal sinus rhythm with a left bundle branch block. No prior tracing is available for comparison. Intravenous heparin, β-blockers, and morphine are administered.
Which of the following is the most appropriate next step in the management of this patient?
A. Administer thrombolytic therapy
B. Administer a glycoprotein IIb/IIIa inhibitor
C. Obtain serial cardiac enzyme measurements
D. Transfer to the nearest hospital with PCI capability
Case 3: Paresthesia and throbbing headache
A 33-year-old woman is evaluated in the emergency department for paresthesia that began in the left face and spread over 30 minutes to the left arm and leg, clumsiness of the left hand that began 30 minutes ago, and an emerging right-sided throbbing headache. She is otherwise healthy but has a family history of migraine. Her only medication is a daily oral contraceptive pill.
On physical examination, temperature is normal, blood pressure is 140/82 mm Hg, pulse rate is 110/min, and respiration rate is 20/min. All other examination findings are normal.
Results of laboratory studies and a CT scan of the head are also normal.
Which of the following is the most likely diagnosis?
A. Migraine with aura
B. Multiple sclerosis
C. Sensory seizure
D. Transient ischemic attack
Case 4: Ischemic stroke
A 79-year-old woman is to be transferred from the emergency department to a hospital ward for ongoing care. She awoke at home five hours ago with slurred speech, difficulty swallowing food and drink, and left hemiparesis. A right hemispheric ischemic stroke was diagnosed in the emergency department after a CT scan of the head confirmed a right hemispheric infarction. Because the time of stroke onset could not be determined, no recombinant tissue plasminogen activator was administered. The patient has no other medical problems and takes no medications.
On physical examination, blood pressure is 168/86 mm Hg, pulse rate is 80/min, and respiration rate is 18/min. Neurologic assessment reveals dysarthria, dysphagia, left facial droop, and left hemiparesis.
Laboratory studies show a plasma LDL cholesterol level of 158 mg/dL (4.09 mmol/L) but no other abnormalities.
Which of the following is the most appropriate first step in management after transfer is completed?
A. Bedside screening for dysphagia
B. Oral administration of an angiotensin-converting enzyme inhibitor
C. Oral administration of a statin
D. Physical therapy and rehabilitation consultation
Case 5: Upper respiratory tract infection
A 28-year-old man is evaluated in the emergency department for a 2-day history of worsening dyspnea and wheezing in conjunction with an upper respiratory tract infection. The patient has a history of asthma, and his medications are inhaled mometasone and albuterol. In the emergency department, the patient is anxious and is using accessory muscles to breathe; he cannot speak in full sentences. The oxygen saturation is 90% while he is breathing ambient air. Breath sounds are reduced bilaterally, with faint diffuse expiratory wheezes. He is given albuterol by nebulizer, and use of accessory muscles is reduced. Bedside spirometry shows an FEV1 of 35% of predicted; he is given two more treatments of nebulized albuterol.
After treatment, the patient is alert with slight use of accessory muscles; he can speak in short full sentences. Vital signs are stable; oxygen saturation is 98% with the patient receiving oxygen, 2 L/min. Breath sounds are louder than on initial examination, and wheezing is more intense. Spirometry shows an FEV1 of 50% of predicted.
Which of the following is the most appropriate next step in the management of this patient?
A. Admit the patient to a regular medicine ward
B. Discharge the patient on his baseline asthma treatment regimen
C. Intubate and admit the patient to the intensive care unit
D. Monitor the patient in the intensive care unit
Answers and commentary
Correct answer: B. Admit to the intensive care unit.
This patient has severe community-acquired pneumonia and should be admitted to the intensive care unit (ICU). Direct admission to the ICU is required for patients with septic shock requiring vasopressors or with acute respiratory failure requiring intubation and mechanical ventilation (major criteria). Although the patient is severely ill, he does not yet meet these major criteria and, therefore, the need for ICU admission is less straightforward. A combined working group of the Infectious Diseases Society of America and the American Thoracic Society developed consensus guidelines recommending that patients with community-acquired pneumonia with at least three of the following minor criteria be admitted to the ICU: respiration rate greater than 30/min; arterial PO2/FiO2 ratio of less than or equal to 250; multilobar infiltrates; confusion/disorientation; uremia (blood urea nitrogen level ≥20 mg/dL [7.1 mmol/L]); leukopenia (leukocyte count <4000/µL [4 × 109/L]); thrombocytopenia (platelet count <100,000/µL [100 × 109/L]); hypothermia (core temperature <36.0° C [96.8° F]); and hypotension requiring aggressive fluid resuscitation. These minor criteria may be used as a guide to determine who would benefit most from ICU admission, but prospective validation of these criteria is needed.
- Intensive care unit admission should be considered for patients with community-acquired pneumonia who meet at least three of the following criteria: respiration rate greater than 30/min; arterial PO2/FiO2 ratio of less than or equal to 250; multilobar infiltrates; confusion; a blood urea nitrogen level of 20 mg/dL (7.1 mmol/L) or greater; leukocyte count less than 4000/µL (4 × 109/L); platelet count less than 100,000/µL (100 × 109/L); core temperature less than 36.0° C (96.8° F); and hypotension requiring aggressive fluid resuscitation.
Correct answer: D. Transfer to the nearest hospital with PCI capability.
This patient with chest pain, tachycardia, crackles, and a left bundle branch block of unknown duration has ongoing discomfort despite therapy. Regardless of her equivocal troponin level, her condition should be treated as an ST-elevation myocardial infarction (STEMI). For the patient who presents with STEMI and symptoms of less than 12 hours in duration, reperfusion therapy must be considered in order to salvage myocardium. The ISIS-2 study demonstrated efficacy of thrombolysis for STEMI for up to 12 hours from the onset of symptoms. However, the greatest benefit of thrombolytic therapy is seen when it can be administered very early in the course of infarction (especially <1 hour). Current guidelines suggest that after 3 hours, PCI is preferable.
In this particular patient, PCI is not immediately available. Since the degree of myocardial salvage is directly related to the time from symptom onset to the time of reperfusion of the infarct-related artery, a decision must be made quickly whether to administer thrombolytic therapy or transfer the patient to another facility for PCI. For the purpose of investigating treatment outcomes in STEMI with respect to thrombolysis versus PCI, several terms have been defined. “Medical contact–to-balloon time” is the elapsed time from the first contact of the patient with the medical system to the time an angioplasty balloon is inflated in the infarct-related artery. This includes the inter-facility transfer time if the patient first arrives at a hospital without PCI capability. “Door-to-balloon time” is the elapsed time from arrival to PCI in a facility with this capability. “Door-to-needle time” is the elapsed time from arrival to delivery of thrombolytic therapy. When the medical contact–to-balloon time is less than 90 minutes, or the door-to-balloon time minus the door-to-needle time is less than 60 minutes, an invasive strategy is preferred.
Outcomes are worse when there are delays in achieving patency of the infarct-related artery, and a national initiative has targeted a door-to-balloon time of less than 90 minutes as a goal. For this patient, transfer to a catheterization laboratory with PCI capability can be performed in 45 minutes, and this is preferred. Additionally, since there is some doubt regarding the diagnosis (left bundle branch block and equivocal biomarker value), angiography may provide a better risk/benefit ratio, as it can establish the correct diagnosis.
A glycoprotein IIb/IIIa inhibitor is not indicated as part of the routine treatment of a STEMI unless it is being delivered as upstream therapy in preparation for urgent PCI. Waiting for additional cardiac enzyme results would allow further myocardial necrosis, and definitive therapy should not be delayed unnecessarily.
- Primary percutaneous coronary intervention is favored over thrombolytic therapy for ST-elevation myocardial infarction if it is available in fewer than 90 minutes; it is also favored in patients with late presentation, shock, contraindications to thrombolysis, or if the diagnosis is unclear.
Correct answer: A. Migraine with aura.
This patient with stroke symptoms is most likely experiencing a migraine with aura and not a stroke. Migraine with aura is a stroke mimicker; stroke mimickers account for nearly one third of all stroke-alert calls in an emergency department. The clinical clues supporting a diagnosis of migraine are the patient's young age, the absence of vascular risk factors, the family history of migraine, and the presence and spread of the sensory symptoms. An MRI with diffusion-weighted imaging can rule out an acute ischemic stroke and thus help confirm the diagnosis of migraine with aura.
Although multiple sclerosis (MS) should be in the differential diagnosis, this patient is less likely to have MS than a migraine or stroke because her presentation was more acute than would be typical in MS. Finding evidence of central nervous system demyelination on an MRI is the usual way MS is diagnosed; when such evidence is lacking, demyelination can sometimes be suggested by abnormal findings in the cerebrospinal fluid.
Symptoms of stroke and transient ischemic attack (TIA) are described as negative or are said to involve loss of function. For example, there may be hemiparesis (a motor deficit affecting half the body) or bland sensory loss (numbness, loss of sensation, diminished sense of touch) in half the body. In contrast, partial seizures account for positive motor symptoms—such as involuntary unilateral muscle movement, twitching, and jerking—or positive sensory symptoms—such as paresthesia, tingling, or a feeling of “pins and needles.” Sensory seizure symptoms generally reflect the anatomic organization of the sensory homunculus on the contralateral primary sensory cortex, whereas migraine symptoms may not. The sensory aura of a migraine generally spreads slowly over half the body. Rapidity of onset is another helpful clue in distinguishing migraine from TIA and seizure. A TIA comes on very rapidly (seconds), and seizures generally manifest in less than 1 minute. Migraine with aura, on the other hand, presents more slowly (over minutes, as with this patient), and symptoms spread slowly from region to region.
- When assessing a patient with the acute onset of focal neurologic deficits, the examiner should include stroke mimickers, such as migraine with aura, in the differential diagnosis.
Correct answer: A. Bedside screening for dysphagia.
On admission to a hospital ward, a patient with stroke should be given nothing by mouth (kept NPO) until a swallowing assessment is conducted. Dysphagia screening is especially appropriate for this patient, who had difficulty swallowing when she first awoke with stroke symptoms. Dysphagia occurs in 45% of all hospitalized patients with stroke and can lead to poor outcomes, including aspiration pneumonia and death. Bedside screening of swallowing ability should thus be completed before oral intake of any medication or food; if the screening results are abnormal, a complete examination of swallowing ability is recommended. The American Heart Association/American Stroke Association recommends a water swallow test performed at the bedside by a trained observer as the best bedside predictor of aspiration. A prospective study of the water swallow test demonstrated a significantly decreased risk of aspiration pneumonia of 2.4% versus 5.4% in patients who were not screened.
Angiotensin-converting enzyme inhibitors, statins, and aspirin are appropriate treatments for secondary stroke prevention in some patients, but they should not be orally administered before ruling out the risk of aspiration.
Like most patients with stroke, this patient will undoubtedly require physical therapy and rehabilitation during her recovery. However, consulting with the department(s) responsible for such care is not an immediate concern and should not be the first step taken when the patient arrives in the hospital ward.
- In a patient with stroke, dysphagia screening should be performed before food, oral medication, or liquids are administered.
Correct answer: A. Admit the patient to a regular medicine ward.
This patient presented with signs of a severe asthma exacerbation. Decreased breath sounds, accessory muscle use, sternocleidomastoid or suprasternal retractions, inability to speak in full sentences, and paradoxical pulse greater than 15 mm Hg are associated with severe airflow obstruction, although the absence of these findings does not necessarily exclude the presence of a high-risk exacerbation. However, the initial physical examination and findings are less predictive of the clinical course in a patient with asthma than the response to bronchodilators. This patient has responded well to bronchodilators, with improved ability to speak and reduced accessory muscle use. Wheezing may become more prominent in the early stages of recovery owing to improved airflow through narrowed airways.
According to the newest National Asthma Education and Prevention Program's guidelines, admission to the intensive care unit is recommended for symptomatic patients with even mild carbon dioxide retention (PCO2 greater than 42 mm Hg) or severely decreased lung function despite aggressive bronchodilator treatment (persistent FEV1 or peak expiratory flow less than 40% of predicted). This patient does not meet the criteria for admission to the intensive care unit or intubation and mechanical ventilation at this time. The best disposition for this patient would be admission to the hospital ward; his FEV1 has not improved enough to warrant discharge.
- The response to inhaled bronchodilators is more predictive of the clinical course in a patient with asthma than initial physical examination and findings.