Vignette

History of Present Illness: A 48-year-old Caucasian female presents to your hospital with fever and chills for the past 4 days as well as rusty colored sputum. There have not been any other sick contacts at home and she denies any recent travel or hospitalizations. She feels like her “mind is foggy;” she is oriented to person, but not place or time.

Past Medical History: Hypertension, hyperlipidemia, bipolar disorder, and post-traumatic stress disorder.

Social History: Drinks two alcoholic drinks most evenings. Smokes 1 pack per day, but denies use of illicit substances. In a monogamous relationship with her boyfriend with whom she lives in an apartment. Works as a realtor.

Current Medications: Citalopram 20mg at night, Ziprasidone 60mg daily, lisinopril 40mg daily, and simvastatin 40mg at night

Allergies: None

Vital Signs: Height 66 inches (167.64 cm); Weight 62 kg Temperature 38.5°C; heart rate (HR) 88 beats/minute; respiratory rate (RR) 30 breaths/minute; blood pressure (BP) 108/64 mm Hg

Lab Values: White blood cells 12.2 x 10³/uL (SI 12.2 x 10⁹/L); Hemoglobin 11.9 g/dL (SI 11.9 g/L); hematocrit 33.9% (SI 0.339); Platelets 222 x 10³/uL (SI 222 x 10⁹/L);sodium 135 mEq/L (SI 135 mmol/L); potassium 3.7 mEq/L (SI 3.7 mmol/L); glucose 107 mg/dL (SI 5.9 mmol/L); calcium 8.6 mg/dL (SI 2.15 mmol/L); BUN (blood urea nitrogen) 21 mg/dL (SI 7.5 mmol/L); serum creatinine (SCr) 0.8mg/dL (SI 70.7 micromoles/L)

Procalcitonin 1.0 mcg/L

Procedure Data: Blood sample obtained and sent for Gram stain and sensitivities.

Chest X-ray obtained which shows an infiltrate in the right lower lobe.

EKG obtained demonstrating normal sinus rhythm and a corrected QT interval of 502 milliseconds.

Question 1

The patient has been diagnosed with community-acquired pneumonia (CAP). Which of the following would be the most likely pathogen?

1. Chlamydia trachomatis
2. Mycoplasma pneumoniae
3. Pseudomonas aeruginosa
4. Streptococcus bovis

Question 2

The emergency department physician is trying to make decisions about the level of care for this patient: outpatient, inpatient, or critical care. You recommend using the CURB-65 scoring system. How many points does this patient have using CURB-65?

1. 1
2. 2
3. 3
4. 4

Question 3

The emergency department physician on call initiates intravenous fluids and resumes all home medications. She plans to transfer the patient to the intensive care unit overnight due to her respiratory status. Which of the following regimens would be most appropriate for her antibiotic coverage?

1. Ceftriaxone plus doxycycline
2. Ertapenem plus azithromycin
3. Levofloxacin
4. Pipercillin-tazobactam plus vancomycin

Question 4

Given the severity of this patient’s community-acquired pneumonia, which of the following might you suggest to reduce this patient’s risk of mechanical ventilation and death?

1. Enoxaparin
2. Filgrastim
3. Methylprednisolone
4. Oseltamivir

Question 5

After 3 days on antibiotic therapy, the patient is clinically improving. A follow up procalcitonin level is drawn which returns as 0.49mcg/L. How would you proceed?

1. Expand coverage to resistant organisms
2. Discontinue antibiotics as a viral infection was the likely pathogen
3. Continue the current regimen
4. Discontinue antibiotics as the regimen was successful

ANSWERS

Question 1

Answer:  2. Mycoplasma pneumoniae

Rationale: Atypical bacteria are pathogens detected in up to a quarter of community-acquired pneumonia cases. Mycoplasma pneumoniae is among the most common. Streptococcus pneumoniae is among the most common bacterial infections in CAP, but S. bovis is not associated with this disease. Pseudomonas is generally a nosocomial pathogen or may be isolated from patients with chronic lung diseases. While Chlamydia trachomatis is not responsible for causing community-acquired pneumonia, but Chlamydophila pneumoniae is.

Citation: DynaMed [Internet database]. Ipswich, MA: EBSCO Industries, Inc. Updated periodically.

Question 2

Answer:  3. 3 points

Rationale: CURB-65 scoring uses the following factors as indicators of increased risk for mortality: confusion (based on a specific mental test or disorientation to person, place, or time), BUN level >19 mg/dL (7 mmol/L), respiratory rate >30 breaths/min, blood pressure (systolic, <90 mm Hg; or diastolic, <60 mm Hg), and age >65 years. This patient exhibits three of these risks: confusion, BUN of 21 mg/dL (SI 7.5 mmol/L), and respiratory rate of 30 RPM. This indicates approximately a 14.5% risk of mortality and the 2007 IDSA/ATS guidelines would suggest admission to the ICU.

Citation: Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/AmericanThoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults. Clin Infect Dis. 2007; 44:S27–72.

Question 3

Answer:  Ceftriaxone plus doxycycline

Rationale: Third generation cephalosporins are recommended in combination with either azithromycin or a fluoroquinolone for CAP admitted to the intensive care unit. Unfortunately, this patient has a prolonged QTc and interacting ziprasidone and citalopram that would preclude use of either a macrolide or a fluoroquinolone. Doxycycline may be used in place of macrolides to provide coverage of atypical bacteria. The regimen of Pipercillin-tazobactam + vancomycin would not be appropriate as there would be no coverage of atypical organisms, nor does this patient have risks for MRSA.

Citation: Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/AmericanThoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults. Clin Infect Dis. 2007; 44:S27–72.

Micromedex® Solutions [Internet database]. Greenwood Village, CO: Truven Health Analytics, Inc. Updated periodically.

Question 4

Answer:  3.  Methylprednisolone

Rationale: Corticosteroids have shown to slightly reduce mortality and need for mechanical ventilation in patients with severe CAP. This patient does not have evidence of influenza, so oseltamivir would not be indicated. While VTE prophylaxis may be indicated in this patient, this is unlikely to reduce mortality or need for mechanical ventilation. Filgrastim is not associated with reduction in mortality in CAP.

Citation: Siemieniuk RAC, Meade MO, Alonso-Coello P, et al. Corticosteroid therapy for patients hospitalized with community-acquired pneumonia: a systematic review and meta-analysis. Ann Intern Med. 2015;163:519-58.

DynaMed [Internet database]. Ipswich, MA: EBSCO Industries, Inc. Updated periodically.

Question 5

Answer: 3.  Continue the current regimen

Rationale: In patients with CAP, procalcitonin guidance can lower rates of antibiotic exposure and antibiotic-associated adverse effects. Using the ProHOSP algorithm, this patient was appropriately initiated on antibiotics as a bacterial infection was likely. After 3 days, a decrease in procalcitonin levels by 80-90% indicates that antimicrobials may be stopped. Rising procalcitonin levels indicate treatment failure. This patient’s level dropped by approximately 50%, so antibiotics should be continued.

Citation: Schuetz P, Christ-Crain M, Thomann R, et al. Effect of procalcitonin-based guidelines vs standard guidelines on antibiotic use in lower respiratory tract infections: the ProHOSP randomized controlled trial. JAMA. 2009;302:1059-66.