Chapter 35: Management of Pneumonias

A 65-year-old man with a past medical history of severe chronic obstructive pulmonary disease (COPD) presents with a 3-day history of fever, decreased appetite, progressive shortness of breath, cough productive of purulent sputum, and pleuritic chest pain. On physical examination, the patient is awake but confused and in moderate respiratory distress with a respiratory frequency of 32 breaths/min. His vital signs include a blood pressure of 120/70 mm Hg, pulse rate of 102/min, and an axillary temperature of 38.7°C (101.5°F). Chest examination shows increased tactile fremitus over the posterior right lung base, as well as dullness to percussion and bronchial breath sounds over this area; inspiratory crackles are evident over the left upper anterior chest. Laboratory findings are significant for a P_aO₂/F_IO₂ ratio of 225, an elevated circulating leukocyte count of 17,000/μL, and a blood urea nitrogen level of 30 mg/dL. A chest x-ray today reveals consolidation in the right lower lung as well as infiltrates in the left upper lobe. Blood and sputum samples for Gram stain and cultures are obtained but results are pending. The most appropriate management of this patient now includes which of the following actions?

a. Admission to the medical floor of the hospital and treatment with a macrolide antibiotic

b. Admission to the intensive care unit (ICU) and observation

c. Admission to the medical floor of the hospital and treatment with a respiratory fluoroquinolone

d. Admission to the ICU and treatment with a β-lactam antibiotic

e. Admission to the ICU and treatment with a β-lactam antibiotic plus a macrolide

The most correct answer is e, admission to the ICU and treatment with a β-lactam antibiotic plus a macrolide.

This patient is elderly, confused, has multilobar pulmonary infiltrates of presumed infectious origin, and is already manifesting signs of acute hypoxemic respiratory failure as well as renal dysfunction. Moreover, he has a CURB-65 score of 4, placing him at increased risk of death from complications of community-acquired pneumonia. For all of these reasons, it is important that the patient be admitted to an ICU rather to the inpatient medical floors (answers a, c). Considering this case presentation, observation in the ICU without antibiotic treatment within 4 hours greatly increases the likelihood of a poor outcome and is never appropriate management for severe CAP (answer b). Although treatment with a β-lactam antibiotic is an important aspect of the management of severe CAP (answer d), it represents incomplete coverage, particularly for Legionella spp. that are not sensitive to this antibiotic class. Thereafter co-treatment with a macrolide antibiotic is indicated for patients requiring ICU treatment.

A 26-year-old man is involved in a motor vehicle accident and suffers a closed head injury with a subdural hematoma, splenic laceration, and bilateral femur fractures. The patient is intubated in the emergency department for airway protection and subsequently undergoes surgical drainage of the subdural hematoma and operative reduction and fixation of the femur fractures. The splenic laceration does not require surgical intervention. One week after admission, the patient develops fever, leukocytosis, and increased purulent secretions from the endotracheal tube. A portable chest radiograph reveals a right lower lobe infiltrate and a pleural effusion. A ventilator-associated pneumonia is suspected and a tracheal aspirate and blood cultures are obtained. The patient is then started on antibiotic therapy with vancomycin, piperacillin/tazobactam, and gentamicin. Over the next 3 days, the patient remains febrile and becomes increasingly tachycardic and hypotensive with a progressively rising leukocyte count. The tracheal aspirate reveals many polymorphonuclear neutrophils and grows methicillin-resistant Staphylococcus aureus sensitive to vancomycin. The blood cultures remain negative. A CT scan of the chest is obtained and reveals a right lower lobe infiltrate with a moderate right-sided pleural effusion. Which of the following actions would be the most appropriate next step in the management of this patient?

a. Conduct bronchoscopy to obtain a lavage sample for Gram stain and culture, while continuing his current antibiotic regimen.

b. Discontinue vancomycin and start linezolid while continuing piperacillin/tazobactam and gentamicin.

c. Discontinue vancomycin, piperacillin/tazobactam, and gentamicin and start linezolid, cefepime and levofloxacin.

d. Perform diagnostic thoracentesis and continue the patient's current antibiotic regimen.

e. Continue current antibiotics and order observation without further diagnostic studies at this time.

The most correct answer is d, perform diagnostic thoracentesis and continuing the current antibiotic regimen.

This patient has developed a ventilator-associated pneumonia and the tracheal aspirate reveals methicillin-resistant S. aureus (MRSA) as the pathogen. Unfortunately, despite appropriate therapy, the patient is not responding after 72 hours of treatment. The most likely reason in this instance is the recent development of an empyema involving the right pleural space. A diagnostic thoracentesis should be obtained and, if the findings are consistent with an empyema, a tube thoracostomy should be performed to allow for drainage and resolution of the empyema. Therefore, ordering bronchoscopy (answer a) or doing no additional diagnostic intervention (answer e) is incorrect; bronchoscopy would be unlikely to yield any additional information since the tracheal aspirate Gram stain and culture are both consistent with a ventilator-associated pneumonia secondary to MRSA. Answers b and c also are incorrect for this patient because the MRSA organism has demonstrated sensitivity to vancomycin. Accordingly, a switch to a different antibiotic regimen including linezolid in place of vancomycin would be unlikely to prove beneficial, assuming the vancomycin was being dosed correctly.