A 55-year-old male with a history of tobacco use disorder presents with 2 days of productive cough, fever, chills, and mild shortness of breath. T 38.4, HR 89, RR 32, BP 100/65, 02 sat 86% on room air. Exam reveals diminished breath sounds and positive egophony over the right lung base. WBC is 16,000 and BUN 22. Chest x-ray reveals right lower lobe consolidation. He is given ceftriaxone and azithromycin.
Brief overview of the issue
Community-acquired pneumonia (CAP) is the leading cause of infectious disease–related death in the United States. Mortality associated with CAP is estimated at 57,000 deaths annually and occurs largely in patients requiring hospitalization.1 The 30-day mortality rate in patients who are hospitalized for CAP is approximately 10%-12%.2 After discharge from the hospital, about 18% of patients are readmitted within 30 days.3 An excessive inflammatory cytokine response may be a major contributor to the high mortality rate in CAP and systemic corticosteroids may reduce the inflammatory response from the infection by down-regulating this proinflammatory cytokine production.
Almost all of the major decisions regarding management of CAP, including diagnostic and treatment issues, revolve around the initial assessment of severity of illness. Between 40% and 60% of patients who present to the emergency department with CAP are admitted4 and approximately 10% of hospitalized patients with CAP require ICU admission.5 Validated instruments such as CURB-65, the pneumonia severity index (PSI), and guidelines from the Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) may predict severity of illness but should always be supplemented with physician determination of subjective factors when determining treatment.5 Although there is no census definition of severe pneumonia, studies generally define the condition in the following order of preference: PSI score of IV or V followed by CURB-65 score of two or greater. If these scoring modalities were not available, the IDSA/ATS criteria was used (1 major or 3 minor). Others define severe CAP as pneumonia requiring supportive therapy within a critical care environment.
Overview of the data
The use of corticosteroids in addition to antibiotics in the treatment of CAP was proposed as early as the 1950s and yet only in the last decade has the body of evidence grown significantly.5 There is evidence that corticosteroids suppress inflammation without acutely impairing the immune response as evidenced by a rapid and sustained decrease in circulating inflammatory markers such as C-reactive protein and interleukin 6 and no effect on the anti-inflammatory interleukin 10.6 Within the last year, three meta-analyses, one by the Cochrane Library, one by the IDSA, and a third in the American Journal of Emergency Medicine, addressed the role of routine low dose (20-60 mg of prednisone or equivalent), short-course (3-7 days) systemic corticosteroids in hospitalized patients with CAP of varying severities.
The Cochrane meta-analysis, the largest and most recent dataset, included 13 trials with a combined 1,954 adult patients and found that corticosteroids significantly lowered mortality in hospitalized patients with severe CAP with a number needed to treat of 19.7 In this group with severe CAP, mortality was lowered from 13% to 8% and there were significantly fewer episodes of respiratory failure and shock with the addition of corticosteroids. No effect was seen on mortality in patients with less severe CAP. In those patients who received adjuvant corticosteroids, length of hospital stay decreased by 3 days, regardless of CAP severity.7
The IDSA meta-analysis was similar and included 1,506 patients from six trials.8 In contrast with the Cochrane study, this analysis found corticosteroids did not significantly lower mortality in patients with severe CAP but did reduce time to clinical stability and length of hospital stay by over 1 day. This study also found significantly more CAP-related, 30-day rehospitalizations (5% vs. 3%; defined as recurrent pneumonia, other infection, pleuritic pain, adverse cardiovascular event, or diarrhea) in patient with non-severe CAP treated with corticosteroids.
The study in the American Journal of Emergency Medicine involved ten trials involving more than 700 patients admitted with severe CAP and found in-hospital mortality was cut in half (RR 0.49) and length of hospital stay was reduced when patients were treated with corticosteroids in addition to standard antibiotic therapy.9
In 2015, two randomized clinical trials, one in the Lancet and the other in JAMA, and a meta-analysis in Annals of Internal Medicine assessed the impact of adjuvant corticosteroids in the treatment of hospitalized patients with CAP. The Lancet study of 785 patients hospitalized with CAP of any severity found shortened time to clinical stability (3.0 vs. 4.4 days) as defined by stable vital signs, improved oral intake, and normalized mental status for greater than 24 hours when oral prednisone 50 mg for 7 days was added to standard therapy.10 Patients in the treatment group were also discharged 1 day earlier compared with the placebo control group.
The study in JAMA was small, with only 100 patients at three teaching hospitals in Spain, but found that patients hospitalized with severe CAP and high inflammatory response based on elevated C-reactive protein were less likely to experience a treatment failure, defined as shock, mechanical ventilation, death, or radiographic progression, when intravenous methylprednisolone 0.5 mg/kg was added to standard antibiotic therapy.11
Finally, the meta-analysis in Annals of Internal Medicine assessed 13 randomized controlled placebo trials of 1,974 patients and found that adjuvant corticosteroids in a dose of 20-60 mg of prednisone or equivalent total daily dose significantly lowered mortality in patients with severe CAP and incidence of respiratory distress syndrome, and need for mechanical ventilation in all patients hospitalized with CAP.12
Importantly, nearly all of the described studies showed a significantly higher incidence of hyperglycemia in patients who received corticosteroids.