Community-acquired Pneumonia

Diagnosis
Metlay JP, Kapoor WN, Fine MJ. Does this patient have CAP? Diagnosing pneumonia by history and physical examination. JAMA 1997;278:1440-5. Systematic review found H & P do not reliably predict the presence of pneumonia in acutely symptomatic, ambulatory patients. Physicians' interobserver agreement on exam findings is poor. Article highlights the importance of chest x-rays in diagnosis of pneumonia but the optimal strategy for their use remains unclear. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9356004

Treatment
Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults.  Clin Infect Dis. 2007;44 Suppl 2:S27-72. An influential new consensus statement from two major societies. http://www.ncbi.nlm.nih.gov/pubmed/17278083?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

Confalonieri M, Urbino R, Potena A et al. Hydrocortisone infusion for severe community-acquired pneumonia: a preliminary randomized study. Am J Respir Crit Care Med 2005; 171:242-8. Compared to placebo, 7 days of continuous infusion of hydrocortisone significantly improved mortality, PaO2: FiO2, chest radiograph scores, incidence of delayed-onset septic shock, and multi-organ dysfunction scores in 46 subjects.  Limitations of the study include small sample size, greater number of mechanically ventilated patients in the placebo group, and subjects’ undocumented adrenal status. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15557131

Marrie TJ, Lau CY, Wheeler SL, et al. A controlled trial of a critical pathway for treatment of CAP. CAPITAL Study Investigators. JAMA 2000; 283:749-55. Instituting a care pathway for CAP resulted in decreased rates of admission of low-risk patients and shorter hospital stays among those admitted without compromising the care of patients. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10683053

Fine MJ, Auble TE, Yealy DM et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med 1997;336:243-50. Oft-cited prediction rule used in above study by Marrie, et al. incorporates patient demographics, co-morbidities, vitals, labs, and chest film to identify patients likely to do well with outpatient treatment of CAP. Rule difficult to memorize and requires an ABG, but otherwise easy to apply. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8995086

Bartlett JG, Gorbach SL. The triple threat of aspiration pneumonia. Chest 1975;68:560-6. Classic review of the presentation, pathophysiology, and natural history of chemical pneumonitis, bacterial pneumonia, and airway obstruction resulting from aspiration of toxic fluids, bacteria, and inert matter respectively. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=1175415

Mittl RL, Schwab RJ, Duchin JS et al. Radiographic resolution of community-acquired pneumonia.  Am J Respir Crit Care Med 1994;149:630-5. Prospective follow-up of both inpatients and outpatients with diagnosis of CAP is cited as a guide for when to look for endobronchial lesions in the setting of slowly clearing pneumonia.  The study found age and multilobar disease were independent predictors of delayed resolution.  Radiographic resolution seen in 51% at 2 weeks, 67% at 4 weeks, and 90% at 12 weeks.  http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8118630