A 62-year-old woman presents with severe, sharp pain in her right mid chestthat worsens when she breathes. The pain began the previous night, shortlyafter she had been awakened by a shaking chill, followed by the sensationof fever. She also has a relatively nonproductive cough of recent onset.
A 62-year-old woman presents with severe, sharp pain in her right mid chestthat worsens when she breathes. The pain began the previous night, shortlyafter she had been awakened by a shaking chill, followed by the sensationof fever. She also has a relatively nonproductive cough of recent onset.HISTORY
The patient has mild diabetes mellitus that is successfully controlled bydiet alone. She has smoked a pack of cigarettes a day for the past 40 years.However, she denies symptoms of chronic obstructive pulmonary disease.She has no history of congestive heart failure or coronary artery disease.PHYSICAL EXAMINATION
This ill-appearing woman is in moderate distress from pleuritic chestpain. Temperature is 39.7C (103.5F); heart rate, 115 beats per minute;respiration rate, 20 breaths per minute; and blood pressure, 100/80 mm Hg.Mucous membranes are dry. Auscultation of the chest reveals rales in theright lung base. The remainder of the examination is noncontributory.LABORATORY AND IMAGING RESULTS
Blood glucose level is 210 mg/dL; the rest of the results of a chemistrypanel are normal. White blood cell count is 25,000/L, with 11% band forms.Oxygen saturation is 95% on 2 L of nasal oxygen. ECG and cardiac enzymelevels are normal. Portable chest radiography reveals an infiltrate in theright lower lobe (RLL).The patient is admitted; specimens for blood, sputum, and urine culturesare obtained, and empiric antibiotic therapy is begun. A posteroanteriorchest film obtained the next morning demonstrates lobar consolidation ofthe RLL. The microbiology laboratory reports that blood cultures are growinggram-positive cocci.Which of the following statements about this patient is true?A. Her cigarette smoking was not a factor in the development of herinfection, nor is smoking a factor in its prognosis.
B. An extended-spectrum β-lactam together with a macrolide is anappropriate initial regimen.
C. The increasing incidence of antibiotic resistance has significantlyworsened her prognosis.
D. Her diabetes is a significant negative prognostic risk factor.CORRECT ANSWER: BThis patient has pneumococcal pneumonia with bacteremia.Pneumococcal pneumonia remains a very commonand serious disease in the United States and worldwide.In 10% to 20% of patients, bacteremia develops andsignificantly increases morbidity and mortality.This woman presented with classic symptoms andsigns of pneumococcal pneumonia. According to AmericanThoracic Society guidelines for the management ofcommunity-acquired pneumonia, her clinical findingsclearly justified admission.1The lungs are by far the most frequent site of infectionin patients with pneumococcal bacteremia; in themost recent review, 85% of cases were in patients withpneumonia.2That same review, which covers the periodfrom 1986 to 2000, calculates the case-fatality rate forpneumococcal bacteremia to be 25%; it also analyzes therelationship of a variety of comorbid conditions and findingsto disease prognosis.2Conditions and findings that clearly increase mortalityinclude malignancy, active coronary artery disease,chronic lung disease, neutropenia, and age of more than65 years. Interestingly, some of the conditions and findingsthat are not associated with an increased mortalityrisk include chronic renal failure, splenectomy, and diabetesmellitus. This patient's mild diabetes should notadversely affect her prognosis; choice D is incorrect.Somewhat surprisingly, although the incidence ofantibiotic resistance in invasive pneumococcal diseaseand bacteremia is continually increasing, this has not translated into a worsening prognosis for affected patients(choice C). In fact, the case-fatality rate in the referencedstudy was lower in the period 1993 to 2000 (34of 198 episodes, 17%) than in the period 1986 to 1993 (68of 207 episodes, 33%).2 Yet, it was after 1993 that penicillin-resistant isolates were first encountered and thattheir prevalence increased to 17% of isolates.A variety of explanations for this incongruity havebeen offered. These include earlier diagnosis and treatmentof the condition, the possibility that resistantstrains of pneumococci may be less virulent than wildtypestrains (because of the metabolic cost of maintainingresistance), and the reduced incidence and improvedmanagement of comorbid illnesses. Whateverthe reason, the data do not support the statement thatthe prognosis for patients with pneumococcal bacteremiahas worsened as a result of the increased incidenceof resistant strains.Cigarette smoking, on the other hand, has both adirect and indirect impact on the incidence and severityof invasive pneumococcal infections and bacteremia. Ina multicenter study in several larger cities, smoking wasfound to be the strongest independent risk factor for invasivedisease among immunocompetent adults aged 18to 64 years, with an odds ratio of 4.1 (95% confidence interval,1.2 to 5.1)..3 In the bacteremia study cited earlier,smoking did not quite attain statistical significance as amortality risk factor, but there was a strong trend in thatdirection (P = .06).2 Thus, choice A is not correct.The correct answer is B: initiation of a regimen effectiveagainst antibiotic-resistant pneumococci. Becausean ever-increasing number of pneumococci are variablydrug-resistant, continue such a regimen until sensitivitiesare known. Appropriate regimens include an extended-spectrum β-lactam (eg, ceftriaxone, cefotaxime)together with a macrolide, or monotherapy with a respiratoryfluoroquinolone (eg, levofloxacin, moxifloxacin[but not ciprofloxacin]).4 There is some evidence thatthis strategy may decrease in-hospital mortality frombacteremic pneumococcal disease.5 It may also help explainthe improvement in survival in recent years, despitethe increased prevalence of resistant strains.Outcome of this case. Subsequent sputum andblood cultures grew pneumococci with intermediatesusceptibility to penicillin. The patient improved markedlyand was discharged on the second hospital day onmoxifloxacin monotherapy. Her pneumonia resolvedcompletely. She stopped smoking at the time of dischargeand at 1 year has not started again.
American Thoracic Society. Guidelines for the management of adults withcommunity-acquired pneumonia: diagnosis, assessment and severity, antimicrobialtherapy and prevention.
Am J Respir Crit Care Med.
Trampuz A, Widmer AF, Fluckiger U, et al. Changes in the epidemiology ofpneumococcal bacteremia in a Swiss university hospital during a 15-year period,1986-2000.
Mayo Clin Proc.
Nuorti JP, Butler JC, Farley MM, et al. Cigarette smoking and invasive pneumococcaldisease.
N Engl J Med.
Maki DG. Pneumococcal bacteremia: lessons learned yet more to learn.Mayo Clin Proc. 2004;78:599-603.
Martinez JA, Horcajada JP, Almela M, et al. Addition of a macrolide to abeta-lactamâbased empirical antibiotic regimen is associated with lower in-hospitalmortality for patients with bacteremic pneumococcal pneumonia.