Pneumonia is the disease is especially important because of its high mortality rate. Staphylococcal pneumonia is most often seen in infants, in children with mucoviscidosis or measles, in adults with influenza, or in debilitated, hospitalized persons being treated with antimicrobials or immunosuppressants. Diagnosis and treatment of staphylococcal pneumonia in adults with predisposing diseases are often difficult. High spiking fever, multiple chills, cyanosis, rapidly progressive dyspnea, chest pain, and the production of thick creamy yellow or reddish-yellow sputum should lead to the suspicion of staphylococcal pneumonia.
Peripheral vascular collapse and marked signs of toxicity should also cause one to suspect the diagnosis in patients with pulmonary infiltrates. In some patients, an unexplained abrupt andnondescript worsening of the general condition is the first clue to the diagnosis. Fever, cough, dyspnea, and chest pain may be minimal during early stages of staphylococcal pneumonia. Staphylococcal pneumonia developing in association with influenza characteristically begins with a sudden and marked worsening of the illness, accompanied by prostration, a peculiar reddish- blue (heliotrope) cyanosis, tachypnea, and high fever. In infants the sudden development of pneumothorax, pneumatoceles, or empyema is a characteristic feature.
The physical signs in patients with staphylococcal pneumonia are variable. A toxic appearance of the patient may be the only detectable manifestation. Patchy bronchopneumonia with multiple small abscesses is usual, and is detected by the presence of coarse or fine rales. Dullness to percussion is not an early sign. Signs of frank consolidation are rarely found. Because pleural effusion and empyema are common, signs of fluid may be found; however, the fluid is commonly loculated in intra- lobar fissures and is not easily detected.
The leukocyte count is usually elevated to between 15,000 and 25,000 per cubic millimeter. Chest roentgenograms show patchy infiltrates, most often near the hilum. Cavity formation and pleural effusion are common. The Gram-stained smear of the sputum shows polymorphonuclear leukocytes and large numbers of clustered gram- positive cocci. When cocci are seen within leukocytes in the sputum, staphylococcal pneumonia should be suspected.
The blood culture is not often positive unless the pneumonia is secondary to staphylococcal bacteremia originating at some other site. As resistant staphylococci frequently colonize the respiratory tract soon after the administration of antimicrobial drugs, it is not proper to diagnose staphylococcal pneumonia solely on the basis of a sputum culture revealing rare or moderate numbers of the organism.
Differential Diagnosis of Pneumonia.
AH other forms of pneumonia must be considered. The distinction from pneumonia caused by gram-negative organisms is especially important in patients developing pneumonia in the hospital. A carefully’performed Gram stain of a good sample of sputum is the keystone of choosing initial therapy, and may be helpful in interpreting subsequent culture reports.
Even under the best of circumstances, the case mortality rate is 15 to 20 per cent. Higher fatality rates are seen in very young infants or in elderly debilitated patients. As this pneumonia is characterized by necrosis of lung parenchyma, recovery is gradual, and usually the illness lasts three to four weeks. Convalescence may be markedly prolonged when empyema is present. Bronchiectasis is sometimes a consequence of staphylococcal pneumonia.
Once the diagnosis is tentatively established, vigorous antimicrobial therapy including use of the parenteral route, should be initiated promptly. Methicillin, oxacillin, nafcil- lin, or cephalothin in doses of at least 1 gram every four to six hours are preferred and equally good. The organism should be considered resistant to.If the organism is susceptible, penicillin G (20 million units intravenously per day) is the drug of choice. If the patient is allergic to penicillin, vancomycin (0.5 gram intravenously every six to eight hours) may be used. Therapy should be continued for 10 to 14 days after the patient shows a definite clinical response.
The clinical response is usually very gradual. Surgical drainage with a chest tube is usually required if empyema is present, because the pus is often loculated or too thick for needle aspiration. Proteolytic enzymes may be instilled into the pleural cavity to help thin the exudate. Oxygen, broncho- dilators, expectorants, fluids, and other supportive measures are also of great importance.