tailieunhanh - Chapter 129. Staphylococcal Infections (Part 7)

Respiratory Tract Infections Respiratory tract infections caused by S. aureus occur in selected clinical settings. S. aureus is a cause of serious infections in newborns and infants; these infections present as shortness of breath, fever, and respiratory failure. Chest x-ray may reveal pneumatoceles (shaggy, thin-walled cavities). Pneumothorax and empyema are recognized complications of this infection. In adults, nosocomial S. aureus pulmonary infections are commonly seen in intubated patients in intensive care units. The clinical presentation is no different from that encountered in pulmonary infections of other bacterial etiologies. Patients produce increased volumes of purulent sputum and develop respiratory distress, fever, and. | Chapter 129. Staphylococcal Infections Part 7 Respiratory Tract Infections Respiratory tract infections caused by S. aureus occur in selected clinical settings. S. aureus is a cause of serious infections in newborns and infants these infections present as shortness of breath fever and respiratory failure. Chest x-ray may reveal pneumatoceles shaggy thin-walled cavities . Pneumothorax and empyema are recognized complications of this infection. In adults nosocomial S. aureus pulmonary infections are commonly seen in intubated patients in intensive care units. The clinical presentation is no different from that encountered in pulmonary infections of other bacterial etiologies. Patients produce increased volumes of purulent sputum and develop respiratory distress fever and new pulmonary infiltrates. Distinguishing bacterial pneumonia from respiratory failure of other causes or new pulmonary infiltrates in critically ill patients is often difficult and relies on a constellation of clinical radiologic and laboratory findings. Community-acquired respiratory tract infections due to S. aureus most commonly follow viral infections or septic pulmonary emboli . in injection drug users . Influenza is the most common cause of the former type of presentation. Patients may present with fever bloody sputum production and midlung-field pneumatoceles or multiple patchy pulmonary infiltrates. Diagnosis is made by sputum Gram s stain and culture. Blood cultures although useful are usually negative. Bacteremia Sepsis and Infective Endocarditis S. aureus bacteremia may be complicated by sepsis endocarditis vasculitis or metastatic seeding establishment of suppurative collections at other tissue sites . The frequency of metastatic seeding during bacteremia has been estimated to be as high as 31 . Among the more commonly seeded tissue sites are bones joints kidneys and lungs. Recognition of these complications by clinical and laboratory diagnostic methods alone is often difficult. .