DRG Category: 177
Mean LOS: 6.9 days
Description: Medical: Respiratory Infections and Inflammations With Major Complication or Comorbidity
DRG Category: 207
Mean LOS: 13.9 days
Description: Medical: Respiratory System Diagnosis With Ventilator Support > 96 Hours
DRG Category: 208
Mean LOS: 6.7 days
Description: Medical: Respiratory System Diagnosis With Ventilator Support ≤ 96 Hours
DRG Category: 3
Mean LOS: 30.3 days
Description: Surgical: ECMO or Tracheostomy With Mechanical Ventilation > 96 Hours or Primary Diagnosis Except Face, Mouth, and Neck With Major Operating Room Procedures
Legionnaires' disease (LD) is an acute bronchopneumonia that was named because of a major outbreak at the 1976 American Legion Convention in Philadelphia, Pennsylvania, in which 182 American Legionnaires contracted the disease, and 29 persons died. It is now known as the most common type of atypical pneumonia in hospitalized patients and the second-most common cause of community-acquired bacterial pneumonia. Approximately 20% of cases occur in late summer and early fall; the rest are spaced throughout the year, and they may be epidemic or confined to a small number of sporadic cases. The Centers for Disease Control and Prevention (CDC) report that approximately 10,000 cases occur each year in the United States.
LD has an incubation period of 2 to 10 days and is characterized by patchy pulmonary infiltrates, lung consolidation, and flu-like symptoms. Pneumonia is the presenting clinical syndrome in more than 95% of cases. LD is spread by direct alveolar infection with the gram-negative bacterium Legionella pneumophila. The bacteria multiply in the alveolar cells of the lungs where, in the macrophages, the bacteria undergo phagocytosis. The bacteria are not destroyed in this process, however, but are released into the surrounding areas and multiply. The infection spreads through the bronchi, blood, and lymphatic systems. Bacteremia occurs in about 30% of the patients and is the source of nonrespiratory infections in most patients.
Complications are extensive and serious with LD. Hypoxemia and acute respiratory failure can result from the severe case of pneumonia. The disease can also cause hypotension and hyponatremia as a result of salt and water loss. Central nervous system involvement is seen in almost 30% of patients. Renal involvement, which ranges from interstitial nephritis to renal failure, may occur. Untreated immunosuppressed patients have a mortality rate of 80%; untreated patients with no immune system compromise have a mortality rate of 25%.
L pneumophila is an aerobic, gram-negative bacillus that seems to be transmitted by air. It is usually classified as a saprophytic water bacterium because it is natural to bodies of water such as rivers, lakes, streams, and thermally polluted waters. Optimal temperature for growth of the bacterium is 98.6°F (37°C ). L pneumophila is also found in habitats such as cooling towers, evaporative condensers, humidifiers, respiratory therapy equipment, whirlpool spas, and water distribution centers, and it has been found in soil samples and at excavation sites. Pathogenic microorganisms can enter the lung by aspiration, direct inhalation, or dissemination from another focus of infection. Risk factors include older age, smoking or alcohol abuse, diabetes mellitus, chronic heart or lung disease, and immune diseases.
Although LD is the result of infection by L pneumophila, susceptibility has been associated with variants in the toll-like receptor-5 (TLR5) gene.
LD is two to three times more common in men than in women; it is uncommon in children, but when children acquire it, they are usually less than a year old. At-risk groups include middle-aged or older people; patients with a chronic underlying disease such as chronic obstructive pulmonary disease, diabetes mellitus, or chronic renal failure; patients with immunosuppressive disorders such as lymphoma or rheumatoid arthritis or those who receive corticosteroids after organ transplantation; people with alcohol dependence; and cigarette smokers.
Approximately 80% of the deaths from LD occur in White persons, with the most common comorbid conditions including leukemia and rheumatoid arthritis. Age-adjusted mortality rates for White and Black persons are similar. Sexual and gender minority status has no known effect on the risk for LD.
LD has been reported throughout the globe and on all populated continents.
PLANNING AND IMPLEMENTATION
Collaborative
Pharmacologic.
Antibiotics can be administered before test results are available. Generally, primary therapy is either levofloxacin or azithromycin. Erythromycin, sometimes in combination with rifampin, is also used, but the gastrointestinal effects of both the disease and drug can be cumulative and problematic. IV fluids and electrolyte therapy may be considered when the patient has fluid volume deficit. Careful monitoring of fluid balance is required because of the possible renal complications from interstitial nephritis or renal failure. If renal failure does ensue, the patient may require temporary renal dialysis.
Oxygen per cannula at 2 to 4 L/minute is effective with many patients, although in some patients with respiratory insufficiency, it is necessary to proceed with intubation and assisted ventilation. Atelectasis may occur at any stage of the pneumonia. Pleural effusion may occur, which may require a diagnostic thoracentesis and a chest tube. The patient may need continuous pulse oximetry to monitor the response to mechanical ventilation and suctioning. Continuous cardiac monitoring and hourly urine outputs may be necessary to assess the patient's response to the disease.
| Medication or Drug Class | Dosage | Description | Rationale |
|---|
| Antibiotics | Varies with drug | Levofloxacin (Levaquin), azithromycin (Zithromax), erythromycin, doxycycline, ciprofloxacin, trimethoprim/sulfamethoxazole | Halt division of bacteria, thereby limiting infection |
| | | |
Other Treatment: Antipyretics
Independent
The most important intervention is maintenance and improvement of airway patency. Retained secretions interfere with gas exchange and may cause slow resolution of the disease. Encourage a high level of fluid intake up to 3 L/day to assist in loosening pulmonary secretions and to replace fluid lost via fever and diaphoresis unless the patient has renal compromise. Provide meticulous sterile technique during endotracheal suctioning of the patient. Chest physiotherapy may be prescribed to assist with loosening and mobilizing secretions.
To maintain the patient's comfort, keep the patient protected from drafts. Institute fever-reducing measures if necessary. To ease the patient's breathing, raise the head of the bed at least 45 degrees and support the patient's arms with pillows. Provide mouth and skin care and emotional support. Include the patient and family in planning care and allow them to make choices.
Evidence-Based Practice and Health Policy
Mudali, G., Kilgore, P., Salim, A., McElmurry, S., & Zervos, M. (2020). Trends in Legionnaires' disease–associated hospitalizations, United States, 2006–2010. Open Forum Infectious Diseases, 7, 1–4.
- The authors aimed to offer an estimate of the annual incidence of LD-associated hospitalizations in the United States, identifying demographic, temporal, and regional characteristics of individuals hospitalized for LD. They conducted a retrospective study using the National Hospital Discharge Survey (NHDS) data from 2006 to 2010. All discharges assigned with the LD diagnostic code (482.84) were included in this study.
- Over the 5-year period, 14,574 individuals were admitted with LD. A summer peak of LD-associated hospitalizations occurred June through September in 2006, 2007, 2008, and 2010. Peak age for infection was in the 60 to 69 years of age group. LD-associated hospitalizations significantly increased over the 5-year study period.