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Causes and symptoms
Specific diagnostic tests include both direct and indirect fluorescent testing for antibodies against L. pneumophila. Other laboratory tests reveal mild leukocytosis; elevated erythrocyte sedimentation rate; increased liver enzymes, especially lactate dehydrogenase; elevated blood urea nitrogen; and abnormal blood gases showing hypoxemia and hypocarbia.
The pulmonary symptoms are typical of pneumonia, but patients do not respond to the usual therapy for pneumonia and there can be permanent lung damage. Possible nonpulmonary complications include liver damage, altered levels of consciousness owing to neuronal involvement, and renal abnormalities that can require renal dialysis.
Treatment consists of antibiotic therapy with macrolides and quinolones. Other antibiotics may also be effective. erythromycin was formerly often used but is no longer the drug of choice. Severe hypoxia requires mechanical ventilation and oxygen therapy. Isolation of the patient is not considered to be necessary; however, respiratory precautions are indicated. Supportive measures to help the patient cope with high fever, nausea and vomiting, and renal failure are essential components of patient care. See also pneumonia.
Le·gion·naires' dis·ease(lē'jŏ-nārz' di-zēz')
Legionnaires' diseaseA type of PNEUMONIA caused by Legionella bacteria which can propagate in warm, moist places such as air-conditioning towers and are spread into the air in water droplets. The disease features headache, muscle aches, diarrhoea, cough, high fever, pneumonia, mental confusion, and kidney and liver damage. The lungs may suffer irremediable damage, and this is the common cause of death. The death rate is about 4%. Most deaths occur among the elderly, the infirm, heavy smokers and heavy drinkers. Treatment is by antibiotics such as ERYTHROMYCIN and RIFAMPICIN. The disease was first recognized in members of the American Legion attending a convention in a hotel in Pennsylvania in 1976.
|Mean LOS:||8.2 days|
|Description:||MEDICAL: Respiratory Infections and Inflammations With Major CC|
|Mean LOS:||14.6 days|
|Description:||MEDICAL: Respiratory System Diagnosis With Ventilator Support 96+ Hours|
|Mean LOS:||7 days|
|Description:||MEDICAL: Respiratory System Diagnosis With Ventilator Support < 96 Hours|
|Mean LOS:||34.5 days|
|Description:||SURGICAL: Tracheostomy With MV 96+ Hours or Primary Diagnosis Except for Face, Mouth, and Neck With Major Operating Room Procedure|
Legionnaires’ disease is an acute bronchopneumonia that was named because of a major outbreak at the 1976 American Legion Convention in Philadelphia, in which 235 American Legionnaires contracted the disease and 34 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. Outbreaks occur in late summer and early fall, and they may be epidemic or confined to a small number of cases. Approximately 18,000 cases occur each year in the United States.
Legionnaires’ disease 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. Legionnaires’ disease is spread by direct alveolar infection with the gram-negative bacterium Legionella pneumophila. From the initial site, the infection spreads through the bronchi and through the 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 Legionnaires’ disease. 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. Elevated temperatures (96.8°F to 158°C) enhance growth of the bacterium. L. pneumophila is also found in habitats such as cooling towers, evaporative condensers, and water distribution centers, and it also 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.
Although Legionnaire’s disease is the result of infection by L. pneumophila, susceptibility has been associated with variants in the Toll-like receptor-5 (TLR5) gene.
Gender, ethnic/racial, and life span considerations
Legionnaires’ disease is three times more common in men than in women; it is uncommon in children. At-risk groups include middle-aged or elderly 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 who receive corticosteroids after organ transplantation; people with alcohol dependence; and cigarette smokers. There are no known racial or ethnic considerations.
Global health considerations
Legionnaires’ disease has been reported throughout the globe and on all populated continents.
Ask about malaise, aching muscles, anorexia, headache, high fever, or recurrent chills. Establish a history of chest pain or coughing, which begins as a nonproductive cough but eventually becomes productive. Ask the patient about gastrointestinal symptoms such as diarrhea, nausea, and vomiting. Because the central nervous system is involved in about 30% of cases, ask the family or significant others if the patient has experienced recent confusion or decreased level of consciousness.
Determine if the patient has been close to a river, lake, or stream, which might have resulted in possible exposure to the bacteria. Establish a work history of employment at an excavation site or water distribution center, in a cooling tower, or near an evaporative condenser. Ask if the patient works or lives in a facility with central air conditioning or humidifiers. Ask if the patient has used a respiratory apparatus or a nasogastric tube in the recent past.
Common symptoms include mild headache, cough, muscle aches, high fever, and chills. Note any neurological signs, such as altered level of consciousness, confusion, or coma. Inspect the patient’s sputum, which may be grayish or rust-colored, nonpurulent, and occasionally blood streaked. Note the respiratory rate, which may be rapid and accompanied by dyspnea.
Determine the breathing; fine or coarse crackles may be audible depending on the stage of the disease process. Auscultate the blood pressure and heart rate; note that some patients develop severe hypotension and bradycardia. Percuss the chest for dullness over areas of secretions and consolidation or pleural effusions. Palpate the peripheral pulses to determine strength.
A previously healthy person with a possible minor upper respiratory infection is at risk for life-threatening complications, such as multiple organ failure. Assess the patient’s ability to cope with a sudden illness. Assess the patient’s level of anxiety and fear.
|Test||Normal Result||Abnormality With Condition||Explanation|
|Sputum culture and sensitivity||Negative||Presence of L. pneumophila||Identify infecting organisms|
|Chest x-ray||Air-filled lungs||Area of increased density of a lung segment, lobe, or entire lung||Identifies the location and extent of infection|
Other Tests: Urinalysis, serology for Legionella (urine antigen testing, indirect fluorescent antibody studies), arterial blood gases, pulse oximetry, complete blood count, blood urea nitrogen, creatinine, serum electrolytes
Primary nursing diagnosis
DiagnosisInfection related to the presence of bacteria
OutcomesImmune status; Risk control; Risk detection; Nutrition status; Treatment behavior: Illness or injury; Hydration; Knowledge: Infection control
InterventionsInfection control; Infection protection; Surveillance; Fluid/electrolyte management; Medication management; Temperature regulation
Planning and implementation
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. Intravenous 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||Halt division of bacteria, thereby limiting infection|
|Rifampin||600 mg/day, PO or IV||Antitubercular||Manages severe disease, such as multilobar pneumonia, respiratory failure, endocarditis, or severe immunosuppression; if erythromycin is contraindicated because of allergy, rifampin may be used alone or combined with doxycycline or cotrimoxazole|
Other Treatment: Antipyretics
The most important intervention is 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. 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
Schuetz, P., Haubitz, S., Christ-Crain, M., Albrich, W.C., Zimmer, W., & Mueller, B. (2013). Hyponatremia and anti-diuretic hormone in Legionnaires’ disease. BMC Infectious Diseases, 13, 585. doi 10.1186/1471-2334-13-585
- Investigators conducted a prospective cohort study among 873 pneumonia patients, of which 27 were positive for L. pneumophila, and found that patients with Legionnaires’ disease may be at increased risk for hyponatremia.
- Sodium levels were significantly lower in the patients with Legionnaires’ disease (mean, 131.6 mmom/L; SD, ± 0.9) when compared with patients without the disease (mean, 135.4 mmom/L; SD, ± 0.2) (p < 0.001).
- A greater proportion of patients with Legionnaires’ disease had sodium levels below 130 mmol/L when compared with patients without the disease (44.4% versus 8.2%; p < 0.001).
- Physical findings: Vital signs, head-to-toe assessment, rate of breathing, breath sounds, description of sputum
- Response to treatments such as chest physiotherapy, oxygen, antipyretics, and fluid therapy
- Presence of complications: Hypotension, dehydration, chest pain, changes in patterns of urination, laboratory findings
Discharge and home healthcare guidelines
Explain the medications to the patient, including the route, dosage, side effects, and need for taking all antibiotics until they are gone. Explain food and drug interactions. Provide information on smoking-cessation programs. Note the source of the patient’s Legionnaires’ disease; if the cause was from within a patient’s home or workplace, recommend appropriate action to prevent recurrence and decrease chances of further outbreaks. Instruct the patient to contact the physician if she or he has a fever or worsening pleuritic pain. Stress the need to go immediately to the nearest emergency department if the patient becomes acutely short of breath.