Pneumonia Disease

DESCRIPTION

An acute, bacterial infection of the lung parenchyma. Infection may be community-acquired or nosocomial (hospital acquired by an inpatient for at least 48 hours or inpatient in the previous 1-3 weeks). Most commonly, community-acquired disease is caused by Streptococcus pneumoniae or Mycoplasma pneumoniae. Hospital-acquired pneumonia is usually due to gram negative rods (60%) such as Pseudomonas; 14.5% from Staphylococcus.

System(s) affected: Pulmonary
Genetics: No known genetic pattern
Incidence/Prevalence in USA:
- Incidence - community-acquired: 1200 cases/100,000 population per year
- Incidence - nosocomial: 800 cases/100,000 admissions per year
Predominant age: Age extremes
Predominant sex: Male > Female

SIGNS AND SYMPTOMS

Cardinal signs and symptoms
- Cough and fever
- Chest pain (pleuritic)
- Chill, with sudden onset
- Dark, thick or bloody (rusty) sputum
Respiratory
- Signs of consolidation
  - Rales
  - Egophony
- Signs of pleural involvement
  - Decreased breath sounds
  - Dullness to percussion
  - Friction rub
Signs of respiratory distress
- Tachypnea/tachycardia (or bradycardia)
- Cyanosis
Central nervous system
- Mentation changes to include anxiety, confusion and restlessness
Gastrointestinal
- Abdominal pain
- Anorexia

CAUSES

Sources
- Aspiration from the oropharynx
- Inhalation
- Hematogenous spread
Bacterial pathogens
- Streptococcus pneumoniae (pneumococcus)
- Haemophilus influenzae
- Mycoplasma pneumoniae
- Staphylococcus aureus
- Legionella pneumophila
- Chlamydia pneumoniae, C. psittaci
- Moraxella catarrhalis (Branhamella catarrhalis)
- Pseudomonas aeruginosa
- Klebsiella pneumoniae (and other gram-negative rods)
- Anaerobes

RISK FACTORS

Recent/concurrent viral infections
Hospitalization to include mechanical ventilation, antecedent antibiotics, NG tubes
Age extremes
Alcoholism
AIDS or other immunosuppression
Tobacco smoking
Renal failure
Cardiovascular disease
Functional asplenia
Chronic obstructive pulmonary disease
Diabetes mellitus
Malnutrition
Malignancy
Altered level of consciousness or gag (e.g., seizures, stroke, neuromuscular disease, etc.)
Occupational exposure
Poorly implemented infection control practices

LABORATORY

Leukocytosis with an immature shift on differential
Hyponatremia (SIADH)
Hypoxemia
Hypocapnia initially, then hypercapnia
Blood culture - positive in 10-20% of patients with community-acquired pneumonia, 8-20% nosocomial pneumonia

Drugs that may alter lab results: Antecedent antibiotics
Disorders that may alter lab results: Refer to lab test reference

PATHOLOGICAL FINDINGS

Lung:
- Segmental, lobar, or multifocal peribronchial consolidation
- Positive gram stain for bacteria

SPECIAL TESTS

Decubitus chest roentgenograms to investigate for empyema or parapneumonic effusion
Gram stain and culture of pleural fluid
pH of pleural fluid (iced, airless sample sent to blood gas laboratory)

IMAGING

Chest roentgenogram (with lateral decubitus views if pleural effusion present)
- Lobar or segmental consolidation (air bronchogram)
- Bronchopneumonia
- Interstitial infiltrate
- Pleural effusion (free-flowing or loculated)

DIAGNOSTIC PROCEDURES

Gram stain and culture of sputum (induced, if necessary)
Nasotracheal suctioning for culture
Transtracheal aspirate for culture
Bronchoscopy with bronchoalveolar lavage or protected telescoping catheter brushing for culture
Thoracentesis for pleural fluid studies
Blood culture, especially if hospitalized - prior to antibiotics

APPROPRIATE HEALTH CARE

Community-acquired - outpatient for mild case, inpatient for moderate to severe case such as hypoxemia, altered mental status, hypotension, significant co-morbid illness, and age extremes.
Nosocomial - patients already hospitalized

GENERAL MEASURES

Empiric antimicrobial therapy for most likely pathogen(s)
Consider oxygen for patients with cyanosis, hypoxia, dyspnea, circulatory disturbances or delirium
Mechanical ventilation for respiratory failure
Chest physiotherapy
Hydration
Nasotracheal suction
Analgesia for pain
Electrolyte correction
Respiratory isolation if TB is a possibility

SURGICAL MEASURES

N/A

ACTIVITY

Bedrest and/or reduced activity during acute phase

DIET

Nothing by mouth if there is incipient respiratory failure
Consider soft, easy-to-eat foods

PATIENT EDUCATION

Printed patient information available from: American Lung Association, 1740 Broadway, New York, NY 100019 (212)315-8700; web site http://www.lungusa.org

PREVENTION/AVOIDANCE

Reduce risk factors where possible
Bedridden and postoperative patients - deep breathing and coughing exercises; prevent aspiration during nasogastric tube feedings
Avoid indiscriminate use of antibiotics during minor viral infections
Annual influenza vaccine for high risk individuals
Polyvalent pneumococcal vaccine

POSSIBLE COMPLICATIONS

Empyema
Pulmonary abscess
Superinfections
Multiple organ dysfunction syndrome (MODS)
Adult respiratory distress syndrome (ARDS)

EXPECTED COURSE AND PROGNOSIS

Usual course - acute. In otherwise healthy individual, improvement seen and fever resolved in 1-3 days; sometimes up to 1 week
Overall mortality is about 5% in community acquired; (~15% if hospitalized and < 1% if not hospitalized) 30-50% in nosocomial
Poorest prognosis - age extremes, positive blood cultures, low WBC, presence of associated disease, immunosuppression respiratory failure, inappropriate antecedent antibiotics, delayed treatment > 8 hours

ASSOCIATED CONDITIONS

Alcoholism
Tobacco smoking
Upper respiratory infection

AGE-RELATED FACTORS

Pediatric: Morbidity and mortality high in children under age 1
Geriatric: Morbidity and mortality high if > 70, especially if associated disease or risk factor
Others: N/A

PREGNANCY

N/A

OTHER NOTES

Pneumococcal vaccine for all adults over age 65 and children over 2 years (and adults) with risk (cardio, pulmonary or metabolic disorders)

ABBREVIATIONS

N/A

Clinical Investigations

ROLE OF HOMOEOPATHY

Holistic healing that treats the person, not just the disease. Experience gentle, lasting wellness with expert constitutional care.