Pneumonia Flashcards
Pneumonia definition, risk factors and C/P
Definition: acute infection of the lung parenchyma
Risk factors:
o Immunodeficiency.
o Malnutrition
o Low socioeconomic status.
o Air pollution and cigarette smoke
o GERD and recurrent aspiration.
o Underlying neuromuscular weakness or cardiopulmonary diseasee
Clinical picture:
Symptoms
- Fever, malaise, vomiting, and poor general condition.
- Abdominal pain (Referred pain from lower lobe pneumonia)
- Cough (dry then productive)
- Dyspnoea and grunting.
Signs:
o Signs of respiratory distress: tachypnoea & working alae nasi, retractions (intercostal & subcostal), and grunting.
o In advanced cases, cyanosis and may be impaired consciousness
o Local chest examination:
- Stage of congestion→ normal breath sounds, decreased air entry and fine crepitation
- Stage of consolidation:
o Inspection: decreased movement on the affected side
o Palpation: central trachea and increased tactile vocal fremitus
o Percussion: impaired note on the affected side.
o Auscultation: decreased air entry, bronchial breathing, medium sized consonating crepitation and bronchophony
- Stage of resolution: coarse crepitation in both phases of respirations.
Pneumonia complications and Investigations
Complications:
- Local: abscess, pleural effusion, empyema, pneumothorax, bronchopleural fistula.
- Systemic: respiratory failure, heart failure, and autoimmune haemolytic anaemia.
- Metastatic infection: meningitis, osteomyelitis, septic arthritis, and sepsis.
- Hyponatremia: due to syndrome of inappropriate secretion of antidiuretic hormone.
- Meningism especially with right upper lobe pneumonia
Investigations
1. Laboratory
- CBC: leucocytosis with neutrophilia → suggest bacterial infection.
- Acute phase reactant: + ve CRP and ±± ESR → suggest bacterial infection and may be helpful to monitor response to therapy in complicated pneumonias.
- Cultures: from blood, pleural fluid, sputum or tracheobronchial secretions aspirate.
- Viral detection: via PCR or antigen detection by immunofluorescence or viral culture
- PCR, serologic testing, cold agglutinin test for mycoplasma can be helpful.
- Consider TB testing based on risk factors.
- Arterial blood gas: → in significant respiratory distress.
2. Radiologic:
1. Chest x ray:
- Can differentiate between different types of pneumonia
o Lobar pneumonia: homogenous opacity in one or more lobes.
o Bronchopneumonia: scattered opacities in both lungs.
o Interstitial pneumonia: scattered bilateral perihilar pulmonary infiltrate, hyperinflation, and atelectasis (usually viral in origin)
- Can detect complications as abscess, effusion & pneumothorax.
2. Contrast CT scan or CT or ultrasonography guided lung biopsy: for complicated cases
Treatment of pneumonia
A. Outpatient therapy: the duration is 7-10 days.
- Patients 3 months to < 5 years → high dose amoxicillin (plus azithromycin if atypical pneumonia is suspected)
- Patients g 5 years → azithromycin (+ amoxicillin if bacterial pneumonia is suspected)
B. Hospitalization therapy:
1-Indications of hospital admission:
- Young age < 3-6 months
- Dehydration or inability to maintain hydration
- Moderate to severe respiratory distress
- Ill and toxic appearance.
- Hypoxaemia (SpO2 < 92% in room air).
- Failed OPD treatment (for 2-3 days)
- Complicated pneumonia
2-Supportive treatment: bed rest, humidified O2 inhalation, fluid support, and antipyretics for fever.
3-Specific treatment:
- Bacterial pneumonia → Antibiotics (depending on clinical picture, radiology, culture & sensitivity if available and better combined antibiotics) are given until clinical improvement (afebrile 1-2 days and can tolerate oral intake) as follow:
o If < 3 months → ampicillin ± aminoglycosides or cefotaxime by IV injection (consider macrolides for chlamydia or pertussis)
o Alternative regimen (mainly for > 3 months) → ceftriaxone or cefotaxime by IV injection ± vancomycin or clindamycin if staphylococci is suspected (consider azithromycin or clarithromycin if atypical mycoplasma pneumonia is suspected)
o For hospital acquired pneumonia → consider broader coverage, including gram negatives (gentamycin, piperacillin-tazobactam, meropenem, ceftazidime, cefepime) and gram positives (clindamycin, vancomycin)
- Viral pneumonia: treatment is mainly supportive in addition to
o Antibiotics may be used as coexisting bacterial infection exists in 30% of cases.
o Antiviral treatment as Ribavirin for RSV in high risk cases or Oseltamivir (Tamiflu) for influenza A or B or H1N1 viruses
4-ttt of complications:
- Heart failure
- Chest tube drainage for massive effusion or empyema
Organisms causing lung cavitations:
Staph pneumonia
Klebsiella pneumonia
Streptococcal pyogenes
TB
Pneumocystis carinii infection
Slowly Resolving or unresolved Pneumonia definition, causes and management?
Definition: Persistent symptoms or radiographic abnormalities beyond the expected time course.
- Clinical improvement for uncomplicated bacterial pneumonia occurs within 3- 4 days of antibiotics.
- Radiographic improvement for uncomplicated bacterial pneumonia improves within 4-6 wk.
Causes:
- Inadequate therapy: inappropriate antibiotic choice, dose, or poor compliance
- Complications from the initial pneumonia like abscess, empyema.
- Development of resistant organisms.
- Underlying immunodeficiencies
- Obstruction in the airways: foreign body
- Decreased muco-ciliary clearance e.g. Ciliary dyskinesia, cystic fibrosis
- Nonbacterial causes: Viruses, fungi, parasites, and Mycobacteria
- Non-infectious causes: hypersensitivity pneumonitis, sarcoidosis and Wegener granulomatosis.
Management:
- Identify the offending organism: culture of blood, sputum, pleural, or bronchoalveolar lavage.
- Chest CT scans (spiral CT)
- Anti-neutrophil cytoplasmic antibodies [ANCA] for Wegener granulomatosis or PCR for TB.
- Flexible fiberoptic bronchoscopy
- Lung biopsy
Clinical differnation between different types of pneumonia in pediatrics
- Viral: common in preschool children
* causes: RSV, rhinovirus, adenovirus, influenza and para influenza virus.
Clinically:
* Preceding upper respiratory tract infection.
* Milder fever and respiratory distress (RD) than bacterial pneumonia.
* May be widespread wheezes and crepitations.
* X Ray: bronchopneumonia or interstitial pneumonia - Bacterial: can occur at any age
* Streptococcal pneumonia: commonest < 5 years, moderate RD, high fever, usually lobar but may be bronchopneumonia in young infants, usually treated by penicillins.
* Staphylococcal pneumonia: common in the 1st year, severe RD, high fever, usually bronchopneumonia with pneumatoceles. treated by Cloxacillin or vancomycin
* Streptococcal pyogenes: common in preschool children with moderate RD, high fever, and usually bronchopneumonia may cause effusion.
* Hemophilus influenza: common in preschool children, gradual onset, prolonged course, high fever and usually lobar involving more than one lobe or bronchopneumonia. treated by 3rd generation cephalosporins
* Klebsiella pneumonia:- Mainly in debilitating child, usually of sudden onset, progressive course with higher fatality, Lobar with complications (abscess, cavitation, ….), treated by amikacin or meropenem. - Atypical or mycoplasma: common cause in 5-15 years (school age)
* Clinically - severe non productive cough without significant RD
* Pharyngitis is common.
* Minimal physical signs (walking pneumonia).
* May be chest wheezes and inspiratory crepitations.
* Cold agglutinins in the blood may support the diagnosis.
* X-ray chest:
* Perihilar lower lobes infiltrate (like interstitial pneumonia).
* Some times lobar consolidation & effusion.
* Complications include autoimmune hemolytic anemia, encephalitis and Steven-Johnson syndrome.
* Treatment: macrolides antibiotics (Azithromycin)
