The document provides a comprehensive overview of pneumonia, including its definition, epidemiology, causes, and classification by anatomical and pathological criteria. It discusses the clinical features, diagnostic approaches, treatment options, and potential complications associated with pneumonia, as well as specific characteristics of various pneumonia-causing organisms. Additionally, it highlights risk factors, predisposing conditions, and methods for assessing severity in patients.

1. Professor Chibueze Haggai Njoku
Department of Internal Medicine
Faculty of Clinical Sciences
College of Medical Sciences
University of Calabar
PNEUMONIA

2.  DEFINITION:
Inflammation of the lung parenchyma, the
portion distal to the bronchioles and
comprising the respiratory bronchioles,
alveolar duct, alveolar sac and alveoli
Normal Lung Resolving Pneumonia

3. EPIDEMIOLOGY
 Estimated worldwide incidence of CAP is 1.5-14 cases per 1000-
affected by geography, season and population characteristics.
 Animal incidence in US – 24.8 cases /10,000 with higher rates as
age increases (2021 August)
 Affects approximately 450 people a year in all parts of the world
 Resulted in 1.4 million deaths in 2010 (7% of the worlds yearly
total )
 3.0 million deaths in 2016 ( the 4th
leading cause of death
worldwide )
 Rates are greatest in children less than five and adults > 75 years
 Five times more frequent in the developing world compared to
developed world.
 Estimated 4 million cases and 200,000 deaths in adults per year
in sub Saharan African (2013 study) published in thorax

4. ASSOCIATED FACTORS
 Rains and may peak in early dry season
 Clustering – mining, military
 Habits – smoking increasing risk in US X4
 Decreased immunity – DM, CKD,
Nephrotic Syndrome, Cirrhosis,
Alcoholism
 Commoner among the blacks

5. IN AFRICA
 2nd
commonest cause of adult admission after
malaria
 Commoner in young adults <40years
 Loss of active work in 60% of survivors for up
to 3 weeks
 Mortality highest in the elderly
 Predisposing Factors – URT, Smoking,Alcohol,
Steroid Therapy, old age,Air pollution,
HIV/AIDS Pre-existing Lung disease, recent
influenza, pregnancy, SCD, bronchiectasis
(cystic fibrosis) , Ca Lung , IV drug users

6. CLASSIFICATION
By anatomy:
 Lobar – immunocompetent
 Broncho – low immunity
By infection:
 Bacterial
 Fungal
 Viral
By Epidemiology:
 Community acquired
 Hospital acquired - nosocomial
 Through inhalation – Aspiration
Lobar Pneumonia
Bronchopneumonia

7. AETIOLOGY
 Unknown in 10-50% of cases
 Empirical treatment – assumption that
organisms in an environment are likely
the same
CONSTRAINTTO DIAGNOSIS
 Standard blood cultures may not be
totally revealing and insensitive
 Accessible diagnostic tool like sputum
culture – non specific

8. COMMON ORGANISMS
BACTERIAL
Gram Positive:
 Strep pneumonia 30-60% (Bacteremia 20-
30%)
 Haemophilus influenza 3-10%
 Staph aureus (including NRSA) 3-5%
Gram Negative:
 Klebsiella pneumoniae, Acinobacter,
Pseudomonas aeroginosa 3-10%
 Haemophilus influenza 3-12%
 Moraxella cataralis 3-5%

9. ATYPICAL
 Legionella, Mycoplasma pneumonia, Chlamydia
pneumonia (2-10%)
FUNGAL
 Histoplasma, Blastomyces, Coccidiodes (variable
depending on location)
VIRAL
 Influenza A – most common
 Parainfluenza
 Respiratory Syncitial virus (commonest in children)
2-15%
 Aspiration Pneumonia 6-10%
 Mycobacterium tuberculosis variable
 Unkown 30-60%

10. OTHERS
 Salmonella spp,Adenovirus, Cytomegalovirus,
Measles, Herpes simplex,Varicella, CoronaVirus
(Urban SARS- associated corona virus
The unknown may include : Pneumocytes jiroveci,
Escherichia coli anerobic bacteria, Chlamydia
psittaci, legionella pneumophila, Coxiella burnetti,
Hstoplasma capsilatum,Actinomyces isrealli,
Norcardia asteroidis,Aspergillus fumigatus ,
Paragonimus and other migrating parasites
 Empirical use of penicillins is permitted because
70% of pneumonias may be due to Streptococcus
pneumonia

11. Pathology – 4 stages
Congestion
 pneumococcal cell wall components stimulate
release of protein rich serous fluids within the
alveoli
 Activate pro-coagulant cascade leading to fibrin
deposition
Red hepatization
 Cell wall components bind to epithelial and
endothelial cells
 Those separate from each other, barrier function
disrupted
 Red blood cells infiltrate the lesion

12. Red Hepatization Grey Hepatization

13. Gray hepatization
 Expression of adhesion molecules or
integrin on endothelial cells
 Recruitment of large numbers of
leucocytes – grossly appears gray
 Amplification of inflammation by
complement cascade
Resolution
 Healing of the inflammatory process
without scarring
 Fibrosis and abscess formation may result.

14. Consolidation
Solidification of the lungs due to filling of the alveoli
with inflammatory exudates
PATHOPHYSIOLOGY OF HYPOXIA
 i) consolidation makes the lungs stiff
 ii) voluntary splinting to reduce pain
 fibrin deposition in small pulmonary vessels leads to
poor perfusion and shunting
CLINICAL FEATURES
 sudden illness
 fever – up to 39.5o
C or higher
 Rigors, shivering, vomiting, poor appetite, headaches

15. PULMONARY SYMPTOMS:
breathlessness, cough – initially dry but
later mucopurulent with pleuritic chest
psin.Tachypnoea /Tachycardia . rusty
sputum ( Strep pneumonia)
INVESTIGATION
 Sputum – gram stain of direct smear . Z-
N- Staining, m/c/s
 May induce sputum or do bronchial
lavage.Tracheal aspirate

16.  Blood – cultures
 Serology – mycoplasm, chlamydia, legionella, viral
infections
 PCR- mycoplasma in throath swabs, legionella, chlamydia
 Cold agglutinins
 Examination of pleural aspirate if para-pneumonic effusion
 Urine antigen test – legionella, pneumococcus
 CXR – homogenous opacity (affected lobe or segment)
within 12-18 hours of illness with treatment assess changes
7-10 days by repeat. After cure, clears within 6 weeks
 Reveals complications e.g effusion, empyema, abscess
 Diffuse alveolar or interstitial infiltrates

17.  FBC- leukocytosis
 Procalcitonin level (70.5microgram /l)
 Pulse oximetry
 PSI – pneumonia severity index
 CURB.65 (BTS – 1987)
ASSESSMENT OF SEVERITY
 1 – C – Confusion
 1 – U- Urea> 7mmol/l
 1 – R – Respiratory Rate > 30/min
 1 – B – BP systolic <90mmHg or Diastolic
<60mmHg
 1 – 65 – Age >65

18.  Score 0- 1 – home treatment
 2 – hospital supervised treatment
 Short stay in patient
 - supervised out patient
 3 or more – severe pneumonia – manage in
hospital
 4 or 5 – manage in ICU
 Mortality rate increases with increasing
score
Other markers of severe pneumonia
 CXR – Consolidation in more than 1 lobe

19.  PaO2 - < 8kpa
 Low Albumin <35g/l
 WBC < 4X109
/L or > 20 X
109
/L
 Blood culture – positive

20. DIFFRENTIAL DIAGNOSIS
 Pulmonary infarction
 Pulmonary / Pleural TB
 Pulmonary Oedema ( esp unilateral)
 Malignancy : bronchoalveolar cell carcinoma
 Pulmonary eosinophilia
 Bronchiolitis
SPECIAL CHARACTERISTICS OFVARIOUS
PNEUMONIAS:
Pneumococcal Pneumonia:
 rusty sputum, Pleuritic chest pain
 Jaundice , usually one lobe involvement

21. Staphylococcal:
 extremes of age, pneumatocoeles, pneumothorax – a
complication
Klebsiella:
 chocolate coloured sputum ( brick red currant jelly)
 Massive consolidation of upper lobe, simulates TB
ATYPICAL
Legionella pneumophila
 shower facilities or coding systems ( hotels,
institutions, hospitals)
 Mainly western world and south Africa
 Dry cough, high fever, headache, malaise, vomiting,
diarrhoea, myalgia, confusion, hyponatraemia, high liver
enzymes, creatine kinase

22. Mycoplasma Pneumonia:
 3-4 years cycle
 Teens to twenties often in boarding institutes
 Headache and malaise then chest symptoms in 1-5
days, scanty cough
 Usually one lobe, but florrid bilateral disease
sometimes
 Complicated by haemolytic anaemia,
thrombocytopenia, Steven-Johnsons syndrome,
erythema nodosum, myocarditis, pericarditis,
meningoencephalitis, Guillian Barre syndrome, myalgia,
arthralgia.
 Cold agglutination +-50% high titres of complement
fixing antibodies – 16% of Zaria studies

23. Chlamydia psittaci:
 Zoonosis- exposure to birds – parrots, budgerigers,
pigeons, cockatoos, . reported in S.Africa
 Protracted illness, high or low grade fever
 Headache, meningism, photophobia, rose spots,
hepatosplenomegaly at times
 Rising titres of complement fixing antibodies
Chlamydia pneumonia:
 Droplet infection, crowded places, runny stuffy nose,
fatigue, low grade fever, hoarseness of voice,
headache, slowly worsening cough that can last for
months, headache, type specific
microimmunoflorescense test, PCR.

24. Rickettsia – Coxiella burnetti (Q fever):
 Contact with goats, sheep, cattle and domestic animals –
cats, dogs, rabbits
 Workers in dairy farm, abattoirs and hide factories
 Amniotic fluid and placenta carry higher risk also urine,
faeces and milk of the pets
 Q-query – until true cause discovered 1930s
 M>F Acute and Chronic forms
 Headache, fever, malaise, multiple lesion on CXR
 Acute – Severe headache, high fever, hepatitis, myalgia,
conjunctivitis
 Chronic – endocarditis, hepatomegaly
 Increasing titre of complement fixing antibodies PCR
 Vaccine-once in life. Effect last 5 years only adults > 15
years

25. Hospital acquired pneumonia (nosocomial):
 Develops > 3 days after admission to hospital
Predisposing Factors
 Coma, malnutrition, severe metabolic acidosis,
alcoholism, burns, COPD, pre-existing neurological
disease, elderly, sedation, steroid therapy,
instrumentation – intubation – pharynx, larynx and for
ventilation
Aetiology
 Gram negative bacilli, Staph aureus,Anaerobic bacteria,
H. influenza, S. pneumonia,Viruses, fungi,TB
Aspiration Pneumonia
Aspiration of pharyngeal contents in patients with
depressed consciousness dysphagia.

26.  Effects – due to combination of chemicals and
infections of periodontal disease
 Multiple aetiology – bacteroides, strept,
fusobacteria
TREATMENT
 Oxygen
 Fluid balance
 Drugs
 CAP – Amoxycillin, Macrolides,
Fluoroquinolones
 Severe – Co-Amoxyclav, Cephalosporins, IV-
macrolides

27. ATYPICAL
 Legionaire – Clarithromycin + Rifampicin
 Chlamydia – Tetracycline or Macrolides
 Pneumoystis jiroveci – high dose cotrimoxazole
 Mycoplasma – Tetracycline / IV erythromycin
 Coxiella – Tetracycline, doxycycline 18 months
course for chronic forms
 Actinomyces – penicillins
 Staph – flucloxacillin
 Klebsiella – Gentamycin, Ceftazidine,
Ciprofloxacin
 Viral – Acyclovir, Vidarabine

28. HOSPITALACQUIRED – Cefuroxime
Metronidazole
Complications:
 Parapneumonic effusion
 Empyema
 Retension of sputum causing lung collapse
 DVT leading to Pulmonary Embolism
 Suppurative pneumonia – lung Absess
 ARD with renal failure and multiple organ failure
 Ectopic abscess formation (esp Staph aureus)
 Hepatitis, pericarditis, myocarditis , meningo
encephalitis
 Fibrosis

29. CAUSES OF SLOW RESOLUTION OF
PNEUMONIA
 Bronchial Obstruction – Neoplasm, Foreign
body especially peanuts
 Inappropriate Chemotherapy esp for staph,
Klebsiella , TB, Myocosis
 Decreased Immunity – cachexia,
agranulocytosis, immunoglobulin defects,
LVF
 Pharyngeal Pouch – with spilling
 Formation of abscess, emphysema, effusion
 Other causes of pulmonary fibrosis