Pneumonia

Question 1

Treatment of mild pneumonia

Answer 1

• amoxycillin 1 g orally, 8-hourly for 5 to 7 days
• doxycycline 100 mg orally, 12-hourly for 5 to 7 days.

Question 2

Treatment of moderate pneumonia

Answer 2

• benzylpenicillin 1.2 g IV, 6-hourly until significant improvement
• then amoxycillin 1 g orally, 8-hourly for a total of 7 days (IV + oral)

PLUS

• doxycycline 100 mg orally, 12-hourly for 7 days.

RISK FACTORS PRESENT

• ceftriaxone IV plus
• gentamycin IV

Question 3

Treatment of severe pneumonia

Answer 3

NONTROPICAL REGIONS

• ceftriaxone 1 g IV
• PLUS
• azithromycin 500 mg IV, daily.

TROPICAL REGIONS

• meropenem 1 g IV (wet season)
• OR
• piperacillin+tazobactam 4+0.5 g IV (dry season)
• PLUS (with either of the above regimens)
• azithromycin 500 mg IV, daily.

Question 4

What is SMART COP?

Answer 4

Severe CAP = a SMART-COP score of 5 or more points.

UNDER 50yrs

• S systolic BP less than 90 mm Hg 2 points
• M multilobar CXR involvement 1 point
• A albumin less than 35 g/L 1 point
• R respiratory rate 25 br/min or more 1 point
• T tachycardia 125 bpm or more 1 point
• C confusion (acute) 1 point
• O oxygen low 2 points
  
  • PaO2 less than 70 mm Hg, or O2 saturation 93% or less, or PaO2 /FiO2 less than 333
• P pH less than 7.35 2 points

OVER 50 yrs

• S systolic BP less than 90 mm Hg 2 points
• M multilobar CXR involvement 1 point
• A albumin less than 35 g/L 1 point
• R respiratory rate 30 br/min or more 1 point
• T tachycardia 125 bpm or more 1 point
• C confusion (acute) 1 point
• O oxygen low 2 points
  
  • PaO2 less than 60 mm Hg, or O2 saturation 90% or less, or PaO2 /FiO2 less than 250
• P pH less than 7.35 2 points

Question 5

What is CURB 65?

Answer 5

• Confusion
• Urea - BUN > 19 mg/dL (> 7 mmol/L)
• Respiratory Rate ≥ 30
• Systolic BP < 90 mmHg or Diastolic BP ≤ 60 mmHg
• Age ≥ 65

Each worth 1 point

>2 = severe score

Question 6

Causative organisms - pneumonia

Answer 6

COMMUNITY-ACQUIRED ACUTE PNEUMONIA: (Lobar pneum.)

• Streptococcus pneumiae (Occurs in Healthy Adults)
• Haemophilus influenzae (COPD exacerbation, kids, CF, bronchiectasis)
• Rarely: M. catarrhalis, S. aureus, Klebsiella pneumoniae

NOSOCOMIAL (HOSPITAL) PNEUMONIA: (Broncho pneum.)

• H.Influenzae (COPD exacerbation)
• Moxerella catarrhalis (COPD exacerbation, elderly)
• Klebsiella pneumoniae (Alchoholics)
• Pseudomonas (CF, CCF, burns, neutropenia)
• E coli.
• Staph. aureus.
• Occurs in already sick patients or very young/ very old

► ATYPICAL PNEUMONIA:

• Mycoplasma.

► ASPIRATION PNEUMONIA:

• Anaerobic oral flora (Bacteroides)

► CHRONIC PNEUMONIA:

• TB, Atypical Mycobacteria, Fungi.

► PNEUMONIA IN THE IMMUNOCOMPROMISED:

• Legionella pneumophilia (organ transplant)
• CMV
• Pneumocystis
• Atypical Mycob.
• Candida
• Aspergillosis
• The usual (community + nosocomial) pathogens can also easily infect an immune compromised host

Question 7

Pathogenesis of pneumonia

Answer 7

Stage 1 - NORMAL (Stage 4 - RESOLUTION)
▪ Normal / resolved alveoli has capillaries + RBCs+
endothelial cells + lymphocytes
▪ Bacteria enters (surpasses immune syst) to release
mediators + toxins + cause inflammation
Stage 2 – CONGESTION
▪ Inflammation causes vasodilation + pain + fever
▪ Vasodilation  ↑ blood in alveoli walls  alveoli
walls thicken
▪ ↑ endothelial permeability  fluid accumulation
in alveoli (plasma)
▪ Congestion  ↓ O2 exchange  SOB
Stage 3 – RED HEPATIZATION

▪ RBCs+ WBCs leak into lumen (diapedesis)
▪ More RBCs than WBCs  whole lung appears red
and solid (like a liver)

Stage 4 – GREY HEPATIZATION
▪ WBCs (macs + lymphocytes) increase in number
▪ They remove the dead tissue + RBCs + dead WBCs
 lung begins to turn grey
▪ Exudate is also coughed up or organized by
fibroblasts growing into it

Question 8

Investigations for pneumonia

Answer 8

► CHEST XRAY = lobar or multilobar infiltrates, cavitation or pleural effusion.
► Assess 02 + BP = oxygen saturation (ABGs if SaO2 <92% or severe)
► Blood tests = FBC, U&E, LFT, CRP, blood cultures (if febrile)
► Sputum = Microscopy and culture
► Pleural fluid = May be aspirated for culture.
► In severe cases:
o Urine pneumococcal + legionella antigen
o Legionella (sputum culture)
o Atypical organism/viral serology (PCR sputum/BAL, complement fixation
tests acutely, paired serology)
o Check for pneumococcal antigen in urine
o Consider bronchoscopy and bronchoalveolar lavage if patient is immunocompromised