PNEUMONIAS

Case History

What are the signs to diagnose severe pneumonia?

Enumerate 4 organisms for community acquired pneumonia

Symptoms( 2 or 3 of the 4 cardinal symptoms missing )

Symptoms

(1) Cough (1) Absent early stage pneumonia, infants, sick elderly, stroke + alcoholism(2) Persistent dry cough in C pneumoniae + M pneumoniae

(2) Chest pain( pleuritic) Often present lobar pneumonia especially when associated with pleuritis

(3) Confusion + unsteadiness among the elderly

(4) Dyspnoea ( shortness of breath)

(5) Fever with Rigors or night sweats> 4 days

Fevers may be absent in infants + the elderly

(6) Nausea or diarrhoea May be prominent symptoms

Signs (None of the signs in 50% patients with pneumonia Dx CXR)Signs

(1)General examination: Fever >38 degrees C >4 days + systematically unwell

(2) Inspection: Respiratory rates raised + significant shortness of breath

(3) Percussion: Dullness

(4) Ascultation: Localised crackles

May be heard in (i)acute bronchitis, (ii) COPD +(iii) Heart failureSpecificity crackles low

(5) Ascultation : Bronchial breathing

(6) Ascultation: Wheezes (i)a concomitant bronchitis(ii) a localised sign of narrowed bronchial branches or mucus plugs in the bronchial tree.

Diagnosis

Chest X ray

Microbiological testing

Blood tests: WCC, ESR,CRP

Chest X Ray

Indicated : severely ill patient + diagnostic doubt

Unreliable : study shows 8 out of 26 pneumonias diagnosed with high resolution CTs were not diagnosed by CXR.

Follow up CXR after 6 weeks : patients with increased risk of lung cancer , smokers > 40 years

Microbiological testing

Specimens: sputum or nasopharynx Common causes of pneumonia :

Streptococcus pneumonia ( pneumococci) , Haemophilus influenzae, Mycoplasma pneumonia, Chlamydia pneumonia and Legionella pneumonia

PCR Analysis(1-2 days) , IgM testing(1-2 days) , Culture ( days)

Common causes of pneumonia

Common aetiological agents Notes

(1) Streptococcus pneumonia( pneumococci)

Most common cause of CAP + hospitalised agents. Sudden onset with high fever . High mortality when not treated with antibiotics

(2) Haemophilus influenzae Similar features to pneumococci infection. Most frequently infected are small children, elderly + COPD or Chronic patients

(3) Mycoplasma pneumonia Outbreaks, Incubation period 2-3 weeks. Prominent fever, headache + cough. Minimal chest signs . Radiographic changes

(4) Chlamydia pneumonia Similar features to mycoplasma infection. Not as frequently in epidemics

(5) Legionella pneumonia Spread via water droplets. Diarrhoea, high fever + hyponatraemia. High mortality

White cell count

Elevated : (usually ) pneumococcal pneumonia

Normal: (usually) pneumonias caused by viruses , M pneumonia and C pneumonia

ESR

Elevated : all pneumonias regardless of aetiology

A few days b4 value exceeds the reference range

CRP: elevated within 12 hours + increase reflects disease severity

CRP Values Diagnosis

(1) <10 mg /dl Acute bronchitis and viral COPD causesUncomplicated viral illnesses after 7-10 days ( <10 mg/dl)

(2) 10mg/dl to 100 mg /dl Uncomplicated viral illnesses after 3-4 days of illness ( influenza may reach 100mg/dl)

(3) >100mg /dl Pneumonias ( persistently elevated value after 1 week of illness)

Treatment

Pneumonia severity index (PSI) US

CURB 65

CRB 65

Patient classificationusing the pneumonia severity

index (PSI)*

PSI risk class l (lowest risk)Patient has none of the following:(1) Age >50(2) History of (i) neoplastic disease(ii) congestive cardiac failure (iii) C erebrovascular (iv) renal (v) liver disease(3) Clinical signs(vi) altered mental state (vii) pulse rate ≥125 bpm (viii) respiratory rate ≥30 breaths/min (ix) systolic blood pressure <90mmHg (x) temperature <35ºC or ≥40ºC.

Patient classificationusing the pneumonia severity

index (PSI)*

PSI risk classes ll–VPatients with any of the above

characteristics are classified according to their PSI score, calculated according to the table on the left.

Pneumonia Severity Index

(1) Factor: age + nursing home resident

(2) Coexisting illness:

(3) Signs on examination: (4) Results of investigation:

PSI: Factor + Coexisting illness

Factor PSI Score

(i)Patient age Age in years ( male) or age -10 ( female)

(ii) Nursing home resident +10

Coexisting illnesses

(i) Neoplastic disease +30

(ii) Liver disease +20

(iii) Cardiac failure +10

(iv) Cerebrovascular disease +10

(v) Renal disease +10

PSI: Signs on examination

Signs on examination PSI Score

Respiratory rate >30 breaths/minute

+20

Altered mental state +20

Systolic blood pressure <90 mm Hg

+20

Temperature <35 degrees C or >40 degrees C

+15

Pulse rate >125 beats per minute

+10

PSI: Results of investigations

Results of investigations PSI Score

Arterial ph<7.35 +30

Serum urea level >11 mmol/l +20

Serum sodium level<130mmol/l +10

Serum glucose level >14 mmol/l +10

Haematocrit<30% +10

P a O2<60 mm Hg or O2 saturation <90%

+10

Pleural effusion +10

Interpretation of PSI Risk score

Class PSI Risk score

II 1-70

III 71-90

IV 91-130

V .130

Treatment of CAP:PSI risk

Class I (low risk) or class II - treatment outside hospital

(1) Amoxycillin 500-1000mg orally tds for seven days (if penicillin allergy, use cefuroxime 500mg orally bd for seven days)

(2) AND if Mycoplasma or Chlamydia are suspected change to, or add, either:

(i) Oral doxycycline 200mg orally for the first dose, followed by 100mg daily for five days or alternatively

(ii) Roxithromycin 300mg orally daily for five days

Treatment of CAP: PSI risk

Class III and IV* — treatment in hospital

Should be managed as inpatients using (1) IV penicillins (or

ceftriaxone/cefotaxime) + oral agents such as doxycyclineOr (2) clarithromycin or roxithromycin

as per antibiotic guidelines

Pneumonia in children

Severity assessment —indicators for admission to hospital

Infants Children

Not feeding Signs of dehydration

Family not able to provide observation or support

Family not able to provide observation or support

Difficulty breathing Difficulty breathing

Intermittent apnoea Grunting

Sa O2 < 92%, Cyanosis S a O2 < 92% , Cyanosis

Respiratory rate > 70 / minute Respiratory rate > 50 /minute