Consolidation of lung

It means pneumonia which is defined as “inflammation in the lung characterized by accumulation of secretion and inflammatory cells in alveoli”.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 125

Pneumonia is as an acute respiratory illness associated with recently developed radiological pulmonary shadowing, which may be segmental, lobar or multilobar.

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 682

Pneumonia is the infection of lung parenchyma.

* Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 89

As follows:

1. Anatomically 2 types:
   • Lobar: Commonly involves one or more lobe.
   • Lobular (bronchopneumonia): It is characterized by nonpatchy alveolar opacity with bronchial and bronchiolar inflammation. Commonly, involves both lower lobes.
2. Clinically 4 types:
   • Community acquired pneumonia (CAP)
   • Nosocomial pneumonia (hospital acquired)
   • Pneumonia in immunocompromised
   • Suppurative and aspiration pneumonia.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 125

New episode of pneumonia occurring at least 2 days after admission in the hospital is called nosocomial pneumonia or hospital-acquired pneumonia (HAP).

* Long Cases in Clinical Medicine, ABM Abdullah Page: 128

It is defined as wide spread diffuse patchy alveolar opacity associated with bronchial and bronchiolar inflammation, often affecting both lower lobes.

• In children, it occurs as a complication of measles or whooping cough and in elderly, a complication following bronchitis or influenza.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 129

Typical pneumonia is characterized by high temperature with cough, pleuritic chest pain, features of consolidation, caused by Streptococcus pneumoniae, Staphylococcus aureus, etc.

• Respiratory symptoms are more with constitutional symptoms.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 129

When pneumonia is caused by mycoplasma, legionella, coxiella, chlamydia. In these cases, constitutional symptoms are more than respiratory symptoms. Features are:

• Gradual onset
• Dry cough
• Low grade fever
• Constitutional symptoms are more than respiratory symptoms (headache, myalgia, fatigue, nausea, vomiting)
• Less physical finding in the chest.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 129

Aspiration pneumonia is characterized by destruction of the lung parenchyma by the inflammatory process after the inhalation of septic material during operations on the nose, mouth or throat, under general anesthesia, or of vomitus during anesthesia or coma.

* Pre-exam preparation for medicine, HN Sarker

1. Bacterial pneumonia
2. Pulmonary infraction
3. Alveolar cell carcinoma
4. Tubercular consolidation

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 29

It is caused by:

• Common organism:
  • Streptococcus pneumoniae (50%),
  • Mycoplasma pneumoniae,
  • Chlamydia pneumoniae and
  • Legionella pneumophila.
• Others:
  • Bacteria:
    • Staphylococcus aureus,
    • Haemophilus influenzae,
    • Chlamydia psittaci,
    • Coxiella burnetii (Q fever, ‘querry’ fever),
    • Klebsiella pneumoniae (Freidländer’s bacillus),
    • Actinomyces israelii
  • Viruses
    • Influenza, parainfluenza
    • Measles
    • Herpes simplex
    • Varicella
    • Adenovirus
    • Cytomegalovirus (CMV)
    • Coronavirus (Urbani SARS-associated coronavirus) (SARS = severe acute respiratory syndrome)

* Long Cases in Clinical Medicine, ABM Abdullah Page: 126; Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 683

Organisms causing pneumonia:

* Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 89

Factors that predispose to pneumonia

• Cigarette smoking
• Upper respiratory tract infections
• Alcohol
• Corticosteroid therapy
• Old age
• Recent influenza infection
• Pre-existing lung disease
• HIV
• Indoor air pollution

Risk factors for children:

• Severe malnutrition
• Infectious diseases e. g. Measles, pertussis
• Immune deficiency disorders
• Congenital lesions e. g. congenital heart diseases
• Younger age e.g. infants
• Others e.g. Indoor air pollution, overcrowding

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 682; Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 89

Four stages:

1. Stage of congestion—persists for 1 to 2 days
2. Stage of red hepatization (red and solid like liver)—persists for 2 to 4 days
3. Stage of grey hepatization—persists for 4 to 8 days
4. Stage of resolution—8 to 9 days or more.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 126

During stage of resolution.

Note:

There may be pleural rub during pleurisy.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 125

• In early-onset HAP—(within 4–5 days of admission), the organisms as CAP
• In late-onset HAP
  • Gram-negative bacteria (e.g. Escherichia, Pseudomonas and Klebsiella species),
  • Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus (MRSA))
  • Anaerobic organisms

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 30

Predisposing factors:

• Elderly patient
• Bed bound, unconscious (e.g. CVA)
• Postoperative case (thoracic or abdominal surgery)
• Malignancy
• Diabetes mellitus
• Use of steroid, cytotoxic drugs, antibiotics
• Prolonged anesthesia, intubation, tracheostomy, IV canula
• Achalasia of cardia, dysphagia due to any cause, vomiting
• Bulbar or vocal cord palsy
• Nasogastric intubation
• Abdominal sepsis, infected emboli.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 128

As follows:

• Bronchial obstruction (bronchial carcinoma, adenoma, foreign body)
• Lung disease (bronchiectasis, lung abscess, cystic fibrosis, sequestrate segment of lung—commonly left lower lobe)
• Aspiration (achalasia cardia, scleroderma, pharyngeal pouch)
• Immunocompromised patient (HIV, DM, lymphoma, leukemia, multiple myeloma).

* Long Cases in Clinical Medicine, ABM Abdullah Page: 127

The patient may present with:

• Fever, may be with chill and rigor
• Cough, initially short, painful and dry. Later on, expectoration (during resolution). Rusty sputum (due to Streptococcus pneumoniae )
• May be hemoptysis
• Chest pain, pleuritic (may radiate to shoulder or abdomen)
• Other features—dyspnea, anorexia, nausea and vomiting.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 126

Usually after 2 days of onset of symptoms.

* Pre-exam preparation for medicine, HN Sarker

• Inspection
  • Movement is diminished on affected side.
• Palpation
  • Expansibility reduced on affected side,
  • Trachea: central, apex beat in normal position,
  • Vocal fremitus increased on affected side.
• Percussion
  • Woody dull (mention the location)
• Auscultation
  • Bronchial breath sound
  • Increased vocal resonance (and there is whispering pectoriloquy)
  • There is (mention, if any) few crepitations or pleural rub.

* Pre-exam preparation for medicine, HN Sarker; Short Cases in Clinical Medicine, ABM Abdullah, 5th Edition Page: 148

Read more about breath sound at Examination of respiratory system

The sputum is usually rusty.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 125

Blood

• Full blood count
  • Very high (> 20 × 10⁹/L) or low (< 4 × 10⁹/L) white cell count: marker of severity
  • Neutrophil leucocytosis > 15 × 10⁹/L: suggests bacterial aetiology
  • Haemolytic anaemia: occasional complication of Mycoplasma
• Urea and electrolytes
  • Urea > 7 mmol/L (~20 mg/dL): marker of severity
  • Hyponatraemia: marker of severity
• Liver function tests
  • Abnormal if basal pneumonia inflames liver
  • Hypoalbuminaemia: marker of severity
• Erythrocyte sedimentation rate/C-reactive protein
  • Non-specifically elevated
• Blood culture
  • Bacteraemia: marker of severity
• Serology
  • Acute and convalescent titres for Mycoplasma, Chlamydia, Legionella and viral infections
• Cold agglutinins
  • Positive in 50% of patients with Mycoplasma
• Arterial blood gases
  • Measure when SaO₂ < 93% or when severe clinical features to assess ventilatory failure or acidosis

Sputum

• Sputum samples
  • Gram stain, culture and antimicrobial sensitivity testing
• Oropharynx swab
  • PCR for Mycoplasma pneumoniae and other atypical pathogens

Urine

• Pneumococcal and/or Legionella antigen

Chest X-ray

• Lobar pneumonia
  • Patchy opacification evolves into homogeneous consolidation of affected lobe
  • Air bronchogram (air-filled bronchi appear lucent against consolidated lung tissue) may be present
• Bronchopneumonia
  • Typically patchy and segmental shadowing
• Complications
  • Para-pneumonic effusion, intrapulmonary abscess or empyema
• Staph. aureus
  • Suggested by multilobar shadowing, cavitation, pneumatocoeles and abscesses

Pleural fluid

• Always aspirate and culture when present in more than trivial amounts, preferably with ultrasound guidance

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 684

After 12–18 hours of onset of symptoms.

* Pre-exam preparation for medicine, HN Sarker

Homogenous opacity with air bronchogram.

X-ray chest PA view showing dense, homogeneous opacity involving the right upper and part of mid zone with air bronchogram within it.

* Pre-exam preparation for medicine, HN Sarker; Short Cases in Clinical Medicine, ABM Abdullah, 5th Edition Page: 539; X-ray: Macleod’s Clinical Examination, 13th Edition Page: 160

As follows:

• Lung abscess
• Bronchiectasis with secondary infection
• Pleural effusion
• Pulmonary infarction.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 124

In case of lung abscess, there will be more profuse foul smelling sputum. Clubbing may be present. Auscultation may show more coarse crepitations. X-ray will show cavity with air fluid level.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 124

With short history, very high temperature and signs of consolidation, tuberculosis is unlikely. In case of TB, there will be low grade continued fever with evening rise, weight loss, anorexia, night sweat, etc.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 124

It indicates pneumonia due to Streptococcus pneumoniae.

* Pre-exam preparation for medicine, HN Sarker

As follows:

* Long Cases in Clinical Medicine, ABM Abdullah Page: 127

We can assess severity of pneumonia by using CURB-65 score.

Other markers of severity of pneumonia¹

• Chest X-ray—more than one lobe involved
• PaO2  < 8 k Pa
• Low albumin (<35 g/L)
• White cell count (<4,000/cmm or >20,000/cmm)
• Blood culture positive.

* Pre-exam preparation for medicine, HN Sarker; ¹Long Cases in Clinical Medicine, ABM Abdullah Page: 128

CURB–65 is:

• Confusion
• Urea >7 mmol/L
• Respiratory rate>30/min
• Blood pressure (systolic < 90 mm Hg or diastolic < 60 mmHg)
• Age>65 years (Score 1 point for each feature).

Score 3 or more indicates severe pneumonia.

Figure: Hospital CURB-65. *Defined as a Mental Test Score of 8 or less, or new disorientation in person, place or time. (Urea of 7 mmol/L ≅ 20 mg/dL.)

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 683

Any child under 5 years of age who is brought with fever, cough and difficult breathing should be assessed after, 3 doses of salbutamol nebulization in an interval of 20 minutes. The patients who responds to nebulization will be considered as wheezy child e.g. Bronchiolitis, asthma but who do not : respond to nebulization should be classified as follows –

* Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 92

After admission in the hospital, associated with predisposing factors, if the patient develops purulent sputum, fever associated with radiological infiltrate, leukocytosis or leukopenia unexplained increase in oxygen requirement.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 129

Pneumonia is the diagnosis.

* Pre-exam preparation for medicine, HN Sarker

Antibiotic treatment for CAP:

Supportive treatment:

• Oxygen—Maintaining the PaO₂ ≥ 8 kPa (60 mmHg) or SaO₂ ≥ 92%.
• Maintain fluid balance.

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 685; Short and Long Cases in Clinical Medicine, HN Sarker Page: 30

Counsel the patient about pneumonia, its complications, treatment and outcome.

A. Antibiotic therapy:

Children 2 months – 5 years

1. Severe pneumonia
   • Inj. ampicillin 50 mg/kg IM/IV 6 hourly +
   • Inj. gentamicin 7.5 mg/kg IM/IV once daily for 5 days
   • If no response by 48 hours and suspected staph:
     • Gentamicin 7.5 mg/kg IM/IV once daily +
     • Cloxacillin 50 mg/kg/dose IM/IV 6 hourly for 7 days, continue cloxacillin for a total 3 weeks.
     • Failure of first line:
       • Ceftriaxone 80 mg/kg IM/IV once daily
2. Pneumonia
   • Amoxacillin 40 mg/kg/dose 12 hourly for 3 days (5 days in high HIV prevalent areas)
3. Follow up : After 72 hours (Routine) or earlier if clinical status deteriorates.

Neonates and young infants (<2 months)

Pneumonia of any severity should be hospitalized and managed with parenteral antibiotics,O₂ and other supportive care. The antibiotics of choice are:

• Ampicillin and gentamicin for 7-10 days
• If Staph suspected : add cloxacillin
• Choose other antibiotics including macrolides if requires

B. Supportive treatment

1. Oxygen therapy
   • Give Oxygen if SpO₂ < 90% by Pulse Oximeter
   • If pulse oximeter is not available, continue O₂ until the signs of hypoxia e.g. inability to BF or RR ≥ 70/min are no longer present
   • Remove O₂, for a trial period each day to see SpO₂. If SpO₂ remains > 90% (at least 15 min in room air) then discontinueO₂
   • Check 3 hourly that nasal prongs are not blocked with mucus and are in the correct place and that all connections are secure.
2. Other supports
   • Manage Airway e. g. remove any thick secretions from nose or throat
   • Give paracetamol for fever (≥ 39 °C or ≥102. 2 ° F)
   • Give a rapid-aciting bronchodilator for wheeze
   • Soothe the throat, relieve cough with a safe remedy e.g. warm water, tulsi leaf juice, lemon tea
   • Encourage breast feeding and oral fluids
   • Start NG tube feeding, if child cannot drink
   • Avoid overhydration

* Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 92, 93

Usually 4 weeks, but may take long time, even months.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 30

To discharge, the patient should be clinically stable with no more than one of the following clinical signs:

• Temperature > 37.8 ºC
• Heart rate > 100/min
• Respiratory rate > 24/min
• Systolic BP < 90 mm Hg
• SaO₂  < 90%
• Inability to maintain oral intake
• Abnormal mental status.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 131

Delayed resolution means when the physical signs persist for more than 2 weeks and radiological features persist for more than 4 weeks after antibiotic therapy. Causes are:

• Incorrect microbiological diagnosis
• Fungal, tubercular or atypical pneumonia
• Improper antibiotic or insufficient dose
• Bronchial obstruction (bronchial carcinoma, adenoma, foreign body)
• Empyema or atelectasis
• Immunocompromised patient (HIV, DM, lymphoma, leukemia, multiple myeloma).

Note:

• Physical signs of consolidation may appear within 2 days, and disappear within 2 weeks with proper treatment
• Radiological opacity appears within 12 to 18 hours, and disappears within 4 weeks with proper treatment
• If radiological opacity persists after 8 weeks (with treatment), it is called non-resolution

* Long Cases in Clinical Medicine, ABM Abdullah Page: 127

As follows:

• CURB score 4 to 5
• Persistent hypoxia despite high concentration of oxygen (PO₂ < 8 kPa or 60 mm Hg)
• Progressive hypercapnia
• Severe acidosis
• Shock
• Depressed consciousness.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 128

• Antibiotics
  • Third-generation cephalosporin (e.g. cefotaxime) +
  • Aminoglycoside (e.g. gentamicin) or
    • meropenem or
    • a monocyclic β-lactam (e.g. aztreonam) +
  • Flucloxacillin.
  • These antibiotics are all given intravenously, at least initially.
• Physiotherapy is important in those who are immobile or old.
• Adequate oxygen therapy, fluid support and monitoring are essential.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 30

Complications of pneumonia

• Para-pneumonic effusion – common
• Empyema
• Retention of sputum causing lobar collapse
• Deep vein thrombosis and pulmonary embolism
• Pneumothorax, particularly with Staph. aureus
• Suppurative pneumonia/lung abscess
• ARDS, renal failure, multi-organ failure
• Ectopic abscess formation (Staph. aureus) e.g. brain abscess
• Hepatitis, pericarditis, myocarditis, meningoencephalitis
• Pyrexia due to drug hypersensitivity

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 685; Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 92

• Immunisation: Against pneumococcus, Hib, measles
• Improvement of nutritional status: By breat feeding and energy dense complementary feeding
• Hand washing.

* Step on to Paediatrics, Md Abid Hossain Mollah, 3rd Edition Page: 93

It is common in children and young adult and is usually associated with headache, malaise and severe cough. Physical signs are less marked. Epidemics occur in cycle every 3 to 4 years.

Investigations:

• WBC (normal)
• Chest X-ray (commonly lower lobe involvement), may show bilateral patchy consolidation
• Cold agglutinin (positive in 50% cases)
• Rising antibody titer for Mycoplasma pneumoniae
• Others (CFT and hemagglutination test).

Extrapulmonary complications of Mycoplasma pneumonia:

• Maculopapular skin rash, erythema multiforme and Stevens Johnson syndrome
• Myocarditis and pericarditis
• Hemolytic anemia (Coombs test may be positive) and thrombocytopenia
• Meningoencephalitis, GBS and other neurological abnormalities
• Myalgia and arthralgia
• Gastrointestinal symptoms like vomiting, diarrhea.

Treatment:

• Clarithromycin 500 mg twice daily orally or IV or
  • Erythromycin 500 mg 6 hourly orally or IV for 7 to 10 days
• Or,  Doxycycline 100 mg twice daily
• Rifampicin 600 mg 12 hourly.

Note

The term atypical pneumonia is abandoned

* Long Cases in Clinical Medicine, ABM Abdullah Page: 129, 130

Three patterns of Legionnaires’ disease may occur:

• Outbreak of infection is usually associated with contaminated water supply or cooling system, or from stagnant water in cistern or shower head.
• Sporadic case, where source is unknown. It is usually common in middle aged and elderly, more in smokers.
• Outbreaks may occur in immunocompromised patients as for example those on corticosteroid therapy. Diabetes and CKD also increase risk.

Features are: Initially viral-like illness with high fever, chill and rigor, malaise, myalgia and headache. Dry cough, which is later productive and purulent. There may be nausea, vomiting, diarrhea and pain abdomen. Mental confusion and other neurological signs, even coma may be present. Occasionally, renal failure and hematuria may be seen.

Investigations:

• WBC—lymphopenia without marked leukocytosis.
• Chest X-ray—usually shows lobar and then multilobar shadowing. A small pleural effusion may be present. Cavitation is rare
• Hyponatremia
• Hypoalbuminemia
• High serum aminotransferases, creatine phosphokinase
• Direct immunofluorescent for Legionella in pleural fluid, sputum or bronchial washings. Culture on special media can be done, but takes 3 weeks
• Legionella serology—4 fold rise is highly suggestive
• Urine for antigen (highly specific)
• Urine R/E shows hematuria.

Treatment:

• Clarithromycin 500 mg twice daily orally or IV or
  • Erythromycin 500 mg 6 hourly orally or IV for 7 to 10 days
• Rifampicin 600 mg 12 hourly.

Prognosis: 10% mortality (may be up to 30% in elderly).

* Long Cases in Clinical Medicine, ABM Abdullah Page: 130