Pneumonia Flashcards
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Pneumonia: What is it?
Pneumonia= inflammation of the lung alveoli. Usually due to pathogenic infection, usually bacterial, but can also be due to aspiration, chemical inhalation, or radiation. A lower respiratory tract infection (LRTI)
It is a lower respiratory tract, along with acute bronchitis
Pneumonia: Classification
Pneumonia can be classified based on where the infection was acquired:
- Community-acquired pneumonia(CAP) develops in the community
- Hospital-acquired pneumonia(HAP) develops aftermore than 48 hoursin a hospital
- Ventilator-acquired pneumonia(VAP) develops inintubatedpatients in ICU
- Aspiration pneumoniadevelops due to the aspiration of food or fluids, usually in patients with impaired swallowing (e.g., following a stroke or advanced dementia, oesophageal obstruction or reflux of gastric contents).
- right lower lobe consolidation
- itu, ng tube risk factors
Pneumonia: Aetiology
The top causes of typical bacterial pneumonia are:
- Streptococcus pneumoniae(most common in CAP). cold sores.
- Haemophilus influenzae - Often seen in patients with COPD.
Other bacterial causes include:
-Staphylococcus aureusin patients with cystic fibrosis. Common in post-influenza and hospital settings. cavitating lesions
- Pseudomonas aeruginosain patients with cystic fibrosis or bronchiectasis or immunocompromised states.
- Methicillin-resistantStaphylococcus aureus(MRSA) in hospital-acquired infections
- Klebsiella pneumoniae:Common in alcoholics and those with impaired swallowing.
Viral Pneumonia
- Influenza Virus:Most common viral aetiology.
- Respiratory Syncytial Virus (RSV):Common in infants and elderly.
- Covid-19virus**(SARS-CoV-2): The symptoms vary enormously but can include Anosmia (loss of smell) and silent hypoxia, where patients may not feel particularly short of breath despite havinglow oxygen saturations.
- Covid-19 pneumonia is treated with respiratory support (e.g., oxygen), dexamethasone and monoclonal antibodies. Prevented with vaccination.
Fungal Pneumonia
- Fungi such as Pneumocystis jirovecii, Histoplasma capsulatum, Cryptococcus neoformans, and Aspergillus spp.
- Pneumocystis jiroveciipneumonia (PCP), afungal pneumonia, occurs inimmunocompromisedpatients. Patients with poorly controlledHIVand alow CD4 count<200/mm3 are particularly at risk.
- It usually presents subtly withdry cough(without sputum),shortness of breath on exertionandnight sweats.Co-trimoxazole(trimethoprim/sulfamethoxazole) treats PCP (brand nameSeptrin).
- Patients with a low CD4 count are prescribedprophylacticco-trimoxazoleto protect againstPCP.
Pneumonia: Risk Factors
Risk Factors are associated with increased susceptibilty to (bacterial) infection or aspiration:
- less than 5yrs or over 65yrs
- smoking, alcohol, IV drug users
- recent pathogenic airway infection
- respiratory co-morbidites ie. chronic respiratory disease (eg. COPD, cystic fibrossis)
- non-respiratory co-morbidities (eg. diabetes, CVD)
- immunocompromised (eg. cytotoxic drugs and HIV)
- at risk of aspiration (eg. neurological diseases, oesophageal obstruction, GORD)
- chemicals and radiation
legions of psittaci MCQs:
- inhalation of infected water from infected water systems (air conditioning in cheap hotels). deranged LFTs. hyponatraemia, headache and dry cough.
- infected birds and animals
Pneumonia: Symptoms
- Dysponea
- Wheeze (rare but seen in children)
- Cough with sputum or blood
- Pleuritic Chest pain
- Confusion - sepsis
- Fever, fatigue, myalgia, malaise
- Anorexia and weight loss - severe disease
- Night sweats
- Erythema multiforme (pink ring rash with pale centre)
Pneumonia: Examination Signs
- Tachyponea, tachycardia
- bronchial (harsh) breath sounds
- focal coarse crackles
- dullness to percussion
Signs of sepsis:
* tachyponea, tachycardia, hypoxia, hypotension (shock), fever, confusion
Pneumonia: Investigations (CURB-65)
CRB-65/CURB-65 score in primary/secondary care, respectively, to predict mortality risk and decide management:
- C–Confusion (new disorientation in person, place or time) - AMTS <= 8/10
- U–Urea > 7 mmol/L
- R–Respiratory rate ≥ 30
- B–Blood pressure (low) < 90 systolic or ≤ 60 diastolic.
- 65– Age ≥65
- Score 0/1: Consider treatment at home
- Score ≥ 2: Consider hospital admission
- Score ≥ 3: Consider intensive care + sepsis 6/urgen hospital admission (CRB65)
Pneumonia: Investigations
- FBC, CRP, U+Es (CURB-65 and AKI), LFTs, Blood culture, Urine culture/PneumococcalandLegionella urinary antigen tests, Sputum culture
- CRP level can be used as apoint-of-caretest in primary care settings to help guide the use of antibiotics:
- CRP < 20 mg/L - do not routinely offer antibiotic therapy
- CRP 20 - 100 mg/L - consider a delayed antibiotic prescription
- CRP > 100 mg/L - offer antibiotic therapy
- CRP level can be used as apoint-of-caretest in primary care settings to help guide the use of antibiotics:
- Sepsis 6 (if suspected): blood culture, lactate, urine output. Give high-flow oxygen, IV fluids, IV antibiotics
- Chest X-ray
typically shows consolidation (opacity on the X-ray film) in the area of infection
may also show effusion
Pneumonia: Mangement
Follow yourlocal area guidelines, which are specific to local antibiotic resistance:
- Mild CAPis typically treated with 5 days of oral antibiotics:
- Amoxicillin (first-line)
- Doxycycline (penicillin allergy or atypical pathogens), Clarithromycin (atypical pneumonia), erythromyocin (pregnant)
- Moderate or severe pneumoniais usually treated initially withintravenous antibioticsand stepped down to oral antibiotics as the condition improves.Respiratory support(e.g., oxygen or intubation and ventilation) is also used.
- moderate CAP: dual antibiotic therapy is recommended with IV amoxicillin and a macrolide (clarithromyocin). 7-10 day course
- severe CAP: beta-lactamase stable penicillin such as co-amoxiclav, ceftriaxone or piperacillin with tazobactam and a macrolide (clarithromyocin)
- a 7-10 day course is recommended
Flucloxacillin is given in addition to amoxicillin for a CAP where staphylococcal infection is suspected e.g. following recent influenza infection.
co-amoxiclav as first-line in non-penicillin allergic patients who have been in hospital for 3-5 days (HAP)
COPD - corticosteroids
Pneumocystis jiroveci penumonia is treated with co-trimoxazole, which is a mix of trimethoprim and sulfamethoxazole.
all patients with a CD4 count < 200/mm³ should receive PCP prophylaxis with co-trimoxazole
All patients with HIV require highly active anti-retroviral therapy (HAART) at the time of diagnosis.
Discharge criteria and advice post-discharge NICE
- Patients can only be discharged 24hours AFTER they have presented with 2 or more of the following findings:
- temperature higher than 37.5°C (delay discharge if found alone)
- respiratory rate >/= 24 bpm
- heart rate over 100 bpm
- low systolic blood pressure </= 90 mmHg
- oxygen saturation under 90% on room air
- abnormal mental status
- inability to eat without assistance.
- repeat CXR in 6 weeks
- Give to patients to describe how quickly their symptoms should symptoms should resolve:
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Pneumonia: Complications
- Acute Respiratory Distress Syndrome (ARDS): A severe form of acute lung injury characterized by diffuse alveolar damage, increased capillary permeability, and non-cardiogenic pulmonary oedema. Caused by conditions that damage lung tissue ie. sepsis, pneumonia etc. ARDS can lead to respiratory failure, requiring mechanical ventilation and intensive care management.
- Pleural effusion: Accumulation of fluid in the pleural space, which can be classified as exudative (due to increased capillary permeability) or transudative (due to increased hydrostatic pressure or decreased oncotic pressure).
- Lung abscess: A localized collection of pus within the lung parenchyma, usually caused by aspiration of oropharyngeal contents or secondary bacterial infection. Treatment often involves antibiotics and, in some cases, surgical drainage or percutaneous catheter placement.
- Empyema: A complicated pleural effusion characterized by the presence of pus in the pleural space, typically resulting from bacterial pneumonia. This condition requires more aggressive management, such as chest tube drainage or surgical intervention.
- Pneumothorax: Accumulation of air in the pleural space, which can result from rupture of a pneumonic cavity or pleural bleb. Pneumothorax may lead to partial or complete lung collapse, with small pneumothoraces potentially resolving spontaneously, while larger or tension pneumothoraces requiring immediate intervention, such as needle decompression or chest tube placement.
- Bacteremia and sepsis: Dissemination of the infectious agent into the bloodstream, which may lead to systemic inflammatory response syndrome (SIRS) and septic shock, characterized by hypotension, organ dysfunction, and potentially, multi-organ failure.
- Metastatic infections: Hematogenous spread of the infection to distant sites, such as endocarditis, meningitis, septic arthritis, or osteomyelitis. These complications often require prolonged antimicrobial therapy and, in some cases, surgical intervention.
- Pericarditis: Inflammation of the pericardium, which can result from the direct extension of pneumonia or hematogenous spread. Pericarditis may lead to pericardial effusion, cardiac tamponade, and constrictive pericarditis, all of which can cause hemodynamic compromise.
- Acute kidney injury (AKI): Can result from sepsis, hypovolemia, or drug-induced nephrotoxicity. AKI may necessitate renal replacement therapy in severe cases.
mycoplasma pneumonia
