Week 8: Respiratory Flashcards
Symptoms of SARS-CoV2
Most Common:
* fever
* cough
* tiredness
* loss of taste or smell
Less Common
* sore throat headache
* aches and pains diarrhoea
* a rash on skin, or discolouration of fingers or toes red or irritated eyes
Serious Symptoms
difficulty breathing or shortness of breath loss of speech or mobility, or confusion chest pain
Phase I of SARS-CoV2 infection
Infection of epithelial cells
Virus spreading in the respiratory and gastrointestinal tracts,
Early innate immune response (e.g. macrophages and monocytes)
Detection of PAMPs related to SARS-COV2 and activation of PRRs Release of cytokines at local levels
Clinically mild symptoms
Phase II of SARS-CoV2 infection
Virus infection leads to cytokine responses
Cytokines production results in influx of various immune cells such as macrophages, neutrophils, and T cells from the circulation into the site of infection
Destructive effects on human tissue resulting from: destabilization of endothelial cell to cell interactions,
damage of vascular barrier,
capillary damage,
diffuse alveolar damage (rapidly progresses to ARDS)
Continuous virus replication and excessive production of cytokines Inflammatory PCD and positive feedback loop resulting in a cytokine storm. Life-threatening damage to host tissues and organs
Covid attached to what cell receptors
Primary receptor: ACE2 (Angiotensin-converting enzyme 2) Role: virus attachment to host cell
Co-receptor: TMPRSS2 (A serine protease)
Role: facilitate fusion of virus particle with the host cell
SARS-CoV2 stages of replication
- Attachment: ACE2
- Entry
Surface fusion: mediated by TMPRSS2 Endocytosis: mediated by ACE2 - Release of genome
- mRNA & proteins (including RdRp)
- Genome replication
- Assembly of NC (helical)
- Packaging of genome
- Released
(budding into ER and exocytosis)
Acute respiratory distress syndrome
a serious lung condition characterised by structural changes in alveolus including fluid builds up and surfactant breaks down.
These physiological changes affect lungs functions and consequently lead to reduced oxygen levels.
Symptom of ARDS:
shortness of breath.
low blood oxygen,
rapid breathing,
rattling sounds in the lungs when breathing.
SARS-CoV2 - Risk factors
certain treatments ( eg chemotherapy/immunotherapy)
particular illnesses and conditions
Age, especially if you are over 70 years old
environment smoking
being pregnant being male.
Treatments and prevention for covid
Prevention:
- Vaccination: Primary and booster doses for immunity.
- Public Health Measures: Masking, hand hygiene, social distancing, and good ventilation.
- Testing & Contact Tracing: Rapid tests, PCR, isolation, and quarantine.
- Public Awareness: Education on symptoms and preventive actions.
Treatment:
- Supportive Care: Symptom relief, oxygen therapy for hypoxemia.
- Antivirals: Remdesivir, Paxlovid, Molnupiravir for early high-risk cases.
- Monoclonal Antibodies: For high-risk patients to prevent severe illness.
- Corticosteroids: Dexamethasone for severe cases needing oxygen.
- **Anti-inflammatory Agents: **Tocilizumab, Baricitinib for severe inflammation.
- Complication Management: Anticoagulants, ventilatory support, post-COVID rehabilitation.
Aetiological Classifications of Pneumonia
- Bacterial
- Viral
- Aspiration - foreign material eg gastric compounds
- Atypical - caused by atypical pathogens like Mycoplasma or Chlamydia
- Opportunistic - occurring in individuals with weakened immune systems, caused by pathogens not typically harmful to healthy individuals.
Acquisition-based Classifications of Pneumonia
- Community acquired - Pneumonia acquired outside of healthcare settings, often caused by common bacteria or viruses.
- Healthcare acquired- Pneumonia that develops during or after hospitalisation or other healthcare interventions, often involving drug-resistant bacteria.
- Ventilator associated - Pneumonia developing in patients on mechanical ventilation, often due to hospital- acquired infections.
Clinical features of Pneumonia
- Productive cough
- Dyspnoea
- Pluertic chest pain (worsened by deep brething/coughing)
- Hypoxia
- Dullness to percussion
- Decreased breathing sounds
- Bronchial Breathing
- Coarse Crackles
Pathophysiology of community acquired pneumonia
- underlying agent (eg virus/bacteria)
- colonisation of nasopharynx
- micro aspiration
- programmed cell death
- release of pro-inflmatory cytokines
- systemic inflamatory response
- end organ and systemic inflammatory associated damage
Pneumonia complications
- Sepsis
- Lung abscess
- Resp failure
- Kidney failure
- Neurological effects
Pneumonia Severity parameters
S ystolic Blood pressure. (over 90)
M ultilobar CXR involvement
A lbumin over 3.5g/dl
R esp rate over 30 or over 25 if over 50 y/o
T achycardia over 125bpm
C onfusion
O oxygen saturation (2pts)
P h under 7.35
High risk pr needing IRVS = 5-6 points
7+ points = very high risk
Diagnosis of Pneumonia Tests
- CBC High WBC
- EUCA Impact on renal function
- Viral Swab
- Sputum MCS
- CXR consolidatoon and parapneumonic effusion/empyema
- Bronchoscopy
role of bronchoscopy in the investigation of pulmonary infection
- Bronchoscopy describes the use of a flexible camera and attached suction device to ‘suck out’ mucous from the lungs.
- The bronchoscope enters via the oral or nasal cavity and enters the lung through navigation via an attached camera.
- Sputum MCS and viral PCR are the first line investigations, however, so most patients will not require bronchoscopy upon suspected pneumonia diagnosis.
CF Clasifications
