Respiratory Patho Flashcards
Hypoxia
Definition
Low oxygen at the tissues
Ex. lung disease or systemic disease
Hypoxemia
Definition
Low partial pressure oxygen in blood
PaO2 < 60mmHg
Etiology: Lung
Respiratory Failure
Two types
- Type I - Hypoxemia
- PaO2 low < 60mmHg
- normal or low PaCO2 (compensation , increase RR)
- more common
- Lung etiology - Type II - Hypercapnic
- PaCO2 > 50mmHg
- PaO2 < 60mmHg
- problem with respiratory drive (air trapping)
- not always lung etiology
Acute Respiratory Distress (ARD) Syndrome
Definition
Life threatening
Inflammation systemic –> inflammation alveoli –> destruction alveolar membrane, inflammation (vascular permeability, edema) –> decrease air exchange (CO2 and O2)
*Cannot eliminate CO2
*Cannot inhale O2
Community Aquired Pneumonia
CAP
Etiology
Most common cause is viral –> bacterial
Viruses
- Influenza
- RSV
- COVID
- rhinovirus
- metpneumovirus
Bacterial
- Most common
- Streptococcus pneumoniae (+), Chlamydia pneumoniae (atypical), Mycobacterium pnuemoniae (atypical)
- Others:
- Legionella (atypical)
- STaphylococcus aureus (+)
- hemophilus influenzae B (-)
- Moraxella catarrhalis (-)
Types of Pneumoniae
- viral
- bacterial
- Fungal
- aspiration pneumoniae
Pathophysiology
Pnuemoniae
Inhalation/infection pathogen
- upper airway
- evade primary defense
1. IgA mucous
2. cilia
3. coughing
infection lower airway and alveoli
- replication
- toxin production -> damage alveoli membrane/epithelium -> immune response
- macrophage phagocytize -> activation complement, neutrophils, adaptive immune response
- pro-inflammatory mediators (TNF alpha, IL, IFN gamma, ROS) damage epithelium
Damaged epithelium
- inflammation
- vascular permeability, edema
- increased blood flow, increased WBC, increase inflammation
Pulmonary edema -> exudate -> impaired gas exchange
- ARDs
- death
- Type I hypoxemic respiratoyr failrue (decrease PaO2, normal/low PaCO2 initially –> high PaCO2
Community acquired pneumonia
Labs, Diagnostic Imaging, Blood Work
Gold standard: Xray
- Anterior/posterior and lateral
- heart blocks LLL
- consolidation
Clinical signs and symptoms
- dry cough
- dyspnea
- +- fever
- fatigue
- tachycardia
- decreased SpO2
CURB65 Score
- Confusion (Ox3)
- Uremia (BUN > 20)
- RR (> 30)
- Blood pressure < 90/60
*3 hospital
*2 secondary care
*1 home
CAP
Treatment
*Low risk case
Pathogens:
S. pneumoniae +
mycoplasm
chlamydia (atypical)
First line:
Amoxicillin TID for 7-10 days
Second line:
macrolide antibiotics (azithromycin, clarithromycin) (atypicals)
doxycycline (MRSA +-)
CAP Treatment
Comorbidities, LTC or Abx last 30 days
DUAL ANTIBIOTIC TREATMENT
amoxicillin/cef + Macrolide/doxycycline
*clavulanate is required for anaerobic coverage
Pathogens:
S. pneumonia
mycoplasm
chlamydia
H. influenzae -
First line: (amoxicillin/Cef + macrolide/doxycycline)
Amoxicillin
Amoxicillin with clavulanate
Cefuroxime
Cefprozil
doxycycline
azithromycin
clarithromycin
CAP Treatment
Aspiration
Polymicrobial
Amoxicillin/Clavulanate + Clindamycin/Doxycycline?
*anaerobic coverage is required for aspiration
addition of clavulanate is required
CAP resistant to treatment
Fluroquinolones
Gram + / - and pseudomonas
*recent antibiotics
*allergies
* resistance
Comorbidities with CAP needing dual antibiotic treatment
heart, lung, liver, kidney disease
DM
alcoholism
malignancies
asplenia
immunosupression
> 65 years of age
COVID 19 Virus
Definition
SAR-COV-2
severe acute respiratory syndrome
corona virus 2
aerosol, droplet/contact
most contagious 7-10 days
highest viral load
most likely detection NAAT and RAT
COVID 19 virus
infection pathophysiology
S Spike protein
binds host cell ACE 2 receptors
ACE 2 located on
- heart, kidney, lungs, GI, blood vessels, liver
Transmembrane serine protease II
- cleavage S protein
- invasion host cell
- replication and inflammation response
Complications
- heart myocarditis, arrhythmias
- AKI
- clotting disorders etc.
Covid 19
Clinical signs and sypmtoms
dyspnea
fever
fatigue
dry cough
loss of taste and smell
rhinorrhea
N/V/D
Labs and imaging
COVID19
RAAT and NAT
- positive likely in first 7 days
Blood work
- INR, PTT high, D dimers high, low platelets (clotting)
- ESR, CRP high
- GFR low
X ray
- glass oppacities, lower lobe infilrates, constilation
Management COVID 19
- NSAIDS, tylenol, fluids, rest
- Antivirals
- paxlovid
- remdesivir
Paxlovid
MOA
Paxlovid =
Nirmatrelvir + Rotinavir
Nirmatrelvir
- protease inhibitor
- blocks COVID19 protease
Rotinavir
- protease inhibitor
- blocks digestion of Nirmatrelvir
- keeps it in body longer
Paxlovid
Indications
mild to moderate COVID19
High risk populations
- heart, liver, kidney, GI, blood vessel disorders
- HTN, CAD, HF, kidney disease
- Intellectual deficit
- lung diseases, CF, CP etc
- Sickle cell
- Diabetes
- Obesity
- liver disease…
Paxlovid
SE
Nirmatrelvir + Ritonavir
CYP3A4 inhibitor
- cannot take home medications
- clopidogrel (risk of blood clots)
- amiodarone (risk of arrythmmia fatal) etc.
- statins
Reboudn COVID19
- cannot use antiviral again
Remdesivir
Indication
Unable to take Paxlovid
mild-moderate infection with complication riskR
Remdesivir
Route
Subcutaneous injection
duration: three days
Remdesivir
MOA
inhibits COVID19 RNA polymerase
Nucleotide analog
stops the RNA replication
Patient Education
Vaccination COVID19
every 6 months
prevents hospitalization, severe illness, death
*no seasonal variation with COVID19
RSV
Pathophysilogy
Respiratory syncytial virus
- negative sense RNA virus
- infections brochiole epithelial cells
- makes synsytials (multi-nucleated merged cells)
- RSV A and RSV B
- have antigens 1. RSV-F (fushion protein, the same, vaccination) 2. RSV-G (attachment protein, variable)
- Trigger IgA and IgG antiboties
- antibody dependent cell mediated toxicity
- NK and inflammation of lungs
RSV Clinical signs and symptoms
Similar to common cold
very infectious, droplet/contact
- fever
- fatigue
- myalgias
- HA
- sore throat
- rhinorrhea
- dypsnea
- wheezing
- coughing
- sputum
RSV
incidence, prevalence
infectious
> 65 years 22%
< 5 years 70%
Deaths
> 65 years 85%
< 5 years 3%
Vaccination group
> 60 years
AREXVY vaccine
RSV-Fusion antigen
seasonal vaccination
wait 14 days between RSV vaccine and flu vaccine
Atelectasis
Collapse of alveolar airways
- External pressure
- pressure outside of the alveoli
- ex. tumours, fluid volume overload (blood), air (pneumothorax), bowel obstructions - Internal absorption (plug)
- plugged airway (ex. tumour, foreign body, mucus)
- air is absorbed into the capillaries
- collapses the airway
Treatment
Atelectasis
Prevention
- walking
- turning
- coughing
- deep breathing
Pulmonary Edema
Fluid in the interstitial spaces -> alveoli
- Cardiogenic pulmonary edema
- most common type
- LV unable to pump
- increase pressure in pulmonary circulation
- hydrostatic pressure pushes fluid out
- interstitial space -> alveolar space -> decrease gas exchange - Non-Cardiogenic pulmonary edema
- inflammation triggered by infection/toxin/drug
- inflammation epithelium, endothelium
- vascular permeability, edema
- impaired gas exchange
Pulmonary embolism
Clinical Signs and Symptoms
Depends on degree of obstruction
mild
- dyspnea
- tachcycardia, palpitations
- anxiety
- pleuritic chest pain (sharp, increase when bend over)
moderate/Severe
- MASSIVE PE = > 50% perfusion blocked
- decrease LV blood
- decrease CO -> hypotensive shock
- dilation RV (thin wall)
- systemic venous pressure increases (back up into venous system)
- syncope
- hypotension
- hemoptysis (infarct)
treatment
Anti-coagulation therapy
3-6 monts
