Respiratory Flashcards
function of respiratory system
gas exchange between air and bloodstream
moves air in and out of body
filters, warms and humidify incoming air
vocalisation: speech
what does the upper and lower respiratory tract consist of
upper:
- nasal cavity
- pharynx
- larynx
lower:
- trachea
- primary bronchi
- lungs
function of upper airway tract
- hair and mucous membrane trap particles like dust and smoke
- inhaled air is moistened, warmed
- during exhalation the nasal cavity collects and retains the moisture from the air that is leaving the body
function of larynx and epiglottis
- larynx allow the passage of air through the trachea
- with the help of the epiglottis, the larynx prevents food or liquid from entering the lower respiratory tract while swallowing
zones of the lower respiratory tract
conducting zone
- trachea to bronchus
- no gas exchange occurs
- supported by cartilages
respiratory zone
- bronchioles with alveoli
- gas exchange occurs here
what are alveoli
moist, thin walled pockets which are site of gas exchange
slightly oily surfactant prevents the alveoli walls from collapsing and sticking together
what controls ventilation
PaCO2 in the central chemoreceptors
PaO2 and blood pH in peripheral chemoreceptor
define respiratory failure
- when lungs fail to oxygenate the arterial blood adequately or fails to prevent carbon dioxide retention
hypoxemia
- partial pressure of oxygen PO2 <60mmHg, can lead to tissue hypoxia
hypercapnia
- partial pressure of carbon dioxide PCO2 >50mmHg
symptoms of hypoxemia
spectrum of symptoms depending on severity
- mild: impairment of mental performance, diminished visual acuity, tachypnea
- profound:
a. CNS: headache, seizures, somnolence, loss of consciousness
b. CVS: palpitations, chest pains
c. respiratory: SOB
complication of tissue hypoxia
CNS - hypoxic ischemic encephalopathy
myocardium - acute myocardial infarction
renal - acute kidney injury
vascular - vasoconstriction
symptoms of hypercapnia
spectrum of symptoms depend on severity
- restlessness, tremor, slurred speech, asterixis
- headache
- altered mental status, loss of consciousness, comatose state
what is asthma
heterogenous disease, usually characterised by chronic airway inflammation
defined by the history if respiratory symptoms such as wheeze, SOB, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation
risk factor for developing asthma
genetic characteristics
occupation exposures
environmental exposures
symptoms of asthma
- troublesome cough, particularly at night
- awakened by coughing
- coughing or wheezing after physical activity
- breathing problems during particular season
- coughing, wheezing or chest tightness after allergen exposure
- colds that last > 10 days
- relief when medication is used
what is used to diagnose asthma
spirometry - to test lung function
risk factors for adverse outcomes of asthma
- uncontrolled asthma symptoms
- having more than 1 exacerbation in last 12 months
- ever intubated for asthma
- low lung function on spirometry
- incorrect inhaler technique and/or poor adherence
- smoking
- obesity, pregnancy, blood esoinophilia
definition of COPD
common, preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases
risk factors for COPD
- smoking
- genetic reasons
- occupational dust and chemicals
- indoor smoke from wood, coal, cow dungs, crop residues used for cooking
- frequent lung infections as a child
risk factor for lung cancer
- smoking
- radon
- asbestos
- environmental tobacco exposure
- genetics
- other lung disease
- prior radiation
symptoms of lung cancer
related to primary lesion
- cough, SOB, hemoptysis, localised wheeze
related to intrathoracic spread
- pleural, pericardial effusion, SVCO, hoarseness, brachial plexus/ skeletal invasion (chest pain)
related to distant metastasis
- brain, bone, (liver, adrenal), skin
paraneoplastic
principles of management of respiratory failure
- identify: clinical symptoms and signs
- resuscitate/stabilise
- investigate
- treat the cause
symptoms of respiratory failure
respiratory: SOB, wheeze, chest tightness, cough
CNS: light headedness, giddiness, lethargy, headache, anxious, confusion, delirium, seizures
constitutional, manifestation with underlying disorder
what are the asthma management goals
- achieve and maintain control of symptoms
- maintain normal activity levels, including exercise
- maintain pulmonary function as close to normal levels as possible
- prevent asthma exacerbations
- avoid adverse effects from asthma medications
- prevent asthma mortality
2 types of COPD
chronic bronchitis
- inflammation and excess mucus
emphysema
- alveolar membranes break down
systemic manifestation of COPD
- skeletal muscle weakness (cachexia)
- ischemic heart disease
- cardiac failure
- osteoporosis
- diabetes metabolic syndrome
- normocytic anaemia
- depression
role of spirometry
- diagnosis
- assessment of severity of airflow obstruction
- follow up assessment
result of spirometry
measures amount of air expired
FEV1/FVC <0.7 indicates obstructive disease
COPD classification
most minimal symptoms - Group A
most severe - Group D
treatment for the different groups of people for COPD
Group A - A bronchodilator
Group B - LABA or LAMA
Group C - LAMA
Group D - LAMA or LAMA+LABA or LABA+ICS
non drug based interventions for COPD
- immunisation
- long term home oxygen
- lung reduction surgery for emphysema
- bronchoscopic directed therapy
- surgical therapy
- rehab
- lung transplant
- palliative
management of COPD
diagnosis -> initial assessment -> initial management -> review adjust
management of acute exacerbation
- assess severity of symptoms, blood gases and chest radiographs
- administer appropriate amount of oxygen
- bronchodilators
- steroids
- consider antibiotics
- consider non invasive mechanical ventilation
- manage comorbidities
diagnosis of lung cancer
imaging:
- chest xray
- CT
- PET scan
definitive diagnosis can be made only by viewing a tissue sample (biopsy) under microscope. obtaining tissue biopsy:
- bronchoscopy
- thorascopy
- mediastinoscopy
- transbronchial needle (open lung) biopsy
- sputum cytology
TNM staging of lung cancer
stage 1: tumour 1-4cm; disease not spread outside the lung
stage 2: tumour 3-7cm; disease may be in the lymph nodes or nearby tissues, but not in distant parts of the body
stage 3: tumour 3 to more than 7cm; disease can be in more than 1 LN, but not in distant parts of body
stage 4: cancer has spread to distant part of body
ways to stage lung cancer
- CT and bone scan
- PET-CT scan
- endobronchial ultrasonography (EBUS)
- mediastinoscopy
- bronchoscopy
- endobronchio ultrasound
- navigation bronchoscopy
- biopsy of pleural fluid
