Respiratory Flashcards
Patient’s ABG shows high C02 but normal pH, do they have chronic or acute hypercapnia?
Chronic- as compensatory mechanisms are being utilised.
Indicates 02 sats should be aimed at 88-92%
What colour are Venturi masks delivering 24-28% O2?
Blue- 24%
White- 28%
Which type of O2 mask should not be used if patient is requiring less than 5L of 02?
Face mask, at low flow rates = more C02 rebreathing
A patient is known COPD, so 02 sats of 88-92% are aimed for with venturi mask. What would prompt you to start aiming treatment to 94-98%?
ABG shows low PaC02 (under 6)
Unless they have a PMH of needing NIV or IPPV.
If over 6, suggests hypercapnia- keep on lower sats.
If acidic pH <35 consider NIV.
Accessory muscle usage suggests what 3 things?
Small airway disease- asthma or COPD
Pneumothorax
Pleural effusion
3 respiratory causes of central cyanosis:
- Cor pulmonale
- Idiopathic fibrosis
- Bronchiectasis
Causes of lymphadenopathy in the respiratory exam:
Carcinoma
TB
Lymphoma
Sarcoidosis
Which muscles are the accessory muscules used in respiratory distress?
From front to back- sternocleidomastoid, scalene, trapezius
Causes of stridor:
Heard on inspiration, partial obstruction of upper aiways + larynx
Children- Pertussis, Croup, Epiglottitis
Adults- extubation, vocal cord paralysis, airway foreign body
What is the normal cricosternal angle height and cause of a shortened one?
3cm- shortened when chest is hyperexpanded in COPD
5 causes of reduced chest expansion:
External aspects restricting expansion:
- Effusion
- Consolidation
- Pneumothorax
Parenchymal aspects restricting:
- Fibrosis
- Collapse
Cause of dullness on percussion
Increased solid matter: Consolidation Effusion Pleural thickening Raised hemidiaphragm
Lack of air entry:
Pneumonectomy, lobectomy (fluid and great vessels move to fill the space)
How do you differentiate an exudate from a transudate?
Light’s criteria: helpful when fluid protein is 25-35g/L
Pleural:serum protein ratio >0.5 (exudate)
Pleural:serum LDH ratio >0.6 (exudate)
Or pleural LDH 2/3s upper limit of normal serum LDH
Causes of bronchiectasis:
Conned by the Postman, had a Measley Tustle, but I Pneu he was TB Obstructive Over this + Underhand:
Congenital (CF, Kartagener’s, primary ciliary dyskinesia)
Post-infection (Measles, Pertussis, Pneumonia, TB)
Bronchial obstruction (tumour, foreign body)
Overactive immune (RA, UC, APBA)
Underactive immune (hypogammaglobulinaemia)
Lung complications of rheumatoid arthritis:
Fibrosing alveolitis (due to RA or secondary to methotrexate)
Pleural effusion
Bronchiectasis
Obliterative bronchiolitis (inflamed small airways- terminal)
Causes of Apical fibrosis (BREASTS-X)
Berylliosis (beryllium metal allergic response)
Radiation
Extrinsic allergic alveolitis (organic allergens- dust, mushroom, sugar)
Ank spond (HLA B27)
Sarcoidosis
TB
Silicosis
Histiocytosis X (granulomas of dendritic cells
Causes of basal fibrosis of lung:
RAAID
Rheumatoid arthritis Autoimmune disease Asbestosis Idiopathic pulmonary fibrosis Drugs- amiodarone, nitrofurantoin, methoxtrexate, crystal meth)
Commonest cause of interstitial lung disease?
Idiopathic pulmonary fibrosis
What causes early inspiratory crackles?
Asthma + COPD
What causes mid/end expiratory crackles?
‘Fine’
Mid- bronchiectasis
End- pulmonary oedema, pneumonia, fibrosis
Causes of bronchial breathing:
Increased solids:
Consolidation
Fibrosis
Which connective tissue diseases are associated with interstitial lung disease (pulmonary fibrosis)?
RUTSSS:
Rheumatoid arthritis Ulcerative colitis Thyroid (autoimmune) SLE Systemic sclerosis Sjogrëns
Drug causes of fibrosis:
Methotrexate (rheum)
Amiodarone (anti-arrhythmic)
Nitrofurantoin (UTIs)
What are the 4 diagnostic criteria for a diagnosis of ARDS?
Acute injury or systemic condition = release of inflammatory mediators + ^ capillary permeability = non-cardiogenic pulmonary oedema
ARDS: Acute onset Refractory hypoxaemia Diffuse bilateral infiltrates on CXR Small pulmonary capillary wedge pressure <19mmHg (or no CCF clinically)- a high pressure would suggest cardiac failure and blood backing up was the cause instead