Investigations - respiratory Flashcards
What conditions are FEV1/FVC ratio impaired in?
Obstructive lung disease
Why is there normal FEV1/FVC ratio in restricitve lung disease?
Equal impairment of each
What is BNP
Brain Natiuretic peptide - hormone secreted by myocardium in response to wall stress eg pressure overload. Normally only small levels.
When do you test BNP
Testing for heart failure when patient presents with SOB, fatigue and pneumonia
What is NIV
Non invasive ventilation eg CPAP
What does CPAP do
VENTURI mask
What does PERC do?
Rules out the possibility of a PE with no criteria prior and a chance of <15%
Criteria for PERC
Age over 50
HR over 100
O2 less than 95% oRA
Unilateral leg swell
Haemoptysis
Recent surgery or trauma
Prior PE or DVT
Hormone use
If anyone of above is positive, cannot rule out PE
What is an sPESI?
simplified PE severtiy index
Groups patients into low or high rusk groups for mortality based on clinical parameters for PE within 30 days
What sPESI score predicts high risk mortality?
1 or more = high risk adverse outcomes next 30 days
What does Wells score test?
Risk of developing DVT
What is WELLS score used for?
Whether to have CTPA to investigate for PE
Criteria for Wells
Active cancer, or cancer that’s been treated within last six months 1
Paralyzed leg 1
Recently bedridden for more than three days or had major surgery within last four weeks 1
Tenderness near a deep vein 1
Swollen leg 1
Swollen calf with diameter that’s more than 3 centimeters larger than the other calf’s 1
Pitting edema in one leg 1
Large veins in your legs that aren’t varicose veins 1
Previously diagnosed with DVT 1
Other diagnosis more likely
Criteria sPESI
Age, years >80
History of cancer
History of chronic cardiopulmonary disease
Heart rate, bpm ≥110
Systolic BP, mmHg <100
O₂ saturation
Gold/yellow top bloods
Kidney function - U+Es
HcG
Troponin
CRP
LFTs
Bone Profile
Thyroid function
when is someone unsuitable for spirometry
- Recent surgery eg opthalmology/abdominal/thoracic
- Recent cardiac arrest
- haemoptysis
- Vomiting
- TB
- AAA - if aneurysm >6cm - relaxed VC if required for surgery
- Pneumothroax
- Caution with cough syncope
- Confusion, dementia
What should be avoided pre spirometry
SABA - 4 hours
LABA - 12 hoours
SA anticholinergics - 6 hours
LA anticholinergics - 24 hours
Performing vigorous exercise 30 mins
Smoking 24 hours
Wear tight fit clothing
Alcohol - 4 hours
Eating substantial meal 2 hours
Relaxed as possible, seated 5-10 mins before
What are normal spirometry values?
FEV >80%
FVC >80%
FEV1/FVC - 70-80%
Hallmarks of obstruction
- Reduced FEV1/FVC ratio
- Reduced FEV1
- Increased exhalation time
- ate or no plateu on volume time curve
Hallmarks of restrictions
- Reduced FVC
- Normal or elevated ratio
- Reduced exhalation time
- Early plateu on volume time curve
Extrapulmonary causes of restrvitive disease
- Kyphoscoliosis
- Ankylosing spndylitis
- Lung volume reduction surgery
- Muscle weakness
Intrapulmonary causes of restrictive lung disease
- Pulomonary fibrosis
- Sarcoidosis
- Asbestosis
- Fibrosing alveolitis
What is peak flow a measure of?
- Measure of how FAST air out of lungs
- Large AW claibre measure
What normal values depend on in peak flow?
- Age
- Height
- Weight
Normally over 20%
What sort of conditions cause reduced PEFR?
OBSTRUCTIVE
Asthma, COPD, tumour
What use spirometry measure?
- Registers AMOUNT of air exhaled or inhaled
- RATE at which aire goes in and out lungs
- Forceful and complete exhalation after maximal inhalation
- FEV1/FVC/Ratio/trace itself