Week 2 Flashcards
What is the aim of lung function tests
assess the effectiveness of lung function to meet metabolic demands of the body’s tissues
- ventilation
- pulmonary blood flow
- diffusion
- control of ventilation
What is spirometry
a physiological test of lung function, assessing the mechanical properties of the pulmonary system
- timed measurement of how the lungs work and is used to
- measure how effectively air moves into and out of the lungs : how fast it flows and how much volume
–provides measure of airway size, lung size and muscle strength
Uncomplicated, non invasive investigation
affordable, portable equipment
minimal training required to perform
most broadly used test
**important test to detect, quantify and monitor diseases that limit ventilator capacity
What is COPD
Chronic Obstructive Pulmonary Disease
Indications for spirometry (8)
screening, detecting and assessing for respiratory disease
Assessing respiratory function
differentiating respiratory and cardiac diseases as the cause of breathlessness
diagnosing respiratory diseases - obstructive vs restrictive
Assessing the severity of disease
Assessing the response to treatment
Assessing pre-operative risk
Occupational health related assessments
Complications of spirometry
Requires maximal effort and subject cooperation -Transient breathlessness oxygen desaturation syncope chest pain cough light-headedness bronchospasm
Contra-indications of spirometry
High positive intr-thoracic pressure and its transmission to vascular, abdominal and other body parts may be detrimental = best to delay spirometry
Recent eye surgery (1-4wks) or recent brain surgery(3-6wks)
Recent thoracic and abdominal surgery (in last 7 days)
Aneurysms (cerebral or abdominal)
Recent CVAs
Unstable cardiac function / angina or recent myocardial infarction in past 7 days
uncontrolled hypertension
haemoptysis of unknown cause
Pneumonthorax in last 3 weeks
Nausea, vomiting or diarrhoea
Untreated pulmonary embolism
What can cause an inaccurate result
Chest or abdominal pain pain in mouth or face stress incontinence dementia recent alcohol consumption
Patient related problems with spirometry
variable or submaximal effort insufficient inspiration or expiration leaks between the lips and mouthpiece slow or hesitation at the start of the test cough particularly within the 1 sec glottis closure tongue blocking mouth piece
Repeatability criteria for spirometry
to ensure that the tests are producing reliable and consistent results
these criteria determine when more than 3 manoeuvres are required to achieve an accurate result
- the difference between the best FEV1 and the second best FEV1 must be within 0.15L
- -if FEV is
Acceptability Criteria for spirometry
•Used to determine that the patient has performed the test manoeuvre correctly
•Criteria required to be met:
–Test begins from full inspiration (start of test)
-Rapid start of test (start of test)
–Continuous maximal expiratory flow (end of test)
–Expiration time >6 secs (adult) and >3 secs (child) or no change in volume for at least 1 sec (end of test)
–No obstruction, hesitation or artefact impeding the blow (end of test)
On x-ray signs of a pneumothorax
- visible lung edge - sharply outlined diaphragm
- loss of lung parenchyma markings within the lung fields
Pneumothorax is
A pneumothorax involves damage to the lung tissue and pleura so that air accumulates within the pleural space.
Presenting complaints of a pneumothorax
- pleuritic chest pain
- dyspnea – decreased breath sounds on affected side
- tachypnoea
- tachycardia
- low O2 sats (not necessary in all cases)
- history of recent chest wall injury (not necessary in all cases)
- previous history of spontaneous pneumothorax (not necessary all cases)
- tracheal deviation (late sign).
Haemothorax is
A haemothorax involves damage to the lung tissue and pleura so that fluid (i.e. blood) accumulates within the pleural space.
On x-ray signs of haemothorax
On an upright x-ray, a haemothorax may present with a visible fluid level. aka. Air-fluid level
–No mensicus sign
Although the cause of a pleural effusion is quite different to a haemothorax, radiologically they are similar in appearance.
On x-ray signs of Pleural Effusion
–Fluid collects in pleural cavity
–Collects in the costophrenic angles
–“Mensicus sign”
Acid-Base balance Equation
H2O + CO2 = H2CO3 = H+ + HCO3-
Hyperventilation signs and symptoms
•Low PaCO2
•Rise in pH
•Symptoms
–Tingling around the mouth and extremities
–Light‐headedness
–Syncope
•Secondary hyperventilation occurs in Metabolic Acidosis
Clinical signs of hypercapnia
- Confusion
- Flapping tremor
- Warm extremities
- Drowsiness
- Bounding pulse
- Headache
- Flushed skin
- Coma
Clinical Signs of Hypoxaemia
- Restlessness
- Confusion
- Aggression
- Sweating
- Fittng or convulsions
- Plucking
- Increased RR, HR and BP
- ECG changes
- Blurred vision, tunnel vision
- Pallor
Type 2 Respiratory Impairment
•High PaCO2 (>50mmHg)
•Usually low PaO2
•Due to inadequate alveolar ventilation
•Type 1 Respiratory Impairment – can lead to Type 2
•Treatment
•Improve ventilation
•SaO2
– no help to monitor as doesn’t monitor CO2
Type 1 Respiratory Impairment
•Low PaO2 (
3 Disorders of Gas Exchange
- Hypoxia
- Hypoxeamia
- Impaired oxygenation
Hypoxia is
any state in which tissues receive an
inadequate oxygenation to support normal
aerobic metabolism