IV Sedation I Flashcards
What is sedation?
Range extending from normal alert consciousness to complete unresponsiveness
What is conscious sedation?
Technique using drug/ drugs to provide depression of CNS enabling treatment to be carried out, verbal communication maintained
How is responsiveness, airway, ventilation and CV system affected in minimal sedation?
Responsiveness: normal
Airway: unaffected
Ventilation: unaffected
CV: unaffected
How is responsiveness, airway, ventilation and CV system affected in moderate sedation?
Responsiveness: response to verbal/ tactile stimulation
Airway: maintained w/o intervention
Ventilation: adequate
CV: maintained
How is responsiveness, airway, ventilation and CV system affected in deep sedation?
Responsiveness: to repeated or painful stimulation
Airway: intervention may be required
Ventilation: inadequate
CV: maintained
How is responsiveness, airway, ventilation and CV system affected in GA?
Responsiveness: unrousable
Airway: intervention
Ventilation: inadequate
CV: impaired
Function of respiratory system?
Ventilate lungs to allows gas exchange - addition of o2 and elimination CO2
5 steps of ventilation?
- ventilation - gas in and out lungs
- diffusion - gas from lungs o blood
- transport - to/ from cells
- diffusion - gas blood to lungs
- oxidation - use oxygen too produce energy within cells
What are 2 main parts of ventilation?
Inspiration and expiration
What is inspiration
Active process initiated by diaphragm
What is expiration?
Passive process caused by recoil of lungs
Where does gas exchange occur and why?
Alveolus
Gases diffuse down concentration gradient
How is oxygen transported?
Oxygen binds to haemoglobin which is carried within the red blood cells - released when reaches tissue
How is breathing rate altered?
From [co2] in blood
Detected by peripheral chemoreceptors in aorta and carotid –> cause response central chemoreceptor in medulla
What are basic clinical signs to check respiration?
Respiratory rate
Depth breathing
Pattern breathing
Check cyanosis
What is average respiratory rate?
10-18
What are more advanced ways to check respiration?
Pulse oximetry
What can limit pulse oximeter?
Ambient light
Movement
Cold peripheries
Nail varnish
What is capnography?
Detects CO2 exhaled in Brea via nasal prongs
See is adequate ventilation
Problem w/ capnography?
Requires nose breathing
What are 2 respiratory complications seen in sedation?
Upper airway obstruction
Hypoventilation
How does sedation cause upper airway obstruction?
sedation leads to decreased muscle tone
If pharynx lose tone can collapse, tongue falls against wall of pharynx leading to airway obstruction
What are signs of airway obstruction?
Snoring
Stidor
Drop O2 sat
Management of airway obstruction?
Supplementary oxygen
Basic airway opening manuevers
Airway adjunct
Careful titration sedatives
How can hypoventilation occur in sedation?
Sedative drugs can sedate respiratory centre in brain and reduce recetor sensitivity to CO2 = reduced respiratory rate causing CO2 levels build
Detect hypoventilation?
Monitor respiration rate
Drop O2 sats
Manage hypoventilation?
Reverse sedation (e.g flumazenil) Assist ventilation e.g ambu bag
What is function of CV system?
Deliver oxygenated blood to body organs and tissue
What happens in cardiac ischemia?
Angina which can lead myocardial infarct
What happens in cerebral ischemia?
Faint/ collapse –> stroke
Main determinant of organ perfusion?
Blood pressure
How is blood pressure displayed?
Systolic and diastolic
systolic over diastolic - 120/80
How is blood pressure determined?
cardiac output
systemic vascular resistance
What is cardiac output?
Amount of blood ejected by heart in minute
What is systemic vascular resistance?
resistance produced by vascular system to flow of blood - predominately through small arterioles in body
What is acute control of blood pressure?
Baroreceptors in aortic arch and internal carotids - autonomic nervous system alters heart contraction/ constriction blood vessels
What is chronic control of blood pressure?
Renin-angiotensin system - via blood sodium [] and body fluid retention
Basic clinic signs to monitor CV system?
HR
Consciousness level
Skin colour
Capillary refill
Advanced ways to monitor CV system?
Non-invasive blood pressure
ECG monitoring
What can blood pressure cuff be affected by?
Movement
Wrong sized cuff
When should ECG monitoring be used?
Pt significant hx of cardiovascular disease
What are 2 CV complications caused by sedation?
Hypotension
Cardiac arrhythmia
How is hypotension caused in sedation?
Drugs cause vasodilation
Some drugs decrease strength heart contractions
Tx hypotension?
Stop administering
Pt head down, feet elevated
IV fluids may be required
How can cardiac arrhythmia be caused?
Precipitated by adrenaline in LA
How manage cardiac arrhythmia?
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