Sedation Flashcards
What does ASA stand for
Amercian Society of Anaesteologist of medical status
ASA I and ASA II tx
done by trained sedation dentist
ASA III
done in a hospital setting
ASA I
normal healthy person
non smoker
minimium alcohol
ASA II
mild systemic disease - preg, well controlled asthma, epilepsy, diabetes
blood pressure - 140154/90-94
ASA III
severe systemic disease - type 1 diabetes, stable angina, COPD, 6months MI and CVA
Blood pressure = 160-199/95-114
ASA IV
severe systemic disease, constant threat to life
unstable angina
severe COPD
<6months MI and CVA
Blood pressure 200/115
ASA V
moribud, not expected to survive operation
ASA VI
brain dead, organs for dontation
Vital signs to monitor during sedation
blood pressure
heart rate
O2 levels - pulse oximeter
weight - weight/height2
Contraindications of sedation
severe uncontrolled systemic disease
severe physical or mental handicap
pyschaitric disorders
hypothyroidism
prep pts
COPD
spreading infection which could comrpomise airway
Indications for sedation
pt with poor co-operation
mild learning difficutlies
cerbral palsy
Parkinsons
phobias/gagging
neddle phobias
What drugs do sedation interact with
alcohol
opoids
erythomycin
recreational drugs
antidepressants
antihistamines
antipsychiotics
Complications of sedation
sexual fantasy
allergic reaction
over sedation
hyop repsonders
hyper responders
fainting
haematoma
intra-arterial injection
venospasm
extravascular injection
Indications of inhalation sedation
anxious
needle phobia
gaggers - nitrous oxide reduces gag reflex
medical conditions aggravated by stress
unaccompained but required sedation
liver problems
Contraindications of inhalation sedation
common cold
severe COPD
first trimester of pregnancy
fear of mask
tonsillar/ adenoid enlargement
Advantages of inhlation sedation
no amnesia
no injection
rapid onset and peak
quick revoery
few side effects
Disadvantages of inhaltion sedation
equipement and gas expensive
requires to breathe through nose
space for equipment
not potent
staff can become addicted to it
What colour os oxygen cylinder
black
what colour is NO2
blue
Equipment for inhalation sedation
gas cyclinders
pressure reducing valves
flow control meter
reservoir bag
gas delivery hoses
nasal hood
waste gaas scavenging system
Pre op insturctions before inhalation sedation
light meal before
meds as normal
children accompained by adult
adults accompained for 1st sedation appt
no alcohol
sensible clothing
Signs of adequate inhaltion sedation
relaxed and comfortable
pt awake
reduced blink reflex
verbal contact maininted
decrease reaction to painful stimuli
decrease in spontaneous movement
Oversedation signs
nasuea/vomiting
mouth closes repeatdely
decreased co-operation
uncontrollable laughter/tears
loss of consciuness
incoherent speech
sluggish response
Sites for cannulation of iv sedation
dorsum of hand
antecubital fossa
Vernil’s sign
drooping of eyelids
Eve’s sign
touch nose with finger
Midazolam
5mg/5ml (1mg/1ml)
pH 3.5 - allows to be soluble when injected
more potent and rapid
metabolised in liver and extra hepatic metabolism in bowel
What can unsedate a pt if required
flumazenil - benzodiazepine antagonsit
200mcg then 100mcg every 60 secs
4 main valves in the hearrt
tricuspud
pulpmnary
mitral
aortic
Pulmonary circulation
oxygen depleted blood leaves the ringth ventricle reached the lung and replinshed with oxygen and back to left atrium
Systemic circulation
sino atrial node sends eletrical signals through atria causing contraction pushing blood into ventricles
incrseased pressure pushes bi and tricuspic vavlves open
electircal activity reached avn and action poteitnals trasferred along purkinje system
The cardiac cycle
atrial systole
ventricular systole
verntricular diastole
Ventricular systole
isovolumetirc ventricular contraction - contraction but no change in volume, increase in pressure
Ventricular diastole
isovolumetric relaxation - volume does not change and ventricles passively fill up
What is starling’s law
related to end diastolic volume
higher it is the higher the stroke volume
what is the afterload
the force the heart has on systole
the pressure needed to pump against arterial blood pressure and total pherpieral resistance
What is dead space
air inhaled but does not reach the alveoli
Anatomical dead space
air breathed in but stays in conducting zone (no active gas trasnfer)
Alveolar dead space
due to perfusion of alveolus
Haemogloblin
globular protein - 2 apha and 2 beta chains
4 haem groups within a porphyrin ring
in sedation does nitrous oxide bind to haem
does not bind to haemogloblin and carried in blood
How is carbon dioxide transported
by erythrocytes and blood plasma
Hypocapnia
what should physiologically drive breathing
detected by central chemorecptors
Hypoxia
how breathing is driven in COPD
Hypoxic
decrease in oxygen reaching alveoli or decrased amount of oxygen diffusion into blood
Anaemaia hypoxia
decrease in oxygen in blood due to low haem
Stagnany (ischamic) hypoxia
low blood flow decreasing oxygen
cytotoix hypoxia
low utilisation of oxygen by cells themselves
Cyanosis
> 5g of deoxygenated haem/ 1 litre of blood
Central cyanosis
affects the whole body, decrase in oxygen to blood
What is central cyanosis caused by
low atomospheric oxygen pressure
decrseased airflow in airways
decreased oxygen diffusion into blood
decreased pulmonary blood flow
shunting
Peripheral cyanosis
decreased oxygen delivery to localised and peripheral body part
decreased blood flow to tissues (stagnant hypoxia)
