sedation Flashcards
why is midazolam very safe for conscious sedation?
0.5mg = sedated 25/30g = anaesthetised
3 medical conditions that would benefit from sedation
ischaemic heart disease, hypertension, asthma
all aggravated by stress - but have to balance risk
why can’t you sedate very old
liver + kidney compromised metabolism
why can’t you sedate very young
sensitive to dosage
medical contraindication for sedation
severe + uncontrolled systemic disease - especially cardio-resp e.g. MI, COPD
hepatic or renal insufficiency
pregnancy + lactation
how long should sedation treatments take max
40mins
what happens if pt takes antihypertensive and is sedated with midazolam
high drop in BP
what drug has extreme risk of respiratory depression with midazolam
antiviral agent’s - ritonavir
4 vital signs needed for sedation
pulse
BP
resp rate
BMI
what is the classification used to assess fitness for sedation
ASA
I = without systemic disease II = mild systemic disease III = moderate systemic disease, limits activity IV = incapacitating systemic disease - constant threat t life V = not expected to survive 24hrs
what type of sedation is CI in pregnancy
IV - midazolam passes placenta
inhalation ok
describe ASA1
normal healthy patient <60yrs
minimal anxiety
BP <140/90
decribe ASA2
any healthy patient >60yrs heathy but phobic, overweight, pregnant or special needs BP <160/95 drug allergy mild controlled systemic disease
describe ASA3
well controlled insulin diabetes or epilepsy poorly controlled asthma stable angina post MI or cerebrovascular accident >6/12 chronic bronchitis or emphysema congestive heart failure thyroid disease BP <200/115
describe ASA4
poorly ontorlled insulin diabetes or epilepsy unstable angina post MI or CVA <6/12 COAD or CHF requiring O2 therapy uncontrolled dysrhythmias BP >200/115
which ASA grades can be sedated in GDP
ASA1 + 2
higher must be done in hospital
what gauge cannula is used for IV sedation
22 - blue
conc of midazolam used in IV sedation
5mg/5ml
chemotherapeutic drug that has bad interaction for BDZ
methotrexate
2 monitoring techniques used
oximeter - oxygen saturation in arterial pressure + pulse
BP monitor
when does consent for treatment expire
after 1 year
why must patient not have drank alcohol night before/morning of appointment
alcohol + midazolam = synergistic effect
what can patients eat before sedation
light meal
technique for inserting midazolam
1mg injected slowly
wait 1 min
1mg every minute after
2-5mg/l in total
arm brain circulation time?
25 seconds
5 signs of sedation
- slurring/slowing of speech
- relaxed appearance
- delayed response to commands
- ptosis
- willingness to undergo treatment
how long after should arterial saturation be measure for
1 hour
5 complications of IV sedation
- respiratory depression - decreased O2 conc
- over-sedation
- disinhibition - react in complete opposite way expected
- medical emergency - not epilepsy
- allergy
what is used to reverse midazolam
flumazenil 200ug initially
100ug/min max
2 possible sites for cannulation
- dorsal vein of hand - no vital structures
2. antecubital fossa - large veins, danger of brachial artery + median nerve, problems with joint movement
what is used to irrigate cannula + check in correct position
5ml 0.9 sterile saline - 18g needle
where is tourniquet positioned
10cm above cannula
what angle is cannula inserted
10-15
4 complications of cannulation
- difficult vein - lower arm, warm hands, apply BP cuff, palpate veins
- extra venous cannulation - pain, formation of subcutaneous lump, resite
- intra-arterial injection - avoid medial antecubital fossa, signicatn pain, pulsatile blood, remove, pressure +/- refer
- haematoma formation - avoid multiple venipuncture, avoid penetrating wall of vein, pressure after
2 types of unit for inhalation sedation
- stand alone
2. piped in
colour of nitrous oxide cylinder
blue
colour of oxygen cylinder
black
4 components of quantify MDM head
- flow meter
- % dial
- flow regulator
- oxygen flush button
what is a scavenging unit
activity removed exhaled gases - long term exposure can be detrimental
2 types of mask system for inhalation sedation
1 mask or 2 mask (NDH)
what would happen if 100% nitrous oxide given
patient become hypoxic - many safety features to ensure this doesn’t happen
define inhalation sedation
semi-hypnotic technique of conscious sedation which enhance pt suggestibility
pt reamins cooperative with all vital reflexes intact
advantages of inhalation sedation
rapid onset 2-3mins rapid peak 3-5mins easily regaled duration flexible rapid recovery - 3-5mins on 100% O2 moderate anaglesia no injection few side effects
disadvantages of inhalation sedation
cost of equipment space occupying not a potent agent degree of cooperation necessary chronic exposure bad
contraindications for inhalation sedation
claustrophic middle ear/sinus infections ocular surgery URTI severe anxiety pregnancy methotrexate bleomycin therapy
maximum percentage of n2o + oxgygen
70% N2o 30%o2
start from 100% o2 and titrate by 10 10 10 5 5 5 … every min
how to monitor inhalation sedation
communicate + watch pt
signs over slight over sedation in inhalation sedation
hearing more acute, blurred vision, sleepiness, laughing, crying, caused, increased movement
signs of over sedation in inhalation sedation
nausea/headache
vomiting/loss of consciousness
management of over sedation in inhalation sedation
reduce nitrous oxide by 5-10%
pressure pt + monitor
encourage to keep o2 mask off
cause of vasovagal syncope
vasodilation of vessel going towards skeletal muscles - BP drops
not enough CO to maintain blood to brain
if pt having MI what may help that is available on sedation clinic
50% n2o 50% o2
increases vasodilation + analgesic
