Complications of Sedation

Question 1

concentration of midazolam used for IV sedation

Answer 1

1mg/1ml midazolam concentration

used due to National Pt Safety Agency report into reducing risk of midazolam overdose injections

Question 2

2 categories of complication for IV sedation

Answer 2

complications during cannulation

complications during drug adminstration

Question 3

5 complications during cannulation

Answer 3

• Venospasm
• Extravascular injection
• Intraarterial injection
• Haematoma
• Fainting

Question 4

5 complications during drug administration

Answer 4

• Hyper-responders
• Hypo-responders
• Parodoxical reactions
• Oversedation
• Allergic reactions

Question 5

what is venospasm

Answer 5

Disappearing vein syndrome

• Veins collapse at attempted venepuncture

May be accompanied by burning

Associated with poorly visible veins

Question 6

management of venospasm

Answer 6

• Time dilating vein
  
  • Tourniquet on and tap vein
  • Worse with repeated attempts
• Efficient technique (smooth)
  
  • Slow skin puncture makes worse
• Warm water / gloves in winter

Question 7

what is extravascular injection

Answer 7

active drug placed into interstital space

Question 8

dx for extravascular injection

Answer 8

pain

swelling

Question 9

potential problem due to extravascular IV injection

Answer 9

delayed absorption

Question 10

2 prevention strategies of extravascular IV injection

Answer 10

• Good cannulation
• Test dose of saline
  
  • Flush before
  • If get pain/swelling – reposition

Question 11

3 tx for extravascular IV injection

Answer 11

• Remove cannula
• Apply pressure
• Reassure

Question 12

what is intra-arterial injection when trying to do IV sedation

Answer 12

• Cannula into brachial artery
  
  • Not superficial, unlike veins

Question 13

dx intra-arterial injection

Answer 13

• Pain on venepuncture
• Red blood in cannula (oxygenated)
• Difficult to prevent leaks (under pressure too so will bubble)
• Pain radiating distally from site of cannulation
• Loss of colour or warmth to limb / weakening pulse

Question 14

2 prevention strategies for intra-arterial injection

Answer 14

• Avoid anatomically prone sites- ACF Medial to biceps tendon (lateral to tendon)
• Palpate before attack – pulse? Not vein

Question 15

3 management strategies for intra-arterial injections

Answer 15

• Take cannula out and Apply pressure for 5mins, stop bleeding - OK
• Check for loss of pulse
  
  • Cold
  • Discolouration
• Leave cannula in situ for 5 mins post drug (notice after giving drug)
  
  • No problems – remove
  • Symptomatic leave & refer to hopspital (procaine 1%)

Question 16

what is haematoma due to IV sedation

Answer 16

• Extravasation of blood into soft tissues
• Due to damage to vein walls
• At venepuncture
  
  • Poor technique
• Removal of cannula
  
  • Failure to apply pressure
  • Care with elderly patients

Question 17

3 ways to prevent haematoma during IV sedation

Answer 17

• Good cannulation technique
  
  • Avoid multiple holes in vein wall
• Pressure post operatively
  
  • Operator not pt
• Care with elderly

Question 18

tx strategies for haematoma

Answer 18

Time
Rest
Reassurance

If severe

• Initial ice pack
• Moist heat 20mins in hour after 24hours

Consider heparin containing gel

Question 19

how can fainting occur during IV sedation (venopuncture)

Answer 19

• Anxiety related to venepuncture
• Worse if starved

Question 20

4 prevention strategies for fainting during venopuncture

Answer 20

• Don’t starve patients
• Topical skin anaesthesia
• RA First – easier to get legs up
• Position of patient

Question 21

what are hyper-responders to IV sedation

Answer 21

• Deep sedation with minimal dose
  
  • 1-2mg midazolam

Question 22

prevention of hyper-responders to IV sedation

Answer 22

care with titration

1mg increments

slow titration in elderly esp

Question 23

hypo-responders to IV sedation

Answer 23

little sedative effect with large doses

Question 24

management of hypo-responders to IV sedation

Answer 24

• Check cannula in vein!!
• May be due to tolerance
  
  • BZD induced
  • Cross tolerance
    
    • E.g. not told you about a drug habit they have (cocaine, benzo habit)
  • Idiopathic

Threshold to abandon??

• 10mg common in dentistry
• BNF 7.5mg

Question 25

paradoxical reactions to IV sedation

Answer 25

Appear to not sedate normally Or sedate normally but React extremely to all stimuli * Relax when stimuli removed * Don’t remember what caused it as midazolam gives amnesia

Question 26

management for paradoxical reactions to IV sedation

Answer 26

* Check for failure of LA * DO NOT GO ON ADDING SEDATIVE * Find other management technique * Watch immature teenagers * More likely in younger individuals

Question 27

4 signs of oversedation

Answer 27

* Loss of responsiveness * Respiratory depression * Loss of ability to maintain airway * Respiratory arrest

Question 28

management of oversedation 4 points

Answer 28

* Stop procedure * Try to rouse patient * Alert – voice, pain or unresponsive * Breathing * Circulation * If no response to stimulation and support (as soon as Alert failed) * Reverse with flumazenil 200mg then 100mg increments at minute intervals * Watch for 1- 4 hours * Flumazenil has shorter half life than midazolam * Be more careful next time

Question 29

management of respiratory depression 4 points

Answer 29

* Check the oximeter (not in isolation check with how they look) * Stimulate patient * Ask to breathe * Supplemental oxygen * Nasal cannulae 2 litres per minute * Reverse with flumazenil * If sats drop below 90% and not rising

Question 30

5 management points for loss of airway control and/or respiratory arrest

Answer 30

* Stimulate the patient / assess consciousness * Maintain / clear airway * Ventilate the patient * Reverse sedation * Consider other medical incident

Question 31

allergic reactions in IV sedation

Answer 31

Rare to sedatives * Remember Latex and elastoplast involved Do not use flumazenil * Benzodiazepine like midazolam – could make it worse, if unknown cause Manage as if not sedated – advantage of IV access * Give IM adrenaline * A B C check and go for help

Question 32

sexual fantasy due to IV sedation management

Answer 32

* No idea of incidence or aetiology * No idea how to prevent ## Footnote **Ensure chaperoned!!!**

Question 33

reversal drug for midazolam

Answer 33

flumazenil

Question 34

2 complications due to IHS

Answer 34

oversedation pt panics *very safe machine has* * *max dose built in (hypoxic rare as unable to give 100% N₂O)* * *cut off*

Question 35

oversedations with IHS can occur how initally later

Answer 35

Initially * Misjudge dose Later * Traumatic procedure over * E.g. needle phobic, so high level to give LA but that’s happened, pt more relaxed now but still at high level which is too high now so OD * Mouth breathing ceases * Adjust fit so concentration is higher suddenly * Technical problem

Question 36

7 signs and symptoms of N₂O overdose

Answer 36

* Patient discomfort * Lack of co-operation * Mouthbreathing * Giggling * Nausea * **_Vomiting_** * Loss of consciousness

Question 37

3 points for tx of N₂O overdose

Answer 37

* Decrease N₂O concentration by 5-10% * Reassure * _Don’t remove nosepiece_ * Diffusion hypoxia * If get really panicked can give them 100% O2 through mask but need to keep nosepiece on for 3-5mins

Question 38

pt panics during IHS why?

Answer 38

* Have you used the correct sedation technique? * IHS light sedative, may not be enough for them

Question 39

pt panics during IHS management

Answer 39

Reassurance If cannot cope with sedation abort

Question 40

complications with oral/transmucosal sedation

Answer 40

same as IV sedation

Question 41

undersedation in transmucosal sedation management

Answer 41

place cannula and top up with IV