Complications of Conscious Sedation

Question 1

What is conscious sedation?

Answer 1

• Technique in which the use of a drug or drugs produces state of depression of CNS enabling txt to be carried out
• Verbal contact with pt must be maintained throughout sedation
• The drugs and techniques used should carry margin of safety wide enough to render loss of consciousness unlikely

Question 2

What are the types of sedation?

Answer 2

• Intravenous sedation (most commonly used in dentistry)
• Inhalation sedation

Question 3

During intravenous sedation what are some complications of cannulation that can occur?

Answer 3

• Venospasm
• Extravascular injection
• Intra arterial injection
• Haematoma
• Fainting

Question 4

What is a Venospasm?

Answer 4

• Disappearing vein syndrome
• Sudden constriction of a vein , reducing its diameter and flow rate at attempted venepuncture

Question 5

What can a venospasm be associated with?

Answer 5

• May be accompanied by burning
• Associated with poorly visible veins

Question 6

What does the management of a Venospasm include?

Answer 6

• Use efficient technique (slow skin puncture makes it worse)
• ## Warm water or gloves in winter can be used by pt to dilate the vein

Question 7

What is an extravascular injection?

Answer 7

• When active drug is placed into interstitial space and not the vein
• Symptoms are pain and swelling
• Has problem of delayed absorption so pt may sedate 20 mins later, risk doubling the drug up

Question 8

What is the management of the extravascular injection?

Answer 8

• Prevention by good cannulation and test dose of saline
• Txt by removing cannula, applying P and reassure pt

Question 9

What are the signs and symptoms of Intra-arterial injection?

Answer 9

• Pain on venepuncture
• Red blood in cannula
• Difficult to prevent leaks
• Pain radiating distally from site of cannulation
• Loss of colour or warmth to limb/weakening pulse

Question 10

Hoe can you prevent intra-arterial injection?

Answer 10

• Avoid anatomically prone sites - ACF Medial to biceps tendon (cannula lateral to bicep tendon)
• Palpate before attack

Question 11

What is the management of Intra-arterial injection?

Answer 11

• Monitor for loss of pulse (look for cold and discolouration)
• Leave cannula in situ for 5 mins post drug
• No problems then can remove cannula
• Symptomatic leave and refer to hospital (procaine 1%)

Question 12

What is a haematoma?

Answer 12

• Extravasation of blood into soft tissues
• Due to damage to vein walls

Question 13

How can a Haematoma form during intravenous sedation?

Answer 13

• At venepuncture by poor technique and multiple injection spots
• Removal of cannula failure to apply pressure
• Care should be taken for elderly pts

Question 14

How can you prevent formation of a haematoma?

Answer 14

• Good cannulation technique (avoid multiple holes in vein wall)
• Pressure post op by operator
• Care with elderly

Question 15

What is the txt of Haematoma?

Answer 15

• Time
• Rest
• Reassurance
• If severe use ice initially then moist heat 20 mins an hour after 24hrs
• Consider heparin containing gel

Question 16

Why might a pt faint during venepuncture?

Answer 16

• Anxiety
• Worse if pt hasn’t eaten

Question 17

What are some types of complications during drug administration of intravenous sedation?

Answer 17

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

Question 18

What is the average dose of midazolam given in intravenous sedation?

Answer 18

• 5-6mg

Question 19

What does it mean when a person is a hyper-responder?

Answer 19

• pt recieves deep sedation with minimal dose e.g. 1-2mg midazolam
• Need to take care with titration so do 1mg increments
• Slow titration in elderly

Question 20

What does it mean when a pt is hypo-responder?

Answer 20

• Little sedative effect with large doses
• Need to check cannula in vein
• May be due to tolerance
  
  • BZD induced (Benzodiazepiam)
  • Cross tolerance
  • Ideopathic

Question 21

What do most practices give as a max amount of midazolam?

Answer 21

• Practice setting 10mg
• Hospital 15mg

Question 22

What does it mean when a pt has a Parodoxical reaction?

Answer 22

• Appear to sedate normally but then react extremely to all stimuli
• Use flumazenil to reverse the midazolam (do not go on adding sedative) Use 200ug then 100ug increments at minute intervals
• rare occurence

Question 23

What can occur if oversedation happens?

Answer 23

• Loss of responsiveness
• Respiratory depression (autonomic breathing system reduces)
• Loss of ability to maintain airway
• Can go into respiratory arrest

Question 24

How would you manage a pt that has been oversedated?

Answer 24

• Stop procedure
• Try to rouse the pt
• DR ABC
• If no response to stimulation and support then reverse with flumazenil 200ug then 100ug increments at minute intervals
• Watch for 1-4hrs

Question 25

What is the management of Respiratory depression?

Answer 25

• Check the oximeter
• Stimulate pt and ask them to breath
• Supplemental oxygen in nasal cannulae 2 litres per min
• Reverse with flumazenil

Question 26

What to do if pt has allergic reaction to midazolam?

Answer 26

• Rare to sedatives
• Do not use flumazenil as this is also benzodiazepim (may be allergic to this as well)
• Latex and elastoplast
• Manage as if they are not sedation and use epinephrine (adrenaline)

Question 27

What are some complications of inhalation sedation?

Answer 27

• Oversedation
• Pt panics and can’t do procedure

Question 28

What are the signs and symptoms of Nitrous oxide overdose?

Answer 28

• Pt discomfort
• Lack of co-operation
• Mouthbreathing
• Giggling
• Nausea
• Vomiting
• Loss of consciousness

Question 29

What is the txt of overdose in inhalation sedation?

Answer 29

• Decrease N2O conc by 5-10%
• Reassure
• Don’t remove nosepiece

Question 30

What to do if the pt panics in inhalation sedation?

Answer 30

• Have you done correct sedation technique
• Reassurance
• If cannot cope with sedation abort