Complications of Conscious Sedation Flashcards
What is conscious sedation?
- 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
What are the types of sedation?
- Intravenous sedation (most commonly used in dentistry)
- Inhalation sedation
During intravenous sedation what are some complications of cannulation that can occur?
- Venospasm
- Extravascular injection
- Intra arterial injection
- Haematoma
- Fainting
What is a Venospasm?
- Disappearing vein syndrome
- Sudden constriction of a vein , reducing its diameter and flow rate at attempted venepuncture
What can a venospasm be associated with?
- May be accompanied by burning
- Associated with poorly visible veins
What does the management of a Venospasm include?
- Use efficient technique (slow skin puncture makes it worse)
- ## Warm water or gloves in winter can be used by pt to dilate the vein
What is an extravascular injection?
- 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
What is the management of the extravascular injection?
- Prevention by good cannulation and test dose of saline
- Txt by removing cannula, applying P and reassure pt
What are the signs and symptoms of Intra-arterial injection?
- 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
Hoe can you prevent intra-arterial injection?
- Avoid anatomically prone sites - ACF Medial to biceps tendon (cannula lateral to bicep tendon)
- Palpate before attack
What is the management of Intra-arterial injection?
- 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%)
What is a haematoma?
- Extravasation of blood into soft tissues
- Due to damage to vein walls
How can a Haematoma form during intravenous sedation?
- At venepuncture by poor technique and multiple injection spots
- Removal of cannula failure to apply pressure
- Care should be taken for elderly pts
How can you prevent formation of a haematoma?
- Good cannulation technique (avoid multiple holes in vein wall)
- Pressure post op by operator
- Care with elderly
What is the txt of Haematoma?
- Time
- Rest
- Reassurance
- If severe use ice initially then moist heat 20 mins an hour after 24hrs
- Consider heparin containing gel
Why might a pt faint during venepuncture?
- Anxiety
- Worse if pt hasn’t eaten
What are some types of complications during drug administration of intravenous sedation?
- Hyper-responders
- Hypo-responders
- Parodxical reactions
- Oversedation
- Allergic reactions
What is the average dose of midazolam given in intravenous sedation?
- 5-6mg
What does it mean when a person is a hyper-responder?
- 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
What does it mean when a pt is hypo-responder?
- Little sedative effect with large doses
- Need to check cannula in vein
- May be due to tolerance
- BZD induced (Benzodiazepiam)
- Cross tolerance
- Ideopathic
What do most practices give as a max amount of midazolam?
- Practice setting 10mg
- Hospital 15mg
What does it mean when a pt has a Parodoxical reaction?
- 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
What can occur if oversedation happens?
- Loss of responsiveness
- Respiratory depression (autonomic breathing system reduces)
- Loss of ability to maintain airway
- Can go into respiratory arrest
How would you manage a pt that has been oversedated?
- 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
