Sedation - IV Complications

Question 1

What are the types of complications that can occur during cannulation? (5)

Answer 1

1. Venospasm
2. Extravascular injection
3. Intraarterial injection
4. Haematoma
5. Fainting

Question 2

what is venospasm?

Answer 2

(Disappearing vein syndrome)
- Veins collapse at attempted venepuncture
- May be accompanied by burning/pain
- Associated with poorly visible veins

Question 3

How do we prevent vasospasm? (3)

Answer 3

• Ensure vein dilated (i.e. with tourniquet and tapping) = Worse with repeated attempts
• Efficient technique = Slow skin puncture makes worse
• Use warm water / gloves in winter to ensure good veins for puncture

Question 4

What is an extravascular injection?

Answer 4

A complication where the active drug placed into interstitial space as canula isn’t placed in the vein.

Question 5

How do we Diagnose an extravascular injection? (2)

Answer 5

• Pain
• Swelling

Question 6

How do we avoid extravascular injections?

Answer 6

Flush the canula with saline before providing the active drug and if no pain/swelling = correct placement.
Bubble appears = incorrect placement and must replace

Question 7

What are the potential problem associated with an extravascular injection? (1)

Answer 7

Delayed absorption (30 mins for midazolam) through the tissues so can be a potential for overdose if more drug given with the correct placement of the canula.

Question 8

How do we manage an extravascular injection? (2)

Answer 8

• Prevention
- Good cannulation
- Test dose of saline

• Treatment:
- Remove cannula
- Apply pressure
- Reassure
- Replace

Question 9

How do we diagnose an Intra-arterial injection? (6)

Answer 9

• Pain on venepuncture since artery wall thicker
• Bright red blood in cannula
• Canula will buckle from pressure within artery
• Difficult to prevent leaks
• Pain radiating distally from site of cannulation
• Loss of colour or warmth to limb / weakening pulse

Question 10

What puncture location does an intra-arterial injection commonly occur?

Answer 10

antecubital fossa

Question 11

How do we prevent an intra-arterial injection? (3)

Answer 11

• Avoid anatomically prone sites – avoid ACF which is medial to biceps tendon
• Palpate before puncture: if there is a pule = NOT a vein

Question 12

How do we manage an intra-arterial injection when no drug has been administered? (2)

Answer 12

• Remove and apply pressure for prolonged period of time
• When you remove the canula monitor for loss of pulse or colour
  = Cold: caused when artery gets irritated and constricts
  = Discolouration

Question 13

How do we manage an intra-arterial injection when drugs have been administered? (3)

Answer 13

Leave cannula in situ for 5 mins post drug;
- No problems with colour or temp = remove
- Symptomatic = refer to A&E (procaine 1%) as artery can get irritated and constrict

Question 14

What is a haematoma?

Answer 14

Extravasation of blood into soft tissues due to damage to vein walls
- Common and expected

Question 15

What is the cause of haematoma during puncture?

Answer 15

poor technique

Question 16

What is the cause of haematoma during cannula removal?

Answer 16

Failure to apply pressure quickly and for long enough

Question 17

How do we prevent haematomas? (3)

Answer 17

• Good cannulation technique
- Avoid multiple holes in vein wall (scratching the vein walls)

• Pressure post operatively – quickly and for long enough (Operator and patient)

• Care with the elderly

Question 18

How do we treat haematomas? (6)

Answer 18

• Time
• Rest
• Reassurance

(Usually not needed)
however, If severe:
- Initial ice pack
- Moist heat pack for 20mins an hour after
- After 24hours consider heparin containing gel

Question 19

What causes fainting during venepuncture? (2)

Answer 19

• Anxiety related to venepuncture (needle)
• px not eaten (worsened)

Question 20

How do we prevent fainting during venepuncture? (6)

Answer 20

• Good technique
• Ask if px prone to fainting
• Don’t starve patients
• Topical skin anaesthesia
• Inhalation sedation First: to relax before canulation
• Position of patient: have patients slightly reclined so that there is room to have them reclined all the way back if the faint

Question 21

What are the types of complications that can occur during drug administration? (5)

Answer 21

1. Hyper-responders
2. Hypo-responders
3. Parodoxical reactions
4. Oversedation
5. Allergic reactions

Question 22

What is a hyper-response to IV sedation?

Answer 22

Where a patient is deeply sedated with minimal dose of 1-2mg midazolam (very quick)

Question 23

What causes a hyper-response to IV sedation?

Answer 23

Usually age – over 60’s have a different titration path to avoid this

Question 24

How do we prevent a hyper-response? (2)

Answer 24

Care with titration;
- 1mg increments
- Slow titration in elderly: 0.5mg initially to gage response then small increments after this

Question 25

What is a hypo-response to IV sedation?

Answer 25

Where a patient has little sedative effect with large doses of drug (midazolam)

Question 26

How do we manage a hypo-responder? (3)

Answer 26

• Check cannula in vein – flush to confirm

• Take time - Could be a slow effect – caution

• May be due to tolerance - explore history further
- BZD induced: check if px has a history of taking benzodiazepines = high tolerance
- Cross tolerance (if px have other drug habits)
- Idiopathic (unsure)

Question 27

If a patient is a hypo-responder what is the threshold to abandon?

Answer 27

don’t go over 10mg if not having an effect

Question 28

What is a paradoxical reaction?

Answer 28

Px doesn’t sedate how you would expect

Question 29

How do we manage a paradoxical reaction? (4)

Answer 29

• Check for failure of LA
• DO NOT GO ON ADDING SEDATIVE
• use other management techniques

Question 30

In what px group do we have to be cautious with paradoxical reactions?

Answer 30

immature teenagers (most common between 12-16 years old)

Question 31

How do we identify oversedation? (4)

Answer 31

• Loss of responsiveness: no verbal contact
• Respiratory depression: can be manageable (give oxygen and ask patient to take deep breathes if responsive) or unmanageable
• If drug continues to be given = Loss of ability to maintain airway
• Respiratory arrest

Question 32

How do we manage oversedation? (4)

Answer 32

• Stop procedure

• Try to rouse patient

• Carry out ACVPU and if patient unresponsive carry out A B C = airways, breathing, circulation.

• If no response to stimulation and support;
- Reverse with flumazenil
- Watch for 1- 4 hours

If managed = patient able to breathe by themselves again

Question 33

What dose of flumazenil is used to reverse over sedation?

Answer 33

200mg initial dose

then 100mg increments at minute intervals after to reverse

Question 34

How do we manage respiratory depression? (3)

Answer 34

• Stimulate patient: Ask to take a deep breathe if saturation is below 90%
• Supplemental oxygen = Nasal cannulae with 3 litres per minute
• If saturation drps below 90% and doesn’t rise = Reverse with flumazenil

Question 35

How do we manage allergy during IV sedation? (2)

Answer 35

Do not reverse the drug as the reversal drug is also a benzodiazepine (further allergy)

Same as any other allergy emergency - IM adrenaline
- keep IV access (can be useful for other medical professionals)