Conscious sedation complications

Question 1

iv sedation - types of complication (related to cannulation)

Answer 1

venospasm
extravascular injection
intra-arterial injection
haematoma
fainting

Question 2

What is venospasm?

Answer 2

disappearing vein syndrome
veins collapse at attempted venepuncture
may be accompanied by burning
associated with poorly visible veins

Question 3

What is meant by ‘extravascular injection’? give the signs and potential problems

Answer 3

active drug placed into interstitial space
diagnosis
- pain
- swelling
potential problems
- delayed absorption

Question 4

how to prevent extravascular injection

Answer 4

good cannulation
use a test dose of saline

Question 5

extravascular injection - management

Answer 5

remove cannula
apply pressure
reassure patient

Question 6

intra-arterial injection - diagnosis

Answer 6

pain on venepuncture
red blood in cannula
difficult to prevent leaks
pain radiating distally from cannulation site
loss of colour or warmth to limb/weakening pulse

Question 7

how to prevent intra arterial injection

Answer 7

palpate before attack
avoid anatomically prone sites

Question 8

Intra arterial injection management

Answer 8

monitor for loss of pulse
- cold
- discolouration
leave cannula for 5 mins post drug
- remove if no problems
- if symptomatic leave cannula in and refer to hospital (procaine 1%)

Question 9

What is a haemotoma and how can it occur during iv sedation?

Answer 9

outflow of blood into soft tissue
- due to damage of vein walls
can occur at venepuncture due to poor technique
can occur at removal of cannula
- failure to apply pressure

Question 10

haematoma prevention

Answer 10

good cannulation technique
operator must apply pressure post operatively
take care with elderly

Question 11

haemotoma treatment

Answer 11

time
rest
reassurance
if severe
- initial ice pack
- moist heat for 20 mins an hour after
after 24 hours
- consider heparin containing gel

Question 12

fainting during venepuncture - potential causes

Answer 12

anxiety related to venepuncture
worse if starved

Question 13

prevention of fainting during venepuncture

Answer 13

don’t starve patients
topical skin anaesthesia
position of patient

Question 14

types of complications - drug related

Answer 14

hyper or hypo responders
paradoxical reactions
over sedation
allergic reactions

Question 15

hyper responders - briefly describe - give ways to manage

Answer 15

deep sedation with minimal dose
- 1-2mg midazolam
take care with titration
- 1mg increments
- slow titration in elderly

Question 16

hypo responders - briefly describe and give ways to manage

Answer 16

little sedative effect with large doses
management
- check cannula in vein
- may be due to tolerance - cross tolerance, idiopathic, BZD induced

Question 17

paradoxical reactions - briefly describe and give ways to manage

Answer 17

appear to sedate normal
react extremely to all stimuli
relax when stimuli removed

management
- check for failure of LA
- do not continue adding sedative
- watch immature teenagers

Question 18

over sedation - signs and symptoms

Answer 18

loss of responsiveness
respiratory depression
loss of ability to maintain airway
respiratory arrest

Question 19

over sedation - management

Answer 19

stop procedure
attempt to wake patient
ABC
if no response to stumlation and support
- reverse with flumazenil 200ug then 100ug at minute intervals
- watch for 1-4 hours

Question 20

management of respiratory depression

Answer 20

check oximeter
stimulate patient
- ask them to breathe
supplemental oxygen
- nasal cannula 2 litres per minute
reverse with flumazenil

Question 21

loss of airway control or respiratory arrest - how to manage

Answer 21

stimulate patient/assess consciousness
maintain or clear airway
ventilate patient
reverse with flumazenl
consider other medical incident

Question 22

allergic reactions - management

Answer 22

rare to sedatives
- do not use flumazenil
manage as if not sedated

Question 23

inhalation sedation - complications

Answer 23

oversedation
patient panics

Question 24

signs of symptoms of nitrous oxide overdose

Answer 24

patient discomfort
lack of co-operation
giggling
nausea
vomiting
loss of consciousness

Question 25

treatment of nitrous oxide overdose

Answer 25

decrease nitrous oxide concentration by 5-10%
reassure patient
do not remove nosepiece
- diffusion hypoxia risk

Question 26

patient panics - management

Answer 26

reassurance
if patient cannot cope with sedation - abort

Question 27

oral/transmucosal sedation complications

Answer 27

same as iv BZD
- manage same way