complications key points Flashcards
issues leading to complications
reliance on flumazenil bolus sedation still used untrained sedationists incorrect doses - labels, incorrect conc
complications of IV cannulation
extravascular injection venospasm intraarterial injection haematoma fainting
venospasm
disappearing vein syndrome - vein disappears as you put cannula in
veins collapse at attempted venepuncture
may be accompanied by burning
associated with poorly visible veins
management of venospasm
time dilating vein - torniquet, tap vein - worse with repeated attempts efficient technique - slow skin puncture makes worse warm water/gloves in winter - dilates vessels
extravascular injection
active drug placed into interstitial space (cannula not in)
diagnosis of extravascular injection
pain
swelling
extravascular injection potential problems
delayed absorption (will get absorbed at some time - oversedation?)
preventing extravascular injection
good cannulation
test dose of saline - flush cannula
tx of extravascular injection
remove cannula
apply pressure
reassure
intra-arterial injection - where is it most likely?
rare antecubital fossa (brachial artery)
diagnosis of intra-arterial injection
pain on venepuncture (wall thicker)
red blood in cannula, bubbles
difficult to prevent leaks
pain radiating distally from cannulation site
loss of colour/warmth to limb/weakening pulse
prevention of intra-arterial injection
avoid anatomically prone sites - ACF medial to biceps tendon
palpate before attack (if pulse not vein)
if have cannulated an artery - take out and apply pressure DON’T inject drug
management of intra-arterial injection
monitor for loss of pulse (if artery irritated may constrict) - cold/discolouration
leave cannula in situ for 5mins post-drug
- no problems then remove
- symptomatic - leave and refer to hospital
haematoma
bruise
extravasation of blood into STs
- due to damage to vein walls
when can haematoma occur?
at venepuncture - poor technique
removal of cannula - failure to apply pressure
care w elderly
prevention of haematoma
good cannulation technique - avoid multiple holes in vein wall
pressure post-op by operator until stops bleeding, then apply pressure and get pt to put pressure
haematoma tx
time, rest, reassurance
if severe initial ice pack, moist heat 20mins in hour after 24hrs
consider heparin containing gel
fainting during venepuncture
quite common anxiety related worse if starved prevention - don't starve pt - topical skin anaesthesia - RA first (IHS 1st - more O2) - position of pt - put them part-reclined tx - raise legs
complications of drug administration
parodoxical reactions hyper-responders hypo-responders sexual fantasy allergic reactions oversedation
hyper-responders
deep sedation with minimal dose (1-2mg) care with titration - 1mg increments - slow in elderly (sensitivity to midazolam increases) and U16s - max 3.5mg for >60yrs
hypo-responders
little sedative effect with large doses check cannula in vein (re-flush) due to tolerance? - BZD induced - cross-tolerance e.g. cocaine - idiopathic threshold to abandon? - not over 10mg, BNF max 7.5mg
parodoxical reactions
don't sedate how you expect appear to sedate normally react extremely to all stimuli relax when stimuli removed check for failure of LA don't continue adding sedative find other management techniques watch immature teenagers (U16s)
allergic reactions
rare to sedatives
- do not use flumazenil (also a BZD)
latex and elastoplast
manage as if not sedated - advantage of IV access
oversedation
loss of responsiveness
resp depression
- sometimes just need to give O2 and tell pt to take deep breaths
loss of ability to maintain airway - collapses
respiratory arrest
complications of IHS
pt panics
oversedation
cause of oversedation in IHS
initially - misjudge dose
later
- traumatic procedure over
- mouthbreathing ceases e.g. if hood doesn’t fit well then fixed later so getting higher conc
IHS pt panics
enough sedation?
reassurance
if cannot cope abort
S+S of oversedation
irrational and sluggish responses pt discomfort fails to respond to verbal cues/mild stimuli incoherent speech LOC lack of cooperation mouth closing repeatedly eyes closed, unable to open nausea and vomiting spontaneous mouth breathing pt no longer enjoying effects drop in O2 sats pulsing head/temples uncontrolled laughter/tears
what are 2 signs you should stop IHS?
ears ringing
sore head
tx of IHS overdose
reduce N2O conc by 5-10%
reassure
don’t remove nosepiece - diffusion hypoxia
- 3-5mins
- diffusion gradient N2O rushes out, stops O2 in
