anaethetics Flashcards
metformin on day of surgery
OD or BD = take as normal
TDS: miss lunchtime dose
assumes only one meal will be missed during surgery, eGFR> 60 and no contrast in procedure
reverse action of benzo eg midazolam
flumazenil
commonly used induction agents
propafol
sodum thiopentone
ketamine
etomidate
what to check before parathyroid surgery
methylene blue to identify gland
checklist before induction of anaesthesia
pt confirmed: site indentity, procedure, consent
site marked
anaesthesia safety check
pulse ox on pt
allergies?
difficut airway/asp risk?
risk of >500ml blood loss (kids7ml/kg)
3 phases of operation checklist
sign in - b4 anaethesia
time out - before incision
sign out - b4 pt leaves op
what to check before thyroid surgery
vocal cord check
sentinal node biopsy
radioactive marker/patent blue dye
surgery involving thoracic duct
consider administration of cream
pheochromocytoma surgery
alpha and beta blockage
surgery for carcinoid tumors
cover with octreotide
colorectal cases
bowel prep esp if left sided surgery
when is adrenaline with local contraindicated
pt taking MOAI or TCAs
tx for local anaesthetic toxicity
IV 20% lipid emulsion
increased risk of local anaesthetic toxicty
liver dysfxn
low protein state
how does lidocaine work
blocks Na channels in axon = disrupts action potential
paralytic ileus what is it and what can contribute
pseudo obstruction bc reduced bowel peristalsis post bowel surgery
deranaged electrolytes can contribute thefore check potassium mag and phos as might show this AND hypovolaemia before nausea and vom begins
mx of post op/paralytic ileus
nil by mouth initially –> small sips clear fluids
nasogastric tube if vomiting
IV fluids (correct any electrolytes also)
total parenteral nutrition for prolonged/severe cases
colonoscopy prep
laxative day before
no food 24hrs
sulfonyurea eg and day of surgery
gliclazide
omit on day of surgery
unless morning surgery in Pt who take BD = can have afternoon dose
hyponatraemic encephalopathy post op causes
hypotonic IV fluid eg 0.45% sodium chloride
also trauma and stress = SIADH
paeds patients fluids caution
dont use hypotonic (0.45%) solution in peads __> in risk of hepatic encephalopathy
when to not use adrenaline with local anaesthetic
on digits = ischaemia
patients with myasthenia gravis sensitive to what paralytic agents and why
non-depolorising agents (rocuranium)
bc they work by competitively antagonising nicotinic acetylcholine receptors in motor end plate
in MG less of these receptors bc autoimmune distruction = more sensitive to non-depolorising blockade
examples of non depolorising paralytics and reversal agents and SE
curoniums eg
rocuranium
vecuranium
tubacurarine
reverse with neostigmine (achesterase inhib) and sugammadex
hypotension
ASA I classification
normal healthy pt
healthy non smoking minimal alcohol use
ASA II classification
pt w mild systemic disease
without major functional limitations ie
current smoker, social alochol drinker, pregnancy, Obesity (BMI30-40), well controlled DM/HTN, mild lung disease
ASA III classification
pt w severe systemic disease
one or more mod to severe disease w big functional limit ie
poor control DM, HTN
COPD
morbid obese (bmi>40)
active hepitis
alcohol abuse
pacemaker
reduced ejection frac
ESRD - undergoing reg dialysis
hx >3months ago MI
CVD accidents
ASA IV classification
pr w severe systemic disease constant threat to life
<3mths MI
CVD accidents
ongoing cardiac ischaemia or severe valve dysfxn
severe red Eject frac
sepsis
DIC
ARD
ESRD not having red dialysis
ASA V classification
moribund pt not expected tto survive w/o op
ruptured AAA
massive trauma
intracran bleed w mass effect
ischaemic bowel in face of sign cardiac pathology
multiple organ system/dysfxn
ASA VI classification
pt declared brain dead whos organs being removed for donor purposes
depolorisng agents examples and how they work
succinycholine ie suxamethonum
binds to nictonic ach receptors (non compet) = persistant depolorization of motor end plate
thats why might get fasciculations
muscle relaxant choice for RSI
suxamethonium
adverse effects of depolorising agents
malignant hyperthermia
hyperkalaemia (normally transient)
suxamethonium contraindication
penetrating eye injuries
acute narrow angle glaucoma
bc increases intraoc pressure
Also hyperkalaemia
signs of paralytic ileus on examination
abdo distension n tenderness
absolute constipation
blood tests = fluid and electrolyte loss
Ci in basel skull fracture airway adjunct
nasopharyngeal airway
neuromuscular blocker (paralytic agent) CI in burns and trauma patients
Depolarising eg suxameth
increse risk of hyperkalameia in Trauma and burns pts
nitrous oxide adverse effects
may diffuse into gas filled body compartments –> increase Pressure
avoid in pneuomothorax ie car accident increases risk of tension pneumothorax
most likely cause of fever day 1-2
‘wind’
pneumonia
aspiriation
pul.embolism
most likely cause of fever day 3-5
‘water’
UTI esp if catheter
most likely cause of fever day 5-7
‘wound’
infection at surgical site
or abscess formation
most likely cause of fever day 5+
‘walking’
DVT or PE
most likely cause of fever anytime
drugs
transfusion reactions
sepsis
line contamination
why does would bad post op pain management predispose to pneumonia
insufficient analgesia = period of pain –> pt shallow breathing
lack of deep breathing risk of atelectasis and Resp tract infections
(Atectasis no fever)
pt on long term 10mg+ pred daily what to do for surgery
IV hydrocortisone supplementation before op
air leak post lung injury ie surg
chest drain will show bare bubbles when suction applied
appendicitis and then subsequent abcesses lead to deranged LFTs week after post op in ITU
intrabdominal sepsis may lead to hypercoaguable state therefore at risk of port vein thrombosis
portal vein supplies most of liver (hepatic artery 25%) therefore deranged LFTs
resp stridor and small haematoma in neck post total thyroidectomy mx
= post op haematoma!!
heamatoma ca compress trachea = resp distress and stridor
1st remove skin clips straight away on the ward to release pressure
hoarse voice post thyroid surg ix
laryngoscopy to see vocal cords to show if larygngeal nerve palsy
hypocalaemic tetany surgical cause and pt
damage to parathyroid glands during thyroid surg = hypocalcaemia
oculogyric crisis and diffuse muscle spams (tetany)
give iv calcium
heamodynamically stable which canulla and only need tempIV access
normal pink 20G peripheral cannula
somone peripherally shut down how to cannulate
intraoesseous infusion
long term option for IV acesss ie chemodrugs etc
hickmann line
(tunneled line)
US used to insert into jug vein and then cuffed into skin and integrates w surrounding tissue, therefore remove surgically
elective Hip VTE proph
Ted stockings and LMWH heparin (dalte) 6-12 post op
stockings till discharge and lmwh for 28 days
or
LMWH for 10days then aspirin (75/150mg) for 28 days
or rivoraxaban
Patients with poor Bm control or taking insulin need what in surgery
When to ideally operate
Sliding scale
Ideally put them 1st on theatre list to prevent complications of poor bm control
What surgeries can thoracic duct be injured
Thoracic surgery ie pneumonectomy
Oesphagectomy
RUQ pain and and bilious fluid in intraabdo drain post cholecystectomy
Biliary leak
How would perforation post laprosscopic cholecystectomy present
Peritonitis
Structure at risk in use of verres needle to to establish pneumoperitoneum
Bowel perf
At risk structure in parotidectomy
Facial nerve
When might accessory nerve be injured
Posterior triangle lymph node biopsy
When might long thoracic be injured and how would it present
Axillaire node clearance
Scapula winging bc paralysis of serratus anterior muscle
Long term mechanical ventilation risks
Tracheooesphageal fistula formation
Increasing risk of ventilator associated pneumonias and aspiration pneumonias (bc stomach contents)
short term sedation ie endoscopy
midazolam
non invasive ventilaton
type 1 resp failure = CPAP
inadeq o2 due to alveolar collapse (pneum) or fluid in alveoli (heart failure)
maintains min airway pressure -> holds alveoli open/forces fluid out
Type 2 = BiPAP
inadeq ventilation -> limited alveolar expansion (COPD, musc dystrophy)
adds further insp pressure = increases expansion
invasive ventilation
ET tube /tracheostomy
volume control and pressure control
increasing HR
anticholinergic - atropine, glycopyrrolate
B-adrenoreceptor agnoist - dobutamine (used in HF)
increasing BP
Alpha agonists
Peripheral – phenylephrine, metaraminol
Central – noradrenaline
increasing hr and Bp
Combined alpha and beta agonist – ephedrine or adrenaline (very potent)
fentanyls
Fentanyl
Alfentanil – onset and offset more rapid
Remifentanil – ultrashort acting. Infusion only.
antiemetic 5HT3
Ondansetron
anto emetic h1
cyclizine
anti emetic d2
domperidone, metoclopramide (Parkinson, QT prolongation), prochlorperazine
lithium before surg
stop 24hrs before major surg
minor = ok
potass sparing diuretics w surg
withhold morning of
acei arbs w surgery
sstop 24 hrs before
fat embolism sx and presentation
post long bone trauma or surgery
resp
neuro
petechial rash after 1st two
also get pyrexia
retinal haemorhhages and inraarterial fat globus
apply cricoid pressure when intubating
to prevent aspiration of gastric contents
