preoperative medicine and critical care Flashcards
airway manoeuvres
chin lift
jaw thrust
D - disability
GCS
AVPU
glucose
mean arterial pressure minimum normal
> 60/65 normal
sepsis 6
take 3:
- lactate - elevated if >2
- blood cultures (before abx)
- urine output
give 3:
- abx - broad spec
- fluid - 30ml/kg crystalloid for hypotension or lactate >4
- O2
- add vasopressors if hypotension to maintain MAP >65
fluid challenge
- 10-30ml/kg bolus crystalloid STAT
repeat to response
decrease dose if possible heart failure (5ml/kg)
colloids are out
Hartmanns, plasmalyte: like saline, but more physiological
type 1 vs type 2 respiratory failure
- blood gas levels
- causes
TYPE 1: hypoxia - low O2 (unable to supply O2) - low CO2 - causes: pneumonia, pulmonary embolism, pulmonary fibrosis, pulmonary oedema
TYPE 2: hypoxia + hypercapnia - low O2 - high CO2 (unable to eliminate CO2) - low pH (acidosis) - causes: asthma, COPD, pneumothorax, muscular dystrophy, chest deformities, opioid, benzo overdose
blood products
- ongoing haemorrhage:
- -> 2222 “major haemorrhage”
- Hb unhelpful if actively bleeding
- check FBC and clotting regularly to correct coagulopathy:
- FFP
- platelets
- cryoprecipitate (fibrinogen)
fasting times for surgery
6hrs for solids
2 hrs for liquids
diabetes surgery fasting
- stop oral hypoglycaemic
- half dose of long acting insulin (patients can become ketotic)
- monitor
- may need variable rate insulin infusion
- met formin does not cause hypoglycaemia (don’t need to stop)
ASA grade
ASA 1: normal healthy
ASA 2: mild systemic disease
ASA 3: severe systemic disease (co-morbidities)
ASA 4: constant threat to life - no surgery
ASA 5: not expected to survive with/out surgery
Pain ladder
mild intermittent:
- paracetamol 1g qds PRN
mild constant:
- reg paracetamol 1g qds
+
PRN NSAIDs (oral ibuprofen 400mg tds)
moderate: - regular paracetamol \+ regular NSAIDs or if unable to do oral, PR diclofenac 50mg tds \+ regular codeine phosphate 30-60mg qds
paracetamol + codeine can be prescribed as co-codamol 30/500 two tablets up to qds
severe: ORAL INTAKE - regular paracetamol \+ - regular NSAIDs \+ - pro morphine (oramorph) 10mg every 2hrs
NO ORAL INTAKE: - regular PR paracetamol \+ regular NSAIDs (PR diclofenac) \+ IV morphine protocol or patient-controlled analgesia/epidural analgesia
epidural analgesia
catheter into spinal column but outside meninges - local anaesthetics/ opioids into nerve roots
can cause hypotension
post operative complications
MI stroke thrombo-embolic renal failure haemorrhage pneumonia sepsis/SIRS wound infection re-operation
venous blood gas:
low pH
high CO2
low O2
bicarb normal
diagnosis
type 2 respiratory failure (low O2, high CO2)
respiratory acidosis
venous blood gas:
low pH
normal CO2
normal O2
bicarb low
diagnosis
metabolic acidosis
venous blood gas:
pH normal
O2 normal
CO2 low
bicarb adjusted
diagnosis
respiratory acidosis with metabolic compensation
85yrs 2 days after hemiarthroplasty moderately severe COPD O2 sats 89% with nasal cannula at 2L/min O2 RR: 20-25bpm comfortable
next action?
non-urgent CXR
raised RR
diseased lungs –> increased risk of post-op complications e.g. atelectasis
target sats for COPD: 88-92%
therefore no indication for extra O2 or blood gas
target O2 sats in COPD
88-92%
max flow rate in nasal cannulae
3L per min
61yrs abdo pain, dehydration and vomiting an 'acute abdomen' suspected perforated colon early warning score (EWS) of 1 due to raised temp so far management has been: - O2 - IV cannulation &bolus fluids - urinary catheter - bloods incl lactate, FBC - urgent CT abdo booked
next action?
blood culture
signs of sepsis –>
sepsis 6
take blood cultures before giving abx if poss
lactate can be measured from a venous sample
may need to go to theatre but CT prior to this
where is intraosseous access most commonly obtained
proximal tibia
at which stage of the procedure is it too late to prevent the wrong site being operated on
the sign out stage
time out stage is last stage where it can be changed
what is a good anaesthetic agent for haemodynamically unstable patients
ketamine
preserves blood pressure and does not cause cardiosuppression
which anaesthetic should be given for excision on digits (fingers and toes)
should adrenaline be given?
lidocaine - local anaesthetic
ring block - 1%
do not give adrenaline as can cause digital ischaemia
- normally given to prolong effects of local anaesthetic
what can hypothermia during anaesthesia cause
- excess blood loss due to reduced ability to clot
- reduced wound healing
- infection
can get hypothermia in anaesthesia
which anaesthetic has anti-emetic properties
propofol
propofol is rapid acting
what comes first in shock tachycardia or hypotension
tachycardia first
RUQ pain + bilious fluid in intraabdo drain following cholecystectomy
biliary leak
american society of anaesthesiologists (ASA) classification
ASA 1:
- normal healthy patient. (healthy, non-smoking, no or minimal, alcohol use)
ASA 2:
- mild systemic disease - without functional limitations
ASA 3:
- severe systemic disease - substantive functional limitations
ASA 4:
- severe systemic disease that is constant threat to life e.g. recent MI, stroke, valve dysfunction, sepsis
ASA 5:
- moribund patient who is not expected to survive without operation e.g. ruptured AAA, massive trauma
ASA 6:
- declared brain dead patient whos organs are being removed for donor purposes
how is susceptibility to malignant hyperthermia inherited
by autosomal dominance
causative agents of malignant hyperthermia
usually seen after administration of anaesthesia
causes:
- halothane
- suxamethonium
- antipsychotics (neuroleptic malignant syndrome)
management for malignant hyperthermia
dantrolene
causes of post operative fever
day 1-2: wind: pneumia, aspiration, PE
day 3-5: water: UTI
day 5-7: wound: infection at surgical site or abscess
day 5+: walking: DVT or PE
any time: drugs, transfusion reactions, sepsis, line contamination
cause of pneumonia post operative
complication of poor post operative pain management
when should LMWH be started for elective hip replacement surgery
LMWH (e.g enoxaparin) 6-12hrs after surgery
LMWH for 10 days then aspirin for further 28days
when are nasopharyngeal airways contraindicated
with suspected or known base of skull fractures
use oropharyngeal airway instead
periorbital ecchymosis and mastoid process bruising
mastoid process bruising (battle's sign) periorbital ecchymosis (raccoon eyes)
signs of basal skull fracture
can also have CSF rhinorrhoea
who is sensitive to non-depolarising paralysis agents (e.g. rocuronium)
myasthenia gravis
Lambert-Eaton myasthenic syndrome (weakness of proximal muscles and improves with use)
give suxamethonium instead
isolated fever in well patient in first 24hrs following surgery
physiological reaction to operation
drug to reverse benzos
flumazenil
anaesthetic agent with anti-emetic effect
propofol
used in day cases
halothane anaesthetic agent side effect
hepatotoxic
anaesthesia of choice in haemodynamically unstable patients
ketamine
due to little myocardial depression
20ml of 2% solution
how much of the solid is present in mg
400mg
general rule: 1% means 1g dissolved in 100ml
therefore 2% = 2g in 100ml
as this is 20ml: 2g / 5 = 400mg
risk of using hypotonic (0.45%) saline in paediatric patients
risk of hyponatraemic encephalopathy
anastomotic leak presentation
post op >5days
very sick with sepsis
pain
hard abdo
fever tachycardia recent surgery - hemicolectomy abdo soft not distended tender around midline wound discharge seeping through dressing
wound infection
usually presents >5 days post op
anaesthetic agent causing malignant hyperthermia
suxamethonium
halothane
antipsychotics - neuroleptic malignant syndrome
mx for malignant hyperthermia
dantrolene
how far in advance do you need to stop the oral contraceptive pill before general anaesthetic surgery
4 weeks - for elective under general anaesthetic
do you need to stop the contraceptive pill before local anaesthetic surgery
no
thyroid surgery preparation
vocal cord check
thyrotoxicosis surgery prep
lugols iodine/ medical therapy
surgery for carcinoid tumour prep
covering with octreotide
non-haemolytic febrile reaction to transfusion mx
fever, chills
slow of stop transfusion
paracetamol
monitor
minor allergic reaction to blood transfusion
pruritis, urticaria
temporarily stop transfusion
antihistamine
monitor
anaphylaxis to blood transfusion
hypotension, dyspnoea, wheezing, angioedema
stop transfusion
IM adrenaline
ABC support: O2, fluids
acute haemolytic reaction to transfusion
incompatible blood e.g due to human error
fever, abdo pain, hypotension
stop transfusion
confirm diagnosis: check identity and blood product
send blood for direct coombs test, repeat typing and cross-matching
fluid resus
