preoperative medicine and critical care

Question 1

airway manoeuvres

Answer 1

chin lift

jaw thrust

Question 2

D - disability

Answer 2

GCS
AVPU
glucose

Question 3

mean arterial pressure minimum normal

Answer 3

> 60/65 normal

Question 4

sepsis 6

Answer 4

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

Question 5

fluid challenge

Answer 5

• 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

Question 6

type 1 vs type 2 respiratory failure

• blood gas levels
• causes

Answer 6

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

Question 7

blood products

Answer 7

• ongoing haemorrhage:
• -> 2222 “major haemorrhage”
• Hb unhelpful if actively bleeding
• check FBC and clotting regularly to correct coagulopathy:
• FFP
• platelets
• cryoprecipitate (fibrinogen)

Question 8

fasting times for surgery

Answer 8

6hrs for solids

2 hrs for liquids

Question 9

diabetes surgery fasting

Answer 9

• 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)

Question 10

ASA grade

Answer 10

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

Question 11

Pain ladder

Answer 11

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

Question 12

epidural analgesia

Answer 12

catheter into spinal column but outside meninges - local anaesthetics/ opioids into nerve roots

can cause hypotension

Question 13

post operative complications

Answer 13

MI
stroke 
thrombo-embolic 
renal failure 
haemorrhage 
pneumonia 
sepsis/SIRS
wound infection 
re-operation

Question 14

venous blood gas:

low pH
high CO2
low O2
bicarb normal

diagnosis

Answer 14

type 2 respiratory failure (low O2, high CO2)

respiratory acidosis

Question 15

venous blood gas:

low pH
normal CO2
normal O2
bicarb low

diagnosis

Answer 15

metabolic acidosis

Question 16

venous blood gas:

pH normal
O2 normal
CO2 low
bicarb adjusted

diagnosis

Answer 16

respiratory acidosis with metabolic compensation

Question 17

85yrs 
2 days after hemiarthroplasty 
moderately severe COPD 
O2 sats 89% with nasal cannula at 2L/min O2
RR: 20-25bpm 
comfortable 

next action?

Answer 17

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

Question 18

target O2 sats in COPD

Answer 18

88-92%

Question 19

max flow rate in nasal cannulae

Answer 19

3L per min

Question 20

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?

Answer 20

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

Question 21

where is intraosseous access most commonly obtained

Answer 21

proximal tibia

Question 22

at which stage of the procedure is it too late to prevent the wrong site being operated on

Answer 22

the sign out stage

time out stage is last stage where it can be changed

Question 23

what is a good anaesthetic agent for haemodynamically unstable patients

Answer 23

ketamine

preserves blood pressure and does not cause cardiosuppression

Question 24

which anaesthetic should be given for excision on digits (fingers and toes)
should adrenaline be given?

Answer 24

lidocaine - local anaesthetic
ring block - 1%

do not give adrenaline as can cause digital ischaemia
- normally given to prolong effects of local anaesthetic

Question 25

what can hypothermia during anaesthesia cause

Answer 25

- excess blood loss due to reduced ability to clot - reduced wound healing - infection can get hypothermia in anaesthesia

Question 26

which anaesthetic has anti-emetic properties

Answer 26

propofol propofol is rapid acting

Question 27

what comes first in shock tachycardia or hypotension

Answer 27

tachycardia first

Question 28

RUQ pain + bilious fluid in intraabdo drain following cholecystectomy

Answer 28

biliary leak

Question 29

american society of anaesthesiologists (ASA) classification

Answer 29

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

Question 30

how is susceptibility to malignant hyperthermia inherited

Answer 30

by autosomal dominance

Question 31

causative agents of malignant hyperthermia

Answer 31

usually seen after administration of anaesthesia causes: - halothane - suxamethonium - antipsychotics (neuroleptic malignant syndrome)

Question 32

management for malignant hyperthermia

Answer 32

dantrolene

Question 33

causes of post operative fever

Answer 33

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

Question 34

cause of pneumonia post operative

Answer 34

complication of poor post operative pain management

Question 35

when should LMWH be started for elective hip replacement surgery

Answer 35

LMWH (e.g enoxaparin) 6-12hrs after surgery | LMWH for 10 days then aspirin for further 28days

Question 36

when are nasopharyngeal airways contraindicated

Answer 36

with suspected or known base of skull fractures use oropharyngeal airway instead

Question 37

periorbital ecchymosis and mastoid process bruising

Answer 37

``` mastoid process bruising (battle's sign) periorbital ecchymosis (raccoon eyes) ``` signs of basal skull fracture can also have CSF rhinorrhoea

Question 38

who is sensitive to non-depolarising paralysis agents (e.g. rocuronium)

Answer 38

myasthenia gravis Lambert-Eaton myasthenic syndrome (weakness of proximal muscles and improves with use) give suxamethonium instead

Question 39

isolated fever in well patient in first 24hrs following surgery

Answer 39

physiological reaction to operation

Question 40

drug to reverse benzos

Answer 40

flumazenil

Question 41

anaesthetic agent with anti-emetic effect

Answer 41

propofol used in day cases

Question 42

halothane anaesthetic agent side effect

Answer 42

hepatotoxic

Question 43

anaesthesia of choice in haemodynamically unstable patients

Answer 43

ketamine due to little myocardial depression

Question 44

20ml of 2% solution | how much of the solid is present in mg

Answer 44

400mg general rule: 1% means 1g dissolved in 100ml therefore 2% = 2g in 100ml as this is 20ml: 2g / 5 = 400mg

Question 45

risk of using hypotonic (0.45%) saline in paediatric patients

Answer 45

risk of hyponatraemic encephalopathy

Question 46

anastomotic leak presentation

Answer 46

post op >5days very sick with sepsis pain hard abdo

Question 47

``` fever tachycardia recent surgery - hemicolectomy abdo soft not distended tender around midline wound discharge seeping through dressing ```

Answer 47

wound infection usually presents >5 days post op

Question 48

anaesthetic agent causing malignant hyperthermia

Answer 48

suxamethonium halothane antipsychotics - neuroleptic malignant syndrome

Question 49

mx for malignant hyperthermia

Answer 49

dantrolene

Question 50

how far in advance do you need to stop the oral contraceptive pill before general anaesthetic surgery

Answer 50

4 weeks - for elective under general anaesthetic

Question 51

do you need to stop the contraceptive pill before local anaesthetic surgery

Answer 51

no

Question 52

thyroid surgery preparation

Answer 52

vocal cord check

Question 53

thyrotoxicosis surgery prep

Answer 53

lugols iodine/ medical therapy

Question 54

surgery for carcinoid tumour prep

Answer 54

covering with octreotide

Question 55

non-haemolytic febrile reaction to transfusion mx

Answer 55

fever, chills slow of stop transfusion paracetamol monitor

Question 56

minor allergic reaction to blood transfusion

Answer 56

pruritis, urticaria temporarily stop transfusion antihistamine monitor

Question 57

anaphylaxis to blood transfusion

Answer 57

hypotension, dyspnoea, wheezing, angioedema stop transfusion IM adrenaline ABC support: O2, fluids

Question 58

acute haemolytic reaction to transfusion

Answer 58

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