Anaesthetics Flashcards
1
Q
What is a fistula ?
A
an abnormal connection between 2 epithelial surfaces
2
Q
what is a hernia ?
A
protrusion of a viscus/art of a viscus through a defect of the wall of containing cavity into an abnormal position
3
Q
What is diathermy ? what are the two types ?
A
high frequency electrical current to cut tissues of cauterise small vessels
- monopolar or bipolar diathermy
4
Q
What are the general two types of sutures ? describe a bit
A
- absorbable: slowly absorbed + disappear over time (good for tissues that heal well)
- non-absorbable (stay in place for long time to support other tissues)
5
Q
What is the WHO surgical checklist ? what is the aim ?
A
aim to reduce post op complications + mortality
- contains 19 questions
- done before induction of anaesthesia, before first incision, before patient leaves theatre
6
Q
name some things in the HWO surgical checklist ?
A
- patient identity
- allergies
- operation to be performed
- Risk of bleeding
- count number of needles/sponges
7
Q
What processes need to be done before a patient undergoes surgery ? (7)
A
- Pre-op assessment
- consent
- bloods (plus group and save/cross match)
- patient fasting
- med changes
- VTE risk assessment
- Ensure patient understands procedure/outcomes (consent)
8
Q
What is done in the pre-op assessment ? (5)
A
- establish if patient is fit to undergo procedure
- explore comorbidities
- anaesthetic risk
- frailty status
- cardio/resp fitness
9
Q
What is ASA grading ? how many levels are there ? describe a bit
A
ASA1: normal healthy
ASA5: moribund (will not survive 24 hrs)
- grade to describe current fitness before undergoing anaesthesia/surgery
10
Q
What is DASI ? what does it stand for and what does it indicate ?
A
Duke Activity Status Index
- scoring tool that estimates function capacity (asks about activities)
- higher value => higher functional status
11
Q
What is a MET ? what does it stand for and explain ?
A
Metabolic equivalent
- ratio of working metabolic state to resting metabolic rate
- 1 MET is energy you spend sitting at rest (4 METS => activity takes 4x the energy than at rest)
12
Q
What are patients with IHD at a higher risk of ?
A
increased MI risk preoperatively so ensure continue BB
13
Q
What tests do you generally do for everyone pre-op ? (5)
A
- U+E
- FBC
- finger prick bood glucose
- group + save
- MRSA screening
14
Q
When would you do ECG pre-op ? (4)
A
- > 55
- poor exercise tolorance
- prev MI
- if suspected CVD
15
Q
When would you do an echo pre-op ?
A
- suspected heart murmur
- suspected HF
- suspected poor LV function
16
Q
What is group + save ?
A
send off sample to establish blood group
17
Q
what is crossmatching ?
A
taking unit of blood off shelf and assigning to patient
18
Q
what happens if patient is MRSA positive ?
A
this is no contraindication to surgery
- patient gets put to end of case list
19
Q
what are the surgical fasting rules ?
A
- > 6 hrs no food
- NMB >2hrs pre-op for clear fluids
20
Q
Why NBM for surgery ?
A
make stomach empty to prevent gastric contents refluxing into oropharynx => aspirated into trachea => aspiration pneumonitis, pneumonia => morbidity/mortality
21
Q
When would you check HbA1c pre-op ?
A
if known diabetic
22
Q
Which meds should be continued on the day of surgery ? (10)
A
- ACEI
- Abx
- BB
- Digoxin
- Statin
- Bronchodilators
- PPI
- Steroids
- Levodopa
- Anticonvulsants
23
Q
Should a BB block be taken on morning of surgery ?
A
yes, continue including day of surgery as this reduces cardiovascular risk
23
Q
which meds need to be stopped earlier in advance of surgery (week tie frame) ?
A
- COCP/HRT (4 weeks pre-op and start 2 weeks post op)
24
How old to give consent in the UK ?
>16 yrs can give valid consent
if <16 then need to show hillock competence
- if <18 yrs and refusing life saving surgery then talk to parent + senior
25
What and when Abx prophylaxis given ?
IV prophylaxis 30 min pre op (co-amox)
26
What are the 4 levels of sedation ? at what point may airway intervention be required ?
- minimal
- moderate
- deep (airway intervention make be required at this point)
- GA
27
why is tight glycemic control important in a diabetic patient undergoing surgery ?
Reduce post op infection + cardiac complications risk
28
how to manage a diabetic patient on insulin ? when have last insulin dose ?
- make them first on the list to minimise fasting time
- give all usual insulin the night before surgery (if Am then omit morning dose)
- variable rate IV insulin infusion (VRIII/sliding scale) to achieve normoglycemia (fluid should be prescribe to run with the VRIII)
29
How to manage a diabetic patient on only tablet treated diabetes ? when take last meds ? except which one ? why ?
normal meds night before
- except long acting sulphonylureas (cause prolonged hypos when fasting)
30
How to deal with a patient on warfarin undergoing surgery ? peri op? post op ?
- Im major surgery stop the warfarin (inverse with vit K)
- consider bridging with heparin
- post op: give LMWH until INR is therapeutic (as warfarin is initially prothrombottic)
31
how to manage a patient on long term steroids undergoing surgery ?
may not be able to handle the stress of surgery due to HPA supression
- extra corticosteroid over required (if patient >2 weeks >5mg/d): give hydrocortisone before induction and immediately after surgery
32
What helps enhance recovery post-operatively ? (5)
- good prep (healthy diet + exercise)
- minimally invasive surgery
- adequate analgesia
- good nutritional support
- early mobilisation
33
What causes post-op nausea and vomiting (PONV) ? (4)
- surgical procedure
- anaesthetic
- pain
- opioids
34
PONV RF ? (5)
- Female
- motion sickness
- non-smoker
- post op opiates
- younger age
35
what is given to help with PONV ? (3)
prophylactic antiemetics (ondansetron (5HT-3), dexamethasone, cyclazine)
36
what is TPN ? how is it given ? why this way ?
food given through IV infusion (given through central line due to thrombophlebitis risk)
37
TPN complications ? (3)
- sepsis
- thrombosis (=> PE or SVC obstruction)
- refeeding syndrome
38
what is used to screen for malnourished patients ?
MUST score
(Malnutrition universal screening tool)
39
name some common post-op complications ? (10)
- anaemia
- atelectasis
- infection
- wound dehiscence
- urinary retention
- DVT/PE
- Sepsis
- ACS
- Delirium
- AKI
40
post op anaemia - when do you start oral iron ? when blood transfusion ?
always do FBC to assess haemoglobin
- <100g/l: start oral iron
- <70-80 g/l: blood transfusion
41
in what % of surgical patients does DVT occur in ?
25-50%
42
DVT prevention in a patent undergoing surgery ? holistic approach
- Stop COCP
- mobilise early
- LMWH for high risk patients (enoxaparin)
- compression stockings
43
DVT treatment ?
- calculate wells score (>2 => DVT likely so do D-dimer + USS)
- DOAC
44
Cause of swollen legs (bilateral oedema) (2)
- increased venous pressure (RHF)
- reduced intravascular oncotic pressure (low albumin)
45
In what conditions should you avoid NSAIDs ?
avoid in asthma, renal impairment, heart disease, stomach ulcers
46
What are the 2 main anaesthesia types ? describe a bit
- General (making the patient unconscious): patient is intubated/supraglottal airway device, breathing supported by ventilator
- regional: blocking feeling to isolated area of the body
47
what is pre oxygenation ? what is the aim ?
period of several minutes where patient receives 100% oxygen
- have oxygen reserve for period where los consciousness + successfully intubated
48
when might anxiolytics be needed pre-op ? what drug ?
if anxious, LD, neurodivergent
- diazepam, midazolam
49
What is rapid sequence induction/intubation ? when done ? what is the risk ?
- what do you do to reduce the risk?
fain airway control in emergency
- bigger aspiration risk: so position patient more upright, cricoid pressure
50
what are some indications for gaseous induction ? (3)
- Patient request
- Difficult IV access
- children
51
what is the triad of general anaesthesia ?
- Hypnosis (make patient unconscious)
- Muscle relaxation (block neuromuscular junction from working => relax/paralyse muscles)
- Analgesia (pain relief)
52
What drugs are used for the hypnosis part of GA ? IV ? inhaled ?
- IV: propofol, ketamine, thiopental sodium
- Inhaled: sevoflurane
53
Why is propofol a good GA drug ? what do you have to be careful about once its been drawn up ?
- - its used for GA + induction plus has anti-emetic effects
- once opened, use or discard due to risk of bacterial growth
54
What do you need to be sure of before you give muscle relaxants ?
need to know that ventilation is possible
55
What are the two different types of muscle relaxants ? give an example of each ?
- depolarising (suxamethonium)
- non-depolarising (rocuronium/atracurium)
56
How to depolarising muscle relaxants work ?
partial agonist for Ash so causes initial fasciculation's through depolarisation => paralysis by blocking them
57
how do non-depolarising muscle relaxants work ?
competitive antagonists (compete with Ach at NMJ) => no fasciculations
58
is it depolarising or non-depolarising muscle relaxants that can be easily reversed ? how is this done ?
non depolarising
- their action can be reversed by anticholinesterases which act to increase ACh in NMJ
59
what is usually used as analgesia in surgery. give examples
opiates
- fentanyl, alfentanyl, remifentnyl morhpine
60
what is TIVA ? what is usually used ?
total intravenous anaesthesia
- typically propofol + remifentanyl (ultra short acting opioid)
61
When is the patient extubated after surgery ?
patient regains consciousness => extubated when start breathing for themselves
(muscle relaxant needs to have worn off)
62
what are some risk of GA ? (+intubation) (7)
- post op N&V
- accidental awareness
- aspiration
- dental injury
- anaphylaxis
- MI/stroke
- malignant hyperthermia
63
What is malignant hyperthermia ? what inheritance
rare autosomal dominant condition: hyper metabolic response to anaesthesia precipitated by volatile agent (halothane, suxamethonium)
- 1 degree temp rise every 30 mins
64
how is malignant hypertension treated ?
dantrolene (skeletal muscle relaxant)
65
what is PEEP ? what stand for ?
Positive end-expiratory pressure
- is useful adjunct to mechanical ventilation: allows pressure to be exerted at end of expiration to prevent atelectasis => increase SA for gas exchange
66
What is Rapid sequence induction (RSI) ? how different to normal
in emergency setting (unlikely fasted)
- pre-oxygenate to 100%, apply cricoid pressure, induction agent (propofol) + quick acting muscle relaxant (suxamethonium) and then longer acting (rocuronium)
67
What are peripheral nerve blocks ? and how do they work ? is patient awake ?
regional anaesthesia (patient remains awake)
- local anaesthetic injected around specific nerves => area distal to nerve is anaesthetised
68
what is spinal anaesthetic ? into what space ? name a drug used for this ?
central neuroaxial anaesthesia (spinal): regional anaesthesia
- local anaesthetic (bupivicaine) injected into CSF (sub arachnoid)
- causes numbness + paralysis below injection level (check with cold spray)
69
at what vertebral level is spinal injected ?
L3/4 or l4/5 level
70
What is epidural anaesthesia ? explain how it is done ? which vertebral level ?
insert catheter into epidural space + inject local anaesthetic => diffuse through to surrounding tissues + spinal cord
- L3/4 comments site
71
epidural adverse effects ? (6)
- headache (if dural puncture)
- hypotension
- motor weakness in legs
- nerve damage
- infection
- haematoma
72
name some local anaesthetic agents ? (3)
- lidocaine
- prilocaine
- bupivicaine
73
through what anatomy is an endotracheal tube inserted ?
inserted through mouth => pharynx => larynx => vocal cords => trachea
74
name some supraglottic airway devices ?
- LMA
- I-gel
75
what type of airway device are guedels ? where do they go ?
oropharyngeal airway device: inserted into the oropharynx
76
what are the 4 plans for unanticipated difficulty with intubating a patient (A-D)
Plan A: laryngoscopy + tracheal intubation
Plan B: supraglottic airway device
Plan C: face mask ventilation
Plan D: cricothyroidotomy
77
What are arterial lines ? what are they used for ? what not ?
cannula inserted into artery: can measure BP in real time + ABG smiles taken
- drugs never given through art line
78
what are central venous catheter (CVC)
long tube with several lumens inserted in large vein
79
what is PICC line ?
peripherally inserted central Catheter
- inserted in peripheral vein (arm) and inserted until tip is in central position (vena cava or RA)
80
What is acute vs chronic pain ?
acue pain (new onset of pain) vs chronic (>3 months)
81
what is pain threshold ?
the point at which a sensory input is reported as painful
82
what is allodynia ?
it is where pain is experienced with sensory inputs that don't usually cause pain
83
describe the general pain pathway ? how is pain detected and communicated ?
pain receptors (nociceptors) at end of nerve detect damage/potential damage to tissue => transmitted along afferent nerve (primary afferent nociceptor) => CNS up spinal cord in spinothalamic/reticular tract => brain interprets as pain
84
What is neuropathic pain ?
pain is caused by abnormal functioning or damage of sensory nerves
85
briefly describer WHO analgesic ladder ?
- step 1: non-opioid (paracetamol, NSAIDs)
- step 2: weak opioids (codeine, tramadol)
- step 3: strong opioids (norphine, oxycodone, fentanyl, buprmorphine)
86
NSAID SE ? (5)
- gastritis with dyspepsia
- stomach ulcers
- asthma exacerbation
- HTN
- renal impariemtn
(prescribe PPI to reduce GI SE)
87
NSAID contraindications ? (5)
- asthma
- renal impairment
- heart disease
- stomach ulcers
- uncontrolled HTN
88
Opioid SE ? (5)
- constipation
- skin itching
- N&V
- altered mental state
- resp depression
89
what is multimodal analgesia ? why good ?
using many analgesic types to reduce SE profile of each by avoiding higher doses
90
what are APACHE and SAPS scores for ?
scoring system to predict mortality at admission to ICU
91
why need good nutritional support post surgery ?
they are in hypermetabolic state and have increased nutritional requirements
92
what is ventilator associated lung injury ? what can it lead to ?
from mechanical ventilation => over-inflating alveoli (volutrauma) => pulmonary oedema + hypoxia => fibrosis, infection, cor pulmonale
93
what is ventoliar associated pneumonia ? how to avoid ?
due to increased risk of bacteria aspiration to lungs
- so put bed at 30 degree angle + good mouth cleaning
94
what is critical illness myopathy ?
muscle wasting + weakness of resp muscles => difficult weaning mechanical ventilation => reduced QOL
95
what is ABG used for ? what does it show ?
to assess patents for resp failure + monitoring in ICU
- give info about acid-base balance, blood gases, bicarb, lactate, haemoglobin, electrolytes
96
normal ABG pH range ?
7.35 - 7.45
97
normal ABG PaO2 range ?
10.7 - 13.3 KPa
98
normal ABG PaCO2 range ?
4.7 - 6.0 KPa
99
normal ABG HCO3- range ?
22 - 26 mmol/L
100
normal ABG base excess range ?
-2 to 2
101
normal ABG lactate range ?
0.5 - 1 mmol/L
102
what is type 1 vs type 2 resp failure ? describe blood gas findings
type 1 (1 affected): low PaO2 + normal PaCO2
type 2 (2 affected): low PaO2 + high PaCO2
103
describe the ABG findings in resp acidosis ?
low pH + high PaCO2 (patient is retaining CO2)
104
what would raised bicarb in resp acidosis mean ?
- bicarb: produced in kidneys + acts as a buffer (slow compensatory mechanism so increased bicarb indicates chronically retain CO2 - like COPD)
105
describe ABG findings in resp alkalosis ? caused by ?
raised pH + low PaCO2 (when patient has high resp rate)
106
patient has resp alkalosis. what would low PaO2 indicate ? what would normal PaO2 indicate ?
normal PaO2: hyperventilation (anxiety)
low PaO2: PE
107
describe ABG findings for metabolic acidosis ? caused by ? (4)
low pH + low bicarb
- caused by raised lactate, raised ketones, renal failure, low bicarb)
108
describer ABG findings for metabolic alkalosis ? caused by ?
high pH + raised bicarb
- caused by loss of H+: vomiting, or from kidneys (due to increased aldosterone activity due to conns syndrome, liver cirrhosis, HR, loop diuretics)
109
describe resp support form least to most invasive ?
- oxy therapy
- high flow nasal cannula
- non-invasive ventilation
- intubation + mechanical ventilation
- extracorporeal membrane oxygenation (ECMO)
110
What is acute resp distress syndrome ?
acute onset of collapsing alveoli (atelectasis), pulmonary oedema, reduced lung compliance, fibrosis of lung tissue ( after >10 days)
111
benefits of prone position in patients with acute resp distress mx ? (4)
- reduced compression of lungs by other organs
- improve blood flow to lungs
- clears secretion
- improves oxygenation
112
what is a benefit to Venturi masks ?
can be used to deliver exact concentrations of oxygen (useful in COPD)
113
What is CPAP ? used for what ?
continuous positive airway pressure (CPAP)
- constant pressure added to lungs to keep airway expanded (adds PEEP
- used in OSA
114
what is non-invasive ventilation ? what BiPAP
full face mask to blow air forcefully into lungs + inflate them
- BiPAP involves cycle of low + high pressure (cycle between IPAP + EPAP)
115
what is mechanical ventilation ?
ventilator machine moves air in + out of lungs (patients require a level of sedation)
- ETT or tracheostomy is required
116
what is ECMO ? describe it
Extracorporeal membrane oxygenation: most extreme resp upport
- blood is removed from body, passed through machine, gas exchange, pump back into body
117
What is preload ? after load ?
- preload: amount that heart muscle is stretched when filled with blood before contraction
- afterload: resistance that heart must overcome to eject blood from LV
118
what is MAP ? explain it a bit
mean arterial pressure is average BP throughout entire cardiac cycle (systole and diastole)
119
what can cause low MAP ? (2) what does this cause ?
low MAP may be due to low CO or low SVR => poor tissue perfusion => hypoxia, anaerobic resp, lactate
120
what is often used to estimate preload ?
central venous pressure (CVP)
121
what do inotropes do ? name some positive and negative ones ?
alter contractility of heart
- positive inotropes => increase contractility => increase CO + MAP (adrenaline)
- Negative inotropes: BB, CCB, flecanide
122
what are vasopressors ? affect on MAP ? name some ? (4)
cause vasoconstriction => increase SVR => increase MAP
- noradrenaline, vasopressin, adrenaline, metaraminol
123
indications for acute dialysis ? (5)
AEIOU
- acidosis
- Electrolyte abnormalities (esp treatment resistant hyperkalaemia)
- intoxication (certain med overdose)
- Oedema (severe + unresponsive oedema)
- Uraemia (with sx like seizures + unconsciousness)
124
What causes Obstructive sleep apnoea (OSA)
caused by collapse of the pharyngeal airway => apnoea apisods
125
what tool can be used to screen for OSA patients ? (2) describe it
STOP-BANG
- Snoring
- Tired
- Observed
- blood Pressure
- BMI
- Age
- Neck circumference
- Gender
Hepworth sleepiness scale (assess sx of sleepiness associated with OSA)
126
what is the relevance of OSA to peri-op care ? how to manage this ? management post op ?
sedation + opioids + anaesthesia => increased risk of upper airway collapse => increase risk of post-op complications
- Mx: minimise surgical stress, reduce duration of surgery, consider regional/local, anticipate difficult intubation
- post op mx: minimise opioid use, continuously monitor O2, CPAP after surgery
