Passmedicine Flashcards
1
Q
What tests might you do to prepare for elective surgery?
A
?Pre-admission clinic FBC, UE, LFTs, clotting, group and save Urine analysis Pregnancy test Sickle cell test ECG/CXR
All depends on operation to be carried out and patient fitness
2
Q
Before surgery what condition should you assess risk factors for?
A
DVT - get a plan for thromboprophylaxis in place
3
Q
What is poorly controlled DM a risk factor for post-op?
A
Wound infection
4
Q
How should diabetics alter their anti-diabetes medications pre-surgery?
A
Diet/tablet controlled - omit medications + check BG regularly
Poorly controlled/insulin dependent - variable rate IV insulin infusion + K supplementation
5
Q
What things should you ensure to do before emergency surgery?
A
Stabilise, resus
?Antibiotics
Inform blood bank if major procedure planned esp. if coagulopathies present/anticipated
Consent/inform relatives
6
Q
What special preparation is required in thyroid surgery?
A
Vocal cord check
7
Q
What special preparation is required in parathyroid surgery?
A
Consider methylene blue to identify the gland
8
Q
What special preparation is required in sentinel node biopsy?
A
Radioactive marker/patent blue dye
9
Q
What special preparation is required in surgery involving the thyroid duct?
A
Consider administration of cream
10
Q
What special preparation is required in phaemochromocytoma surgery?
A
Alpha and beta blockade
11
Q
What special preparation is required in carcinoid tumours?
A
Cover with octreotide
12
Q
What special preparation is required in colorectal cases?
A
Bowel preparation
13
Q
What special preparation is required in thyrotoxicosis?
A
Lugols iodine/medical therapy
14
Q
How long are patients allowed to drink clear fluids for prior to an operation?
A
2h
15
Q
What is the action of the neuromuscular blocking drugs?
A
Muscle paralysis which is req. for mechanical ventilation
16
Q
What are the two types of neuromuscular blocking drugs?
A
Depolarising
Non-depolarising
17
Q
What is the mechanism of action of the depolarising neuromuscular blocking drugs?
A
Binds to nicotinic acetylcholine receptors –> persistent depolarisation of the motor end plate
18
Q
What is the mechanism of action of the non-depolarising neuromuscular blocking drugs?
A
Competitive antagonist of nicotinic acetylcholine receptors
19
Q
Give an e.g. of a depolarising neuromuscular blocking drugs
A
Suxamethonium (aka succinylcholine)
20
Q
Give e.g.s of non-depolarising neuromuscular blocking drugs
A
Tubcurarine, atracurium, vecuronium, pancuronium
21
Q
What are possible adverse effects of using depolarising neuromuscular blocking drugs?
A
Malignant hyperthermia
Hyperkalaemia
Fasiculations
22
Q
What are possible adverse effects of using non-depolarising neuromuscular blocking drugs?
A
Hypotension
23
Q
How can you reverse non-depolarising neuromuscular blocking drugs?
A
Acetylcholinesterase inhibitors (e.g. neostigmine)
24
Q
What type of neuromuscular blocking drug is the muscle relaxant of choice for rapid sequence induction for intubation?
A
Depolarising type - suxamethonium
25
What is a CI for suxamethonium use?
Those with penetrating eye injuries or acute angle closure glaucoma as it raises IOP
26
What is malignant hyperthermia?
Autosomal dominant disorder presenting as a hypermetabolic crisis
27
What are the features of malignant hyperthermia?
Increased end tidal CO2, tachycardia, muscle rigidity, rhabdomyolysis, hyperthermia, arrhythmias
28
How is malignant hyperthermia treated?
IV Dantrolene
29
What drug is used for benzodiazepine overdose?
Flumazenil
30
What drug is used for paracetamol overdose?
N-acetylcysteine
31
Is suxamethonium reversible? If so how?
It is not due to its mechanism of non-competitive agonism
32
How does suxamethonium work?
Non-competitive (depolarising) muscle relaxant which induces prolonged depolarisation of the skeletal muscle membrane
33
How do the competitive (non-depolarising) muscle relaxants work?
Competitive antagonism of acetylcholine at nicotinic receptors at the NMJ
34
What degrades suxamethonium in the body?
Plasma cholinesterase and acetylcholinesterase
35
What muscle relaxant has the fastest onset and shortest duration of all muscle relaxants?
Suxamethonium
36
What does suxamethonium cause?
Generalised muscular contraction prior to paralysis
37
What are AEs of atracurium?
Generalised histamine release on administration may --> facial flushing, tachycardia, hypotension
38
How is atracurium broken down in the body?
In the tissues by hydrolysis - not excreted by liver/kidney
39
How is vecuronium broken down in the body?
By liver and kidney (so effects prolonged in organ dysfunction)
40
Can pancuronium be fully reversed by neostigmine?
May be partially reversed by neostigmine - remember duration of action up to 2h
41
What does 2% strength of a liquid medicine mean?
2g is dissolved in 100ml of liquid
42
What is the maximum safe dose of lignocaine?
3mg/kg
43
What is the maximum safe dose of bupivacine?
2mg/kg
44
What is the maximum safe dose of prilocaine?
6mg/kg
45
Where is lidocaine metabolised?
Liver
46
Where is lidocaine excreted?
Kidney
47
What is lidocaine bound to in plasma?
Proteins
48
What can cause lidocaine toxicity?
IV administration or excess administration
Increased risk if liver dysfunction/low protein states
49
What metabolic condition can cause lidocaine to detach from protein bounding?
Acidosis
50
How can you treat LA toxicity?
IV 20% lipid emulsion
51
What drugs can lidocaine have a DDI with?
Beta blockers
Ciprofloxacin
Phenytoin
52
What are features of LA toxicity?
Initial CNS overactivity then depression, cardiac arrhythmias
53
How can you increased an LA dose without causing toxicity?
Use in combination with adrenaline to limit systemic absorption
54
How is cocaine used as a LA?
Applied as a paste
55
What is the advantage of using cocaine as an LA?
Causes marked vasoconstriction
56
What are the adverse effects of cocaine as a LA?
It is lipophilic so easily crosses BBB and can cause systemic effects like cardiac arrhythmias and tachycardia
57
Where does cocaine as a LA tend to be used?
In ENT
| Usually applied topically to the nasal mucosa
58
What is the mechanism of action of bupivacaine?
Binds the intracellular portion of Na channels + blocks Na influx into nerve cells, which prevents depolarization
59
What is the benefit of bupivacaine over lidocaine?
Longer duration - can be used at conclusion of surgery for longer analgesic effects
60
What is the main issue with bupivacaine?
It is cardiotoxic
61
What is the advantage of prilocaine?
Fat less cardiotoxic than other LAs
62
What is the agent of choice for IV regional anaesthesia?
Prilocaine
63
What is the max dose of lignocaine with adrenaline?
7mg/kg
64
What is the max dose of bupivacine with adrenaline?
2mg/kg - does not permit increase in total dose of bupivacaine as toxicity of bupivacaine is related to protein binding
65
What is the max dose of prilocaine with adrenaline?
9mg/kg
66
What are the benefits of using adrenaline with a LA?
Prolongs duration of action at site of injection
| Allows for higher dose use
67
In which patients is adrenaline CI?
Those taking MAOIs/TCAs
68
What are CIs for suxamethonium use?
```
Penetrating eye injuries, acute angle closure glaucoma
Hyperkalaemia
Recent burns
Spinal cord trauma --> paraplegia
Suxamethonium allergy
```
69
What is the preparation for a patient before colonoscopy?
Bowel prep - laxatives the day before the examination and do not eat for 24h before
70
When should patients stop their COCP before surgery? Why?
4w prior
| Due to increased risk of VTE
71
What are the 3 phases of an operation on the surgical safety checklist?
1. before induction of anaesthesia - SIGN IN
2. before incision of skin - TIME OUT
3. before patient leaves operating room - SIGN OUT
72
What must you check in sign in?
Patient has confirmed: Site, identity, procedure, consent
Site is marked
Anaesthesia safety check completed
Pulse oximeter is on patient and functioning
Does the patient have a known allergy?
Is there a difficult airway/aspiration risk?
Is there a risk of > 500ml blood loss (7ml/kg in children)?
73
What things can be done to try and avoid complications before/during/after surgery?
WHO checklists mandatory
Prophylactic antibiotics
DVT/PE risk assessed with prophylaxis
Use tourniquets carefully
Do not use adrenaline/monopola rdiathermy in end artery situations
Handle tissues with care - devitalised tissue is an infection risk
74
What nerve is at risk of damage when undergoing posterior triangle lymph node biopsy?
Accessory
75
What nerve is at risk of damage when undergoing hip surgery (posterior approach)?
Sciatic
76
What nerve is at risk of damage when undergoing axillary node clearance?
Long thoracic
77
What nerve is at risk of damage when undergoing pelvic cancer surgery?
Pelvic autonomic nerves
78
What nerve is at risk of damage when undergoing thyroid surgery?
Recurrent laryngeal nerves
79
What nerve is at risk of damage when undergoing carotid endarterectomy?
Hypoglossal nerve
80
What nerve is at risk of damage when undergoing upper limb fracture repair?
Ulnar/median nerves
81
What structure is at risk of damage when undergoing thoracic surgery?
Thoracic duct
82
What structure is at risk of damage when undergoing thyroid surgery?
Parathyroid gland
83
What structure is at risk of damage when undergoing colonic resections/gynae surgery?
Ureters
84
What structure is at risk of damage if there is failure to delinate Calots triangle or careless use of diathermy?
Bile duct
85
What structure is at risk of damage when undergoing parotidectomy?
Facial nerve
86
What structure is at risk of damage when ligating the splenic hilum?
Tail of pancreas
87
What structure is at risk of damage when undergoing re-do open hernia surgery?
Testicular vessels
88
What structure is at risk of damage when undergoing liver mobilisation?
Hepatic veins
89
What are two very common complications after surgery?
Bleeding
| Infection
90
Why might patients get arrhythmias after cardiac surgery?
Due to hypokalaemia
91
What tends to cause a neurosurgical electrolyte imbalance?
SIADH after cranial surgery
92
What electrolyte abnormality does SIADH lead to?
Hyponatraemia
93
What does ileus following GI surgery lead to?
Fluid sequestration + loss of electrolytes
94
Why are patients who've undergone a pneumonectomy susceptible to pulmonary oedema?
Loss of lung volume makes these patients sensitive to fluid overload
95
What can an anastamotic leak lead to?
Generalised sepsis --> mediastinitis/peritonitis
96
What sort of things might you use to help to diagnose a complication post-surgery?
```
FBC, UE, CRP, serum Ca LFTs, clotting
ABG
ECG + cardiac enzymes if suspected MI
CXR - identify collapse/consolidation
Urine analysis for UTI
```
97
What investigation might you use to check for rectal anastamotic leaks?
Gatrograffin enema
98
What investigation would you use to check for a PE?
CTPA
99
What post-surgical complication may a CT scan be useful for identifying?
Intra-abdominal abscesses, air and if luminal contrast used can see anastamotic leak
100
What post-surgical complication may an echo be useful for identifying?
Pericardial effusion
101
A fever in the first 24h after an operation is usually what?
Physiological reaction to the operation
102
What are the causes of early post-op pyrexia (days 0-5)?
```
Blood transfusion
Cellulitis
UTI
Physiological systemic inflammatory reaction
Pulmonary atelectasis
```
103
What are later causes of post-operative pyrexia (>5days)?
VTE
Pneumonia
Wound infection
Anastamotic leak
104
What is a good mnemonic to remember the post-op pyrexia causes?
Wind
Water
Wound
What did we do? (iatrogenic)
105
How does giving a 20% lipid emulsion treat LA toxicity?
Lipid infusion creates lipid phase that extracts hydrophobic molecules of LA from the aqueous plasma phase and hence reduces LA concentration
106
What may pts over 65 need before major surgery?
ECG
107
What may patients with renal disease need before surgery?
FBC, ECG depending on their ASA grade
108
What may pts with HTN need before surgery?
No specific investigations
109
What may pts with DM need before intermediate surgery?
ECG
110
What classification is used to categorise the health of patients who are going to go under anaesthetic?
American society of anaesthesiologists (ASA) classification
111
What is ASA I?
Healthy
Non-smoking
No/minimal alcohol use
112
What is ASA II?
```
Mild diseases without substantial functional limitations, eg.
Current smoker
Social alcohol drinker
Pregnant
Obese (BMI b/w 30-40)
Well controlled DM/HTN
Mild lung disease
```
113
What is ASA III?
```
Moderate-severe diseases, e.g.
Poorly controlled DM/HTN
COPD
Morbid obesity (>40)
Active hepatitis
Alcohol dependence or abuse
Implanted pacemaker
Moderate reduction of ejection fraction
End stage renal dx undergoing dialysis
Hx MI (>3m ago)
CVA
```
114
What is ASA IV?
```
E.g.s -
Recent (<3m ago) MI
CVA
Ongoing cardiac ischaemia/severe valve dysfunction
Severe reduction of ejection fraction
Sepsis
DIC
ARF
ESRD not undergoing dialysis
```
115
What is ASA V?
```
E.g. -
Ruptured abdominal/thoracic aneurysm
Massive trauma
Intracranial bleed with mass effect
Ischaemic bowel with significant cardiac pathology/multiple organ/system dysfunction
```
116
What is ASA VI?
Declared brain dead pt whose organs are being removed for donor purposes
117
Describe a ASA V patient
Moribund pt who is not expected to survive without the operation
118
Describe ASA IV
Pt with severe systemic dx that is a constant threat to life
119
Describe ASA III
Pt with severe systemic dx
120
Describe ASA II
Pt with mild systemic dx
121
Describe ASA I
Healthy normal pt
122
Finish the sentence:
| All patients admitted to hospital should be individually assessed for risk factors for _______ and ______.
VTE development and bleeding risk.
123
What medical patients would be deemed to be at increased risk of developing a DVT?
Significant reduction in mobility for 3+ days (or anticipated to have significantly reduced mobility)
124
What surgical patients would be deemed to be at increased risk of VTE?
Hip/knee replacement
Hip fracture
GA + surgery duration >90m
Surgery of pelvis/lower limb with GA + lasting >60m
Acute surgical admission with an inflammatory/intra-abdominal condition
Surgery with a significant reduction in mobility
125
What are general risk factors for VTE?
```
Active cancer/chemo
>60
Known clotting disorder
BMI >35
Dehydration
1+ significant medical co-morbs (e.g. heart disease, metabolic/endocrine pathologies, resp. disease, acute infection/inflam conditions)
Critical care admission
Use of HRT
Use of COCP
Varicose veins
Pregnant or <6w post-partum
```
126
How do you decide if a pt needs VTE prophylaxis?
If VTE risk > bleeding risk
127
What are the two mechanical types of VTE prophylaxis?
Compression stockings
| Intermittent pneumatic compression device
128
What are the two types of compression stockings?
Thigh or knee high
129
What are the three types of pharmacological VTE prophylaxis?
Fondaparinux sodium (sc injection)
LMWH (e.g. enoxaparin)
UFH
130
Who is UFH used in for VTE prophylaxis?
Those with kidney disease
131
What are those deemed to be at very high risk of VTE given?
Anti-embolism stockings + pharmacological prophylaxis
132
What are those at low risk of VTE given?
Anti-embolism stockings
133
What post-surgical advice is given to pts to prevent VTE?
Avoid dehydration
| Mobilise ASAP
134
For what operations is VTE prophylaxis recommended for all patients?
Elective hip and knee replacements
| Fragility fracture of pelvis, hip and proximal femur
135
What VTE prophylaxis is given for elective hip replacement?
LMWH for 10d followed by aspirin (75/150mg) for a further 28d
OR
LMWH combined with anti-embolism stockings until discharge
OR
Rivaroxaban
136
What VTE prophylaxis is given for elective knee replacement?
Aspirin (75/150mg) for 14d
OR
LMWH for 14d + anti-embolism stockings
OR
Rivaroxaban
137
What VTE prophylaxis is given for fragility fractures of the pelvis, hip + proximal femur?
LMWH or fondaparinux
Continue until no longer have reduced mobility relative to their normal/anticipated mobility
138
If a pt develops stridor after having a thyroidectomy what is the management?
Immediately remove stick clips (haematoma post-thyroidectomy can compress airway)
139
If a pt has a hoarse voice 3d post-thyroidectomy what may have been the cause?
Damage to laryngeal nerve - req. laparotomy to see if vocal cord is paralysed
140
What has a pt who 24h post-thyroidectomy has developed oculogyric crises and diffuse muscle spasm developed? How is this managed?
Hypocalcaemic tetany
| Immediate calcium supplementation
141
How do you manage post-op ileus?
Nasogastric tube insertion for stomach decompression for symptom control
Nil by mouth to allow bowel rest
142
What investigation is best for diagnosing an anastomotic leak?
Abdominal CT
143
What are risk factors for developing an anastomotic leak?
Steroids/DMARD use
144
How does anastomotic leak present?
5-7 after the procedure
| Abdominal pain, fever
145
What are risk factors for urinary retention?
```
Removal of urinary catheter
Constipation
Immobility
Opiates
Infection
Haematuria
BPH
```
146
What kind of cannulae do you need to provide rapid fluid infusions?
Wide lumen cannulae
147
What drugs can you not give via a peripheral venous cannula?
Vasoactive drugs e.g. inotropes
| Irritant drugs, e.g. TPN
148
What is used to help place central lines?
USS
149
What is the preferred site for central line insertion?
Internal jugular
150
Where apart from the internal jugular can you also put a central line?
Femoral
151
Where is intraosseous access usually sought?
Anteromedial aspect of proximal tibia
152
Give examples of tunnelled lines?
Groshong
| Hickman
153
In which patients are tunnelled lines usually used?
For those with long therapeutic requirements
154
How are tunnelled lines usually inserted?
Using US guidance into IJV then tunnelled under the skin
155
What is at the end of the tunnelled line and what is its purpose?
Cuff of woven material that helps to anchor the device to the tissues
156
What are PICC lines?
Peripherally inserted central cannula
| These are less prone to major complications that conventional central lines
157
What route might you consider to get access to the circulation in cardiac arrest if you cant get IV access?
Intraosseous
158
What are the two most important differentials to be ruled out in a post-op fever?
Thrombosis
| Infection
159
What are commonly used IV induction agents?
Propofol
Sodium thiopentone
Ketamine
Etomidate
160
What are the benefits of Propofol as an induction agent?
Rapid onset of anaesthesia
Rapidly metabolised with little accumulation of metabolites
Anti-emetic
161
True or false:
| Propofol creates severe myocardial depression
False - moderate myocardial suppression
162
What is the anaesthetic of choice for rapid sequence of induction?
Sodium thiopentone - extremely rapid onset of action
163
What are the cons of sodium thiopentone?
Marked myocardial depression can occur
Metabolites build up quickly
Unsuitable for maintenance infusion
Little analgesic effects
164
What are the benefits of ketamine as a induction agent?
Mod-strong analgesic
| Produces little myocardial depression (good for those who are haemodynamically unstable)
165
What is the con of ketamine?
May induce state of dissociative anaesthesia resulting in nightmares
166
What is the pro of etomidate as an induction agent?
Favourable cardiac safety profile
167
What are the cons of etomidate?
No analgesic properties
Unsuitable for maintaining sedation as prolonged use --> adrenal suppression
Post-op vomiting common
168
What is the pathophysiology of malignant hyperthermia?
Excess release of Ca2+ from the sarcoplasmic reticulum of skeletal muscle
169
Where is the genetic defect in malignant hyperthermia?
Chromosome 19 gene encoding the ryanodine receptor
170
What does the ryanodine receptor do?
Controls Ca2+ release from sarcoplasmic reticulum
171
What agents can cause malignant hyperthermia?
Halothane
Suxamethonium
Antipsychotic drugs
172
What investigations might you do for malignant hyperthermia?
CK - raised
| Contracture tests with halothane + caffeine
173
How does dantrolene work in managing malignant hyperthermia?
Prevents Ca2+ release from sarcoplasmic reticulum
174
What are the different types of airways?
Oropharyngeal
Laryngeal mask
Tracheostomy
Endotracheal tube
175
What do oropharyngeal airways tend to be used for?
Bridge to a more definitive airway
176
Is paralysis required to put in an oropharyngeal airway?
No
177
Where does a laryngeal mask sit?
In pharynx, aligns to over airway
178
Does laryngeal mask prevent reflux of gastric contents into the airway?
No
179
Are laryngeal masks suitable for high pressure ventilation?
No
180
How do tracheostomies reduce the work of breathing?
Less airway and less dead space
181
What kind of tracheostomy is widely used in ITU?
Percutaneous tracheostomy
182
What kind of air is usually required through a tracheostomy?
Humidified air
183
What type of airway provides the optimal control of airway?
Endotracheal tube
184
What can errors in insertion of endotracheal airways lead to? How can we check we have put the endotracheal tube in the right place?
Oesophageal intubation
| End tidal CO2
185
Is paralysis required for endotracheal tube insertion?
Often required
186
Can you use higher ventilation pressure in endotracheal tubes?
Yes
187
When might you use a laryngeal mask?
If you don't need to paralyse the muscles
| Day case surgeries that have a quick onset of anaesthesia and recovery
188
When are tracheostomies used?
Facilitate long term weaning
189
Should you treat pre-op anaemia?
Yes
If only short time till surgery with blood transfusion
If noted weeks before can use IV iron/oral iron
190
What agent reverses the action of midazolam?
Flumazenil
191
What anaesthetic is associated with hepatotoxicity?
Halothane
192
In which operations is chance of transfusion unlikely?
Hysterectomy, appendectomy, thyroidectomy, elective lower segment C-section, laparoscopic cholecystectomy
193
How should you prepare for an operation where the chance of transfusion is unlikely?
Group and save
194
In which operations may the chance of transfusion be likely?
Salpingectomy for ruptured ectopic pregnancy, THR
195
What should you do to prepare for an operation where the chance of transfusion is likely?
Cross match 2 units
196
In which operations may the chance of transfusion be definite?
Total gastrectomy, oophorectomy, oesophagectomy, elective AAA repair, cystectomy, hepatectomy
197
What should you do to prepare for an operation where the chance of transfusion is definite?
Cross match 4-6 units
198
In which condition are compression stockings CI?
PAD
199
What is the mode of action of LMWH?
Binds antithrombin resulting in inhibition of factor Xa
200
How is LMWH given?
Sc injection
201
What is the mode of action of UFH?
Binds antithrombin III which affects thrombin + factor Xa
202
How is UFH administered?
IV
203
How can you monitor the activity of UFH?
APTT
204
What drug reverses UFH?
Protamine sulphate
205
What is the mode of action of dabigatran?
Direct thrombin inhibitor
206
How is dabigatran administered?
Orally
207
What therapeutic monitoring does dabigatran require?
Doesn't require any
208
What patients should you not use dabigatran in?
Those at risk of active bleeding or imminent likelihood of surgery
209
What is the best intervention to reduce the incidence of intra-abdominal adhesions?
Laparoscopic approach
210
How do post-op air leaks present?
Persistent pneumothorax that fails to settle despite chest drainage
211
What might you see when you apply suction to the chest drain in an air leak?
Active, persistent bubbling
212
What are the main stages of healing?
Haemostasis
Inflammation
Regeneration
Remodelling
213
What does haemostasis involve?
Vasospasm in adjacent vessels, platelet plug formation, generation of a fibrin rich clot
214
When does haemostasis occur?
Minutes to hours following an injury
215
how long does the inflammation stage of wound healing tend to last?
days 1-5
216
What kind of cells migrate into the wound at the inflammation stage of wound healing?
Neutrophils
NB function impaired in DM
217
What occurs in the inflammation stage of wound healing?
Growth factors released, incl. basic fibroblast growth factors + VEGF
Fibroblasts replicate in adjacent matrix + migrate into wound
Macrophages + fibroblasts couple matrix regeneration + clot substitution
218
What days does the regeneration phase generally expand over?
Days 7 to 56
219
What occurs in the regeneration phase of wound healing?
Platelet derived growth factors + transformation growth factors stimulate fibroblasts + epithelial cells
Fibroblasts make a collagen network
Angiogenesis occurs + wound resembles granulation tissue
220
When does the remodelling phase of wound healing occur?
6 weeks - 1 year
221
What occurs during the remodelling phase of wound healing?
Fibroblasts become differentiated (myofibroblasts) + facilitate wound contraction
Collagen fibres are remodelled
Microvessels regress leaving a pale scar
222
What kind of things may impair normal wound healing?
Vascular disease
Shock, sepsis
(these all compromise microvascular flow)
Jaundice (impairs fibroblast synthetic function + immunity)
223
Define hypertrophic scar
Excessive amounts of collagen within a scar
Tissue is confined to extent of wound itself
Usually full thickness dermal injury
224
What is a complication of a hypertrophic scar
Contractures
225
Define keloid scar
Excessive amounts of collagen within a scar
| Keloid scars will pass beyond boundaries of original injury
226
Do keloid scars regress over time?
No they do not and may require removal
227
Which drugs can impair wound healing?
NSAIDs
Steroids
Immunosupressants
Anti-neoplastic drugs
228
What is delayed primary closure?
The anatomically precise closure that is delayed for a few days but before granulation tissue becomes macroscopically evident
229
What is secondary closure?
Spontaneous closure/surgical closure after granulation tissue has formed
230
What kind of pts should be first on the list?
Diabetics to prevent complications of poor BM control
231
What is pseudocholinesterase deficiency (aka. suxamethonium apnoea)?
Rare abnormality in the production of plasma cholinesterases --> increased duration of action of muscle relaxants (suxamethonium)
232
What is a complication of long term mechanical ventilation?
Tracheo-oesophageal fistula formation
233
What does tracheo-oesophageal fistula formation predispose to?
Ventilator associated pneumonia
| Aspiration pneumonias
234
How does long term mechanical ventilation lead to tracheo-oesophageal fistula formation?
Pressure from endotracheal tube on posterior wall of trachea can --> necrosis that also involves the anterior wall of the oesophagus
235
Define thermoregulation in the perioperative period
Temperature management of pts from 1h prior to surgery until 14h after surgery is completed
236
Define hypothermia
<36
237
Why are pts more likely to become hypothermic under anaesthesia?
They cannot mount their normal behavioural responses to cold
More body is exposed
238
What are RFs for perioperative hypothermia?
```
ASA grade 2+
Major surgery
Low BMI
Large volumes of unwarmed IV infusions
Unwarmed blood transfusions
```
239
It is appropriate to start warming pts ____ mins prior to the anaesthetic induction.
30 mins
240
Patients should not be moved to the theatre suite if their temperature is less than what?
36C
Unless they have a time critical condition that req. urgent management
241
What device is most used to measure temperature during operations?
Oeosphageal probes
242
What patients should get forced air warming devices during their operation?
Any operation of anaesthetic duration >30m or anyone at high risk of perioperative hypothermia
243
Fluid volumes of >____ml should be warmed prior to administration, as should all ____.
500
| Blood products
244
What is intra-operative hyperthermia usually due to?
Over-warming
| anaesthetics/opioids blunt the febrile response
245
After surgery, whilst in the recovery room how often should a patients temperature be documented?
Every 15 minutes
246
Patients should not be transferred to the ward if their temperature is below what?
36C
247
When are surgical patients most likely to start displaying hyperthermia due to fever response?
In post-op phase as anaesthetic is eliminated from the circulation
248
What are the complications of perioperative hypothermia?
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Coagulopathy
Prolonged recovery from anaesthesia
Reduced wound healing
Infection
Shivering
```
249
What coagulopathy can perioperative hypothermia lead to?
Reduces bloods ability to clot -->increased blood loss
250
Why does perioperative hypothermia lead to prolonged recovery time from anaesthesia?
Small decreases in body temp can cause drastic prolongation of anaesthetic drugs
251
Why does perioperative hypothermia lead to reduced wound healing?
Hypothermia --> local vasoconstriction which reduces perfusion to skin
252
Why does perioperative hypothermia lead to increased infection?
Poorer wound healing + reduced no. of immune cells able to access skin
253
Why is shivering post-op a problem?
Can cause significant increase in metabolic rate which can lead to MI in some pts
254
What are the recommendations regarding eating and drinking before an operation?
Clear fluids up to 2h before
No solid food for 6h before
Breast milk safe up to 4h
Normal milk sae up to 6h
255
What anaesthetic technique is used for emergency surgery in a non-fasted non-pregnant patient?
Rapid sequence induction
256
What does RSI involve?
Optimal pre-oxygenation
Induction agent + suxamethonium
Apply cricoid force at onset of unconsciousness
257
How do you manage an anastomotic leak?
Take pt back to surgery ASAP
258
What fluid is preferred for post-operative fluid management?
Electrolyte balanced solutions (Ringers lactate/Hartmans)
259
What may cause post-op hyponatraemia?
Resus with fluids with lower Na content than plasma
260
When should you start LMWH after elective total hip replacement?
6-12h post op
261
Why should you avoid hypotonic (0.45%) fluids in paediatric patients?
They are at particular risk of hyponatraemia encephalopathy
262
What advice does NICE give re post-op wound cleansing?
Sterile saline up to 48h post-op
Can shower after 48h
Use tap water for wound cleansing after48h if surgical wound has separated/has been surgically opened to drain pus
263
How should you manage hypovolaemia post-op?
500ml 0.9% normal saline fluid challenge
264
How does lidocaine work?
Blocks sodium channels --> presynaptic neuron doesn't polarise
265
What are side effects of lidocaine?
Nausea, dizziness, tinnitus, tremor
266
What is nasogastric feeding usually administered by?
Fine bore nasogastric feeding tube
267
What are the complications of nasogastric feeding?
Aspiration of feed
| Misplaced tube
268
What CIs nasogastric feeding?
Head injury
269
What does nasojejunal feeding avoid?
Feed pooling in stomach --> less risk of aspiration
270
What is the con of nasojejunal feeding?
Difficult to put in
271
What is a feeding jejunostomy?
Surgically sited feeding tube
| May be used for long term feeding
272
What are the main risks of a feeding jejunostomy?
Tube displacement
| Peritubal leak leading to peritonitis
273
What is a PEG?
Percutaneous endoscopic gastrostomy - combined endoscopic and percutaneous tube insertion
274
What are the risks of getting a PEG?
Aspiration
| Leakage at insertion site
275
What is the definitive option in pts whom eternal feeding is CI?
TPN - total parenteral nutrition
276
What line can TPN be administered through?
Must be central line as it is highly phlebitis
277
What is long term use of TPN associated with?
Fatty liver
| Deranged LFTs
278
What is the route of administering halothane?
Inhaled
279
What is the route of administering thiopental?
IV
280
What are the adverse effects of halothane?
Hepatotoxicity
Myocardial depression
Malignant hyperthermia
281
What are the adverse effects of thiopental?
Laryngospasm
282
Why does thiopental affect the brain so quickly?
It is very lipid soluble
283
In which situations may you transfuse packed red blood cells?
Chronic anaemia
| Where infusion of large volumes may --> CV compromise
284
What is the process called by which packed red cells are obtained?
Centrifugation
285
In which situations may you transfuse platelet rich plasma?
Thrombocytopenic pts who are bleeding
286
How is platelet rich plasma obtained?
Low speed centrifugation
287
Why might someone need a platelet concentration transfusion?
They are thrombocytopenic
288
How is platelet concentrate obtained?
High speed centrifugation
289
How is FFP prepared?
From single units of blood
290
What does FFP contain?
Clotting factors
Albumin
Ig
291
How much is a unit of FFP?
200-250ml
292
What is FFP usually used for pre-op?
Correcting clotting deficiencies in those with hepatic failure who are due to undergo surgery
293
What is cryoprecipitate rich in?
Fibrinogen
| Factor VIII
294
What is SAG-Mannitol blood?
Removal of all plasma from blood unit and replace with NaCl, adenine, anhydrous glucose, mannitol
295
How many units of SAG Mannitol can you give?
4 - thereafter give whole blood
| After 8 units consider platelets and clotting factors
296
What blood products MUST be cross matched?
Packed red cells
FFP
Cryoprecipitate
Whole blood
297
How do you manage DIC?
Cryoprecipitate and FFP
298
What drug is linked to slowed bone healing?
```
NSAIDs
Steroids
Immunosupressants
Anti-neoplastic drugs
Smoking
```
299
What is paralytic ileus?
Common post-bowel op
| No peristalsis of bowel --> pseudo-obstruction
300
Apart from post-operatively how else can paralytic ileus occur?
In association with a chest infection, MI, stroke or AKI
301
What thing can contribute to development of paralytic ileus and knowing that what tests are useful to order?
Deranged electrolytes
| Check K, Mg, Phosp
302
How must you replace the electrolytes in paralytic ileus?
IV as bowel is not working
303
What are features of paralytic ileus?
Vomiting
Constipated
No bowel sounds
Distended abdomen
304
Excessive administration of sodium chloride can cause what abnormality?
Hyperchloraemic acidosis
305
What should be given to patients regularly taking prednisolone prior to surgery?
Hydrocortisone (due to suppression of HPA)
306
What features post-cholecystectomy wound suggest a bile leak?
RUQ tenderness
| Bilious fluid n the intra-abdominal drain
307
Should you cannulate the foot of a diabetic?
Never
308
What differs about the length of time a cannula can stay in in a diabetic pt?
Non-diabetic 3 days
| Diabetic 24h
309
What are the most common reasons for fever post operatively at different times?
Day 1-2 WIND: pneumonia, aspiration, PE
Day 3-5 WATER: UTI (esp. if was catheterised)
Day 5-7: WOUND: infection at surgical site/abscess formation
Day 5+ WALKING: DVT/PE
ANYTIME: drugs, transfusion reactions, sepsis, line contamination
310
Why can poor post-op pain management lead to pneumonia?
Leads to shallow breathing which is a RF for RTIs
311
When are nasopharyngeal airways useful?
In those with decreasing GCS that you are struggling to get an oropharyngeal airway into (e.g. someone having a seizure)
312
What contraindicates a laryngeal mask?
Patient being nonfasted
| Morbid obesity
