Surgery: Anaesthetics and peri-operative Flashcards

1
Q

How are patients classified under the American society of anaesthesiologists classification?

A

ASA I - VI

I - healthy
II - mild systemic disease, smoke, pregnant etc
III - Severe systemic disease, poorly controlled, BMI > 40, end stage renal disease with dialysis
IV - the above, with threat to life - MI, CVD
V - not survive without operation - aneurysm / ischaemic bowel
VI - brain dead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

If concerned about cervical spinal injury what should be done to open the airway

Simple positional manoeuvre

A

Jaw Thrust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Main device used to open the airway

A

Oropharyngeal airway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are laryngeal masks not suitable for?

A

Patients with Reflux
High pressure ventilation going through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What can errors in endotracheal tube insertion lead to? How should it be monitored?

A

Oesophageal intubation
Monitor end-tidal CO2 (capnography)

Need to be paralysed + suitable for high pressure ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List IV induction agents for anaesthesia

A

Propofol - Gaba agonist, rapid, moderate cardiac, hypotension, pain on entry (TRPA1), anti-emetic

Sodium thiopentone - rapid, not maintainance, laryngospasm, brain

Ketamine - NMDA antagonist, suitable if haemodynamically unstable (no drop in blood pressure) , nightmares - strongest

Etomidate - cardiac safety (less hypotension), adrenal suppression, vomiting, myoclonus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What should amount of blood should be given during each type of surgery?

A

Unlikely - group and save e.g. appendiectomy

Likely - cross match 2 units - ruptured ectopic

Definite - 4-6 units - total gastrectomy, AAA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the inhaled anaesthetics used?

A

Volatile liquid e.g isoflurane - myocardial depression, malignant hyperthermia - induction

Nitrous oxide - avoid in pneumothorax - labour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Types of IV access

A

Venous
Peripheral cannula - no vasoactive drugs
Central line - skill, haemorrhage, multiple infusions
Intraosseous - paediatric
Tunnelled - long term, paediatric
PICC - peripheal central cannula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Types of IV cannula

A

Orange 14g - 270ml/min flow rate
Grey 16 g - 180ml/min flow rate
Green 18g 80ml/min
Pink 20g 54ml/min
Blue 22g 33ml/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Features of Lidocaine

A

Not used in arrythmia patients (Na channels)
Renal excreted
Can cause liver dysfunction
Interacts: Beta blocker, cipro, phenytoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is local anaesthetic toxicity treated?

A

IV 20% lipid emulsion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Max doses of local anaesthetic

A

Maximum total local anaesthetic doses
Lignocaine 1% plain - 3mg/ Kg - 200mg (20ml)
Lignocaine 1% with 1 in 200,000 adrenaline - 7mg/Kg - 500mg (50ml)
Bupivicaine 0.5% - 2mg/kg- 150mg (30ml)

adrenaline prolongs action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is malignant hyperthermia

A

Post anaesthetic induction
excess release Ca2+
autosomal dominant
NMS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Causes of Malignant hyperthermia and how is it treated?

A

Halothane, suxamethonium, antipsychotics

CK raised

Dantrolene - prevents Ca2+ release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Types of muscle relaxants

A

Suxamethonium - depolorising neuromuscular blocker, in acetylcholine, fast (choice for rapid intubation - fasciculations) - hyperkalaemia, malignant hyperthermia and lack of acetylcholinesterase

Atracurium - non depolorising, histamine reaction on use, broken down in tissues, reverse with neostigmine

Vecuronium - non depolar, neostigmine reversal

Pancuronium - quick, neostigmine reversal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When are nasopharyngeal airways contraindicated?

A

Skull fractures

18
Q

What is suxamethonium contraindicated for?

A

Penetrating eye injuries, acute angle glaucoma - increases intra-ocular pressure

19
Q

What are the nutrition options in surgical patients?

A

Oral
Naso gastric - aspiration, no head injury
Naso jejunal - avoids stomach / aspiration, technical
Feeding jejunostomy - surgical, long term, risk of peritonitis
Percutaneous endoscopic gastrostomy - aspiration
Total parenteral nutrition - central vein phlebitic - fatty liver and deranged LFT’s

20
Q

Main fluid to give post operatively

A

Hartmanns - balanced - sodium, potassium, chloride and lactate

21
Q

Early causes of post-op pyrexia (0-5 days)

A

Blood transfusion
cellulitis
UTI
systemic reaction
atelectasis

22
Q

Late causes of post-op pyrexia

A

VTE
Pneumonia
wound infection
anastomotic leak

think 4 Ws wind, water..

23
Q

What is Postoperative ileus and what should be done?

A

reduced bowel peristalsis -> pseudo obstruction
- distension, pain, N/V, no flatus, no oral diet

deranged electolytes can cause - check potassium, magnesium and phosphate

NBM, NGT if vomiting, fluids, total parenteral nutrition

24
Q

What is needed before preping a patient for surgery?

A

Tests - group and save, clotting, urine, preganancy, sickle cell, ecg

Assess DVT rf

Drink fluids until 2 hrs before surgery - reduce headaches e.g. water, tea without milk

Non clear fluids / food - 6 hr before surgery

25
Q

Diabetes during surgery - complications

A

Complications - hypoglycaemia, wound/resp infections, AKI, prolonged stay

26
Q

Diabetes during surgery - medication adjustments

A

good control - adjust insulin reigmen
poor control - varaible rate insulin
oral - manipulate on the day unless - meal missed, poor glycaemic control, renal injury risk - VRIII used

Metformin - normal, if three times a day emit lunch dose
Sulfonylureas - normal, omit morning dose if morning operation, omit before doses if afternoon operation
DPP IV & GLP-1 - normal
SGLT-2 - emit on day of surgery
Once daily insulin e.g. lantus - reduce dose by 20%
Twice daily insulin e.g. novomix - normal, half morning dose and leave evening dose unchanged

27
Q

Examples of special preparation for surgery

A

thryoid - vocal cord check
phaeo - alpha and beta blockade
carcinoid - octreotide

28
Q

Main 3 parts of surgical checklist and what needs to be checked before anaesthesia

A

before anaesthesis
before incision of skin
before patients leaves operating room

confirm patient, mark site, pulse oximeter on patient and working, allergies, difficult airway, risk of more than 500ml blood loss?

29
Q

Risk factors for perioperative hypothermia

A

ASA grade of 2 or above
Major surgery
Low body weight
Large volumes of unwarmed IV infusions3
Unwarmed blood transfusions

30
Q

Complications of perioperative hypothermia

A

Coagulopathy - hypothermia reduces clotting
prolonged recovery
reduced wound healing - vasoconstriction
infection
shivering

31
Q

VTE prophylaxis of patients in hospital

A

mechanical - stockings
pharm - fondaparinux SC, LMWH (reduce in renal), UFH use with CKD

Stop COCP 4 weeks before surgery, mobilise and hydrate

32
Q

Post surgery VTE prophylaxis

A

Hip - LMWH 10 days then aspirin 28 days / stockings with heparin for 28 days

Knee - 14 days same as above

Fragility fractures - VTE one month if risk of VTE > bleeding - LMWH start 6 hrs post surgery or fondaparinux

33
Q

Stages of wound healing

A

Haemostasis
Inflammation
Regeneration
Remodeling (longest)

34
Q

Problems with scars in wound healing

A

Hypertrophic -too much collagen, holds boundaries of orginal wound
Keloid - extend beyoung boundaries

35
Q

Drugs that impair wound healing

A

NSAIDS
Steroids
Immunosupressive agents
anto-neoplastic drugs

36
Q

How can anastomotic leaks be diagnosed?

A

Abdominal CT

37
Q

Excessive administration of sodium chloride causes what

A

hyperchloraemic acidosis

38
Q

When can patients use saline post surgery

A

48 hrs
showering ok as well
tap water 48 hrs after wound has separated

39
Q

What is impaired during the perioperative period?

A

Thermoregulation

40
Q
A