Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anaesthetics > Anaesthetics > Flashcards

Anaesthetics Flashcards

1
Q

Reducing risk of gastric aspiration

A
  1. Reduce gastric residual volume
    Adequate period of fasting, avoid drugs delaying gastric emptying, insertion on NG tube, prominent if drugs (metoclopramide)
  2. Increase pH of gastric contents
    NaCitrate, H2 antagonists e.g ranitidine, PPIs e.g omeprazole
  3. Cricoid pressure (sellicks manoeuvre)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Sellicks manoeuvre

A

Pressure to anterior aspect of cricoid cartilage forcing whole ring backwards as compressing oesophagus against sixth cervical vertebra
One hand should stabilise from back
Maintain pressure even if vomiting

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

Rapid sequence induction of anaesthesia

A

Gain IV access
Preoxygenate
Gentle cricoid pressure
Induction agent given as fast running IV infusion
Suxamethonium given
Mask held against face but not ventilated
Once fasciculations end, perform intubation
Confirm position
Release cricoid pressure

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

Obstetric patient prophylaxis against acid aspiration

A

Elective c sections: a H2 antagonist OR PPI the evening before and morning of surgery
Emergency: a H2 antagonist and 30ml 0.3M sodium citrate immediately before surgery

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

Anaesthesia techniques for c sections

A

Spinal: provides rapid intense reliable relief. Intrathecal diamorphine should be offered as improves post op pain control and reduces need for additional analgesia
Epidural: can be extended from labour epidural but slow process and risk of inadequacy
General: mainly used for urgent emergency c sections due to immediate threat of maternal or foetal life, refusal of regional or failure/contraindication to regional anaesthesia

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

Specific risks of GA in obstetric patients

A

Regurgitation and aspiration due to progesterone relaxation of LOS + increased abdominal pressure

Failed intubation 10x more likely (predominant breast tissue, engorged airway mucosa and full set of teeth)

Increase risk of desat and hypoxia ( reduced FRC and increased oxygen consumption)

Maternal awareness (inadequate dosing due to concern of over sedating foetus)

Aortocaval compression (IvC and aorta therefore reduced BP and reduced perfusion to uterus causing foetal hypoxia) reduce with 15deg left lateral tilt

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

Positioning for obstetric woman

A

15 degree left lateral tilt

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

Signs of gastric aspiration

A

Coughing at induction or recovery from anaesthesia/ during anaesthesia with supraglottic airway

Gastric contents in pharynx at laryngoscopes or around edge of face mask

Progressive hypoxia, bronchospasm, respiratory obstruction (if severe)

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

Management of aspiration at induction before neuromuscular agents given in non essential surgery

A

100% O2 by facemask
Allow patient to recover
Treat bronchospasm with salbutamol or ipratropium
Chest X-ray and physio
Consider ICU/HDU depending on degree of aspiration

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

Management of gastric aspiration at induction before NM blockade in essential surgery

A

Empty stomach with NG tube
30mL sodium citrate via NG
Allow patient to recover
Continue surgery with regional block or RSI with intubation
After intubation, aspirate tracheobronchial tree (consider bronchoscopy)
Treat bronchospasm with salbutamol/ipratropium
Arrange for post op cheat X-ray and physio
Recovery in ICU/HDU with oxygen therapy
+- post op ventilation if required

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

Management of gastric aspiration at induction after deliver of neuromuscular blocking agents

A

Intimate with cuffed tube
Aspirate tracheobronchial tree before beginning positive pressure ventilation
Consider bronchopulmonary saline lab age
Treat bronchospasm with salbutamol or ipratropium
Pass NG tube and empty stomach
If patient stable, surgery may continue
Post op care in ICU/HDU

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

Management of intraoperative gastric aspiration with a supraglottic airway

A

Get help
Stop surgery if safe to do so
Turn patient into left lateral position with head down tilt
Remove supraglottic airway
Suction oro pharynx
Maintain ventilation with 100% oxygen ensure ongoing anaesthesia
Cricoid pressure
Give fast acting neuromuscular block and intubation trachea

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

Causes for anaphylaxis in anaesthetics

A

Anaesthetic drugs:

  • muscle relaxants 50% (suxamethonium, rocuronium etc)
  • latex 17%
  • antibiotics 8% (
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Clinical features of anaphylaxis

A 
Rapid onset
Severe hypotension
Severe bronchospasm - cough and wheeze
Widespread flushing
Hypoxaemia
Urticaria
Angioedema (May involve airway)
Pruritus, nausea and vomiting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Immediate management of anaphylaxis

A

Discontinue trigger
Call for help
Maintain patent airway
Administer 100% oxygen (high-flow, 10-15L/min)
Elevate legs without compromising ventilation
0.5mg IM adrenaline (or if ECG monitoring available, 50micrograms IV slowly)
Further dose every 2 minutes until responding
Rapid IV fluid infusion
Monitor O2 sats, BP, HR/ECG, end tidal CO2
Transfer to ICU for further treatment and monitoring ASAP

Steroids used once stable to prevent biphasic reaction from occurring 6 hours later

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

Failed intubation protocols

A

Plan B:
Face mask, oxygenation and ventilation, max head extension and jaw thrust, oral or nasal airway

If failed oxygenation with facemask->
Plan C:
LMA oxygenate and ventilate, awaken patient
Max 2 attempts at insertion

Can't intubate can't ventilate situation with increasing Hypoxaemia
Plan D:
Emergency airway (cannula or surgical cricothyroidotomy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Techniques to help with difficult intubation

A

BURP procedure
Use of a boogie or stylet
Fibre-optic bronchoscope (usually if identified pre-admission and prepared)
Insert LMA as conduit to pass endotracheal tube
Video laryngoscopes/ other indirect layngoscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Risk of bleeding

A

HAS BLED

Hypertension >160 systolic
Abnormal liver or renal function
Stroke
Bleeding
Labile INR
elderly >65
Drugs and alcohol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Factors predisposing to aspiration

A

Full stomach (inadequate time of fasting, increased gastric contents due to outflow obstruction, distension after face mask ventilation)
Delayed gastric emptying (opiates, trauma, peritoneal irritation, blood in stomach, pain and anxiety)
Obstetric patients
Other (GORD, hiatus hernia, obesity, head down position, bulbar palsy, oesophageal pouch or stricture)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pros and Cons of inhalational induction anaesthesia

A

Pros:
lack of suitable veins
uncooperative patients
patients with airway compromised (IV drugs may cause apnoea and loss of airway patency)
Children
(Sevovlurane is the most pleasant agent to use)

Cons:
Slower onset than IV
Mostly unpleasant to breathe
Hypotension and reduced cardiac output with increasing concentration, difficult to treat without IV access
Causes Vasodilation and hypercapnia (due to respiratory depression) leading to increased cerebral flow - thus unsuitable in patients with raised ICP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Transversus abdominis plane (TAP) block

A

Local anaesthetic in plane between transverse abdominis and internal oblique muscles
Anaethetises skin and muscles of abdo wall + parietal peritoneum
US guidance to locate plane
Midaxillary line, midway between costal margin and iliac crest
bilateral blocks required for midline incisions
most useful in lower abdo surgeries (hernia, appendix, hysterectomy etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Brachial Plexus blocks (types)

A

Supraclavicular/Interscalene:
Above the level of the clavicle
Used for shoulder surgery

Axillary:
used for operations below the elbow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Lignocaine Max. doses

A

Without adrenaline: 3mg/kg up to 200mg
With adrenaline: 6-7mg/kg up to 500mg

Do not use with adrenaline at end arterial sites e.g. fingers, nosetip, ears

Reduce dose in elderly, frail, shocked and liver impaired patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Benefits of regional anaesthesia

A

Reduced need for systemic drugs
Reduced risk of aspiration
Increased post-op analgesia
Reduced autonomic response for painful procedures
No need for mechanical ventilation (e.g. good in patients with airway disease/difficult airways)
Reduced disturbance of control of systemic diseases e.g. DM
Profound muscle relaxation and contraction o bowel, leads to improved access for laparotomy
Reduced blood loss with controlled hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Contraindications to epidural or spinal anaesthesia

A 
Hypovolaemia
Coagulopathy
Low, fixed cardiac output (e.g. Severe AS)
Local skin sepsis
Raised ICP
Known allergy to amide local drugs
Totally uncooperative
\+/- Concurrent CNS disease
\+/- Hx of spinal surgery/abnormal anatomy of spine
26
Q

Signs/Symptoms of local anaesthetic toxicity

A

Mild/Early:
Circumoral paraesthesia, tongue numbness, visual disturbances, light-headedness, slurred speech, twitching, restlessness, mild hypotension and bradycardia

Severe/Late:
Grand mal convulsions, coma, respiratory depression - apnoea, cardiovascular collapse with profound hypotension and bradycardia - cardiac arrest

27
Q

Management of local anaesthetic toxicity

A 
STOP GIVING LOCAL ANAESTHETIC
Airways +/- intubation
B: 100% O2
C: Colloid/Crystalloid fluid, IV atropine
D: diazpam for convulsions
28
Q

Confirming position of a tracheal tube

A 
Measureing CC2 in expired case (waveform capnometry)
Direct visualisation of tube passing between cords
Oesophageal detector (no resistance to aspiration of air)
Fogging of clear plastic tube connectors during expiration

Less reliable signs:
breath sounds on auscultation, chest movement on ventilation, “gurgling/burping” sounds over epigastrium, O2 saturation (late sign)

29
Q

Opioid reversal

A

Naloxone:
Pure antagonist
0.1-0.4mg IV initially
lasts 30-45 minutes, 60s onset
Limited effect against partial or mixed opioids
Duration of action shorter than most opioids - infusion required in severe overdoses

30
Q

Common risks associated with anaesthesia (1 in 10-1 in 100)

A 
Bruising/soreness from IV access attempts
Sore throat
Headache
Dizziness
PONV
Itching
Retention of urine
31
Q

Uncommon risks associated with anaesthesia (less than 1 in 100)

A 
Dental damage
Chest infection
Muscle Pains
Worsening of existing condition (e.g. IHD)
Awareness
VERY RARE:
Allergies
Eye injury
Nerve damage
Hypoxic brain injury
Death
32
Q

Indicators of difficult intubation

A 
Mallampati grade III or IV
Thyromental distance 
Receded mandible
Loose teeth, caps, crowns, dentures
Large tongue
Soft tissue swelling at front of neck
Deviation of larynx or trachea
Limitations in flexion and extension of cervical spine
Limitation of mouth opening
33
Q

Tracheal intubation complications

A

Unrecognised oesophageal intubation
Failed intubation, inability to ventilate
Failed ventilation
Aspiration of regurgitated gastric content
Direct trauma to all structures lips-lungs
Trauma to adjacent structures during the procedure
Hypertension and arrhythmias
Vomiting

34
Q

Risk Factors for post-operative nausea and vomiting

A

Female gender
non-smoker
History of PONV or motion sickness
Opioids as part of anaesthetic technique

35
Q

Complications of central neural blockade (spinal or epidural)

A 
Hypotension
Nausea
Bradycardia
Vomiting
Dysrhythmias
Post-dural puncture headache (spinal only)
36
Q

Uses of capnometry

A

Indicator of degree of alveolar ventilation
- allows controlled hypocapnia in neurosurgery
- avoid hypocapnia in impaired cerebral perfusion
Disconnection indicator
Confirms ETT in trachea
Indicates degree of rebreathing
Indicates cardiac output (V/Q mismatch - low CO2)
Firs clue of development of malignant hyperpyrexia

37
Q

Limitations of pulse oximetry

A

Fails to appreciate severity of hypoxia (sats 90% =PaO2 8kPa)
Unreliable in severe vasoconstriction
Unreliable with carboxyHb (high estimates) and metHB (low estimates >85%)
Underreads sats if Hb falls (not affected by polycythaemia)
Affected by extraneous light
Unreliable with excessive movement of patient
Not an indicator of alveolar ventilation

38
Q

Central effects of opioid analgesics

A 
Analgesia
Sedation
Euphoria
Nausea and Vomiting
Pupillary constriction
Depression of ventilation
- rate more than depth
- reduced response to CO2
Depression of vasomotor centre
Addiction
39
Q

Reversal of neuromuscular block

A

Anticholinesterases: neostigmine (2.5mg IV) + atropine 1.2mg

Sugammadex:
newer drug, reverses aminosteroids (e.g. rocuronium etc.)
Used in emergencies (can’t intubate can’t ventilated) post-rocuronium
Not used routinely, due to cost

40
Q

Suxamethonium side effects

A

Malignant hyperpyrexia
Raised intraocular pressure
Muscular pain
H2 release (usually localised, maybe anaphylactic)
Prolonged apnoea (pseudocholinesterase deficiencies)
Raised serum K+
- 0.5-0.7 mmol predicted in all patients
- significant rise in patients with burns, denervation injury (e.g. post SCI), muscle dystrophies, crush injury

41
Q

Complications of peripheral venous cannulation

A 
Failure
Haematoma
Extravasation of fluid/drugs
Damage to local structures
Air embolus
Shearing of cannula
Thrombophlebitis
42
Q

Indications for mechanical ventilation

A

In setting of neuromuscular blocks
Thoracotomy (prevent paradoxial movement)
Neurosurgery (control CO2 thus cerebral blood flow)
Prolonged surgical procedures
Where anaesthetic will cause unacceptable respiratory depression
Surgery where intubation is required (e.g. prone position, full stomach, shared airway)

43
Q

Opioid Classes

A

Pure agonists: morphine, fentanyl, pethidine
Weak agonists: tramadol
Partial agonist: buprenorphine (30x as potent as morphine)

44
Q

Absolute contraindications to NSAID use

A 
pre-existing renal dysfunction
Hyperkalaemia
Cardiac failure
Severe hepatic dysfunction
History of GI bleeding
Hypersensitivity to NSAIDs
Aspirin-induced asthma
45
Q

Opioid regulation

A

Schedule 1: hallucinogenic drugs (no recognised therapeutic use)
Schedule 2: opioids, major stimulants (amphetamines, cocaine)
Schedule 3: drugs less likley to be misused than 2 (barbituates, minor stimulants, buprenorphine, temaze)
Schedule 4: benzos (excl temaze), ketamine (potential for abuse) OR androgenic steroids, GH, clenbuterol
Schedule 5: preparations with very low concentration of codeine or morphine e.g. cough mixtures

46
Q

Anti-emetics (5 classes)

A

Dopamine antagonists - metoclopramide - end of surgery
5-HT antagonists - ondansetron - end of surgery (better used to treat established vomiting)
Antihistamines - Cyclizine - end of surgery
Anticholinergics - hyoscine - >4h before Sx (transdermal patch)
Corticosteroids - dexamethasone - at induction (also has anti-inflammatory thus analgesic effects)

47
Q

Contraindications and Precautions for using opioid PCA for post-operative analgesia

A
  • Mental or physical barriers (e.g. SCI, cognitive impairment)
  • concurrent sedative use
  • History of opioid use or concurrent opioid use
  • Airway compromise
  • Acute alcohol intoxication
  • OSA, COPD or asthma (may increase risk of respiratory depression)
  • Morbid obesity
  • Renal impairment
  • Hepatic impairment
  • Previous allergy or sensitivity to a specific opioid
48
Q

Types of opioid receptors

A

μ, κ, δ

49
Q

Actions of activation of μ receptors

A 
Analgesia
Nausea/vomiting
Bradycardia
Respiratory depression
Miosis
Reduced gut motility
Pruritus
50
Q

Actions of activation of κ receptors:

A

Analgesia
Sedation
Dysphoria
Diuresis

51
Q

Actions of activation of δ receptors:

A

Analgesia only

52
Q

Endogenous agnoists of μ receptors

A

β-endorphins

53
Q

Endogenous agnoists of κ receptors

A

dynorphins

54
Q

Endogenous agonists of δ receptors

A

Enkephalins

55
Q

Paracetamol metabolism

A

Produces hepatotoxic metabolite that is normally inactivated by hepatic glutathione
In paracetamol overdose, this pathway is saturated, leading to accumulation of metabolite and hepatic cell necrosis
Renally excreted

56
Q

Opioid sparing effect of NSAIDS (%)

A

20-40%

57
Q

Complications of severe post-op pain

A

Myocardial ischaemia (HR, TPR, BP)
VTE (mobility, stasis, clotting)
Hypoxaemia and pneumonia (sputum retention, reduced lung volume, atelectasis, diaphragmatic splinting and cough suppression)
Delayed gastric emptying and reduced gut motility
Urinary retention
Impaired wound healing/immune function, increased protein breakdown (increased cortisol, catecholamines etc.)
Risk of Chronic pain
Psych: anxiety, sleeplessness, fatigue, distress

58
Q

Morphine metabolism

A

Least lipid soluble of commonly used opioids
Mostly metabolised in liver (only 10% excreted unchanged)
Renal excretion (accumulation in red GFR)
1 major metabolite is more potent than morphine, 1 is inactive

59
Q

Fentanyl metabolism

A

Highly lipid soluble - suitable for transdermal administration and short duration of action due to rapid tissue uptake
Inactive metabolites

60
Q

Codeine metabolism

A

Prodrug for morphine - approx 10% converted to morphine

Requires CYP2D6 which 10% of caucasions lack (thus no effect)

61
Q

Adrenaline and amiodarone dosing and timing in adult ALS

A

Shockable:
Adrenaline 1mg after 2nd shock
Amiodarone 300mg after 3rd shock

Non-schockable:
Adrenaline 1mg immediately and then after every 2nd cycle

62
Q

Dose of adrenaline and amiodarone in paediatric ALS

A

0.1mL/kg of 1:1000 (10 mcg/kg) adrenaline

5mg/kg amiodarone after every 3rd shock in shockable rhythms

Anaesthetics (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions