Brainscape's Knowledge GenomeTM

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


See full index

2: Surgical Methods and Perioperative Care > Chapter 21 Anaesthesia Principles and Monitoring > Flashcards

Chapter 21 Anaesthesia Principles and Monitoring Flashcards

1
Q

What two ‘bodily drug’ factors determine the requirement for loading dose and maintenance dose

A
  1. Re-distribution ot other areas
  2. Metabolism and excretion of the drug
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

From the perspective of GA action, the body is divided into three groups. What are they and give an example of each:

A
  1. Vessel rish e.g. heart, brain, kidney
  2. Muscle
  3. Vessel-poor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List 4 factors related to time necessary to achieve steady state anaestehtic for inhalant drugs:

A
  1. Minute ventilation (i.e. rate of delivery)
  2. Cardiac output
  3. Speed of redistribution
  4. Elimination

Speed between different inhalants dependent on solubbility. Less soluble –> more rapid changes

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

What is the approximate metabolic demand of oxygen (ml/kg/min)

A

5 ml/kg/min

Or

10 x (BW)0.75

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

What are the two types of vapourizer outputs and which is most common?

A
  • Variable bypass (splits incoming gas so some directed through vapourizing chamber) = most common
  • Measured flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three methods of vapourization? Which is most commonly used?

A
  • Flow over = most common
  • Bubble through
  • Direct injection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the boiling point of desflourane?

A

23.5°C

Therefore has specific externally warmed vapourizer

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

What is soda lime a combination of?

A

Sodium hydroxide, potassiu hydroxide, calcium hydroxide, water

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

What is the indicator dye in soda lime?

A

Ethyl oxide

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

Label the diagram

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

What is the lower BW limit for use for rebreathing system?

A

5kg

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

What is the formula for recommended fresh gas flow in a non-rebreathing circuit

A

x3 minute volume

MV = RR x tidal volume

Tidal volume = 15 ml/kg

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

What is the side hoel at bottom of ET tube called and what is it for?

A

Murphy eye

In case bottom of tube becomes blocked

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

How long does it take for a non-pre-oxygenated vs pre-oxygenated animal to be come hypoxic (with apnea/obstruction?)

A

30s vs 5 mins

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

What is an adequate oxygen flow rate for pre-oxygenation with a mask?

A

4-5 L/min

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

What colour are the canisters for:

Oxygen

Air

Nitrous oxide

CO2

Nitrogen

A

Oxygen: White

Air: White/black

Nitrous oxide: Blue

CO2: Grey

Nitrogen: Black

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

What does absorbtion atelectasis refer to?

A

Gradual collapse of alveoli as oxygen is removed by pulmonary blood flow (i.e. better to have oxygen:air mix)

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

List 3 safety systems to ensure correct gas attachment

A
  • Cylinder colour
  • Pin index safety system
  • Diameter index safety system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the inspiratory:expiratory ratio range for use with ventilators?

A

1:2 to 1:4

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

What is the recommended peak inspiratory pressure?

A

12 mmHg

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

What is the anaesthetic triad?

A

Narcosis, analgesia and muscle relaxation

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

How does hypoxia lead to cell death?

A
  • Hypoxia –> anaerobic metabolism
  • Insufficient ATP
  • Enzymes e.g. NA-K-ATPase unable to function –> loss of maintenance of electrochemical gradient
  • Cell oedema and death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which patients (5) are at high risk for hypoglycaemia?

A
  • Young
  • Receiving insulin
  • Insulin secreting tumour
  • Sepsis
  • Liver failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the formula for calculating MAP (from systolic and diastolic)?

A

MAP = DAP + ((SAP-DAP)/3)

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

What are normal SAP/DAP values for dog and cat (the same!)

A

125/85 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

At what BP does coronary perfusion become compromised?

A

Diastolic BP <40mm Hg (coronary perfusion occurs during diastole)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is recommended cuff width for BP measurement

A

40-60%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

In cats doppler tends to undersetimate SAP (i.e. we say clsoer to MAP). How much does it underestimate SAP by?

A

25 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

HOw does oscillometric results differ from actual results in dogs and cats?

A

Oscillometric underestimates all (SAP, MAP and DAP) in dogs

Underestimates SAP in cats

Trends well correlated with actual trend though

30
Q

What is electromechanical dissociation?

A

Plausible ECG trace not correlated with any muscular contraction of heart i.e. during arrest

31
Q

What is normal expiratory carbon dioxide level?

A

35-45 mmHg

Significant adverse effects only if over 65 mmHg in anaesthetised patient

32
Q

Identify cause of capnogram chnages

A

(A) normal

(B) hypoventilating (note progressive elevation of the plateau)

(C) rebreathing carbon dioxide (CO2) (note the progressive elevation in the baseline, as it fails to return to 0 with each inspiration)

(D) experiencing a leak in the system due to inadequate cuff inflation or other causes

(E) hyperventilating (note progressive decrease in plateau amplitude)

(F) experiencing cardiac arrest, a sudden decrease in cardiac output, or a circuit disconnect.

33
Q

How does pulse ox work?

A

Emits 2 light frequencies (specific for oxyheamoglobin and deoxyhaemoglobin) through tissue and into a sensor.

Calculates % of oxy- vs deoxy-haemoglobin.

Relies on only the pulsatile portion of blood (absorbance spectrum of pulsatile component)

N.B. Carboxy- or Methaemogloib may confuse thigns!

34
Q

What is normal PaO2 in patient at sea level breathing room air?

and 100% oxygen?

A

110 mmHg (=100% Hb saturation)

500 mmHg on 100% oxygen

35
Q

What is PaO2 of patient with Pulse ox 90% (on room air)

At what pulse ox level should causes of hypoxaemia be investigated in anaesthetised patient breathing 100% oxygen?

A

60 mmHg i.e. hypoxaemia

Investigate if <98%

36
Q

Breifly, how does a nerve stimulator work?

A
  • Two electrodes + generator. Electrodes placed along path of motor nerve (usually peroneal or ulnar).
  • Electrical current applied –> twitch. In NM block –> progressively weaker twitch (train of four)

Dont attempt reversal of NM blockade before all 4 twitches returned (i.e. can reverse when there but not all full magnitude)

37
Q

What is normal central venous pressure in small animals?

A

0-5 mmHg

38
Q

List 4 methods of determining cardiac output (non-invasive cardiac output monitoring)

A
  • Thermodilution
  • Lithium Dilution
  • Pulse Contour Analysis
  • Noninvasive Cardiac Output (NiCO device)
39
Q

How is brainwava activity measured?

A

Bispectral Index.

0-100 (100 being awake). Good in humans - poor in animals

40
Q

What are the three opioid receptors

A

µ (mu), κ (kappa), and δ (delta)

Mu: Regulates majority of clinical effects inc analgesia and side effects

Kappa: Role in alnalgesia but hard to distinguish from Mu.

Delta: Primarily modulating role on Mu.

41
Q

What happens (on cellular level) with activation of opioid receptor?

A
  • Influx of K+ and efflux of Ca2+
  • –> decreased release of neurotransmitter (eg substance P or glutamate) in pre-synaptic cell
  • Hyperpolarization on post-synaptic cell
  • –> Net decreased neuronal activity and transmission of pain signals
42
Q

Analgesia supplied by opioids can reduce inhalant anaesthesia requirement by how much?

A

40-60%

43
Q

What drug and dose is used to reverse opioids?

A

Naloxone, 0.04mg/kg

44
Q

List 5 potential side effects of opioid administration

A
  • Vomiting
  • Ileus
  • Nausea
  • Bradycardia
  • Histamine release
  • Increased pyloric sphincter and sphincter of Oddie (bile duct) tone
  • Respiratory depression (dogs and cats relatively resistant)
  • (Urinary retention when given epidurally)
45
Q

List relative potency of the following drugs (c/f/ morphine which has arbitrary potency of 1):

Methadone

Hydromorphone

Oxymorphone

Fentanyl

Buprenorphine

A
46
Q

What is the term used for sedation + analgesia?

A

Neuroleptanalgesia

47
Q

Broadly speaking, how do benzodiazepines work?

A

Enhance effects of GABA (gamma-aminobutyric acid = inhibitory neurotransmitter in CNS).

Activated GABA receptor allows entry of chloride into neuron –> hyperpolarization and prevention of action potential propagation

48
Q

What is the reversal agent and dose for benzodiazepines?

A

Flumazenil, 0.01-0.02 mg/kg

49
Q

What is the difference between diazepam and midazolam metabolism?

A

Diazepam –> nor-diazepam + oxazepam –> sedative actvity and slower clearance.

Midazolam –> 1-hydroxymethyl midazolam = minimal biologic activity

50
Q

What are 2 storage particulars re diazepam?

A

Light senstive and adsorbs to plastic

51
Q

How does ACP work?

A

Depressed dopamine in reticular activating system.

Alpha 1 receptor antagonist

Tranquilizer, anti-ematic and anti-histamine

52
Q

How do alpha-2 agonists work?

A

Decrease norepinephrine release in CNS.

Hypertension –> reflex bradycardia

53
Q

What is the alpa-2:alpha-2 receptor sleectivity of xylazine vs medetomedine?

A
  • Xylazine 160:1
  • Medetomedine 1600:1
54
Q

How does propofol work?

A

GABA agonist –> CNS inhibition

55
Q

What is meant by dissociative anaesthesia?

A

Dissociation between higher brain functions and unconscious functions i.e. body systems not under conscius control (e.g. airway) maintain basal function c.f. other anaesthetic agents

56
Q

What it the active metabolite of ketamine?

How is ketamine excreted?

A

Norketamine

Renal excretion

57
Q

Define MAC.

A

MAC: Concentration of anaesthetic required to prevent purposeful movement in response to a standard painful stimulus in 50% of normal patients.

58
Q

What is the MAC of Iso, Sevo and Desflourane in cats and dogs?

A

Typically need 1.2-1.5x MAC to prevent movement during surgery.

59
Q

What is the MAC- blockade of adrenergic response (MAC-BAR)?

A

Concentartion of inhalant that prevents a CVresponse after painful standard stimulus.

In cats MAC-BAR usually 10% higher than MAC.

60
Q

Where are inhalant anaesthetics metabolized?

A

Liver

61
Q

Order iso, sevo and desflourance in order of solubility (Most to least soluble)

( i.e. less soluble –> faster induction/change/recovery)

A

Iso > Sevo >Desflourane

62
Q

How do localanaesthetics work?

A

Block fast Na+ channels on afferent nerves –> inhibit afferent nociceptive transmission

63
Q

What is the time until onset and duration of action of lidocaine?

A

5 min onset

60 min duration

64
Q

What is the time until onset and duration of action for bupivacaine (higher lipid solubility cf lidocaine)?

A

45 min onset

6-8 hour duration

65
Q

What is a Bier block?

A

IV regional anaesthesia

66
Q

What are two reversal agents for non-depolarizing NM blockade agents (e.g. atracurium)

A

Edrophonium or neostigmine (they inhibit actions of acetylcholinesterase at nerve terminals

67
Q

Lost 2 anti-cholinergic agents

A

Atropine or glycopyrrolate (parasympatholytic)

68
Q

Which prostaglandin is primarily responsible for inflammatory pain?

A

PGE2

69
Q

What sign on aretrial BP waveform can indicate hypovolaemia?

A

“Delta down” = attenuation of waveform with positive-pressure breath caused by collapse of great vessels in thorax.

70
Q
A

2: Surgical Methods and Perioperative Care (11 decks)

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