Brainscape's Knowledge GenomeTM

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


See full index

Intensive Care > Sedation and Analgaesia > Flashcards

Sedation and Analgaesia Flashcards

1
Q

Why does deep sedation only have a few indications and what are these

A

Deep sedation (with or without paralysis) is associated with increased mortality (? Study)

Indications for deep sedation
1. RICP
- decrease metabolic rate
- avoids straining and coughing
- reduces intracranial pressure

  1. Medical conditions
    - Status epilepticus not responding to usual Rx
    - Tetanus
  2. Hyperpyrexial syndromes
  3. Unusual forms of ventilation that require deep sedation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the problems associated with oversedation?

A

Acute:
CNS: Confounded neurological examination
RSP: Prolonged ventilation
CVS: Haemodynamic Instability
GIT: Stasis and feed intolerance
Immune suppression
PSYCH: Increased delirium

Chronic:
Long term: Post critical care illness risk

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

What are the benefits of appropriate and adequate sedation

A
  1. Ventilator days, Hospital/ICU length of stay, ICU costs
  2. Accidental extubation/line removal
  3. NMB + risk of critical illness myopathy/polyneuropathy
  4. Post ICU functional decline/PTSD/
  5. Sedative side effects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the RASS assessment

A

Richmond Agitation Sedation Score

+4 Combative
+3 Very agitated
+2 Agitated
+1 Restless

0 Alert and Calm

-1 Drowsy with sustained eye contact
-2 Light sedation: No sustained eye contact
-3 Moderate sedation: No eye contact
-4 Deep sedation: Respond to physical stimulus
-5 Unrousable: no response to physical stimulus

Goal is 0 to -2

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

Summarise the principles of effective sedation in ICU

A

Non-pharmacological
1. Counselling. Touch. Family contact
2. Maintain normal sleep cycle

Pharmacological
1. Titrated
2. Short acting agents that don’t accumulate
3. Combine agents for minimum dosing of each
4. Bolus regimen for procedures
5. IV route preferred. PO and IM unpredictable absorption in ICU.
6. Less for encephalopathic patients and elderly
7. Daily spontaneous awakening trial - except if paralysed

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

Describe the loading and maintenance doses of Fentanyl in the ICU

A

Load
1 -2 ug/kg (25 -100ug)

Maintain
1 to 3 ug/kg/hour (50 - 300 ug /hour) with as needed intermittent boluses

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

Describe the onset and duration of an intermittent dose of fentanyl

A

Onset 3 minutes

Duration 30 to 60 minutes

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

Describe the advantages and disadvantages of using fentanyl in the ICU

A

ADVANTAGES
1. Potent analgaesic and sedative effect
2. Minimal CVS effect (relative lack histamine release)

DISADVANTAGES
1. Highly Lipophillic (Long context sensitive half time)
2. Chest wall rigidity with higher dosing
3. CYP hepatic metabolism
4. Dependence and tolerance

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

Describe the loading and maintenance dosing for morphine

A

Load
2 - 10 mg IV

Maintain
2 - 4 mg every 1 to 2 hours
OR
2 to 30 mg/hour infusion (usually 2 - 5mg/hour)

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

Describe the onset and duration of action of morphine

A

Onset 5 to 10 minutes

Duration 4 - 5 hours

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

What are the advantages and disadvantages of morphine in the ICU

A

ADVANTAGE
1. Non-CYP metabolism (glucoronidation)
2. Cheap

DISADVANTAGE
1. Accumulation in hepatic/Liver dysfunction
2. Histamine release and vagally mediated –> venodilation, hypotension, bradycardia
3. Dependence and Tolerance

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

What is the loading and maintenance dosing for remifentanil in the ICU

A

Load
1.5 mg/kg

Maintenance
0.5 to 15 ug/kg/hour (usually 1 - 10 ug/kg/hour) which is a 50ug/ml dilution at 2 to 10 ml/hour

Mix 2mg i(1 amp) n 40 mls to make 50ug/ml.

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

What is the onset and duration of remifentanil

A

Onset 1 to 3 minutes

Offset 5 to 10 minutes after cessation of infusion

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

What are the advantages and disadvantages of remifentanyl in the ICU

A

ADVANTAGES
1. Ultra-short acting
2. Plasma esterase clearance (safe kidney/liver impairment) to inactive matabolites

DISADVANTAGES
1. Anticipate pain upon abrupt cessation
2. Glycine excipient may accumulate in renal failure (glycine toxicity –> high ammonia with organ toxicity). Rare.

NB in patients requiring frequent neurological assessment or those in multiorgan failure

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

What is the mechanism of action of paracetamol

A

Multifactorial
1. Central COX-3 inhibition (effect on central processing of pain)
2. Possible peripheral selective COX 2 inhibition
3. Endocannabinoid modulation (mice)
4. Serotonergic effect (effects of paracetamol inhibited by 5 HT antagonists)

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

What is the maximum dose of paracetamol per day and what is the accepted toxic ingestion dose

A

Maximum dose = 4g/day

Toxic dose > 10g in 24 hours

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

How long does PO vs IV perfalgan take to work

A

PO: 30 to 60 minutes

IV: 5 to 10 minutes

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

What are the advantages and disadvantages of paracetamol in the ICU

A

Advantages
1. No dependence and tolerance
2. No antiplatelet effect
3. No GIT toxicity (NSAIDS)

Disadvantages
1. Lacks significant anti-inflammatory effect
2. IV administration takes 15 minutes
3. Hepatotoxicity in chronic or acute overdose
4. Interacts with warfarin - may prolong INR

Hepatic dysfunction - limit dose to 2 g/day max

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the mechanism of action of ibuprofen

A

Non-selective inhibition of cyclo-oxygenase enzyme during the metabolism of arachidonic acid.

COX 1 is constantly active and has homeostatic role
- GI ulceration
- Acute Kidney Injury

COX 2 is induced by inflammatory cytokines
- Antiplatelet
- Anti-inflammatory

Analgaesic activity is mediated by both enzymes which produce eicosanoids (prostaglandins and leukotrienes).

Inflammatory eicosanoids are responsible for increasing the sensitivity of nociceptors, NSAIDS prevent this.

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

What is the dose of ibuprofen

A

400 mg every 4 hours

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

Whatis the onset and offset of action of ibuprofen

A

Onset 30 minutes

Offset: 4 - 6 hours

22
Q

What are the advantages and disadvantages of ibuprofen in the ICU

A

ADVANTAGES
1. No dependence and tolerance
2. Effective anti-inflammatory

DISADVANTAGE
1. Worsen renal function
2. Gastropathy (dose related)
3. Antiplatelet and bleeding
4. Can alter cardioprotective effect of aspirin
5. Bronchospasm in asthma

23
Q

When should NSAIDS be avoided

A
  1. Renal impairment (and elderly)
  2. GI bleeding
  3. Platelet dysfunction
  4. Ischaemic heart disease
  5. Heart Failure
  6. Hypovolaemia
  7. Asthma
  8. Cirrhosis
24
Q

What is the mechanism of action of Gabapentin in pain

A

Depress neuronal excitability through interactions with calcium channels.
1. Stimulate descending inhibition
2. Inhibit descending serotonergic facilitation

25
Q

What is the dose of gabapentin in pain

A

PO: initially - 100mg tds

Then PO: 1000mg to 3600mg per day in 3 divided doses

26
Q

What are the advantages and disadvantages of Gabapentin in the ICU

A

Advantages
1. Effective for neuropathic pain
2. Low risk of drug interactions

Disadvantages
1. Requires enteral administration
2. Scheduled dosing: individualized dosing titration over days to weeks. (variable oral bioavailability)
3. Side effects: sedation/dizziness/ataxia
4. Cannot stop abruptly due to risk of discontinuation symptoms
5. Dose adjustment needed for renal impairment

27
Q

What is the mechanism of action of propofol

A

Propofol binds to the beta subunit of the post synaptic GABA A receptor where it causes inward directed chloride current that hyperpolarizes the postsynaptic membrane and inhibits neuronal depolarisation.

Essentially a GABA A receptor agonist

28
Q

What is the dose of propofol for use in the ICU

A

Infusion: Usually 50 to 200 mg/hour. Titrate to effect. Less than 4mg/kg/hour (PRIS syndrome)

29
Q

Describe the onset and offset of propofol

A

Onset 1 to 2 minutes

Offset: 3 to 10 minutes (depending on dose and duration)

30
Q

Describe the metabolism and elimination of propofol

A

Metabolism is hepatic - Glucoronidation and sulphate conjugation. All metabolites are inactive and eliminated in urine which can give the urine a healthy green tinge.

31
Q

Describe the clinical effects of propofol

A
  1. Anaesthesia and sedation
  2. Respiratory depression
  3. Decreased CMRO2
  4. Antipruritic
  5. Antiemetic
  6. CVS effects:
    - Indirect and result from SNS inhibition
    - Stable cardiac output
    - Decreased heart rate (blunted baroreceptor reflex)
    - Venodilation and vasodilation
    - Minimal effects on inotropy at normal therapeutic doses
32
Q

What are the advantages and disadvantages of propofol in the ICU

A

Advantages
1. Potent hypnotic
2. Immediate onset
3. Rapid offset
4. Metabolism apparently unaltered in renal and liver dysfunction
5. Few drug interactions
6. Infusion is readily titratable to desired RASS minimizing risk of oversedation
7. Decrease ICP and CMRO2
8. Controls intractable seizures

Disadvantages
1. Hypotension
2. Bradycardia
3. Respiratory depression
4. Elevated TGs
5. Infection site pain
6. PRIS

33
Q

What is the mechanism of action of ketamine

A

NMDA-receptor antagonist with centrally mediated sedation and amnesia nnd spinally mediated analgaesia.

Facilitates endogenous catecholamine release

Co-administer BZP to mitigate neuropsychiatric side effects

34
Q

Describe the dosing of ketamine in the ICU

A

Load or bolus

0.25 to 0.5 mg/kg
(repeat as necessary to max of 2mg/kg in 30 minutes)

Maintenance
0.05 to 0.4 mg/kg/hour
(usually 10 - 20 mg per hour)

35
Q

What is the onset and offset of ketamine

A

Onset 1 minute

Offset 10 to 15 minutes (single dose)

36
Q

What are the advantages and disadvantages of ketamine in the ICU

A

Advantages
1. Potent dissociative sedative-anaesthetic
2. Marked analgaesic properties
3. Maintains CO
4. No inhibition of resp drive
5. does not supress upper airway reflexes

Disadvantages
1. SNS stimulation (O2 demand)
2. Cardiorespiratory depression with rapid administration of high dose
3. Neuropsychiatric effects
4. hypersalivation
5. Nausea and vomiting

37
Q

What is the mechanism of action of dexmedetomidine

A

Central highly specific alpha 2 receptor agonist resulting in a negative feedback with reduced noradrenalin release from the presynaptic terminal resulting in sedation, anxiolysis and a mild analgaesic effect.

Imidazole receptor effects are poorly understood

38
Q

Describe how dexmedetomidine is dosed in the ICU

A

Load
1mcg/kg over 10 minutes if haemodynamically stabler

Maintenance
1 ug/kg/hour.
Start low and titrate up to effect every 30 minutes
0.2 - 1.5 ug/kg/hour

39
Q

Describe the onset and offset of dexmedetomidine

A

onset
- 5 minutes with loading dose
- 15 minutes without loading dose

offset
1 to 2 hours

40
Q

What are the advantages and disadvantages of dexmedetomidine in the ICU

A

Advantages
1. Effective sedative sympatholytic with anxiolysis and analgaesia
2. Character and depth of sedation may permit critically ill and ventilated patient to be interactive and easily awakened yet comfortable
3. Can be used for patient not intubated and ventilated
4. Reduces shivering in the rewarming phase of hypothermia
5. Less likely to cause delirium than other agents

Disadvantages
1. Potentially significant hypotension and bradycardia that do not resolve quickly upon abrupt discontinuation.
2. Hepatic metabolism ( dose reduction recommended in liver and renal disease)
3. Rapid admin of loading dose can lead to haemodynamic instability or dysrhythmia.
4. Does not induce deep sedation needed for neuromuscular blockade

41
Q

What is the mechanism of action of the benzodiazepines

A

Allosteric modulation of the GABA A receptor which potentiates the effect of GABA at these receptors to increase the inward chloride current resulting in hyperpolarization of the neruonal cell membrane.

42
Q

Summarise the dose, onset, offset, route of administration of midazolam, lorazepam, diazepam

A

Midazolam
- load: 1 - 4 mg IV
- maintain: 2 - 8 mg/hour
- onset 5 mins
- offset: 30 mins

Lorazepam
- load: 1- 2 mg
- maintain: 1 - 10 mg/hour
- onset: 15 - 20 mins
- offset: 6 - 8 hours

Diazepam
- load: 5 - 10 mg
- maintain: Infusion contraindicated d/t extremely prolonged context senstiive half time.
- Onset: 5 mins
- Offset: 20 to 60 mins

43
Q

What are the advantages and disadvantages of midazolam in the ICU

A

Advantages
Sedative
Amnestic
Anxiolytic
Anticonvulsant
Immediate onset and short duration
Propylene glycol free (infusion ok)

Disadvantages
CYP3A4 to active metabolites
therefore drug interactions and
Accumulation in liver and renal impairment
Risk of delirium

Need gradual titration and caution in elderly

44
Q

What are the advantages and disadvantages of lorazepam in the ICU

A

Advantages
Sedative
Amnestic
Anxiolytic
Anticonvulsant
Immediate onset and short duration
Glucuronidation to inactive metabolites
Low risk for drug interactions
Safety in mild to moderate renal/liver dysfunction

Disadvantages

Slower onset
Risk of oversedation due to overdosing in delayed response
Accumulation in peripheral tissues
Risk of delirium
IV incompatibilities and risk of line precipitate
Propylene glycol - risk of met acidosis with infusion

Need gradual titration and caution in elderly

45
Q

What are the advantages and disadvantages of Diazepam

A

Advantages
Rapid onset
Potent sedative
Muscle relaxant effects

Disadvantages
CYP3A4 to active metabolites may accumulate in liver/renal dysfunction
Risk of delirium
Drug interactions
Propylene glycol - accumulation –> met acidosis
Injection site pain and phlebitis (limited use IV)

46
Q

What is the dose of haloperidol in the ICU

A

1 to 10 mg every 6 hours

47
Q

What is the onset and offset of haloperidol

A

Onset
5 to 20 minutes

Offset
1 to 6 hours

48
Q

What are the advantages of haloperidol in the ICU

A

Advantages
Control hyperactive delirium and moderately sedating
Minimal CVS effects

Disadvantages
CYP3A4 and 2D6 transformation
QT prolongation
EPSE
NMS (higher risk with oral)

49
Q

What is the dose of Olanzepine in the ICU

A

Bolus
IM 5 - 10 mg repeat every 2 to 4 hours as needed

Maintenance
PO 5 - 10 mg daily (Max 20 mg/day)

50
Q

What is the onset and offset of IM olanzepine

A

Onset 15 to 45 minutes

Offset > 2 hoursW

51
Q

What are the advantages and disadvantages of olanzepine in the ICU

A

ADV
Lower risk EPSE and QT prolong

DISADV
Adverse effects
- Orthostatic hypotension
- Hyperglycaemia
- Somnolence
- QT prolongation
- Prolonged half life in liver/renal dysfxn/older and female (Can be > 50 hours)

52
Q

What are the doses of naloxone and flumazenil

A

Naloxone 400 ug bolus IV

Flumazenil 400 ug bolus

both have short half life (20 mins) and therefore wear off quicker than opioids and benzos

Intensive Care (22 decks)

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