Commonly Used drugs in IV conscious sedation

Question 1

Normal, Healthy patient without systemic disease

Answer 1

ASA I:

Question 2

: Mild systemic disease

Answer 2

ASA II

Question 3

Severe systemic disease, limits activity but no
incapacitating

Answer 3

ASA III:

Question 4

Incapacitating systemic disease that is constant threat to life

Answer 4

ASA IV:

Question 5

Not to survive 24 hours with/without operation

Answer 5

ASA V:

Question 6

Brain-dead patient awaits for organ donation

Answer 6

 ASA VI:

Question 7

: Emergency operation
 Precedes number status ( i.e. ASA E-II)

Answer 7

 ASA E

Question 8

Reduction of irritability or agitation by administration of
sedative drugs, generally to facilitate a medical procedure

Answer 8

sedation

Question 9

 A drug induced depression of consciousness during which
patients respond purposefully to verbal commands, either alone
or accompanied by light tactile stimulation.
 Generally, no interventions are required to maintain a patent
airway, and spontaneous ventilation is adequate.
 Cardiovascular function is usually maintained.

Answer 9

Moderate sedation

Question 10

 A drug-induced depression of consciousness during which
patients cannot be easily aroused but respond purposefully
following repeated or painful stimulation.
 The ability to independently maintain ventilatory function may be
impaired.
 Patients may require assistance in maintaining a patent airway
and spontaneous ventilation may be inadequate.
 Cardiovascular function is usually maintained.

Answer 10

Deep sedation

Question 11

Common Medication used in ______
 Barbiturate
 Propofol
 Ketamine
 Benzodiazepine
 Opioids

Answer 11

IV Sedation

Question 12

General Properties
 Desirable Effect
 Analgesia
 Sedation
 Euphoria
 Anti-tussive
 Undesirable Effect
 Respiratory Depression
 Coma
 Emesis
 Constipation
 Histamine release
 Potential for addiction

Answer 12

Opiods

Question 13

 Mechanism of action
○ Edinger-Westphal nucleus of Oculomotor nerve
○ Enhanced parasympathetic stimulation
 Significance?
○ Most other causes of coma and respiratory depression produce
mydriasis (dilation of pupil)
 All Addicts demonstrate pin-point pupils

Answer 13

Miosis

Question 14

 The Gold Standard of pain med
 Pharmacology
 IM / IV
 Hyperpolarize nerve cell, ↓release of substance P
 Least lipophilic  minimum crossing to BBB
 Onset 5-10mins, peak within 30mins
 T ½ 1.5 – 2 hours
 Duration of action : 4-6 hours
 Do not give to neonate (unable to conjugate)
 Metabolism
 Conjugate with glucuronic acid
○ Morphine-6-glucuronide (potent analgesic)
○ Morphine-3-glucuronide (inactive)
 Elimination
 End product eliminated by kidney
 Renal failure patient may have narcosis and vent failure for days !
 Adverse Effect
 Nausea and Vomiting
○ Stimulate medullary chemoreceptor trigger zone
 Severe respiratory depression
○ Rigid chest syndrome
 Histamine Release
○ May lead to profound drop in BP and systemic vascular resistance

Answer 14

Morphine

Question 15

 100X potency of morphine
 Pharmacology
 Oral / IV / Transdermal
 Analgesic and Sedative effect
 High Lipid solubility  rapid onset / short duration
 Onset of action < 60 sec with peak effect in 2 – 5 mins
 Duration 30 – 60 mins
 Metabolism
 Inactive metabolite
○ Remember the “end “ of the effect is due to redistribution!!
○ Fentanyl will accumulate in body fat with repeated injections
 Elimination
 Little effect on renal patient
 Clearance dependent on hepatic blood flow
 Adverse Effect
 No histamine release
 Rigid Chest Syndrome
○ After large drug bolus !!

Answer 15

Fentanyl

Question 16

 Mechanism of Action
 Competitive antagonist at opioid receptors
 Greater affinity for μ receptors than κ or δ receptors
 Pharmacology
 Reversal of endogenous or exogenous opioid compound
 Rapid antagonizing (1-2 min)
 Brief duration of action (30-45 mins) IV
○ Rapid redistribution from CNS
 T ½ is only 30–80 mins
○ Respiratory depression may linger despite “alert/awake” appearance
 Dosage
 IV administration of 0.4mg IV (Titrate to effect !!!)
Recommended usage
 Any suspicion
○ Support respiration (O2 and continue monitoring)
○ Check oxygen saturation, vital signs
 Continue sluggish response
○ Rule out hypoglycemic shock, CVA, Psychotic episode
○ Consider giving IM, if concern for re-sedation give 0.4mg IM
 Side Effects
 Abrupt reversal  Excessive catecholamine release
○ tachycardia, hypertension, ventricular irritability
 May antagonize Clonidine
 Nausea/Vomiting may be observed

Answer 16

Naloxone (Narcan)

Question 17

_______ cause
 Sedation
 Anxiolysis
 Muscle relaxation
 Anterograde amnesia
 Anticonvulsant effects
 Common Side Effects
 Fatigue
 Drowsiness
 Respiratory depression !
 No direct analgesic Effect

 Enhances inhibitory effect of neurotransmitters
 Facilitates GABA receptor binding
 ↑membrane conductance of Chloride ions
 Enhances the inhibitory effect of GABA

Answer 17

Benzodiazepines

Question 18

 IM injection of diazepam is painful and unreliable
 Pharmacology
 Water-insoluble therefore…..
 Propylene glycol + Sodium Benzoate added but pain upon injection
 Rapid uptake by CNS due to high lipid solubility
 Metabolism
 Hepatic microsomal enzyme  Desmethyldiazepam + Oxazepam
 Desmethyldiazepam is metabolized slowly  sustained effects !
 Phase 1 metabolites of diazepam are pharmacological active
 Elimination
 Long half-life 30 hours

Answer 18

Diazepam

Question 19

 Oral Administration is NOT approved by FDA
but commonly used
 Pharmacology
 No local irritation
 2-3X more potent than diazepam
 Water soluble at low pH
 Lipid soluble at high pH
○ Imidazole ring closes at physiologic pH
 Metabolism
 Hydroxylated in liver
 Elimination
 Conjugated and excreted by kidney
 Short half-life  2 hours
 Crosses placenta
 Unknown effect on fetus
 Paradoxical effect may occur

Answer 19

Midazolam

Question 20

 Mechanism of Action
 Competitive antagonist of benzodiazepine receptors
 Usage
 Reversal of benzodiazepine sedation and/or overdose
 Prompt (<1min) hypnotic reversal, Amnesia is ?
 Respiratory depression may linger despite “alert/awake” appearance
 Dosage
 IV administration of 0.2mg every min until reversal
 Due to rapid hepatic clearance, repeat dose may be needed in 1-2 hours
 T ½ is only ~ 1 hour
 Side Effects
 May induce seizure activity
 Increase Catecholamines
○ ↑ BP and heart rate
 Nausea/Vomiting may be observed

Answer 20

Flumazenil (Romazicon)

Question 21

 The most Frequently administered General Anesthesia induction
agent
 Mechanism of Action:
 Enhance GABA inhibitory neurotransmitter
 Site of action:
 Depress reticular activating system
○ Polysynaptic network responsible for consciousness
 Common Meds
 Thiopental
 Methohexital (Brevital)
 Phenobarbital

Answer 21

Barbiturates

Question 22

 Mechanism of action
 Enhance GABA inhibitory function  ↑Cl channel 
hyperpolarization of cell membrane
 Results Rapid onset of unconsciousness
 Arterial and venous dilatation
 Largely replacing Thiopental (Barbiturates)

Answer 22

Propofol / Diprivan

Question 23

 General Anesthesia Medicine
 Selective NMDA receptor blocker
 Dissociative, Hallucinogenic and Amnesic Effect
 Sympathomimetic medicine
 Disadvantage:
 Hallucinogenic, Nightmare emergence, Increase Salivary flow.

Answer 23

Ketamine