What is propofol used for?
- general anesthesia
- ICU sedation in intubated, mechanically-ventilated patients
What is the MOA of propofol?
- Agonist at GABA receptors
- Blocks NMDA receptors
What is the dosing for propofol?
Increase by 5-10 mcg/kg/minute every 5-10 mins
MD: 5-80 mcg/kg/min
- 5 mcg/kg/minute continuous infusion (0.3 mg/kg/hour)
- lower dose in elderly (80% of adult dose)
- obse patients use IBW
What are the AE of propofol?
- CV effects: hypotension, bradycardia
- Injection site reaction
- Propofol-related infusion syndrom
What interactions does propofol have?
- Increased sedative effects when given with narcotics
- Few drug interactions
- No drug-disease state interactions
Describe the 3 compartement model of propofol.
- 1. Distribution from blood to tissues (rapid)
- 2. Redistribution and metabolic clearance (rapid)
- 3. Slow return from poorly perfused tissue into blood
Discuss propofol's lipophilicity and protein-binding.
- Highly lipophilic (crosses BBB)
- Highly protein bound 98-99%
Discuss the onset, duration, distribution, metabolism and excretion of propofol.
- Onset: 30-40 seconds
- Duration: 3-10 minutes (dose and rate dependent)
- Distribution: 2-10 L/kg (dec in elderly, inc in obese)
- Metabolism: hepatic (2C9; to inactive metabolites)
- Excretion: renal (half-life is biphasic; 40 min initial & 4-7 hrs terminal)
What are neuromuscular blocking agents indicated for?
- Facilitated mechanical ventilation
- Manage increased ICP
- Immobilization during procedures
- Treat muscle spasms
- Decrease oxygen consumption
What is the MOA of Neuromuscular blocking agents?
- Depolarizing agents = activate the receptors (succinylcholine)
- Non-depolarizing agents = do NOT activate the receptors
Whar are the 2 types of neuromuscular blocking agents?
- 1. Depolarizing agents: resemble Ach --> bind to & activate Ach receptors
- 2. Nondepolarizing agents: bind to nicotonic Ach receptors and act as competitive antagonists
What are the classes of non-depolarizing agents of nueromusclar blocking drugs?
What is the distribution of neuromuscular blocking agents?
- highly ionized
- water soluble
- Vd similar to extracellular fluid volume
- ~200 ml/kg
- Atra << cis< roc,vec << pan
- atra = lowest at 87
- pan = highest at 241
How are neuromusclar blocking agents metabolized?
aminosteroidal agents: dacetylated in the liver; production of active metabolites
benzylisoquinolinium agents: hydrolysis; metabolite (laudanosine)
Which neuromuscular blocking agents can be given to renally impaired patients?
benzylisoquinolinium agents (atracurium, cisatracurium)
These are Hofmann eliminated = spontaneously eliminated (not done renally)
How are neuromuscular blocking agents dosed and monitored?
Weight based dosing: bolus or continuous infusion
- Vital signs
- Train-of-four (TOF)
- response to twitch stimuli
Which neuromuscular blocking agents enhance blockade (increase pt time on ventilator)?
- immunosuppresive agents
- inhaled anesthetics
Which neuromuscular blocking agents decrease blockade (decrease pt time on ventilator)?
Which neuromuscular blocking agents are ok to use if a patient has hypertension or tachycardia?
Which neuromuscular blocking agents should be avoided if a patient has hypotension and why?
atracurium and succinlycholine
they are vasodilators and if a patient already has hypotension it will cause further lowering of their BP
Which neuromuscular blocking agents cause myopathy?
most common with aminosteroid compounds
What are the 3 main side effects of neuromuscular blocking agents?
- CV effects (hypertension & tachycardia, hypotension)