Induction Agents Flashcards
Propofol Dosing
- Induction: 1-2.5 mg/kg OR 2 mg
- Sedation maintenance: 25-200 mcg/kg/min
Propofol Onset/Duration
Onset: 30 sec
Duration: dose & rate dependent
Propofol MOA
- GABAa agonist (stimulates these receptors)
- Highly lipid soluble
Propofol contraindications
- soy allergy
- egg allergy (proteins trigger egg allergy; prop is made from egg white; still avoid to be safe)
Propofol CV effects?
- decrease HR
- decrease SVR
- decrease BP
not a good choice for low CO states, hypovolemia, and hypotension
Propofol CNS effects?
- decrease CBF
- decrease ICP
- decrease CMRO2
- loss of consciousness
- anticonvulsant
- minimal residual CNS effects due to fast on/fast off
Propofol respiratory effects?
- respiratory depression (dose-dependent)
- apnea
- bronchodilation
Propofol protein binding
97 - 99%
How is propofol metabolized?
- mostly by the liver
- kidney and lungs (30%)
When is propofol used?
- TIVA
- induction
- outpatient surgery
- endoscopy
- MAC
- antiemetic (10-15mg)
- antipuritis (10mg)
Propofol bacteria considerations
- 12 hours in an opened infusion vial
- 6 hours in a syringe
Elderly considerations with propofol?
more sensitive and prolonged effects due to decreased CO and clearance (may need lower dose)
Pediatric considerations with propofol?
may need larger dose because of larger Vd and quicker clearance
Obesity considerations with propofol?
base dosing on lean body weight (LBW), NOT by actual body weight
In what cases would a patient need higher doses of propofol due to decreased sensitivity?
- chronic alcoholism
- daily marijuana use
In what cases would a patient need lower doses of propofol due to increased sensitivity?
- CV disease
- elderly
What can we expect with higher doses of propfol and rapid clearance?
ramped up liver enzymes
Lidocaine Dosing
0.5 - 1.5 mg/kg
What is the concentration of 1% lidocaine?
10 mg/ml
What is the concentration of 2% lidocaine?
20 mg/ml
When is lidocaine used?
- suppress coughing reflex during laryngoscopy, intubation, and EGD
- reduce airway responsiveness to noxious stimuli
- reduce pain caused by IV injection agents
- drip for ERAS protocols (enhanced recovery after surgery)
What can be used to decrease painful injection of propofol?
lidocaine
Lidocaine is given at a dose of ______ and administered _______ minutes before intubation or extubation to __________ and _________
- 1.5mg/kg
- 3 min
- suppress cough reflex
- attenuate the increase in airway resistance from laryngoscopy and intubation
Careful for lidocaine use in _________ patients due to ___________
- cardiac patients
- hypotensive effects
What is the effect of lidocaine on CBF?
decrease CBF and attenuate intracranial hypertensive response to laryngoscopy and intubation
What is the most common and effective ERAS lidocaine drip dosing?
1-2 mg/kg/hr
What is the rationale for administering a lidocaine infusion per ERAS protocol?
- analgesia
- ANTI-hyperalgesia
- ANTI-inflammatory
What is the concentration in a lidocaine infusion bag?
4 mg/ml
1 gm lidocaine in 250ml
OR
2 gm lidocaine in 500 ml
What is the MOA of ketamine?
- noncompetitive NMDA receptor antagonist that blocks glutamate
- stimulates SNS; inhibits reuptake of norepinephrine
Ketamine is considered a ___________ anesthetic
dissociative anesthetic
What is ketamine used for?
- induction
- sedation
- patients with CV collapse
- sedation for mentally challenged
- “bad” epidural/spinal
- trauma induction
Ketamine CV effects?
- increase in BP
- increase in HR
- increase in CO
- increase in PAP
- increase in CVP
- increase in CI
Ketamine respiratory effects?
- minimal respiratory depression
- able to maintain upper airway reflexes
- increased oral secretions (may give 0.2mg of glycopyrrolate)
- major bronchodilator (great for patient that is actively wheezing)
Ketamine stimulates SNS or PNS? What effects will be seen?
- stimulates SNS
- increased HR, SVR, BP
How does ketamine cause intense analgesia?
Binds to opioid receptors (mu, kappa, delta)
Children are at risk for ___________ when administered ketamine
emergence delirium