Induction Agents and Opioids

• -blocks polysynaptic reflexes in the spinal cord
• -interacts with opioid receptors and possibly ketamine receptors
• -inhibits excitatory neurotransmitters
• -dissociates thalamus from the limbic system (dissociative anesthesia)

Increases activity of GABA synapses

bind to receptors that are separate from but adjacent to GABA receptors, these receptors cause opening of Cl ion channels that result in a hyperpolarization of the neuron

• -depresses the RAS
• -mimics inhibitory effects of GABA
• -possible inhibitory effect on part of CNS that controls extrapyramidal motor activity

• -depresses RAS
• -suppress excitatory neurotransmitters
• -augment inhibitory neurotransmitters
• -decreases transmission impulses to SNS

• -sedative/hypnotic effects
• -decrease CBF, CMRO2 and ICP in dose dependant manner
• -activates seizure foci

• -minimal
• -etomidate induction agent of choice for cardiovascular compromise

• -dose dependent decrease in RR and TV
• -less effect on respiration than other agents

0.2-0.5 mg/kg

• A: IV
• D: higly lipid soluble
• B: metabolized in liver to inactive, metabolites; metabolized by plasma esterases
• E: renal

• -myoclonus (decresed with opioid administration)
• -nausea and vomitting
• -venous irritation
• -fentanyl increases elimination 1/2 life

• A: Oral, IV, IM
• D: highly lipid soluble at physiologic pH, small, midazolam and diazepam more lipid soluble than lorazepam
• B: liver to water soluble metabolites, midazolam 5X faster than lorazepam and 10X faster than diazepam, diazepam has active metabolites, duration of action determined by metabolisma and excretion
• E: renal

• amnesia
• hypnotic/sedative
• decrease anxiety
• prevention and control of grand mal seizure (especially diazepam)
• spinal cord mediated muscle relaxation
• anterograde amnesia
• decreased CBF

• mild systemic vasodilation and decreased CO
• possible vagolytic increase in HR
• dose dependend hemodynamic changes

• decreased ventilatory response to increased CO2
• dose dependent decrease in RR and TV

• drug interactions: valproate-psychotic effects
• heparin-displaces diazepam from protein
• erythromycin-inhibits midazolam metabolism
• Benzo's and opioids: decreased HR and SVR, birth defects (cleft lip and palate), crosses placenta

• Midazolam: 0.5-2.5 mg/kg
• Diazepam: 2.5-5.0 mg/kg
• Lorazepam: 0.5-2.0 mg/kg

• A: IV
• D: highly lipid soluble
• B: metabolized in liver to inactive metabolites
• E: 0.3% excreted unchanged in urine

• unconciousness or sedation
• decrease CPP, CBF and ICP
• anticonvulsant properties
• decreases intraocular pressure

• dose dependent decrease in BP (greater with hypovolemic, elderly and the cv compromised)
• unchanged HR (occassional bradycardia and heart block

• decrease ventilation
• transient apnea
• opioids enhance respiratory depression
• bronchodilation with COPD

• care with pancreatitis and hyper lipidemia
• antiemetic effects (10-20 mg)
• phenols turn urine green

• containdicated with egg yolk allergy
• pain on injection
• good bacterial growth medium (only keep 6 hours after drawn)
• crosses placenta
• decreases pruritus with neuroaxial opiods

• Baxter (Sodium Metabisulfite): sulfite sensitivities-anaphylaxis or asthmatic episode
• Stewart (EDTA): chelating effects (Ca, Mg and Zi homeostasis effects), nephrotoxicity, negative effect on cardiac conduction, increased toxicity with long term use

• Induction: 2-2.5 mg/kg
• Sedation: 25-100 mcg/kg/min
• GA: 20-200 mcg/kg/min

• A: IV, IM
• D: highly lipid soluble (greater than thiopental), less PRO bound than thiopental, equally ionized at body pH, redistribution
• B: liver with some active metabolites (Norketamine 1/3-1/5 as potent)
• E. Renal

• dissociative state
• amnesia and analgesia
• increased CBF and CMRO2
• cerebral vasodilation
• increased ICP
• activates seizure foci (with known seizure disorders)

• increased HR, BP and pulmonary pressures
• myocardial depressent if hypovolemic, ANS blockade or maximal SNS stimulation

• mild decrease in RR and TV
• minimal effect on response to hypercarbia
• maintains laryngeal reflexes longer
• alleviates bronchospasm

• increased oral secretions
• emotional disturbances (increases with age, female and >2mg/kg)
• myocardialo depression
• increased ICP, CMRO2 and CBF
• increased muscle tone
• eye movements (nystagmus, diplopia and blepharospasms)
• increased intraoccular pressure
• difficult to assess depth

• Induction: IV 1-2 mg/kg, IM 5-10 mg/kg
• Sedation: 0.2 mg/kg

• A: IV, IM, Oral, Rectal
• D: highly lipid soluble, 1 arm to brain circulation time, dependent on redistribution (quick recovery), thiopental highly PRO bound
• B: liver to inactive metabolites
• E: Renal, methohexital fecal

• unconsciousness (hyperalgesia in subhypnotic doses)
• amnesia
• cerebral vasoconstriction
• decreased CMRO2 and ICP
• anticonvulsant (except methohexital)

• decreased BP and CO
• increased HR

• dose dependent decreased RR ad TV (may cause apnea)
• laryngeal reflex and cough not depressed
• histamine release

induces cytochrome P-450

• myoclonus and hiccupping
• anaphylaxis
• CI in pt with Porphiria
• pain at injection site
• tissue necrosis with infiltration
• histamine release
• thiopental may cause bronchospasm in asthmatics
• decreased effect of theophylline, beta adrenergic blcokers, corticosteroids, digitoxin and tricyclic antidepressents (induction of P-450)

• thiopental induction 3-5 mg/kg
• methohexital induction 1-2 mg/kg

• barbiturates
• opioids
• etomidate
• benzodiazepines
• droperidol

• barbiturates
• propofol
• etomidate
• benzodiazepines

• opioids
• benzodiazepines

• etomidate
• remifentanil

• etomidate
• morphine
• meperidine

• propofol
• etomidate
• diazepam, lorazepam
• barbiturates

• benzodiazepines
• barbiturates

• opioids
• ketamine

• morphine
• meperidine
• thiopental

• fentanyl
• sufentanil
• alfentanil
• remifentanil

• opioids
• etomidate