Inhalational agents: effects
MAC (minimum alveolar concentration)
Smallest concentration of inhalation agent at which 50% of patients will not move with incision
Nitrous oxide (NO2)
Fast, minimal myocardial depression; tremors at induction
Halothane
Manifestations of halothane hepatitis
Fever, eosinophilia, jaundice, increased LFTs
Sevoflurane
Fast, less laryngospasm and less pungent; good for mask induction
Isoflurane
Good for neurosurgery (lowers brain oxygen consumption; no increase in ICP)
Enflurane
Can cause seizures
Sodium thiopental
- Side effects: decrease CBF and metabolic rate, decrease blood pressure
Propofol
Ketamine
Dissociation of thalamic / limbic systems; places patient in a cataleptic state (amnesia, analgesia).
- No respiratory depression
- Contraindicated in patients with head injury
- Good for children
Side effects: hallucinations, cathetcholamine release (increase CO2, tachycardia), increased airway secretions and increased cerebral blood flow
Etomidate
Fewer hemodynamic changes; fast acting
- Continuous infusions can lead to adrenocortical suppression
When is RSI indicated?
Last muscle to go down and first muscle to recover from paralytics
Diaphragm
First to go down and last to recover from paralytics
Neck muscles and face
Malignant hyperthermia: pathophysiology
- Calcium released from sarcoplasmic reticulum causes muscle excitation: contraction syndrome
Malignant hyperthermia: signs
Increased end-tidal CO2…
then fever, tachycardia, rigidity, acidosis, hyperkalemia
Malignant hyperthermia: treatment
dantrolene (10mg/kg) inhibits calcium release and decouples excitation; cooling blankets, HCO3, glucose, supportive care
When do you NOT use succinylcholine?
Severe burns. Neurologic injury. Neuromuscular disorders. Spinal cord injury. Massive trauma. Acute renal failure.
Complications of succinylcholine
Nondepolarizing agents: mechanism
Cis-atracurium
Non-depolarizer
Rocuronium
Non-depolarizer: Fast, intermediate duration; hepatic metabolism
Pancuronium
Non-depolarizer: